PCI: aardvark: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Link: https://lore.kernel.org/linux-pci/20230321193208.366561-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

PCI: aardvark: Switch to using devm_gpiod_get_optional()

Switch the driver to the generic version of gpiod API (and away from
OF-specific variant), so that we can stop exporting
devm_gpiod_get_from_of_node().

Link: https://lore.kernel.org/r/Y3KMEZFv6dpxA+Gv@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Pali Rohár <pali@kernel.org>

PCI: aardvark: Add support for PCI Bridge Subsystem Vendor ID on emulated bridge

Register with Subsystem Device/Vendor ID is at offset 0x2c.

Export it via the emulated bridge to enable support for the Subsystem
Device/Vendor ID - by reading it in the PCI controller config space and
storing it in the emulated bridge control structures, so that it is
exposed in the respective PCI capability.

After this change Subsystem ID is visible in lspci output at line:

Capabilities: [40] Subsystem

Link: https://lore.kernel.org/r/20220711225915.13896-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

PCI: pci-bridge-emul: Set position of PCI capabilities to real HW value

mvebu and aardvark HW have PCIe capabilities on different offset in PCI
config space. Extend pci-bridge-emul.c code to allow setting custom driver
custom value where PCIe capabilities starts.

With this change PCIe capabilities of both drivers are reported at the same
location as where they are reported by U-Boot - in their real HW offset.

Link: https://lore.kernel.org/r/20220824112124.21675-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>

PCI: aardvark: Fix reporting Slot capabilities on emulated bridge

Slot capabilities are currently not reported because emulated bridge does
not report the PCI_EXP_FLAGS_SLOT flag.

Set PCI_EXP_FLAGS_SLOT to let the kernel know that PCI_EXP_SLT* registers
are supported.

Move setting of PCI_EXP_SLTCTL register from "dynamic" pcie_conf_read
function to static buffer as it is only statically filled the
PCI_EXP_SLTSTA_PDS flag and dynamic read callback is not needed for this
register.

Set Presence State Bit to 1 since there is no support for unplugging the
card and there is currently no platform able to detect presence of a card -
in such a case the bit needs to be set to 1.

Finally correctly set Physical Slot Number to 1 since there is only one
port and zero value is reserved for ports within the same silicon as Root
Port which is not our case for Aardvark HW.

Link: https://lore.kernel.org/r/20220524132827.8837-3-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: aardvark: Add support for AER registers on emulated bridge

Aardvark controller supports Advanced Error Reporting configuration
registers.

Export these registers on the emulated root bridge via new .read_ext() and
.write_ext() methods.

Note that in the Advanced Error Reporting Capability header the offset to
the next Extended Capability header is set, but it is not documented in
Armada 3700 Functional Specification. Since this change adds support only
for Advanced Error Reporting, explicitly clear PCI_EXT_CAP_NEXT bits in AER
capability header.

Now the pcieport driver correctly detects AER support and allows PCIe AER
driver to start receiving ERR interrupts. Kernel log now says:

pcieport 0000:00:00.0: AER: enabled with IRQ 52

Link: https://lore.kernel.org/r/20220524132827.8837-2-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Revert "PCI: aardvark: Rewrite IRQ code to chained IRQ handler"

This reverts commit 1571d67dc190e50c6c56e8f88cdc39f7cc53166e.

This commit broke support for setting interrupt affinity. It looks like
that it is related to the chained IRQ handler. Revert this commit until
issue with setting interrupt affinity is fixed.

Fixes: 1571d67dc190 ("PCI: aardvark: Rewrite IRQ code to chained IRQ handler")
Link: https://lore.kernel.org/r/20220515125815.30157-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Revert "PCI: aardvark: Fix initialization with old Marvell's Arm Trusted Firmware"

This reverts commit b0c6ae0f8948a2be6bf4e8b4bbab9ca1343289b6.

Armada 3720 phy driver (phy-mvebu-a3700-comphy.c) does not return
-EOPNOTSUPP from phy_power_on() callback anymore.

So remove dead code which handles -EOPNOTSUPP return value.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20220203214444.1508-6-kabel@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

PCI: Add defines for normal and subtractive PCI bridges

Add these PCI class codes to pci_ids.h:

PCI_CLASS_BRIDGE_PCI_NORMAL
PCI_CLASS_BRIDGE_PCI_SUBTRACTIVE

Use these defines in all kernel code for describing PCI class codes for
normal and subtractive PCI bridges.

[bhelgaas: similar change in pci-mvebu.c]
Link: https://lore.kernel.org/r/20220214114109.26809-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: aardvark: Update comment about link going down after link-up

Update the comment about what happens when link goes down after we have
checked for link-up. If a PIO request is done while link-down, we have
a serious problem.

Link: https://lore.kernel.org/r/20220110015018.26359-23-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Drop __maybe_unused from advk_pcie_disable_phy()

This function is now always used in driver remove method, drop the
__maybe_unused attribute.

Link: https://lore.kernel.org/r/20220110015018.26359-22-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Don't mask irq when mapping

By default, all Legacy INTx interrupts are masked, so there is no need to
mask this interrupt during irq_map() callback.

Link: https://lore.kernel.org/r/20220110015018.26359-21-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Remove irq_mask_ack() callback for INTx interrupts

Callback for irq_mask_ack() is the same as for irq_mask(). As there is no
special handling for irq_ack(), there is no need to define irq_mask_ack()
too.

Link: https://lore.kernel.org/r/20220110015018.26359-20-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>

PCI: aardvark: Use separate INTA interrupt for emulated root bridge

Emulated root bridge currently provides only one Legacy INTA interrupt
which is used for reporting PCIe PME and ERR events and handled by kernel
PCIe PME and AER drivers.

Aardvark HW reports these PME and ERR events separately, so there is no
need to mix real INTA interrupt and emulated INTA interrupt for PCIe PME
and AER drivers.

Register a new advk-RP (as in Root Port) irq chip and a new irq domain
for emulated root bridge and use this new separate irq domain for
providing INTA interrupt from emulated root bridge for PME and ERR events.

The real INTA interrupt from real devices is now separate.

A custom map_irq callback function on PCI host bridge structure is used to
allocate IRQ mapping for emulated root bridge from new irq domain. Original
callback of_irq_parse_and_map_pci() is used for all other devices as before.

Link: https://lore.kernel.org/r/20220110015018.26359-19-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix support for PME requester on emulated bridge

Enable aardvark PME interrupt unconditionally by unmasking it and read PME
requester ID to emulated bridge config space immediately after receiving
interrupt.

PME requester ID is stored in the PCIE_MSG_LOG_REG register, which contains
the last inbound message. So when new inbound message is received by HW
(including non-PM), the content in PCIE_MSG_LOG_REG register is replaced by
a new value.

PCIe specification mandates that subsequent PMEs are kept pending until the
PME Status Register bit is cleared by software by writing a 1b.

Support for masking/unmasking PME interrupt on emulated bridge via
PCI_EXP_RTCTL_PMEIE bit is now implemented only in emulated bridge config
space, to ensure that we do not miss any aardvark PME interrupt.

Reading of PCI_EXP_RTCAP and PCI_EXP_RTSTA registers is simplified as final
value is now always stored into emulated bridge config space by the
interrupt handler, so there is no need to implement support for these
registers in read_pcie callback.

Clearing of W1C bit PCI_EXP_RTSTA_PME is now also simplified as it is done
by pci-bridge-emul.c code for emulated bridge config space. So there is no
need to implement support for clearing this bit in write_pcie callback.

Link: https://lore.kernel.org/r/20220110015018.26359-18-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Add support for PME interrupts

Currently enabling PCI_EXP_RTSTA_PME bit in PCI_EXP_RTCTL register does
nothing. This is because PCIe PME driver expects to receive PCIe interrupt
defined in PCI_EXP_FLAGS_IRQ register, but aardvark hardware does not
trigger PCIe INTx/MSI interrupt for PME event, rather it triggers custom
aardvark interrupt which this driver is not processing yet.

Fix this issue by handling PME interrupt in advk_pcie_handle_int() and
chaining it to PCIe interrupt 0 with generic_handle_domain_irq() (since
aardvark sets PCI_EXP_FLAGS_IRQ to zero). With this change PCIe PME driver
finally starts receiving PME interrupt.

Link: https://lore.kernel.org/r/20220110015018.26359-17-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Optimize writing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME on emulated bridge

To optimize advk_pci_bridge_emul_pcie_conf_write() code, touch
PCIE_ISR0_REG and PCIE_ISR0_MASK_REG registers only when it is really
needed, when processing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME bits.

Link: https://lore.kernel.org/r/20220110015018.26359-16-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix reading PCI_EXP_RTSTA_PME bit on emulated bridge

The emulated bridge returns incorrect value for PCI_EXP_RTSTA register
during readout in advk_pci_bridge_emul_pcie_conf_read() function: the
correct bit is BIT(16), but we are setting BIT(23), because the code
does
*value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16
where
PCIE_MSG_PM_PME_MASK
is
BIT(7).

