x86: always initialize xen-swiotlb when xen-pcifront is enabling

Remove the dangerous late initialization of xen-swiotlb in
pci_xen_swiotlb_init_late and instead just always initialize
xen-swiotlb in the boot code if CONFIG_XEN_PCIDEV_FRONTEND is
enabled and Xen PV PCI is possible.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Juergen Gross <jgross@suse.com>

PCI: Introduce pci_dev_for_each_resource()

Instead of open-coding it everywhere introduce a tiny helper that can be
used to iterate over each resource of a PCI device, and convert the most
obvious users into it.

While at it drop doubled empty line before pdev_sort_resources().

No functional changes intended.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230330162434.35055-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>

xen: make remove callback of xen driver void returned

Since commit fc7a6209d571 ("bus: Make remove callback return void")
forces bus_type::remove be void-returned, it doesn't make much sense for
any bus based driver implementing remove callbalk to return non-void to
its caller.

This change is for xen bus based drivers.

Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Link: https://lore.kernel.org/r/TYCP286MB23238119AB4DF190997075C9CAE39@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/pcifront: move xenstore config scanning into sub-function

pcifront_try_connect() and pcifront_attach_devices() share a large
chunk of duplicated code for reading the config information from
Xenstore, which only differs regarding calling pcifront_rescan_root()
or pcifront_scan_root().

Put that code into a new sub-function. It is fine to always call
pcifront_rescan_root() from that common function, as it will fallback
to pcifront_scan_root() if the domain/bus combination isn't known
yet (and pcifront_scan_root() should never be called for an already
known domain/bus combination anyway). In order to avoid duplicate
messages for the fallback case move the check for domain/bus not known
to the beginning of pcifront_rescan_root().

While at it fix the error reporting in case the root-xx node had the
wrong format.

As the return value of pcifront_try_connect() and
pcifront_attach_devices() are not used anywhere make those functions
return void. As an additional bonus this removes the dubious return
of -EFAULT in case of an unexpected driver state.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

xen-pcifront: Handle missed Connected state

An HVM guest with linux stubdomain and 2 PCI devices failed to start as
libxl timed out waiting for the PCI devices to be added. It happens
intermittently but with some regularity. libxl wrote the two xenstore
entries for the devices, but then timed out waiting for backend state 4
(Connected) - the state stayed at 7 (Reconfiguring). (PCI passthrough
to an HVM with stubdomain is PV passthrough to the stubdomain and then
HVM passthrough with the QEMU inside the stubdomain.)

The stubdomain kernel never printed "pcifront pci-0: Installing PCI
frontend", so it seems to have missed state 4 which would have
called pcifront_try_connect() -> pcifront_connect_and_init_dma()

Have pcifront_detach_devices() special-case state Initialised and call
pcifront_connect_and_init_dma(). Don't use pcifront_try_connect()
because that sets the xenbus state which may throw off the backend.
After connecting, skip the remainder of detach_devices since none have
been initialized yet. When the backend switches to Reconfigured,
pcifront_attach_devices() will pick them up again.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220829151536.8578-1-jandryuk@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/pcifront: use xenbus_setup_ring() and xenbus_teardown_ring()

Simplify pcifront's shared page creation and removal via
xenbus_setup_ring() and xenbus_teardown_ring().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>

xen/grant-table: remove readonly parameter from functions

The gnttab_end_foreign_access() family of functions is taking a
"readonly" parameter, which isn't used. Remove it from the function
parameters.

Signed-off-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220311103429.12845-3-jgross@suse.com
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

xen/pcifront: Rework MSI handling

Replace the about to vanish iterators.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210748.251752714@linutronix.de

PCI/MSI: Use msi_desc::msi_index

The usage of msi_desc::pci::entry_nr is confusing at best. It's the index
into the MSI[X] descriptor table.

Use msi_desc::msi_index which is shared between all MSI incarnations
instead of having a PCI specific storage for no value.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211210221814.602911509@linutronix.de

genirq/msi, treewide: Use a named struct for PCI/MSI attributes

The unnamed struct sucks and is in the way of further cleanups. Stick the
PCI related MSI data into a real data structure and cleanup all users.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211206210224.374863119@linutronix.de

xen/pcifront: Use to_pci_driver() instead of pci_dev->driver

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pdev->driver with to_pci_driver(). This is a step toward removing
pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

xen/pcifront: Drop pcifront_common_process() tests of pcidev, pdrv

pcifront_common_process() exits early if pcidev or pcidev->driver are NULL,
so simplify it by not checking them again.

