dmaengine: dw-edma: Add support for native HDMA

Add support for HDMA NATIVE, as long the IP design has set
the compatible register map parameter-HDMA_NATIVE,
which allows compatibility for native HDMA register configuration.

The HDMA Hyper-DMA IP is an enhancement of the eDMA embedded-DMA IP.
And the native HDMA registers are different from eDMA, so this patch
add support for HDMA NATIVE mode.

HDMA write and read channels operate independently to maximize
the performance of the HDMA read and write data transfer over
the link When you configure the HDMA with multiple read channels,
then it uses a round robin (RR) arbitration scheme to select
the next read channel to be serviced.The same applies when you
have multiple write channels.

The native HDMA driver also supports a maximum of 16 independent
channels (8 write + 8 read), which can run simultaneously.
Both SAR (Source Address Register) and DAR (Destination Address Register)
are aligned to byte.

Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20230520050854.73160-4-cai.huoqing@linux.dev
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Rename dw_edma_core_ops structure to dw_edma_plat_ops

The dw_edma_core_ops structure contains a set of the operations:
device IRQ numbers getter, CPU/PCI address translation. Based on the
functions semantics the structure name "dw_edma_plat_ops" looks more
descriptive since indeed the operations are platform-specific. The
"dw_edma_core_ops" name shall be used for a structure with the IP-core
specific set of callbacks in order to abstract out DW eDMA and DW HDMA
setups. Such structure will be added in one of the next commit in the
framework of the set of changes adding the DW HDMA device support.

Anyway the renaming was necessary to distinguish two types of
the implementation callbacks:
1. DW eDMA/hDMA IP-core specific operations: device-specific CSR
setups in one or another aspect of the DMA-engine initialization.
2. DW eDMA/hDMA platform specific operations: the DMA device
environment configs like IRQs, address translation, etc.

Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20230520050854.73160-2-cai.huoqing@linux.dev
Signed-off-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Prepare dw_edma_probe() for builtin callers

When CONFIG_DW_EDMA=m, dw_edma_probe() is built as a module. Previously
edma.h declared it as extern, but the implementation isn't available for
builtin callers. A subsequent commit will add calls from
dw_pcie_host_init() and dw_pcie_ep_init(), which can only be built-in.

Make it safe for such builtin callers to call dw_edma_probe() by using
IS_REACHABLE() to define a stub when CONFIG_DW_EDMA=m.

When CONFIG_DW_EDMA=m, these builtin callers will fail to detect and
register eDMA devices, so eDMA won't be usable even if the dw-edma module
is loaded.

[bhelgaas: split to separate patch, commit log]
Link: https://lore.kernel.org/r/20230113171409.30470-25-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Add mem-mapped LL-entries support

Currently the DW eDMA driver only supports the linked lists memory
allocated locally with respect to the remote eDMA engine setup. It means
the linked lists will be accessible by the CPU via the MMIO space only. If
eDMA is embedded into the DW PCIe Root Ports or local Endpoints (which
support will be added in subsequent commits) the linked lists are supposed
to be allocated in the CPU memory. In that case the LL-entries can be
directly accessed, while the former case implies using the MMIO accessors
for that.

In order to have both cases supported by the driver, the dw_edma_region
descriptor should be fixed to contain the MMIO-backed and just memory-based
virtual addresses. The linked lists initialization procedure will use one
of them depending on the eDMA device nature. If the eDMA engine is embedded
into the local DW PCIe Root Port/Endpoint controllers, the list entries
will be directly accessed by referencing the corresponding structure
fields. Otherwise the MMIO accessors usage will be preserved.

Link: https://lore.kernel.org/r/20230113171409.30470-24-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Replace chip ID number with device name

Using an abstract number as the DW eDMA chip identifier isn't practical
because there can be more than one DW eDMA controller on the platform. Some
may be detected as the PCIe Endpoints, and others may be embedded in DW
PCIe Root Port/Endpoint controllers. An abstract number in, for instance,
the IRQ handlers list, doesn't give a notion regarding their reference to
the particular DMA controller.

To preserve the code simplicity and support multi-eDMA platforms, use the
parental device name to create the DW eDMA controller name.

Link: https://lore.kernel.org/r/20230113171409.30470-22-Sergey.Semin@baikalelectronics.ru
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Add CPU to PCI bus address translation

Since 9575632052ba ("dmaengine: make slave address physical"), the source
and destination addresses of the DMA slave device have been converted to
physical addresses in the CPU address space. It's the DMA device driver's
responsibility to convert them to the DMA bus address space. In case of the
DW eDMA device, the source or destination peripheral (slave) devices reside
in PCI bus space. Thus we need to perform the PCI Host/Endpoint windows-
based (i.e. DT "ranges" property) address translation; otherwise the eDMA
transactions won't work as expected (or can be even harmful) if the CPU and
PCI address spaces don't match.