The code should probably have been something like
*value = (!!(isr0 & PCIE_MSG_PM_PME_MASK)) << 16,
but we are better of using an if() and using the proper macro for this
bit.

Link: https://lore.kernel.org/r/20220110015018.26359-15-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Add support for ERR interrupt on emulated bridge

ERR interrupt is triggered when corresponding bit is unmasked in both ISR0
and PCI_EXP_DEVCTL registers. Unmasking ERR bits in PCI_EXP_DEVCTL register
is not enough. This means that currently the ERR interrupt is never
triggered.

Unmask ERR bits in ISR0 register at driver probe time. ERR interrupt is not
triggered until ERR bits are unmasked also in PCI_EXP_DEVCTL register,
which is done by AER driver. So it is safe to unconditionally unmask all
ERR bits in aardvark probe.

Aardvark HW sets PCI_ERR_ROOT_AER_IRQ to zero and when corresponding bits
in ISR0 and PCI_EXP_DEVCTL are enabled, the HW triggers a generic interrupt
on GIC. Chain this interrupt to PCIe interrupt 0 with
generic_handle_domain_irq() to allow processing of ERR interrupts.

Link: https://lore.kernel.org/r/20220110015018.26359-14-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Enable MSI-X support

According to PCI 3.0 specification, sending both MSI and MSI-X interrupts
is done by DWORD memory write operation to doorbell message address. The
write operation for MSI has zero upper 16 bits and the MSI interrupt number
in the lower 16 bits, while the write operation for MSI-X contains a 32-bit
value from MSI-X table.

Since the driver only uses interrupt numbers from range 0..31, the upper
16 bits of the DWORD memory write operation to doorbell message address
are zero even for MSI-X interrupts. Thus we can enable MSI-X interrupts.

Testing proves that kernel can correctly receive MSI-X interrupts from PCIe
cards which supports both MSI and MSI-X interrupts.

Link: https://lore.kernel.org/r/20220110015018.26359-13-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix setting MSI address

MSI address for receiving MSI interrupts needs to be correctly set before
enabling processing of MSI interrupts.

Move code for setting PCIE_MSI_ADDR_LOW_REG and PCIE_MSI_ADDR_HIGH_REG
from advk_pcie_init_msi_irq_domain() to advk_pcie_setup_hw(), before
enabling PCIE_CORE_CTRL2_MSI_ENABLE.

After this we can remove the now unused member msi_msg, which was used
only for MSI doorbell address. MSI address can be any address which cannot
be used to DMA to. So change it to the address of the main struct advk_pcie.

Link: https://lore.kernel.org/r/20220110015018.26359-12-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org # f21a8b1b6837 ("PCI: aardvark: Move to MSI handling using generic MSI support")

PCI: aardvark: Add support for masking MSI interrupts

We should not unmask MSIs at setup, but only when kernel asks for them
to be unmasked.

At setup, mask all MSIs, and implement IRQ chip callbacks for masking
and unmasking particular MSIs.

Link: https://lore.kernel.org/r/20220110015018.26359-11-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Refactor unmasking summary MSI interrupt

Refactor the masking of ISR0/1 Sources and unmasking of summary MSI interrupt
so that it corresponds to the comments:
- first mask all ISR0/1
- then unmask all MSIs
- then unmask summary MSI interrupt

Link: https://lore.kernel.org/r/20220110015018.26359-10-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Use dev_fwnode() instead of of_node_to_fwnode(dev->of_node)

Use simple
dev_fwnode(dev)
instead of
struct device_node *node = dev->of_node;
of_node_to_fwnode(node)
especially since the node variable is not used elsewhere in the function.

Link: https://lore.kernel.org/r/20220110015018.26359-9-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Make msi_domain_info structure a static driver structure

Make Aardvark's msi_domain_info structure into a private driver structure.
Domain info is same for every potential instatination of a controller.

Link: https://lore.kernel.org/r/20220110015018.26359-8-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Make MSI irq_chip structures static driver structures

In [1] it was agreed that we should use struct irq_chip as a global
static struct in the driver. Even though the structure currently
contains a dynamic member (parent_device), In [2] the plans to kill it
and make the structure completely static were set out.

Convert Aardvark's priv->msi_bottom_irq_chip and priv->msi_irq_chip to
static driver structure.

[1] https://lore.kernel.org/linux-pci/877dbcvngf.wl-maz@kernel.org/
[2] https://lore.kernel.org/linux-pci/874k6gvkhz.wl-maz@kernel.org/

Link: https://lore.kernel.org/r/20220110015018.26359-7-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Check return value of generic_handle_domain_irq() when processing INTx IRQ

It is possible that we receive spurious INTx interrupt. Check for the
return value of generic_handle_domain_irq() when processing INTx IRQ.

Link: https://lore.kernel.org/r/20220110015018.26359-6-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Rewrite IRQ code to chained IRQ handler

Rewrite the code to use irq_set_chained_handler_and_data() handler with
chained_irq_enter() and chained_irq_exit() processing instead of using
devm_request_irq().

advk_pcie_irq_handler() reads IRQ status bits and calls other functions
based on which bits are set. These functions then read its own IRQ status
bits and calls other aardvark functions based on these bits. Finally
generic_handle_domain_irq() with translated linux IRQ numbers are called.

Link: https://lore.kernel.org/r/20220110015018.26359-5-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix support for MSI interrupts

Aardvark hardware supports Multi-MSI and MSI_FLAG_MULTI_PCI_MSI is already
set for the MSI chip. But when allocating MSI interrupt numbers for
Multi-MSI, the numbers need to be properly aligned, otherwise endpoint
devices send MSI interrupt with incorrect numbers.

Fix this issue by using function bitmap_find_free_region() instead of
bitmap_find_next_zero_area().

To ensure that aligned MSI interrupt numbers are used by endpoint devices,
we cannot use Linux virtual irq numbers (as they are random and not
properly aligned). Instead we need to use the aligned hwirq numbers.

This change fixes receiving MSI interrupts on Armada 3720 boards and
allows using NVMe disks which use Multi-MSI feature with 3 interrupts.

Without this NVMe disks freeze booting as linux nvme-core.c is waiting
60s for an interrupt.

Link: https://lore.kernel.org/r/20220110015018.26359-4-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix reading MSI interrupt number

In advk_pcie_handle_msi() it is expected that when bit i in the W1C
register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is
updated to contain the MSI number corresponding to index i.

Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG
always contains the number of the last received MSI, overall.

Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
number. Since Aardvark already forbids more than 32 interrupts and uses
own allocated hwirq numbers, the msi_idx already corresponds to the
received MSI number.

Link: https://lore.kernel.org/r/20220110015018.26359-3-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Replace custom PCIE_CORE_INT_* macros with PCI_INTERRUPT_*

Header file linux/pci.h defines enum pci_interrupt_pin with corresponding
PCI_INTERRUPT_* values.

Link: https://lore.kernel.org/r/20220110015018.26359-2-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: pci-bridge-emul: Make struct pci_bridge_emul_ops as const

It is read-only constant structure, so properly mark it with const keyword.

Link: https://lore.kernel.org/r/20220104153529.31647-3-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: pci-bridge-emul: Correctly set PCIe capabilities

Older mvebu hardware provides PCIe Capability structure only in version 1.
New mvebu and aardvark hardware provides it in version 2. So do not force
version to 2 in pci_bridge_emul_init() and rather allow drivers to set
correct version. Drivers need to set version in pcie_conf.cap field without
overwriting PCI_CAP_LIST_ID register. Both drivers (mvebu and aardvark) do
not provide slot support yet, so do not set PCI_EXP_FLAGS_SLOT flag.

Link: https://lore.kernel.org/r/20211124155944.1290-6-pali@kernel.org
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix checking for MEM resource type

IORESOURCE_MEM_64 is not a resource type but a type flag.

Remove incorrect check for type IORESOURCE_MEM_64.

Link: https://lore.kernel.org/r/20211125160148.26029-2-kabel@kernel.org
Fixes: 64f160e19e92 ("PCI: aardvark: Configure PCIe resources from 'ranges' DT property")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Disable common PHY when unbinding driver

Disable the PCIe PHY when unbinding driver. This should save some power.

Link: https://lore.kernel.org/r/20211130172913.9727-12-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Disable link training when unbinding driver

Disable link training circuit in driver unbind sequence. We want to
leave link training in the same state as it was before the driver was
probed.

Link: https://lore.kernel.org/r/20211130172913.9727-11-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Assert PERST# when unbinding driver

Put the PCIe card into reset by asserting PERST# signal when unbinding
driver. It doesn't make sense to leave the card working if it can't
communicate with the host. This should also save some power.

Link: https://lore.kernel.org/r/20211130172913.9727-10-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix memory leak in driver unbind

Free config space for emulated root bridge when unbinding driver to fix
memory leak. Do it after disabling and masking all interrupts, since
aardvark interrupt handler accesses config space of emulated root
bridge.