[bhelgaas: split flag change to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

swiotlb: Update is_swiotlb_active to add a struct device argument

Update is_swiotlb_active to add a struct device argument. This will be
useful later to allow for different pools.

Signed-off-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen/pcifront: Removed unnecessary __ref annotation

An unnecessary "__ref" annotation was removed from the
"drivers/pci/xen_pcifront.c" file. The function where the annotation
was used was "pcifront_backend_changed()", which does not call any
functions annotated as "__*init" nor "__*exit". This makes "__ref"
unnecessary since this annotation is used to make the compiler ignore
section miss-matches when they are not happening here in the first
place.

In addition to the aforementioned change, some code style issues were
fixed in the same file.

Signed-off-by: Sergio Miguéns Iglesias <sergio@lony.xyz>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20210830175305.13370-1-sergio@lony.xyz
Signed-off-by: Juergen Gross <jgross@suse.com>

swiotlb: remove swiotlb_nr_tbl

All callers just use it to check if swiotlb is active at all, for which
they can just use is_swiotlb_active. In the longer run drivers need
to stop using is_swiotlb_active as well, but let's do the simple step
first.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Xen/gnttab: introduce common INVALID_GRANT_{HANDLE,REF}

It's not helpful if every driver has to cook its own. Generalize
xenbus'es INVALID_GRANT_HANDLE and pcifront's INVALID_GRANT_REF (which
shouldn't have expanded to zero to begin with). Use the constants in
p2m.c and gntdev.c right away, and update field types where necessary so
they would match with the constants' types (albeit without touching
struct ioctl_gntdev_grant_ref's ref field, as that's part of the public
interface of the kernel and would require introducing a dependency on
Xen's grant_table.h public header).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/db7c38a5-0d75-d5d1-19de-e5fe9f0b9c48@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

dma-mapping: split <linux/dma-mapping.h>

Split out all the bits that are purely for dma_map_ops implementations
and related code into a new <linux/dma-map-ops.h> header so that they
don't get pulled into all the drivers. That also means the architecture
specific <asm/dma-mapping.h> is not pulled in by <linux/dma-mapping.h>
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

xen/pci: Get rid of verbose_request and use dev_dbg() instead

Information printed under verbose_request is clearly used for debugging
only. Remove it and use dev_dbg() instead.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/1590719092-8578-1-git-send-email-boris.ostrovsky@oracle.com
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc

Replace dev_printk(KERN_DEBUG) with dev_info(), etc to be more consistent
with other logging and avoid checkpatch warnings.

The KERN_DEBUG messages could be converted to dev_dbg(), but that depends
on CONFIG_DYNAMIC_DEBUG and DEBUG, and we want most of these messages to
*always* be in the dmesg log.

Link: https://lore.kernel.org/lkml/1555733240-19875-1-git-send-email-mohankumar718@gmail.com
Signed-off-by: Mohan Kumar <mohankumar718@gmail.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/pci/proc.c: In function ‘proc_bus_pci_ioctl’:
drivers/pci/proc.c:216:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (arch_can_pci_mmap_wc()) {
^
drivers/pci/proc.c:225:2: note: here
default:
^~~~~~~

drivers/pci/xen-pcifront.c: In function ‘pcifront_backend_changed’:
drivers/pci/xen-pcifront.c:1105:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (xdev->state == XenbusStateClosed)
^
drivers/pci/xen-pcifront.c:1108:2: note: here
case XenbusStateClosing:
^~~~

Notice that, in this particular case, the /* fall through */
comment is placed at the very bottom of the case statement,
which is what GCC is expecting to find.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add SPDX GPL-2.0 when no license was specified

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.

Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Add wrappers for dev_printk()

Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly. No functional change intended.

Signed-off-by: Frederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

xen/pcifront: Deprecate pci_get_bus_and_slot()

pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
where a PCI device is present. This restricts the device drivers to be
reused for other domain numbers.

