linux.git/drivers/pci/iov.c, branch v5.8

s390/pci: create links between PFs and VFs

2020-05-20T08:22:51+00:00

On s390 PCI Virtual Functions (VFs) are scanned by firmware and are made
available to Linux via the hot-plug interface. As such the common code
path of doing the scan directly using the parent Physical Function (PF)
is not used and fenced off with the no_vf_scan attribute.

Even if the partition created the VFs itself e.g. using the sriov_numvfs
attribute of a PF, the PF/VF links thus need to be established after the
fact. To do this when a VF is plugged we scan through all functions on
the same zbus and test whether they are the parent PF in which case we
establish the necessary links.

With these links established there is now no more need to fence off
pci_iov_remove_virtfn() for pdev->no_vf_scan as the common code now
works fine.

Signed-off-by: Niklas Schnelle 
Acked-by: Bjorn Helgaas 
Reviewed-by: Pierre Morel 
Link: https://lore.kernel.org/r/20200506154139.90609-3-schnelle@linux.ibm.com
Signed-off-by: Vasily Gorbik

PCI/IOV: Introduce pci_iov_sysfs_link() function

2020-05-20T08:22:50+00:00

Currently pci_iov_add_virtfn() scans the SR-IOV BARs, adds the VF to the
bus and also creates the sysfs links between the newly added VF and its
parent PF.

With pdev->no_vf_scan fencing off the entire pci_iov_add_virtfn() call
s390 as the sole pdev->no_vf_scan user thus ends up missing these sysfs
links which are required for example by QEMU/libvirt.

Instead of duplicating the code refactor pci_iov_add_virtfn() to make
sysfs link creation callable separately.

Signed-off-by: Niklas Schnelle 
Acked-by: Bjorn Helgaas 
Reviewed-by: Pierre Morel 
Link: https://lore.kernel.org/r/20200506154139.90609-1-schnelle@linux.ibm.com
Signed-off-by: Vasily Gorbik

PCI/IOV: Fix memory leak in pci_iov_add_virtfn()

2019-12-09T21:51:32+00:00

In the implementation of pci_iov_add_virtfn() the allocated virtfn is
leaked if pci_setup_device() fails. The error handling is not calling
pci_stop_and_remove_bus_device(). Change the goto label to failed2.

Fixes: 156c55325d30 ("PCI: Check for pci_setup_device() failure in pci_iov_add_virtfn()")
Link: https://lore.kernel.org/r/20191125195255.23740-1-navid.emamdoost@gmail.com
Signed-off-by: Navid Emamdoost 
Signed-off-by: Bjorn Helgaas

Merge branch 'pci/trivial'

2019-11-28T14:54:55+00:00

  - Fix typos and comments (Bjorn Helgaas)

  - Fix Kconfig whitespace errors (Krzysztof Kozlowski)

* pci/trivial:
  PCI: Fix indentation
  PCI: Fix typos
  PCI: Remove useless comments and tidy others
  PCI: Remove unnecessary includes

# Conflicts:
#	drivers/pci/probe.c

PCI: Remove unnecessary includes

2019-10-17T20:18:44+00:00

Remove unnecessary includes.

Signed-off-by: Bjorn Helgaas

PCI/IOV: Serialize sysfs sriov_numvfs reads vs writes

2019-10-15T21:39:12+00:00

When sriov_numvfs is being updated, we call the driver->sriov_configure()
function, which may enable VFs and call probe functions, which may make new
devices visible.  This all happens before before sriov_numvfs_store()
updates sriov->num_VFs, so previously, concurrent sysfs reads of
sriov_numvfs returned stale values.

Serialize the sysfs read vs the write so the read returns the correct
num_VFs value.

[bhelgaas: hold device_lock instead of checking mutex_is_locked()]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=202991
Link: https://lore.kernel.org/r/20190911072736.32091-1-pierre.cregut@orange.com
Signed-off-by: Pierre Crégut 
Signed-off-by: Bjorn Helgaas

Merge branch 'pci/resource'

2019-09-23T21:10:15+00:00

  - Convert pci_resource_to_user() to a weak function to remove
    HAVE_ARCH_PCI_RESOURCE_TO_USER #defines (Denis Efremov)

  - Use PCI_SRIOV_NUM_BARS for idiomatic loop structure (Denis Efremov)

  - Fix Resizable BAR size suspend/restore for 1MB BARs (Sumit Saxena)

  - Correct "pci=resource_alignment" example in documentation (Alexey
    Kardashevskiy)

* pci/resource:
  PCI: Correct pci=resource_alignment parameter example
  PCI: Restore Resizable BAR size bits correctly for 1MB BARs
  PCI: Use PCI_SRIOV_NUM_BARS in loops instead of PCI_IOV_RESOURCE_END
  PCI: Convert pci_resource_to_user() to a weak function

# Conflicts:
#	drivers/pci/pci.c

PCI/IOV: Remove group write permission from sriov_numvfs, sriov_drivers_autoprobe

2019-09-05T18:26:23+00:00

Previously the sriov_numvfs and sriov_drivers_autoprobe sysfs files had
0664 permissions, which allowed group write.  libvirt runs as root when
dealing with PCI, and it chowns files needed by qemu, so group write
permission should not be needed.

Change these permissions from 0664 to 0644, which is what DEVICE_ATTR_RW()
does by default.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20190905063226.43269-1-skunberg.kelsey@gmail.com
Link: https://lore.kernel.org/r/850cf536-0b72-d78c-efaf-855dcb391087@redhat.com
Signed-off-by: Kelsey Skunberg 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Greg Kroah-Hartman 
Acked-by: Donald Dutile

PCI/IOV: Move sysfs SR-IOV functions to iov.c

2019-08-20T19:05:05+00:00

The sysfs SR-IOV functions are only needed when the kernel is built with
SR-IOV support.  Rather than put them in pci-sysfs.c under #ifdef
CONFIG_PCI_IOV, move them to iov.c, which is only compiled when
CONFIG_PCI_IOV=y.

Link: https://lore.kernel.org/r/20190813204513.4790-4-skunberg.kelsey@gmail.com
Signed-off-by: Kelsey Skunberg 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Donald Dutile 
Reviewed-by: Kuppuswamy Sathyanarayanan

PCI: Use PCI_SRIOV_NUM_BARS in loops instead of PCI_IOV_RESOURCE_END

2019-08-08T20:12:12+00:00

Writing loop conditions as "i < NUM" is a common C idiom; using "i <= END"
is unusual and thus prone to errors.  Change loops to use the former.

Link: https://lore.kernel.org/r/20190806140715.19847-1-efremov@linux.com
Signed-off-by: Denis Efremov 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Kuppuswamy Sathyanarayanan