Link: https://lore.kernel.org/r/20211130172913.9727-9-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Mask all interrupts when unbinding driver

Ensure that no interrupt can be triggered after driver unbind.

Link: https://lore.kernel.org/r/20211130172913.9727-8-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Disable bus mastering when unbinding driver

Ensure that after driver unbind PCIe cards are not able to forward
memory and I/O requests in the upstream direction.

Link: https://lore.kernel.org/r/20211130172913.9727-7-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Comment actions in driver remove method

Add two more comments into the advk_pcie_remove() method.

Link: https://lore.kernel.org/r/20211130172913.9727-6-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Clear all MSIs at setup

We already clear all the other interrupts (ISR0, ISR1, HOST_CTRL_INT).

Define a new macro PCIE_MSI_ALL_MASK and do the same clearing for MSIs,
to ensure that we don't start receiving spurious interrupts.

Use this new mask in advk_pcie_handle_msi();

Link: https://lore.kernel.org/r/20211130172913.9727-5-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Add support for DEVCAP2, DEVCTL2, LNKCAP2 and LNKCTL2 registers on emulated bridge

PCI aardvark hardware supports access to DEVCAP2, DEVCTL2, LNKCAP2 and
LNKCTL2 configuration registers of PCIe core via PCIE_CORE_PCIEXP_CAP.
Export them via emulated software root bridge.

Link: https://lore.kernel.org/r/20211130172913.9727-4-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Drop error data fabrication when config read fails

If config pci_ops.read() methods return failure, the PCI_OP_READ() and
PCI_USER_READ_CONFIG() wrappers use PCI_SET_ERROR_RESPONSE() to set the
data value, so there's no need to set it in the pci_ops.read() methods
themselves.

Drop the unnecessary data value fabrication when pci_ops.read() fails.

Link: https://lore.kernel.org/r/335014f2b44cdf24ed1e37cb7c88f6c5de896cc2.1637243717.git.naveennaidu479@gmail.com
Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>

Revert "PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge"

This reverts commit 239edf686c14a9ff926dec2f350289ed7adfefe2.

239edf686c14 ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated
bridge") added support for the Type 1 Expansion ROM BAR at config offset
0x38, based on the register being listed in the Marvell Armada A3720 spec.
But the spec doesn't document it at all for RC mode, and there is no ROM in
the SOC, so remove this emulation for now.

The PCI bridge which represents aardvark's PCIe Root Port has an Expansion
ROM Base Address register at offset 0x30, but its meaning is different than
PCI's Expansion ROM BAR register, although the layout is the same. (This
is why we thought it does the same thing.)

First: there is no ROM (or part of BootROM) in the A3720 SOC dedicated for
PCIe Root Port (or controller in RC mode) containing executable code that
would initialize the Root Port, suitable for execution in bootloader (this
is how Expansion ROM BAR is used on x86).

Second: in A3720 spec the register (address 0xD0070030) is not documented
at all for Root Complex mode, but similar to other BAR registers, it has an
"entangled partner" in register 0xD0075920, which does address translation
for the BAR in 0xD0070030:

- the BAR register sets the address from the view of PCIe bus

- the translation register sets the address from the view of the CPU

The other BAR registers also have this entangled partner, and they can be
used to:

- in RC mode: address-checking on the receive side of the RC (they can
define address ranges for memory accesses from remote Endpoints to the
RC)

- in Endpoint mode: allow the remote CPU to access memory on A3720

The Expansion ROM BAR has only the Endpoint part documented, but from the
similarities we think that it can also be used in RC mode in that way.

So either Expansion ROM BAR has different meaning (if the hypothesis above
is true), or we don't know it's meaning (since it is not documented for RC
mode).

Remove the register from the emulated bridge accessing functions.

[bhelgaas: summarize reason for removal (first paragraph)]
Fixes: 239edf686c14 ("PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge")
Link: https://lore.kernel.org/r/20211125160148.26029-3-kabel@kernel.org
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pali Rohár <pali@kernel.org>

PCI: aardvark: Fix support for PCI_ROM_ADDRESS1 on emulated bridge

This register is exported at address offset 0x30.

Link: https://lore.kernel.org/r/20211028185659.20329-8-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix support for PCI_BRIDGE_CTL_BUS_RESET on emulated bridge

Aardvark supports PCIe Hot Reset via PCIE_CORE_CTRL1_REG.

Use it for implementing PCI_BRIDGE_CTL_BUS_RESET bit of PCI_BRIDGE_CONTROL
register on emulated bridge.

With this, the function pci_reset_secondary_bus() starts working and can
reset connected PCIe card. Custom userspace script [1] which uses setpci
can trigger PCIe Hot Reset and reset the card manually.

[1] https://alexforencich.com/wiki/en/pcie/hot-reset-linux

Link: https://lore.kernel.org/r/20211028185659.20329-7-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Set PCI Bridge Class Code to PCI Bridge

Aardvark controller has something like config space of a Root Port
available at offset 0x0 of internal registers - these registers are used
for implementation of the emulated bridge.

The default value of Class Code of this bridge corresponds to a RAID Mass
storage controller, though. (This is probably intended for when the
controller is used as Endpoint.)

Change the Class Code to correspond to a PCI Bridge.

Add comment explaining this change.

Link: https://lore.kernel.org/r/20211028185659.20329-6-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix support for bus mastering and PCI_COMMAND on emulated bridge

From very vague, ambiguous and incomplete information from Marvell we
deduced that the 32-bit Aardvark register at address 0x4
(PCIE_CORE_CMD_STATUS_REG), which is not documented for Root Complex mode
in the Functional Specification (only for Endpoint mode), controls two
16-bit PCIe registers: Command Register and Status Registers of PCIe Root
Port.

This means that bit 2 controls bus mastering and forwarding of memory and
I/O requests in the upstream direction. According to PCI specifications
bits [0:2] of Command Register, this should be by default disabled on
reset. So explicitly disable these bits at early setup of the Aardvark
driver.

Remove code which unconditionally enables all 3 bits and let kernel code
(via pci_set_master() function) to handle bus mastering of Root PCIe
Bridge via emulated PCI_COMMAND on emulated bridge.

Link: https://lore.kernel.org/r/20211028185659.20329-5-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # b2a56469d550 ("PCI: aardvark: Add FIXME comment for PCIE_CORE_CMD_STATUS_REG access")

PCI: aardvark: Read all 16-bits from PCIE_MSI_PAYLOAD_REG

The PCIE_MSI_PAYLOAD_REG contains 16-bit MSI number, not only lower
8 bits. Fix reading content of this register and add a comment
describing the access to this register.

Link: https://lore.kernel.org/r/20211028185659.20329-4-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix return value of MSI domain .alloc() method

MSI domain callback .alloc() (implemented by advk_msi_irq_domain_alloc()
function) should return zero on success, since non-zero value indicates
failure.

When the driver was converted to generic MSI API in commit f21a8b1b6837
("PCI: aardvark: Move to MSI handling using generic MSI support"), it
was converted so that it returns hwirq number.

Fix this.

Link: https://lore.kernel.org/r/20211028185659.20329-3-kabel@kernel.org
Fixes: f21a8b1b6837 ("PCI: aardvark: Move to MSI handling using generic MSI support")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix reporting Data Link Layer Link Active

Add support for reporting PCI_EXP_LNKSTA_DLLLA bit in Link Control register
on emulated bridge via current LTSSM state. Also correctly indicate DLLLA
capability via PCI_EXP_LNKCAP_DLLLARC bit in Link Control Capability
register.

Link: https://lore.kernel.org/r/20211005180952.6812-14-kabel@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix checking for link up via LTSSM state

Current implementation of advk_pcie_link_up() is wrong as it marks also
link disabled or hot reset states as link up.

Fix it by marking link up only to those states which are defined in PCIe
Base specification 3.0, Table 4-14: Link Status Mapped to the LTSSM.

To simplify implementation, Define macros for every LTSSM state which
aardvark hardware can return in CFG_REG register.

Fix also checking for link training according to the same Table 4-14.
Define a new function advk_pcie_link_training() for this purpose.

Link: https://lore.kernel.org/r/20211005180952.6812-13-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org
Cc: Remi Pommarel <repk@triplefau.lt>

PCI: aardvark: Fix link training

Fix multiple link training issues in aardvark driver. The main reason of
these issues was misunderstanding of what certain registers do, since their
names and comments were misleading: before commit 96be36dbffac ("PCI:
aardvark: Replace custom macros by standard linux/pci_regs.h macros"), the
pci-aardvark.c driver used custom macros for accessing standard PCIe Root
Bridge registers, and misleading comments did not help to understand what
the code was really doing.