Use pci_get_domain_bus_and_slot() with a domain number of 0 where we can't
extract the domain number. Other places, use the actual domain number from
the device.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>

xen: make use of xenbus_read_unsigned() in xen-pcifront

Use xenbus_read_unsigned() instead of xenbus_scanf() when possible.
This requires to change the type of the read from int to unsigned,
but this case has been wrong before: negative values are not allowed
for the modified case.

Cc: bhelgaas@google.com
Cc: linux-pci@vger.kernel.org

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>

treewide: replace obsolete _refok by __ref

There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485fb50 ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok __ref
#define __initdata_refok __refdata
#define __exit_refok __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xen/pcifront: Fix mysterious crashes when NUMA locality information was extracted.

Occasionaly PV guests would crash with:

pciback 0000:00:00.1: Xen PCI mapped GSI0 to IRQ16
BUG: unable to handle kernel paging request at 0000000d1a8c0be0
.. snip..
<ffffffff8139ce1b>] find_next_bit+0xb/0x10
[<ffffffff81387f22>] cpumask_next_and+0x22/0x40
[<ffffffff813c1ef8>] pci_device_probe+0xb8/0x120
[<ffffffff81529097>] ? driver_sysfs_add+0x77/0xa0
[<ffffffff815293e4>] driver_probe_device+0x1a4/0x2d0
[<ffffffff813c1ddd>] ? pci_match_device+0xdd/0x110
[<ffffffff81529657>] __device_attach_driver+0xa7/0xb0
[<ffffffff815295b0>] ? __driver_attach+0xa0/0xa0
[<ffffffff81527622>] bus_for_each_drv+0x62/0x90
[<ffffffff8152978d>] __device_attach+0xbd/0x110
[<ffffffff815297fb>] device_attach+0xb/0x10
[<ffffffff813b75ac>] pci_bus_add_device+0x3c/0x70
[<ffffffff813b7618>] pci_bus_add_devices+0x38/0x80
[<ffffffff813dc34e>] pcifront_scan_root+0x13e/0x1a0
[<ffffffff817a0692>] pcifront_backend_changed+0x262/0x60b
[<ffffffff814644c6>] ? xenbus_gather+0xd6/0x160
[<ffffffff8120900f>] ? put_object+0x2f/0x50
[<ffffffff81465c1d>] xenbus_otherend_changed+0x9d/0xa0
[<ffffffff814678ee>] backend_changed+0xe/0x10
[<ffffffff81463a28>] xenwatch_thread+0xc8/0x190
[<ffffffff810f22f0>] ? woken_wake_function+0x10/0x10

which was the result of two things:

When we call pci_scan_root_bus we would pass in 'sd' (sysdata)
pointer which was an 'pcifront_sd' structure. However in the
pci_device_add it expects that the 'sd' is 'struct sysdata' and
sets the dev->node to what is in sd->node (offset 4):

set_dev_node(&dev->dev, pcibus_to_node(bus));

__pcibus_to_node(const struct pci_bus *bus)
{
const struct pci_sysdata *sd = bus->sysdata;

return sd->node;
}

However our structure was pcifront_sd which had nothing at that
offset:

struct pcifront_sd {
int domain; /* 0 4 */
/* XXX 4 bytes hole, try to pack */
struct pcifront_device * pdev; /* 8 8 */
}

That is an hole - filled with garbage as we used kmalloc instead of
kzalloc (the second problem).

This patch fixes the issue by:
1) Use kzalloc to initialize to a well known state.
2) Put 'struct pci_sysdata' at the start of 'pcifront_sd'. That
way access to the 'node' will access the right offset.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

PCI: Use for_each_pci_msi_entry() to access MSI device list

Use accessor for_each_pci_msi_entry() to access MSI device list, so we
could easily move msi_list from struct pci_dev into struct device
later.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: xen-devel@lists.xenproject.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Stuart Yoder <stuart.yoder@freescale.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Link: http://lkml.kernel.org/r/1436428847-8886-7-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

xen/pcifront: Don't use deprecated function pci_scan_bus_parented()

Use pci_scan_root_bus() instead of deprecated function
pci_scan_bus_parented().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: xen-devel@lists.xenproject.org

xen/pcifront: Remove usage of struct timeval

struct timeval uses a 32-bit field for representing seconds, which
will overflow in the year 2038 and beyond. Replace struct timeval with
64-bit ktime_t which is 2038 safe. This is part of a larger effort to
remove instances of 32-bit timekeeping variables (timeval, time_t and
timespec) from the kernel.

Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

xenbus_client: Extend interface to support multi-page ring

Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.

The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.

Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront

The interface is documented, as before, in xenbus_client.c.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

PCI: Delete unnecessary NULL pointer checks

The functions pci_dev_put(), pci_pme_wakeup_bus(), and put_device() return
immediately if their argument is NULL. Thus the test before the call is
not needed.

Remove these unnecessary tests.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

xen/pcifront: Process failure for pcifront_(re)scan_root()

When pcifront_try_connect() finds no PCI roots, it falls back to calling
pcifront_scan_root() for 0000:00. If that fails, it used to switch to
XenbusStateConnected and return success (because xenbus_switch_state()
currently always succeeds).

If pcifront_scan_root() fails, leave the XenbusState unchanged and return
an error code.

Similarly, pcifront_attach_devices() falls back to calling
pcifront_rescan_root() for 0000:00. If that fails, it used to switch to
XenbusStateConnected and return an error code.

If pcifront_rescan_root() fails, leave the XenbusState unchanged and return
the error code.

[bhelgaas: changelog]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen: remove DEFINE_XENBUS_DRIVER() macro

The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse
errors.

Replace the uses with standard structure definitions instead. This is
similar to pci and usb device registration.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>

arch: Mass conversion of smp_mb__*()

Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

xen/pcifront: Use global PCI rescan-remove locking

Multiple race conditions are possible between the Xen pcifront device
addition and removal and the generic PCI device addition and removal that
can be triggered via sysfs.

To avoid those race conditions make the Xen pcifront code use global PCI
rescan-remove locking.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

xen/pvhvm: If xen_platform_pci=0 is set don't blow up (v4).

The user has the option of disabling the platform driver:
00:02.0 Unassigned class [ff80]: XenSource, Inc. Xen Platform Device (rev 01)

which is used to unplug the emulated drivers (IDE, Realtek 8169, etc)
and allow the PV drivers to take over. If the user wishes
to disable that they can set:

xen_platform_pci=0
(in the guest config file)

or
xen_emul_unplug=never
(on the Linux command line)

except it does not work properly. The PV drivers still try to
load and since the Xen platform driver is not run - and it
has not initialized the grant tables, most of the PV drivers
stumble upon:

input: Xen Virtual Keyboard as /devices/virtual/input/input5
input: Xen Virtual Pointer as /devices/virtual/input/input6M
------------[ cut here ]------------
kernel BUG at /home/konrad/ssd/konrad/linux/drivers/xen/grant-table.c:1206!
invalid opcode: 0000 [#1] SMP
Modules linked in: xen_kbdfront(+) xenfs xen_privcmd
CPU: 6 PID: 1389 Comm: modprobe Not tainted 3.13.0-rc1upstream-00021-ga6c892b-dirty #1
Hardware name: Xen HVM domU, BIOS 4.4-unstable 11/26/2013
RIP: 0010:[<ffffffff813ddc40>] [<ffffffff813ddc40>] get_free_entries+0x2e0/0x300
Call Trace:
[<ffffffff8150d9a3>] ? evdev_connect+0x1e3/0x240
[<ffffffff813ddd0e>] gnttab_grant_foreign_access+0x2e/0x70
[<ffffffffa0010081>] xenkbd_connect_backend+0x41/0x290 [xen_kbdfront]
[<ffffffffa0010a12>] xenkbd_probe+0x2f2/0x324 [xen_kbdfront]
[<ffffffff813e5757>] xenbus_dev_probe+0x77/0x130
[<ffffffff813e7217>] xenbus_frontend_dev_probe+0x47/0x50
[<ffffffff8145e9a9>] driver_probe_device+0x89/0x230
[<ffffffff8145ebeb>] __driver_attach+0x9b/0xa0
[<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
[<ffffffff8145eb50>] ? driver_probe_device+0x230/0x230
[<ffffffff8145cf1c>] bus_for_each_dev+0x8c/0xb0
[<ffffffff8145e7d9>] driver_attach+0x19/0x20
[<ffffffff8145e260>] bus_add_driver+0x1a0/0x220
[<ffffffff8145f1ff>] driver_register+0x5f/0xf0
[<ffffffff813e55c5>] xenbus_register_driver_common+0x15/0x20
[<ffffffff813e76b3>] xenbus_register_frontend+0x23/0x40
[<ffffffffa0015000>] ? 0xffffffffa0014fff
[<ffffffffa001502b>] xenkbd_init+0x2b/0x1000 [xen_kbdfront]
[<ffffffff81002049>] do_one_initcall+0x49/0x170