Note 1: Even though the DMA interleaved template has both source and
destination addresses declared as dma_addr_t, only the CPU memory range
should be mapped to be seen by the DMA device since it's a subject of the
DMA getting towards the system side. The device part must not be mapped
since the slave device resides in the PCI bus space, which isn't affected
by IOMMUs or iATU translations. DW PCIe eDMA generates corresponding
MWr/MRd TLPs on its own.

Note 2: This functionality is mainly required for the remote eDMA setup
since the CPU address must be manually translated into the PCI bus space
before being written to LLI.{SAR,DAR}. If eDMA is embedded in the locally
accessible DW PCIe Root Port/Endpoint, software-based translation isn't
required since hardware will translate it via the Outbound iATU as long as
the DMA_BYPASS flag is cleared. If DMA_BYPASS is set or there is no
Outbound iATU entry that contains the SAR or DAR (for Read and Write
channel respectively), there won't be any translation performed but DMA
will proceed with the corresponding source/destination address as-is.

Link: https://lore.kernel.org/r/20230113171409.30470-8-Sergey.Semin@baikalelectronics.ru
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Convert ll/dt phys address to PCI bus/DMA address

The dw_edma_region.paddr field should be a memory base address visible by
the DW eDMA controller. If the DMA engine is embedded in the DW PCIe
Host/Endpoint controller, the address should belong to the Local CPU/
Application memory. If eDMA is remotely accessible across the PCI bus via
PCI memory IOs, the address should be part of the PCI bus memory space.
The latter case hasn't been well covered in the corresponding glue-driver.

Since pci_dev.resource[] contains resources defined in the CPU memory
space, they need to be converted to the PCI bus address space. Convert the
LL, DT and CSRs PCI memory ranges with pci_bus_address().

In addition, extend the dw_edma_region.paddr field size. The field normally
contains a memory range base address to be set in the DW eDMA Linked-List
pointer register or as a base address of the Linked-List data buffer. In
accordance with [1] the LL range is supposed to be created in the Local
CPU/Application memory, but depending on the DW eDMA utilization the memory
can be created as a part of the PCI bus address space (as in the case of
the DW PCIe Endpoint prototype kit).

In the former case dw_edma_region.paddr should be a dma_addr_t, while in
the latter one it should be a pci_bus_addr_t. Since the corresponding CSRs
are always 64 bits wide, convert dw_edma_region.paddr to be u64, and let
the client make sure it has a valid address visible by the DW eDMA
controller. For instance, the DW eDMA PCIe glue-driver initializes the
field with addresses from the PCI bus memory space.

[1] DesignWare Cores PCI Express Controller Databook - DWC PCIe Root Port,
v.5.40a, March 2019, p.1103

Link: https://lore.kernel.org/r/20230113171409.30470-4-Sergey.Semin@baikalelectronics.ru
Fixes: 41aaff2a2ac0 ("dmaengine: Add Synopsys eDMA IP PCIe glue-logic")
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Add support for chip-specific flags

Add a "flags" field to the "struct dw_edma_chip" so that the controller
drivers can pass flags that are relevant to the platform.

DW_EDMA_CHIP_LOCAL - Used by the controller drivers accessing eDMA
locally. Local eDMA access doesn't require generating MSIs to the remote.

Link: https://lore.kernel.org/r/20220524152159.2370739-8-Frank.Li@nxp.com
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Rename wr(rd)_ch_cnt to ll_wr(rd)_cnt in struct dw_edma_chip

The struct dw_edma contains wr(rd)_ch_cnt fields. The EDMA driver gets
write(read) channel number from register, then saves these into dw_edma.
The wr(rd)_ch_cnt in dw_edma_chip actually means how many link list memory
are available in ll_region_wr(rd)[EDMA_MAX_WR_CH]. Rename it to
ll_wr(rd)_cnt to indicate actual usage.

Link: https://lore.kernel.org/r/20220524152159.2370739-5-Frank.Li@nxp.com
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Change rg_region to reg_base in struct dw_edma_chip

struct dw_edma_region rg_region included virtual address, physical address
and size information. But only the virtual address is used by EDMA driver.
Change it to void __iomem *reg_base to clean up code.

Link: https://lore.kernel.org/r/20220524152159.2370739-4-Frank.Li@nxp.com
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Detach the private data and chip info structures

"struct dw_edma_chip" contains an internal structure "struct dw_edma" that
is used by the eDMA core internally and should not be touched by the eDMA
controller drivers themselves. But currently, the eDMA controller drivers
like "dw-edma-pci" allocate and populate this internal structure before
passing it on to the eDMA core. The eDMA core further populates the
structure and uses it. This is wrong!