After doing more tests and experiments I've come to the conclusion that the
SPEED_GEN register in aardvark sets the PCIe revision / generation
compliance and forces maximal link speed. Both GEN3 and GEN2 values set the
read-only PCI_EXP_FLAGS_VERS bits (PCIe capabilities version of Root
Bridge) to value 2, while GEN1 value sets PCI_EXP_FLAGS_VERS to 1, which
matches with PCI Express specifications revisions 3, 2 and 1 respectively.
Changing SPEED_GEN also sets the read-only bits PCI_EXP_LNKCAP_SLS and
PCI_EXP_LNKCAP2_SLS to corresponding speed.

(Note that PCI Express rev 1 specification does not define PCI_EXP_LNKCAP2
and PCI_EXP_LNKCTL2 registers and when SPEED_GEN is set to GEN1 (which
also sets PCI_EXP_FLAGS_VERS set to 1), lspci cannot access
PCI_EXP_LNKCAP2 and PCI_EXP_LNKCTL2 registers.)

Changing PCIe link speed can be done via PCI_EXP_LNKCTL2_TLS bits of
PCI_EXP_LNKCTL2 register. Armada 3700 Functional Specifications says that
the default value of PCI_EXP_LNKCTL2_TLS is based on SPEED_GEN value, but
tests showed that the default value is always 8.0 GT/s, independently of
speed set by SPEED_GEN. So after setting SPEED_GEN, we must also set value
in PCI_EXP_LNKCTL2 register via PCI_EXP_LNKCTL2_TLS bits.

Triggering PCI_EXP_LNKCTL_RL bit immediately after setting LINK_TRAINING_EN
bit actually doesn't do anything. Tests have shown that a delay is needed
after enabling LINK_TRAINING_EN bit. As triggering PCI_EXP_LNKCTL_RL
currently does nothing, remove it.

Commit 43fc679ced18 ("PCI: aardvark: Improve link training") introduced
code which sets SPEED_GEN register based on negotiated link speed from
PCI_EXP_LNKSTA_CLS bits of PCI_EXP_LNKSTA register. This code was added to
fix detection of Compex WLE900VX (Atheros QCA9880) WiFi GEN1 PCIe cards, as
otherwise these cards were "invisible" on PCIe bus (probably because they
crashed). But apparently more people reported the same issues with these
cards also with other PCIe controllers [1] and I was able to reproduce this
issue also with other "noname" WiFi cards based on Atheros QCA9890 chip
(with the same PCI vendor/device ids as Atheros QCA9880). So this is not an
issue in aardvark but rather an issue in Atheros QCA98xx chips. Also, this
issue only exists if the kernel is compiled with PCIe ASPM support, and a
generic workaround for this is to change PCIe Bridge to 2.5 GT/s link speed
via PCI_EXP_LNKCTL2_TLS_2_5GT bits in PCI_EXP_LNKCTL2 register [2], before
triggering PCI_EXP_LNKCTL_RL bit. This workaround also works when SPEED_GEN
is set to value GEN2 (5 GT/s). So remove this hack completely in the
aardvark driver and always set SPEED_GEN to value from 'max-link-speed' DT
property. Fix for Atheros QCA98xx chips is handled separately by patch [2].

These two things (code for triggering PCI_EXP_LNKCTL_RL bit and changing
SPEED_GEN value) also explain why commit 6964494582f5 ("PCI: aardvark:
Train link immediately after enabling training") somehow fixed detection of
those problematic Compex cards with Atheros chips: if triggering link
retraining (via PCI_EXP_LNKCTL_RL bit) was done immediately after enabling
link training (via LINK_TRAINING_EN), it did nothing. If there was a
specific delay, aardvark HW already initialized PCIe link and therefore
triggering link retraining caused the above issue. Compex cards triggered
link down event and disappeared from the PCIe bus.

Commit f4c7d053d7f7 ("PCI: aardvark: Wait for endpoint to be ready before
training link") added 100ms sleep before calling 'Start link training'
command and explained that it is a requirement of PCI Express
specification. But the code after this 100ms sleep was not doing 'Start
link training', rather it triggered PCI_EXP_LNKCTL_RL bit via PCIe Root
Bridge to put link into Recovery state.

The required delay after fundamental reset is already done in function
advk_pcie_wait_for_link() which also checks whether PCIe link is up.
So after removing the code which triggers PCI_EXP_LNKCTL_RL bit on PCIe
Root Bridge, there is no need to wait 100ms again. Remove the extra
msleep() call and update comment about the delay required by the PCI
Express specification.

According to Marvell Armada 3700 Functional Specifications, Link training
should be enabled via aardvark register LINK_TRAINING_EN after selecting
PCIe generation and x1 lane. There is no need to disable it prior resetting
card via PERST# signal. This disabling code was introduced in commit
5169a9851daa ("PCI: aardvark: Issue PERST via GPIO") as a workaround for
some Atheros cards. It turns out that this also is Atheros specific issue
and affects any PCIe controller, not only aardvark. Moreover this Atheros
issue was triggered by juggling with PCI_EXP_LNKCTL_RL, LINK_TRAINING_EN
and SPEED_GEN bits interleaved with sleeps. Now, after removing triggering
PCI_EXP_LNKCTL_RL, there is no need to explicitly disable LINK_TRAINING_EN
bit. So remove this code too. The problematic Compex cards described in
previous git commits are correctly detected in advk_pcie_train_link()
function even after applying all these changes.

Note that with this patch, and also prior this patch, some NVMe disks which
support PCIe GEN3 with 8 GT/s speed are negotiated only at the lowest link
speed 2.5 GT/s, independently of SPEED_GEN value. After manually triggering
PCI_EXP_LNKCTL_RL bit (e.g. from userspace via setpci), these NVMe disks
change link speed to 5 GT/s when SPEED_GEN was configured to GEN2. This
issue first needs to be properly investigated. I will send a fix in the
future.

On the other hand, some other GEN2 PCIe cards with 5 GT/s speed are
autonomously by HW autonegotiated at full 5 GT/s speed without need of any
software interaction.

Armada 3700 Functional Specifications describes the following steps for
link training: set SPEED_GEN to GEN2, enable LINK_TRAINING_EN, poll until
link training is complete, trigger PCI_EXP_LNKCTL_RL, poll until signal
rate is 5 GT/s, poll until link training is complete, enable ASPM L0s.

The requirement for triggering PCI_EXP_LNKCTL_RL can be explained by the
need to achieve 5 GT/s speed (as changing link speed is done by throw to
recovery state entered by PCI_EXP_LNKCTL_RL) or maybe as a part of enabling
ASPM L0s (but in this case ASPM L0s should have been enabled prior
PCI_EXP_LNKCTL_RL).

It is unknown why the original pci-aardvark.c driver was triggering
PCI_EXP_LNKCTL_RL bit before waiting for the link to be up. This does not
align with neither PCIe base specifications nor with Armada 3700 Functional
Specification. (Note that in older versions of aardvark, this bit was
called incorrectly PCIE_CORE_LINK_TRAINING, so this may be the reason.)

It is also unknown why Armada 3700 Functional Specification says that it is
needed to trigger PCI_EXP_LNKCTL_RL for GEN2 mode, as according to PCIe
base specification 5 GT/s speed negotiation is supposed to be entirely
autonomous, even if initial speed is 2.5 GT/s.

[1] - https://lore.kernel.org/linux-pci/87h7l8axqp.fsf@toke.dk/
[2] - https://lore.kernel.org/linux-pci/20210326124326.21163-1-pali@kernel.org/

Link: https://lore.kernel.org/r/20211005180952.6812-12-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>

PCI: aardvark: Simplify initialization of rootcap on virtual bridge

PCIe config space can be initialized also before pci_bridge_emul_init()
call, so move rootcap initialization after PCI config space initialization.

This simplifies the function a little since it removes one if (ret < 0)
check.

Link: https://lore.kernel.org/r/20211005180952.6812-11-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>

PCI: aardvark: Implement re-issuing config requests on CRS response

Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") fixed
handling of CRS response and when CRSSVE flag was not enabled it marked CRS
response as failed transaction (due to simplicity).

But pci-aardvark.c driver is already waiting up to the PIO_RETRY_CNT count
for PIO config response and so we can with a small change implement
re-issuing of config requests as described in PCIe base specification.

This change implements re-issuing of config requests when response is CRS.
Set upper bound of wait cycles to around PIO_RETRY_CNT, afterwards the
transaction is marked as failed and an all-ones value is returned as
before.

We do this by returning appropriate error codes from function
advk_pcie_check_pio_status(). On CRS we return -EAGAIN and caller then
reissues transaction.

Link: https://lore.kernel.org/r/20211005180952.6812-10-kabel@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>

PCI: aardvark: Deduplicate code in advk_pcie_rd_conf()

Avoid code repetition in advk_pcie_rd_conf() by handling errors with
goto jump, as is customary in kernel.

Link: https://lore.kernel.org/r/20211005180952.6812-9-kabel@kernel.org
Fixes: 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value")
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Do not unmask unused interrupts

There are lot of undocumented interrupt bits. To prevent unwanted
spurious interrupts, fix all *_ALL_MASK macros to define all interrupt
bits, so that driver can properly mask all interrupts, including those
which are undocumented.