.. snip..

which is hardly nice. This patch fixes this by having each
PV driver check for:
- if running in PV, then it is fine to execute (as that is their
native environment).
- if running in HVM, check if user wanted 'xen_emul_unplug=never',
in which case bail out and don't load any PV drivers.
- if running in HVM, and if PCI device 5853:0001 (xen_platform_pci)
does not exist, then bail out and not load PV drivers.
- (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=ide-disks',
then bail out for all PV devices _except_ the block one.
Ditto for the network one ('nics').
- (v2) if running in HVM, and if the user wanted 'xen_emul_unplug=unnecessary'
then load block PV driver, and also setup the legacy IDE paths.
In (v3) make it actually load PV drivers.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it
Reported-by: Anthony PERARD <anthony.perard@citrix.com>
Reported-and-Tested-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Add extra logic to handle the myrid ways 'xen_emul_unplug'
can be used per Ian and Stefano suggestion]
[v3: Make the unnecessary case work properly]
[v4: s/disks/ide-disks/ spotted by Fabio]
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [for PCI parts]
CC: stable@vger.kernel.org

xen/pcifront: Deal with toolstack missing 'XenbusStateClosing' state.

There are two tool-stack that can instruct the Xen PCI frontend
and backend to change states: 'xm' (Python code with a daemon),
and 'xl' (C library - does not keep state changes).

With the 'xm', the path to disconnect a single PCI device (xm pci-detach
<guest> <BDF>) is:

4(Connected)->7(Reconfiguring*)-> 8(Reconfigured)-> 4(Connected)->5(Closing*).

The * is for states that the tool-stack sets. For 'xl', it is similar:

4(Connected)->7(Reconfiguring*)-> 8(Reconfigured)-> 4(Connected)

Both of them also tear down the XenBus structure, so the backend
state ends up going in the 3(Initialised) and calls pcifront_xenbus_remove.

When a PCI device is plugged back in (xm pci-attach <guest> <BDF>)
both of them follow the same pattern:

2(InitWait*), 3(Initialized*), 4(Connected*)->4(Connected).

[xen-pcifront ignores the 2,3 state changes and only acts when
4 (Connected) has been reached]

Note that this is for a _single_ PCI device. If there were two
PCI devices and only one was disconnected 'xm' would show the same
state changes.

The problem is that git commit 3d925320e9e2de162bd138bf97816bda8c3f71be
("xen/pcifront: Use Xen-SWIOTLB when initting if required") introduced
a mechanism to initialize the SWIOTLB when the Xen PCI front moves to
Connected state. It also had some aggressive seatbelt code check that
would warn the user if one tried to change to Connected state without
hitting first the Closing state:

pcifront pci-0: PCI frontend already installed!

However, that code can be relaxed and we can continue on working
even if the frontend is instructed to be the 'Connected' state with
no devices and then gets tickled to be in 'Connected' state again.

In other words, this 4(Connected)->5(Closing)->4(Connected) state
was expected, while 4(Connected)->.... anything but 5(Closing)->4(Connected)
was not. This patch removes that aggressive check and allows
Xen pcifront to work with the 'xl' toolstack (for one or more
PCI devices) and with 'xm' toolstack (for more than two PCI
devices).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: stable@vger.kernel.org
[v2: Added in the description about two PCI devices]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: Handle backend CLOSED without CLOSING

Backend drivers shouldn't transition to CLOSED unless the frontend is
CLOSED. If a backend does transition to CLOSED too soon then the
frontend may not see the CLOSING state and will not properly shutdown.