Hence, move all the "struct dw_edma" specifics from controller drivers to
the eDMA core.

Link: https://lore.kernel.org/r/20220524152159.2370739-3-Frank.Li@nxp.com
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

dmaengine: dw-edma: Remove unused irq field in struct dw_edma_chip

The "irq" field of struct dw_edma_chip was never used. Remove it.

Link: https://lore.kernel.org/r/20220524152159.2370739-2-Frank.Li@nxp.com
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-By: Vinod Koul <vkoul@kernel.org>

dmaengine: Add Synopsys eDMA IP core driver

Add Synopsys PCIe Endpoint eDMA IP core driver to kernel.

This IP is generally distributed with Synopsys PCIe Endpoint IP (depends
of the use and licensing agreement).

This core driver, initializes and configures the eDMA IP using vma-helpers
functions and dma-engine subsystem.

This driver can be compile as built-in or external module in kernel.

To enable this driver just select DW_EDMA option in kernel configuration,
however it requires and selects automatically DMA_ENGINE and
DMA_VIRTUAL_CHANNELS option too.

In order to transfer data from point A to B as fast as possible this IP
requires a dedicated memory space containing linked list of elements.

All elements of this linked list are continuous and each one describes a
data transfer (source and destination addresses, length and a control
variable).

For the sake of simplicity, lets assume a memory space for channel write
0 which allows about 42 elements.

+---------+
| Desc #0 |-+
+---------+ |
V
+----------+
| Chunk #0 |-+
| CB = 1 | | +----------+ +-----+ +-----------+ +-----+
+----------+ +->| Burst #0 |->| ... |->| Burst #41 |->| llp |
| +----------+ +-----+ +-----------+ +-----+
V
+----------+
| Chunk #1 |-+
| CB = 0 | | +-----------+ +-----+ +-----------+ +-----+
+----------+ +->| Burst #42 |->| ... |->| Burst #83 |->| llp |
| +-----------+ +-----+ +-----------+ +-----+
V
+----------+
| Chunk #2 |-+
| CB = 1 | | +-----------+ +-----+ +------------+ +-----+
+----------+ +->| Burst #84 |->| ... |->| Burst #125 |->| llp |
| +-----------+ +-----+ +------------+ +-----+
V
+----------+
| Chunk #3 |-+
| CB = 0 | | +------------+ +-----+ +------------+ +-----+
+----------+ +->| Burst #126 |->| ... |->| Burst #129 |->| llp |
+------------+ +-----+ +------------+ +-----+

Legend:
- Linked list, also know as Chunk
- Linked list element*, also know as Burst *CB*, also know as Change Bit,
it's a control bit (and typically is toggled) that allows to easily
identify and differentiate between the current linked list and the
previous or the next one.
- LLP, is a special element that indicates the end of the linked list
element stream also informs that the next CB should be toggle

On every last Burst of the Chunk (Burst #41, Burst #83, Burst #125 or
even Burst #129) is set some flags on their control variable (RIE and
LIE bits) that will trigger the send of "done" interruption.

On the interruptions callback, is decided whether to recycle the linked
list memory space by writing a new set of Bursts elements (if still
exists Chunks to transfer) or is considered completed (if there is no
Chunks available to transfer).

On scatter-gather transfer mode, the client will submit a scatter-gather
list of n (on this case 130) elements, that will be divide in multiple
Chunks, each Chunk will have (on this case 42) a limited number of
Bursts and after transferring all Bursts, an interrupt will be
triggered, which will allow to recycle the all linked list dedicated
memory again with the new information relative to the next Chunk and
respective Burst associated and repeat the whole cycle again.

On cyclic transfer mode, the client will submit a buffer pointer, length
of it and number of repetitions, in this case each burst will correspond
directly to each repetition.

Each Burst can describes a data transfer from point A(source) to point
B(destination) with a length that can be from 1 byte up to 4 GB. Since
dedicated the memory space where the linked list will reside is limited,
the whole n burst elements will be organized in several Chunks, that
will be used later to recycle the dedicated memory space to initiate a
new sequence of data transfers.

The whole transfer is considered has completed when it was transferred
all bursts.

Currently this IP has a set well-known register map, which includes
support for legacy and unroll modes. Legacy mode is version of this
register map that has multiplexer register that allows to switch
registers between all write and read channels and the unroll modes
repeats all write and read channels registers with an offset between
them. This register map is called v0.

The IP team is creating a new register map more suitable to the latest
PCIe features, that very likely will change the map register, which this
version will be called v1. As soon as this new version is released by
the IP team the support for this version in be included on this driver.

According to the logic, patches 1, 2 and 3 should be squashed into 1
unique patch, but for the sake of simplicity of review, it was divided
in this 3 patches files.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Joao Pinto <jpinto@synopsys.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>