Link: https://lore.kernel.org/r/20211005180952.6812-8-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Do not clear status bits of masked interrupts

The PCIE_ISR1_REG says which interrupts are currently set / active,
including those which are masked.

The driver currently reads this register and looks if some unmasked
interrupts are active, and if not, it clears status bits of _all_
interrupts, including the masked ones.

This is incorrect, since, for example, some drivers may poll these bits.

Remove this clearing, and also remove this early return statement
completely, since it does not change functionality in any way.

Link: https://lore.kernel.org/r/20211005180952.6812-7-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix configuring Reference clock

Commit 366697018c9a ("PCI: aardvark: Add PHY support") introduced
configuration of PCIe Reference clock via PCIE_CORE_REF_CLK_REG register,
but did it incorrectly.

PCIe Reference clock differential pair is routed from system board to
endpoint card, so on CPU side it has output direction. Therefore it is
required to enable transmitting and disable receiving.

Default configuration according to Armada 3700 Functional Specifications is
enabled receiver part and disabled transmitter.

We need this change because otherwise PCIe Reference clock is configured to
some undefined state when differential pair is used for both transmitting
and receiving.

Fix this by disabling receiver part.

Link: https://lore.kernel.org/r/20211005180952.6812-6-kabel@kernel.org
Fixes: 366697018c9a ("PCI: aardvark: Add PHY support")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix preserving PCI_EXP_RTCTL_CRSSVE flag on emulated bridge

Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") started
using CRSSVE flag for handling CRS responses.

PCI_EXP_RTCTL_CRSSVE flag is stored only in emulated config space buffer
and there is handler for PCI_EXP_RTCTL register. So every read operation
from config space automatically clears CRSSVE flag as it is not defined in
PCI_EXP_RTCTL read handler.

Fix this by reading current CRSSVE bit flag from emulated space buffer and
appending it to PCI_EXP_RTCTL read response.

Link: https://lore.kernel.org/r/20211005180952.6812-5-kabel@kernel.org
Fixes: 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>

PCI: aardvark: Don't spam about PIO Response Status

Use dev_dbg() instead of dev_err() in advk_pcie_check_pio_status().

For example CRS is not an error status, it just says that the request
should be retried.

Link: https://lore.kernel.org/r/20211005180952.6812-4-kabel@kernel.org
Fixes: 8c39d710363c1 ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix PCIe Max Payload Size setting

Change PCIe Max Payload Size setting in PCIe Device Control register to 512
bytes to align with PCIe Link Initialization sequence as defined in Marvell
Armada 3700 Functional Specification. According to the specification,
maximal Max Payload Size supported by this device is 512 bytes.

Without this kernel prints suspicious line:

pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 16384, max 512)

With this change it changes to:

pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 512, max 512)

Link: https://lore.kernel.org/r/20211005180952.6812-3-kabel@kernel.org
Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix masking and unmasking legacy INTx interrupts

irq_mask and irq_unmask callbacks need to be properly guarded by raw spin
locks as masking/unmasking procedure needs atomic read-modify-write
operation on hardware register.

Link: https://lore.kernel.org/r/20210820155020.3000-1-pali@kernel.org
Reported-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Configure PCIe resources from 'ranges' DT property

In commit 6df6ba974a55 ("PCI: aardvark: Remove PCIe outbound window
configuration") was removed aardvark PCIe outbound window configuration and
commit description said that was recommended solution by HW designers.

But that commit completely removed support for configuring PCIe IO
resources without removing PCIe IO 'ranges' from DTS files. After that
commit PCIe IO space started to be treated as PCIe MEM space and accessing
it just caused kernel crash.

Moreover implementation of PCIe outbound windows prior that commit was
incorrect. It completely ignored offset between CPU address and PCIe bus
address and expected that in DTS is CPU address always same as PCIe bus
address without doing any checks. Also it completely ignored size of every
PCIe resource specified in 'ranges' DTS property and expected that every
PCIe resource has size 128 MB (also for PCIe IO range). Again without any
check. Apparently none of PCIe resource has in DTS specified size of 128
MB. So it was completely broken and thanks to how aardvark mask works,
configuration was completely ignored.

This patch reverts back support for PCIe outbound window configuration but
implementation is a new without issues mentioned above. PCIe outbound
window is required when DTS specify in 'ranges' property non-zero offset
between CPU and PCIe address space. To address recommendation by HW
designers as specified in commit description of 6df6ba974a55, set default
outbound parameters as PCIe MEM access without translation and therefore
for this PCIe 'ranges' it is not needed to configure PCIe outbound window.
For PCIe IO space is needed to configure aardvark PCIe outbound window.

This patch fixes kernel crash when trying to access PCIe IO space.

Link: https://lore.kernel.org/r/20210624215546.4015-2-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # 6df6ba974a55 ("PCI: aardvark: Remove PCIe outbound window configuration")

PCI: aardvark: Fix reporting CRS value

Set CRSVIS flag in emulated root PCI bridge to indicate support for
Completion Retry Status.

Add check for CRSSVE flag from root PCI brige when issuing Configuration
Read Request via PIO to correctly returns fabricated CRS value as it is
required by PCIe spec.

Link: https://lore.kernel.org/r/20210722144041.12661-5-pali@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # e0d9d30b7354 ("PCI: pci-bridge-emul: Fix big-endian support")

PCI: aardvark: Increase polling delay to 1.5s while waiting for PIO response

Measurements in different conditions showed that aardvark hardware PIO
response can take up to 1.44s. Increase wait timeout from 1ms to 1.5s to
ensure that we do not miss responses from hardware. After 1.44s hardware
returns errors (e.g. Completer abort).

The previous two patches fixed checking for PIO status, so now we can use
it to also catch errors which are reported by hardware after 1.44s.

After applying this patch, kernel can detect and print PIO errors to dmesg:

[ 6.879999] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100004
[ 6.896436] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100004
[ 6.913049] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100010
[ 6.929663] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100010
[ 6.953558] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100014
[ 6.970170] advk-pcie d0070000.pcie: Non-posted PIO Response Status: CA, 0xe00 @ 0x100014
[ 6.994328] advk-pcie d0070000.pcie: Posted PIO Response Status: COMP_ERR, 0x804 @ 0x100004

Without this patch kernel prints only a generic error to dmesg:

[ 5.246847] advk-pcie d0070000.pcie: config read/write timed out

Link: https://lore.kernel.org/r/20210722144041.12661-3-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org # 7fbcb5da811b ("PCI: aardvark: Don't rely on jiffies while holding spinlock")

PCI: aardvark: Fix checking for PIO status

There is an issue that when PCIe switch is connected to an Armada 3700
board, there will be lots of warnings about PIO errors when reading the
config space. According to Aardvark PIO read and write sequence in HW
specification, the current way to check PIO status has the following
issues:

1) For PIO read operation, it reports the error message, which should be
avoided according to HW specification.

2) For PIO read and write operations, it only checks PIO operation complete
status, which is not enough, and error status should also be checked.

This patch aligns the code with Aardvark PIO read and write sequence in HW
specification on PIO status check and fix the warnings when reading config
space.

[pali: Fix CRS handling when CRSSVE is not enabled]

Link: https://lore.kernel.org/r/20210722144041.12661-2-pali@kernel.org
Tested-by: Victor Gu <xigu@marvell.com>
Signed-off-by: Evan Wang <xswang@marvell.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Victor Gu <xigu@marvell.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org # b1bd5714472c ("PCI: aardvark: Indicate error in 'val' when config read fails")

PCI: Bulk conversion to generic_handle_domain_irq()

Wherever possible, replace constructs that match either
generic_handle_irq(irq_find_mapping()) or
generic_handle_irq(irq_linear_revmap()) to a single call to
generic_handle_domain_irq().

Link: https://lore.kernel.org/r/20210802162630.2219813-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

PCI: aardvark: Implement workaround for the readback value of VEND_ID

Marvell Armada 3700 Functional Errata, Guidelines, and Restrictions
document describes in erratum 4.1 PCIe value of vendor ID (Ref #: 243):

The readback value of VEND_ID (RD0070000h [15:0]) is 1B4Bh, while it
should read 11ABh.

The firmware can write the correct value, 11ABh, through VEND_ID
(RD0076044h [15:0]).

Implement this workaround in aardvark driver for both PCI vendor id and PCI
subsystem vendor id.

This change affects and fixes PCI vendor id of emulated PCIe root bridge.
After this change emulated PCIe root bridge has correct vendor id.

Link: https://lore.kernel.org/r/20210624222621.4776-5-pali@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix checking for PIO Non-posted Request

PIO_NON_POSTED_REQ for PIO_STAT register is incorrectly defined. Bit 10 in
register PIO_STAT indicates the response is to a non-posted request.