So, treat an unexpected backend CLOSED state the same as CLOSING.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

PCI: Remove __dev* markings

CONFIG_HOTPLUG is going away as an option so __devexit_p, __devint,
__devinitdata, __devinitconst, and _devexit are no longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xen/pcifront: Use Xen-SWIOTLB when initting if required.

We piggyback on "xen/swiotlb: Use the swiotlb_late_init_with_tbl to init
Xen-SWIOTLB late when PV PCI is used." functionality to start up
the Xen-SWIOTLB if we are hot-plugged. This allows us to bypass
the need to supply 'iommu=soft' on the Linux command line (mostly).
With this patch, if a user forgot 'iommu=soft' on the command line,
and hotplug a PCI device they will get:

pcifront pci-0: Installing PCI frontend
Warning: only able to allocate 4 MB for software IO TLB
software IO TLB [mem 0x2a000000-0x2a3fffff] (4MB) mapped at [ffff88002a000000-ffff88002a3fffff]
pcifront pci-0: Creating PCI Frontend Bus 0000:00
pcifront pci-0: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io 0x0000-0xffff]
pci_bus 0000:00: root bus resource [mem 0x00000000-0xfffffffff]
pci 0000:00:00.0: [8086:10d3] type 00 class 0x020000
pci 0000:00:00.0: reg 10: [mem 0xfe5c0000-0xfe5dffff]
pci 0000:00:00.0: reg 14: [mem 0xfe500000-0xfe57ffff]
pci 0000:00:00.0: reg 18: [io 0xe000-0xe01f]
pci 0000:00:00.0: reg 1c: [mem 0xfe5e0000-0xfe5e3fff]
pcifront pci-0: claiming resource 0000:00:00.0/0
pcifront pci-0: claiming resource 0000:00:00.0/1
pcifront pci-0: claiming resource 0000:00:00.0/2
pcifront pci-0: claiming resource 0000:00:00.0/3
e1000e: Intel(R) PRO/1000 Network Driver - 2.0.0-k
e1000e: Copyright(c) 1999 - 2012 Intel Corporation.
e1000e 0000:00:00.0: Disabling ASPM L0s L1
e1000e 0000:00:00.0: enabling device (0000 -> 0002)
e1000e 0000:00:00.0: Xen PCI mapped GSI16 to IRQ34
e1000e 0000:00:00.0: (unregistered net_device): Interrupt Throttling Rate (ints/sec) set to dynamic conservative mode
e1000e 0000:00:00.0: eth0: (PCI Express:2.5GT/s:Width x1) 00:1b:21:ab:c6:13
e1000e 0000:00:00.0: eth0: Intel(R) PRO/1000 Network Connection
e1000e 0000:00:00.0: eth0: MAC: 3, PHY: 8, PBA No: E46981-005

The "Warning only" will go away if one supplies 'iommu=soft' instead
as we have a higher chance of being able to allocate large swaths of
memory.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: Use hotplug-safe pci_get_domain_bus_and_slot()

Following code has a race window between pci_find_bus() and pci_get_slot()
if PCI hotplug operation happens between them which removes the pci_bus.
So use PCI hotplug safe interface pci_get_domain_bus_and_slot() instead,
which also reduces code complexity.

struct pci_bus *pci_bus = pci_find_bus(domain, busno);
struct pci_dev *pci_dev = pci_get_slot(pci_bus, devfn);

Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static.

There is no need for those functions/variables to be visible. Make them
static and also fix the compile warnings of this sort:

drivers/xen/<some file>.c: warning: symbol '<blah>' was not declared. Should it be static?

Some of them just require including the header file that
declares the functions.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen/pcifront: avoid pci_frontend_enable_msix() falsely returning success

The original XenoLinux code has always had things this way, and for
compatibility reasons (in particular with a subsequent pciback
adjustment) upstream Linux should behave the same way (allowing for two
distinct error indications to be returned by the backend).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

PCI: Rename pci_remove_bus_device to pci_stop_and_remove_bus_device

The old pci_remove_bus_device actually did stop and remove.