Link: https://lore.kernel.org/r/20210624213345.3617-2-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org

PCI: aardvark: Fix kernel panic during PIO transfer

Trying to start a new PIO transfer by writing value 0 in PIO_START register
when previous transfer has not yet completed (which is indicated by value 1
in PIO_START) causes an External Abort on CPU, which results in kernel
panic:

SError Interrupt on CPU0, code 0xbf000002 -- SError
Kernel panic - not syncing: Asynchronous SError Interrupt

To prevent kernel panic, it is required to reject a new PIO transfer when
previous one has not finished yet.

If previous PIO transfer is not finished yet, the kernel may issue a new
PIO request only if the previous PIO transfer timed out.

In the past the root cause of this issue was incorrectly identified (as it
often happens during link retraining or after link down event) and special
hack was implemented in Trusted Firmware to catch all SError events in EL3,
to ignore errors with code 0xbf000002 and not forwarding any other errors
to kernel and instead throw panic from EL3 Trusted Firmware handler.

Links to discussion and patches about this issue:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=3c7dcdac5c50
https://lore.kernel.org/linux-pci/20190316161243.29517-1-repk@triplefau.lt/
https://lore.kernel.org/linux-pci/971be151d24312cc533989a64bd454b4@www.loen.fr/
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1541

But the real cause was the fact that during link retraining or after link
down event the PIO transfer may take longer time, up to the 1.44s until it
times out. This increased probability that a new PIO transfer would be
issued by kernel while previous one has not finished yet.

After applying this change into the kernel, it is possible to revert the
mentioned TF-A hack and SError events do not have to be caught in TF-A EL3.

Link: https://lore.kernel.org/r/20210608203655.31228-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Cc: stable@vger.kernel.org # 7fbcb5da811b ("PCI: aardvark: Don't rely on jiffies while holding spinlock")

PCI: Unify ECAM constants in native PCI Express drivers

Add ECAM-related constants to provide a set of standard constants
defining memory address shift values to the byte-level address that can
be used to access the PCI Express Configuration Space, and then move
native PCI Express controller drivers to use the newly introduced
definitions retiring driver-specific ones.

Refactor pci_ecam_map_bus() function to use newly added constants so
that limits to the bus, device function and offset (now limited to 4K as
per the specification) are in place to prevent the defective or
malicious caller from supplying incorrect configuration offset and thus
targeting the wrong device when accessing extended configuration space.

This refactor also allows for the ".bus_shift" initialisers to be
dropped when the user is not using a custom value as a default value
will be used as per the PCI Express Specification.

Thanks to Qian Cai <qcai@redhat.com>, Michael Walle <michael@walle.cc>,
and Vladimir Oltean <olteanv@gmail.com> for reporting a pci_ecam_create()
issue with .bus_shift and to Vladimir for proposing the fix.

[bhelgaas: incorporate Vladimir's fix, update commit log]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20201129230743.3006978-2-kw@linux.com
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: aardvark: Update comment about disabling link training

According to PCI Express Base Specifications (rev 4.0, 6.6.1
"Conventional reset"), after fundamental reset a 100ms delay is needed
prior to enabling link training.

Update comment in code to reflect this requirement.

Link: https://lore.kernel.org/r/20201202184659.3795-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix initialization with old Marvell's Arm Trusted Firmware

Old ATF automatically power on pcie phy and does not provide SMC call for
phy power on functionality which leads to aardvark initialization failure:

[ 0.330134] mvebu-a3700-comphy d0018300.phy: unsupported SMC call, try updating your firmware
[ 0.338846] phy phy-d0018300.phy.1: phy poweron failed --> -95
[ 0.344753] advk-pcie d0070000.pcie: Failed to initialize PHY (-95)
[ 0.351160] advk-pcie: probe of d0070000.pcie failed with error -95

This patch fixes above failure by ignoring 'not supported' error in
aardvark driver. In this case it is expected that phy is already power on.

Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Link: https://lore.kernel.org/r/20200902144344.16684-3-pali@kernel.org
Fixes: 366697018c9a ("PCI: aardvark: Add PHY support")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: <stable@vger.kernel.org> # 5.8+: ea17a0f153af: phy: marvell: comphy: Convert internal SMCC firmware return codes to errno

PCI: aardvark: Move PCIe reset card code to advk_pcie_train_link()

Move code which belongs to link training (delays and resets) into
advk_pcie_train_link() function, so everything related to link training,
including timings is at one place.

After experiments it can be observed that link training in aardvark
hardware is very sensitive to timings and delays, so it is a good idea to
have this code at the same place as link training calls.

This patch does not change behavior of aardvark initialization.

Link: https://lore.kernel.org/r/20200907111038.5811-6-pali@kernel.org
Tested-by: Marek Behún <marek.behun@nic.cz>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Implement driver 'remove' function and allow to build it as module

Providing driver's 'remove' function allows kernel to bind and unbind devices
from aardvark driver. It also allows to build aardvark driver as a module.

Compiling aardvark as a module simplifies development and debugging of
this driver as it can be reloaded at runtime without the need to reboot
to new kernel.

Link: https://lore.kernel.org/r/20200907111038.5811-5-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

PCI: aardvark: Check for errors from pci_bridge_emul_init() call

Function pci_bridge_emul_init() may fail so correctly check for errors.

Link: https://lore.kernel.org/r/20200907111038.5811-3-pali@kernel.org
Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

PCI: aardvark: Fix compilation on s390

Include linux/gpio/consumer.h instead of linux/gpio.h, as is said in the
latter file.

This was reported by kernel test bot when compiling for s390.

drivers/pci/controller/pci-aardvark.c:350:2: error: implicit declaration of function 'gpiod_set_value_cansleep' [-Werror,-Wimplicit-function-declaration]
drivers/pci/controller/pci-aardvark.c:1074:21: error: implicit declaration of function 'devm_gpiod_get_from_of_node' [-Werror,-Wimplicit-function-declaration]
drivers/pci/controller/pci-aardvark.c:1076:14: error: use of undeclared identifier 'GPIOD_OUT_LOW'

Link: https://lore.kernel.org/r/202006211118.LxtENQfl%25lkp@intel.com
Link: https://lore.kernel.org/r/20200907111038.5811-2-pali@kernel.org
Fixes: 5169a9851daa ("PCI: aardvark: Issue PERST via GPIO")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Marek Behún <marek.behun@nic.cz>

PCI: Set bridge map_irq and swizzle_irq to default functions

The majority of DT based host drivers use the default .map_irq() and
.swizzle_irq() functions, so let's initialize the function pointers to
the default and drop setting them in the host drivers.

Drivers like iProc which don't support legacy interrupts need to set
.map_irq() back to NULL.

Link: https://lore.kernel.org/r/20200722022514.1283916-20-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: Move DT resource setup into devm_pci_alloc_host_bridge()

Now that pci_parse_request_of_pci_ranges() callers just setup
pci_host_bridge.windows and dma_ranges directly and don't need the bus
range returned, we can just initialize them when allocating the
pci_host_bridge struct.

With this, pci_parse_request_of_pci_ranges() becomes a static function.

Link: https://lore.kernel.org/r/20200722022514.1283916-19-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: Move setting pci_host_bridge.busnr out of host drivers

Most host drivers only parse the DT bus range to set the root bus number
in pci_host_bridge.busnr. The ones that don't set busnr are buggy in
that they ignore what's in DT. Let's set busnr in pci_scan_root_bus_bridge()
where we already check for the bus resource and remove setting it in
host drivers.

Link: https://lore.kernel.org/r/20200722022514.1283916-12-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: linux-tegra@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org

PCI: aardvark: Use pci_is_root_bus() to check if bus is root bus

Use pci_is_root_bus() rather than tracking the root bus number to
determine if the bus is the root bus or not. This removes storing
duplicated data as well as the need for the host bridge driver to have
to care about the bus numbers in most cases.

Link: https://lore.kernel.org/r/20200722022514.1283916-5-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: Drop unnecessary zeroing of bridge fields

The struct pci_host_bridge is 0 initialized when allocated, so there's
no need to explicitly set fields to 0.

Link: https://lore.kernel.org/r/20200722022514.1283916-4-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: Set default bridge parent device

The host bridge's parent device is always the platform device. As we
already have a pointer to it in the devres functions, let's initialize
the parent device. Drivers can still override the parent if desired.

Link: https://lore.kernel.org/r/20200722022514.1283916-3-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: aardvark: Don't touch PCIe registers if no card connected

When there is no PCIe card connected and advk_pcie_rd_conf() or
advk_pcie_wr_conf() is called for PCI bus which doesn't belong to emulated
root bridge, the aardvark driver throws the following error message:

advk-pcie d0070000.pcie: config read/write timed out

Obviously accessing PCIe registers of disconnected card is not possible.

Extend check in advk_pcie_valid_device() function for validating
availability of PCIe bus. If PCIe link is down, then the device is marked
as Not Found and the driver does not try to access these registers.

This is just an optimization to prevent accessing PCIe registers when card
is disconnected. Trying to access PCIe registers of disconnected card does
not cause any crash, kernel just needs to wait for a timeout. So if card
disappear immediately after checking for PCIe link (before accessing PCIe
registers), it does not cause any problems.

Link: https://lore.kernel.org/r/20200702083036.12230-1-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: controller: Convert to devm_platform_ioremap_resource()

Use devm_platform_ioremap_resource() to simplify the code, since t
contains platform_get_resource() and devm_ioremap_resource() calls
respectively.

Link: https://lore.kernel.org/r/20200708155614.308-1-zhengdejin5@gmail.com
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>

PCI: aardvark: Indicate error in 'val' when config read fails

Most callers of config read do not check for return value. But most of the
ones that do, checks for error indication in 'val' variable.

This patch updates error handling in advk_pcie_rd_conf() function. If PIO
transfer fails then 'val' variable is set to 0xffffffff which indicates
failture.

Link: https://lore.kernel.org/r/20200528162604.GA323482@bjorn-Precision-5520
Link: https://lore.kernel.org/r/20200601130315.18895-1-pali@kernel.org
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Replace custom macros by standard linux/pci_regs.h macros

PCI-E capability macros are already defined in linux/pci_regs.h.
Remove their reimplementation in pcie-aardvark.

Link: https://lore.kernel.org/r/20200430080625.26070-9-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Add PHY support

With recent proposed changes for U-Boot it is possible that bootloader
won't initialize the PHY for this controller (currently the PHY is
initialized regardless whether PCI is used in U-Boot, but with these
proposed changes the PHY is initialized only on request).

Since the mvebu-a3700-comphy driver by Miquèl Raynal supports enabling
PCIe PHY, and since Linux' functionality should be independent on what
bootloader did, add code for enabling generic PHY if found in device OF
node.

The mvebu-a3700-comphy driver does PHY powering via SMC calls to ARM
Trusted Firmware. The corresponding code in ARM Trusted Firmware skips
one register write which U-Boot does not: step 7 ("Enable TX"), see [1].
Instead ARM Trusted Firmware expects PCIe driver to do this step,
probably because the register is in PCIe controller address space,
instead of PHY address space. We therefore add this step into the
advk_pcie_setup_hw function.

[1] https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/drivers/marvell/comphy/phy-comphy-3700.c?h=v2.3-rc2#n836

Link: https://lore.kernel.org/r/20200430080625.26070-8-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquèl Raynal <miquel.raynal@bootlin.com>

PCI: aardvark: Add FIXME comment for PCIE_CORE_CMD_STATUS_REG access

This register is applicable only when the controller is configured for
Endpoint mode, which is not the case for the current version of this
driver.

Attempting to remove this code though caused some ath10k cards to stop
working, so for some unknown reason it is needed here.

This should be investigated and a comment explaining this should be put
before the code, so we add a FIXME comment for now.

Link: https://lore.kernel.org/r/20200430080625.26070-7-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Issue PERST via GPIO

Add support for issuing PERST via GPIO specified in 'reset-gpios'
property (as described in PCI device tree bindings).

Some buggy cards (e.g. Compex WLE900VX or WLE1216) are not detected
after reboot when PERST is not issued during driver initialization.

If bootloader already enabled link training then issuing PERST has no
effect for some buggy cards (e.g. Compex WLE900VX) and these cards are
not detected. We therefore clear the LINK_TRAINING_EN register before.

It was observed that Compex WLE900VX card needs to be in PERST reset
for at least 10ms if bootloader enabled link training.

Tested on Turris MOX.

Link: https://lore.kernel.org/r/20200430080625.26070-6-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Improve link training

Currently the aardvark driver trains link in PCIe gen2 mode. This may
cause some buggy gen1 cards (such as Compex WLE900VX) to be unstable or
even not detected. Moreover when ASPM code tries to retrain link second
time, these cards may stop responding and link goes down. If gen1 is
used this does not happen.

Unconditionally forcing gen1 is not a good solution since it may have
performance impact on gen2 cards.

To overcome this, read 'max-link-speed' property (as defined in PCI
device tree bindings) and use this as max gen mode. Then iteratively try
link training at this mode or lower until successful. After successful
link training choose final controller gen based on Negotiated Link Speed
from Link Status register, which should match card speed.

Link: https://lore.kernel.org/r/20200430080625.26070-5-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <marek.behun@nic.cz>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Don't blindly enable ASPM L0s and don't write to read-only register

Trying to change Link Status register does not have any effect as this
is a read-only register. Trying to overwrite bits for Negotiated Link
Width does not make sense.

In future proper change of link width can be done via Lane Count Select
bits in PCIe Control 0 register.

Trying to unconditionally enable ASPM L0s via ASPM Control bits in Link
Control register is wrong. There should be at least some detection if
endpoint supports L0s as isn't mandatory.

Moreover ASPM Control bits in Link Control register are controlled by
pcie/aspm.c code which sets it according to system ASPM settings,
immediately after aardvark driver probes. So setting these bits by
aardvark driver has no long running effect.

Remove code which touches ASPM L0s bits from this driver and let
kernel's ASPM implementation to set ASPM state properly.

Some users are reporting issues that this code is problematic for some
Intel wifi cards and removing it fixes them, see e.g.:
https://bugzilla.kernel.org/show_bug.cgi?id=196339

If problems with Intel wifi cards occur even after this commit, then
pcie/aspm.c code could be modified / hooked to not enable ASPM L0s state
for affected problematic cards.

Link: https://lore.kernel.org/r/20200430080625.26070-3-pali@kernel.org
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Train link immediately after enabling training

Adding even 100ms (PCI_PM_D3COLD_WAIT) delay between enabling link
training and starting link training causes detection issues with some
buggy cards (such as Compex WLE900VX).

Move the code which enables link training immediately before the one
which starts link traning.

This fixes detection issues of Compex WLE900VX card on Turris MOX after
cold boot.

Link: https://lore.kernel.org/r/20200430080625.26070-2-pali@kernel.org
Fixes: f4c7d053d7f7 ("PCI: aardvark: Wait for endpoint to be ready...")
Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: Check for platform_get_irq() failure consistently

The platform_get_irq*() interfaces return either a negative error number or
a valid IRQ. 0 is not a valid return value, so check for "< 0" to detect
failure as recommended by the function documentation.

On failure, return the error number from platform_get_irq*() instead of
making up a new one.

Link: https://lore.kernel.org/r/cover.1583952275.git.amanharitsh123@gmail.com
[bhelgaas: commit log, squash into one patch]
Signed-off-by: Aman Sharma <amanharitsh123@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Cc: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Marc Gonzalez <marc.w.gonzalez@free.fr>

PCI: Remove unused includes and superfluous struct declaration

Remove <linux/pci.h> and <linux/msi.h> from being included directly as part
of the include/linux/of_pci.h, and remove superfluous declaration of struct
of_phandle_args.

Move users of include <linux/of_pci.h> to include <linux/pci.h> and
<linux/msi.h> directly rather than rely on both being included transitively
through <linux/of_pci.h>.

Link: https://lore.kernel.org/r/20190903113059.2901-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>

PCI: of: Add inbound resource parsing to helpers

Extend devm_of_pci_get_host_bridge_resources() and
pci_parse_request_of_pci_ranges() helpers to also parse the inbound
addresses from DT 'dma-ranges' and populate a resource list with the
translated addresses. This will help ensure 'dma-ranges' is always
parsed in a consistent way.

Tested-by: Srinath Mannam <srinath.mannam@broadcom.com>
Tested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> # for AArdvark
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Srinath Mannam <srinath.mannam@broadcom.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Will Deacon <will@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Toan Le <toan@os.amperecomputing.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Tom Joseph <tjoseph@cadence.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Cc: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: rfi@lists.rocketboards.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org

PCI: aardvark: Use pci_parse_request_of_pci_ranges()

Convert aardvark to use the common pci_parse_request_of_pci_ranges().

There's no need to assign the resources to a temporary list first. Just
use bridge->windows directly and remove all the temporary list handling.

Tested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

PCI: aardvark: Fix big endian support

Initialise every multiple-byte field of emulated PCI bridge config
space with proper cpu_to_le* macro. This is required since the structure
describing config space of emulated bridge assumes little-endian
convention.

Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Don't rely on jiffies while holding spinlock

advk_pcie_wait_pio() can be called while holding a spinlock (from
pci_bus_read_config_dword()), then depends on jiffies in order to
timeout while polling on PIO state registers. In the case the PIO
transaction failed, the timeout will never happen and will also cause
the cpu to stall.

This decrements a variable and wait instead of using jiffies.

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Fix PCI_EXP_RTCTL register configuration

PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
should not modify other interrupts' mask. The ISR mask polarity was also
inverted, when PCI_EXP_RTCTL_PMEIE is set PCIE_MSG_PM_PME_MASK mask bit
should actually be cleared.

Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Wait for endpoint to be ready before training link

When configuring pcie reset pin from gpio (e.g. initially set by
u-boot) to pcie function this pin goes low for a brief moment
asserting the PERST# signal. Thus connected device enters fundamental
reset process and link configuration can only begin after a minimal
100ms delay (see [1]).