Make the name reflect that to reduce confusion.

This patch is done by sed scripts and changes back some incorrect
__pci_remove_bus_device changes.

Suggested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

xen/pci[front|back]: Use %d instead of %1x for displaying PCI devfn.

.. as the rest of the kernel is using that format.

Suggested-by: Марк Коренберг <socketpair@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

PCI/XEN: Fix bug introduced by a recent change

This patch (as1516) fixes a bug introduced during the removal of
put_driver() and get_driver() from drivers/pci/xen-pcifront.c.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Remove useless get_driver()/put_driver() calls

As part of the removal of get_driver()/put_driver(), this patch
(as1512) gets rid of various useless and unnecessary calls in several
drivers. In some cases it may be desirable to pin the driver by
calling try_module_get(), but that can be done later.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: "David S. Miller" <davem@davemloft.net>
CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: Michael Buesch <m@bues.ch>
CC: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Xen: consolidate and simplify struct xenbus_driver instantiation

The 'name', 'owner', and 'mod_name' members are redundant with the
identically named fields in the 'driver' sub-structure. Rather than
switching each instance to specify these fields explicitly, introduce
a macro to simplify this.

Eliminate further redundancy by allowing the drvname argument to
DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from
the ID table will be used for .driver.name).

Also eliminate the questionable xenbus_register_{back,front}end()
wrappers - their sole remaining purpose was the checking of the
'owner' field, proper setting of which shouldn't be an issue anymore
when the macro gets used.

v2: Restore DRV_NAME for the driver name in xen-pciback.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: Update warning comment to use 'e820_host' option.

With Xen changeset 23428 "libxl: Add 'e820_host' option to config file"
the E820 as seen from the host can now be passed into the guest.
This means that a PV guest can now:
- Use the correct PCI I/O gap. Before these patches, Linux guest would
boot up and would tell:
[ 0.000000] Allocating PCI resources starting at 40000000 (gap: 40000000:c0000000)
while in actuality the PCI I/O gap should have been:
[ 0.000000] Allocating PCI resources starting at b0000000 (gap: b0000000:4c000000)

- The PV domain with PCI devices was limited to 3GB. It now can be booted
with 4GB, 8GB, or whatever number you want. The PCI devices will now _not_ conflict
with System RAM. Meaning the drivers can load.

CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: linux-pci@vger.kernel.org
CC: stable@kernel.org
[v2: Made the string less broken up. Suggested by Joe Perches]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pci/xen: Cleanup: convert int** to int[]

Cleanup code. Cosmetic change to make the code look easier
to read.

Reviewed-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: Sanity check the MSI/MSI-X values

Check the returned vector values for any values that are
odd or plain incorrect (say vector value zero), and if so
print a warning. Also fixup the return values.

This patch was precipiated by the Xen PCIBack returning the
incorrect values due to how it was retrieving PIRQ values.
This has been fixed in the xen-pciback by
"xen/pciback: Utilize 'xen_pirq_from_irq' to get PIRQ value"
patch.

Reviewed-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: don't use flush_scheduled_work()

flush_scheduled_work() is scheduled for deprecation. Cancel ->op_work
directly instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ryan Wilson <hap9@epoch.ncsc.mil>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: fix PCI reference leak

Stanse found that when pdev is found and has no driver a reference is
leaked in pcifront_common_process. So add pci_dev_put there. For the
pdev == NULL case, pci_dev_put(NULL) is fine.

[v2: Updated to not dereference pcidev->dev per Milton's observation]

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Milton Miller <miltonm@bga.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>

xen-pcifront: Remove duplicate inclusion of headers.

In drivers/pci/xen-pcifront.c the xen/xenbus.h header is included twice -
once is enough.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen-pcifront: Xen PCI frontend driver.

This is a port of the 2.6.18 Xen PCI front driver with fixes
to make it build under 2.6.34 and later (for the full list of
changes: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
historic/xen-pcifront-0.1). It also includes the fixes
to make it work properly.

[v2: Updated Kconfig, removed crud, added Reviewed-by]
[v3: Added 'static', fixed grant table leak, redid Kconfig]
[v4: Added one more 'static' and removed comments]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Jan Beulich <JBeulich@novell.com>