Because the pin configuration comes from the "default" pinctrl it is
implicitly configured before the probe callback is called:

driver_probe_device()
really_probe()
...
pinctrl_bind_pins() /* Here pin goes from gpio to PCIE reset
function and PERST# is asserted */
...
drv->probe()

[1] "PCI Express Base Specification", REV. 4.0
PCI Express, February 19 2014, 6.6.1 Conventional Reset

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: aardvark: Use LTSSM state to build link training flag

Aardvark's PCI_EXP_LNKSTA_LT flag in its link status register is not
implemented and does not reflect the actual link training state (the
flag is always set to 0). In order to support link re-training feature
this flag has to be emulated. The Link Training and Status State
Machine (LTSSM) flag in Aardvark LMI config register could be used as
a link training indicator. Indeed if the LTSSM is in L0 or upper state
then link training has completed (see [1]).

Unfortunately because after asking a link retraining it takes a while
for the LTSSM state to become less than 0x10 (due to L0s to recovery
state transition delays), LTSSM can still be in L0 while link training
has not finished yet. So this waits for link to be in recovery or lesser
state before returning after asking for a link retrain.

[1] "PCI Express Base Specification", REV. 4.0
PCI Express, February 19 2014, Table 4-14

Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: Fix typos and whitespace errors

Fix typos in drivers/pci. Comment and whitespace changes only.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>

PCI: aardvark: Fix a leaked reference by adding missing of_node_put()

The call to of_get_next_child() returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

irq_domain_add_linear() also calls of_node_get() to increase refcount,
so irq_domain will not be affected when it is released.

Detected by coccinelle with the following warnings:
./drivers/pci/controller/pci-aardvark.c:826:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 798, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

PCI: aardvark: Make symbol 'advk_pci_bridge_emul_ops' static

Fix the following sparse warning:

drivers/pci/controller/pci-aardvark.c:469:28: warning:
symbol 'advk_pci_bridge_emul_ops' was not declared. Should it be static?

Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

PCI: pci-bridge-emul: Extend pci_bridge_emul_init() with flags

Depending on the capabilities of the PCI controller/platform, the
PCI-to-PCI bridge emulation behavior might need to be different. For
example, on platforms that use the pci-mvebu code, we currently don't
support prefetchable memory BARs, so the corresponding fields in the
PCI-to-PCI bridge configuration space should be read-only.

To implement this, extend pci_bridge_emul_init() to take a "flags"
argument, with currently one flag supported:

PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR

that will make the prefetchable memory base and limit registers
read-only.

The pci-mvebu and pci-aardvark drivers are updated accordingly.

Fixes: 1f08673eef123 ("PCI: mvebu: Convert to PCI emulated bridge config space")
Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Reported-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Leigh Brown <leigh@solinno.co.uk>
Tested-by: Luis Mendes <luis.p.mendes@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Cc: Luís Mendes <luis.p.mendes@gmail.com>
Cc: Leigh Brown <leigh@solinno.co.uk>

PCI: aardvark: Implement emulated root PCI bridge config space

The PCI controller in the Marvell Armada 3720 does not implement a
software-accessible root port PCI bridge configuration space. This
causes a number of problems when using PCIe switches or when the Max
Payload size needs to be aligned between the root complex and the
endpoint.

Implementing an emulated root PCI bridge, like is already done in the
pci-mvebu driver for older Marvell platforms allows to solve those
issues, and also to support features such as ASR, PME, VC, HP.

Signed-off-by: Zachary Zhang <zhangzg@marvell.com>
[Thomas: convert to the common emulated PCI bridge logic.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Fix I/O space page leak

When testing the R-Car PCIe driver on the Condor board, if the PCIe PHY
driver was left disabled, the kernel crashed with this BUG:

kernel BUG at lib/ioremap.c:72!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
Hardware name: Renesas Condor board based on r8a77980 (DT)
Workqueue: events deferred_probe_work_func
pstate: 80000005 (Nzcv daif -PAN -UAO)
pc : ioremap_page_range+0x370/0x3c8
lr : ioremap_page_range+0x40/0x3c8
sp : ffff000008da39e0
x29: ffff000008da39e0 x28: 00e8000000000f07
x27: ffff7dfffee00000 x26: 0140000000000000
x25: ffff7dfffef00000 x24: 00000000000fe100
x23: ffff80007b906000 x22: ffff000008ab8000
x21: ffff000008bb1d58 x20: ffff7dfffef00000
x19: ffff800009c30fb8 x18: 0000000000000001
x17: 00000000000152d0 x16: 00000000014012d0
x15: 0000000000000000 x14: 0720072007200720
x13: 0720072007200720 x12: 0720072007200720
x11: 0720072007300730 x10: 00000000000000ae
x9 : 0000000000000000 x8 : ffff7dffff000000
x7 : 0000000000000000 x6 : 0000000000000100
x5 : 0000000000000000 x4 : 000000007b906000
x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
x1 : 0000000040000000 x0 : 00e80000fe100f07
Process kworker/0:1 (pid: 39, stack limit = 0x (ptrval))
Call trace:
ioremap_page_range+0x370/0x3c8
pci_remap_iospace+0x7c/0xac
pci_parse_request_of_pci_ranges+0x13c/0x190
rcar_pcie_probe+0x4c/0xb04
platform_drv_probe+0x50/0xbc
driver_probe_device+0x21c/0x308
__device_attach_driver+0x98/0xc8
bus_for_each_drv+0x54/0x94
__device_attach+0xc4/0x12c
device_initial_probe+0x10/0x18
bus_probe_device+0x90/0x98
deferred_probe_work_func+0xb0/0x150
process_one_work+0x12c/0x29c
worker_thread+0x200/0x3fc
kthread+0x108/0x134
ret_from_fork+0x10/0x18
Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)

It turned out that pci_remap_iospace() wasn't undone when the driver's
probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
the probe was retried, finally causing the BUG due to trying to remap
already remapped pages.

The Aardvark PCI controller driver has the same issue.
Replace pci_remap_iospace() with its devm_ managed version to fix the bug.

Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver")
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
[lorenzo.pieralisi@arm.com: updated the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

PCI: aardvark: Convert to use pci_host_probe()

Part of advk_pcie_probe() is exactly an open-coded version of
pci_host_probe(). So instead of duplicating this code, use
pci_host_probe() directly.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: aardvark: Size bridges before resources allocation

The PCIE I/O and MEM resource allocation mechanism is that root bus
goes through the following steps:

1. Check PCI bridges' range and computes I/O and Mem base/limits.

2. Sort all subordinate devices I/O and MEM resource requirements and
allocate the resources and writes/updates subordinate devices'
requirements to PCI bridges I/O and Mem MEM/limits registers.

Currently, PCI Aardvark driver only handles the second step and lacks
the first step, so there is an I/O and MEM resource allocation failure
when using a PCI switch. This commit fixes that by sizing bridges
before doing the resource allocation.

Fixes: 8c39d710363c1 ("PCI: aardvark: Add Aardvark PCI host controller
driver")
Signed-off-by: Zachary Zhang <zhangzg@marvell.com>
[Thomas: edit commit log.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <stable@vger.kernel.org>

PCI: aardvark: Remove PCIe outbound window configuration

Outbound window is used to translate CPU space addresses to PCIe space
addresses when the CPU initiates PCIe transactions.

According to the suggestion of the HW designers, the recommended
solution is to use the default outbound parameters, even though the
current outbound window setting does not cause any known functional
issue.

This patch doesn't address any known functional issue, but aligns to
HW design guidelines, and removes code that isn't needed.

Signed-off-by: Evan Wang <xswang@marvell.com>
[Thomas: tweak commit log.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[lorenzo.pieralisi@arm.com: handled host->controller dir move]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Victor Gu <xigu@marvell.com>
Reviewed-by: Nadav Haklai <nadavh@marvell.com>

PCI: aardvark: Introduce an advk_pcie_valid_device() helper

In other to mimic other PCIe host controller drivers, introduce an
advk_pcie_valid_device() helper, used in the configuration read/write
functions.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[lorenzo.pieralisi@arm.com: updated host->controller dir move]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

PCI: Collect all native drivers under drivers/pci/controller/

Native PCI drivers for root complex devices were originally all in
drivers/pci/host/. Some of these devices can also be operated in endpoint
mode. Drivers for endpoint mode didn't seem to fit in the "host"
directory, so we put both the root complex and endpoint drivers in
per-device directories, e.g., drivers/pci/dwc/, drivers/pci/cadence/, etc.

These per-device directories contain trivial Kconfig and Makefiles and
clutter drivers/pci/. Make a new drivers/pci/controllers/ directory and
collect all the device-specific drivers there.

No functional change intended.

Link: https://lkml.kernel.org/r/1520304202-232891-1-git-send-email-shawn.lin@rock-chips.com
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>