linux-toradex.git/drivers/pci/vpd.c, branch v6.11-rc3 Linux kernel for Apalis and Colibri modules PCI/VPD: Add runtime power management to sysfs interface 2023-08-11T19:19:16+00:00 Alex Williamson alex.williamson@redhat.com 2023-08-03T17:12:32+00:00 5cd903bce9ddd234d76e67d0dfaf0aab0f11a2e0 Unlike default access to config space through sysfs, the VPD read and write functions don't actively manage the runtime power management state of the device during access. Since commit 7ab5e10eda02 ("vfio/pci: Move the unused device into low power state with runtime PM"), the vfio-pci driver will use runtime power management and release unused devices to make use of low power states. Attempting to access VPD information in D3cold can result in incorrect information or kernel crashes depending on the system behavior. Wrap the VPD read/write bin attribute handlers in runtime PM and take into account the potential quirk to select the correct device to wake. Link: https://lore.kernel.org/r/20230803171233.3810944-2-alex.williamson@redhat.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com> [bhelgaas: tweak pci_dev_put() test to match the pci_get_func0_dev() test] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Unlike default access to config space through sysfs, the VPD read and write
functions don't actively manage the runtime power management state of the
device during access.  Since commit 7ab5e10eda02 ("vfio/pci: Move the
unused device into low power state with runtime PM"), the vfio-pci driver
will use runtime power management and release unused devices to make use of
low power states.  Attempting to access VPD information in D3cold can
result in incorrect information or kernel crashes depending on the system
behavior.

Wrap the VPD read/write bin attribute handlers in runtime PM and take into
account the potential quirk to select the correct device to wake.

Link: https://lore.kernel.org/r/20230803171233.3810944-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
[bhelgaas: tweak pci_dev_put() test to match the pci_get_func0_dev() test]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Use pci_read_vpd_any() in pci_vpd_size() 2021-10-26T00:12:23+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-09-10T06:22:49+00:00 3331325c6347492dfbe31f6b2bfdaee9b0689cd5 Use new function pci_read_vpd_any() to simplify the code. [bhelgaas: squash in fix for stack overflow reported & tested by Qian [1] and Kunihiko [2]: [1] https://lore.kernel.org/netdev/e89087c5-c495-c5ca-feb1-54cf3a8775c5@quicinc.com/ [2] https://lore.kernel.org/r/2f7e3770-ab47-42b5-719c-f7c661c07d28@socionext.com Link: https://lore.kernel.org/r/6211be8a-5d10-8f3a-6d33-af695dc35caf@gmail.com Reported-by: Qian Cai <quic_qiancai@quicinc.com> Tested-by: Qian Cai <quic_qiancai@quicinc.com> Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> ] Link: https://lore.kernel.org/r/049fa71c-c7af-9c69-51c0-05c1bc2bf660@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> 
Use new function pci_read_vpd_any() to simplify the code.

[bhelgaas: squash in fix for stack overflow reported & tested by
Qian [1] and Kunihiko [2]:
[1] https://lore.kernel.org/netdev/e89087c5-c495-c5ca-feb1-54cf3a8775c5@quicinc.com/
[2] https://lore.kernel.org/r/2f7e3770-ab47-42b5-719c-f7c661c07d28@socionext.com
Link: https://lore.kernel.org/r/6211be8a-5d10-8f3a-6d33-af695dc35caf@gmail.com
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Tested-by: Qian Cai <quic_qiancai@quicinc.com>
Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
]

Link: https://lore.kernel.org/r/049fa71c-c7af-9c69-51c0-05c1bc2bf660@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
PCI/VPD: Add pci_read/write_vpd_any() 2021-10-11T20:10:11+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-09-10T06:22:06+00:00 bf2928c7a284e31f9f91a004b5dca09c522157c0 In certain cases we need a variant of pci_read_vpd()/pci_write_vpd() that does not check against dev->vpd.len. Such cases are: - Reading VPD if dev->vpd.len isn't set yet (in pci_vpd_size()) - Devices that map non-VPD information to arbitrary places in VPD address space (example: Chelsio T3 EEPROM write-protect flag) Therefore add pci_read_vpd_any() and pci_write_vpd_any() that check against PCI_VPD_MAX_SIZE only. Link: https://lore.kernel.org/r/93ecce28-a158-f02a-d134-8afcaced8efe@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> 
In certain cases we need a variant of pci_read_vpd()/pci_write_vpd() that
does not check against dev->vpd.len. Such cases are:

  - Reading VPD if dev->vpd.len isn't set yet (in pci_vpd_size())

  - Devices that map non-VPD information to arbitrary places in VPD address
    space (example: Chelsio T3 EEPROM write-protect flag)

Therefore add pci_read_vpd_any() and pci_write_vpd_any() that check against
PCI_VPD_MAX_SIZE only.

Link: https://lore.kernel.org/r/93ecce28-a158-f02a-d134-8afcaced8efe@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
PCI/VPD: Defer VPD sizing until first access 2021-09-15T21:26:13+00:00 Bjorn Helgaas bhelgaas@google.com 2021-09-13T21:13:26+00:00 00e1a5d21b4ff514593554167b28a8caeda1497f 7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()") reads VPD at enumeration-time to find the size. But this is quite slow, and we don't need the size until we actually need data from VPD. Dave reported a boot slowdown of more than two minutes [1]. Defer the VPD sizing until a driver or the user (via sysfs) requests information from VPD. If devices are quirked because VPD is known not to work, don't bother even looking for the VPD capability. The VPD will not be accessible at all. [1] https://lore.kernel.org/r/20210913141818.GA27911@codemonkey.org.uk/ Link: https://lore.kernel.org/r/20210914215543.GA1437800@bjorn-Precision-5520 Fixes: 7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()") reads VPD at
enumeration-time to find the size.  But this is quite slow, and we don't
need the size until we actually need data from VPD.  Dave reported a boot
slowdown of more than two minutes [1].

Defer the VPD sizing until a driver or the user (via sysfs) requests
information from VPD.

If devices are quirked because VPD is known not to work, don't bother even
looking for the VPD capability.  The VPD will not be accessible at all.

[1] https://lore.kernel.org/r/20210913141818.GA27911@codemonkey.org.uk/
Link: https://lore.kernel.org/r/20210914215543.GA1437800@bjorn-Precision-5520
Fixes: 7bac54497c3e ("PCI/VPD: Determine VPD size in pci_vpd_init()")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Use unaligned access helpers 2021-08-31T21:10:18+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:58:07+00:00 2c208abd4f9efac02622d8f3c9989f4b7b1ad973 Use unaligned access helpers to simplify the code. Link: https://lore.kernel.org/r/0f1c7e21-5330-72ab-139d-f5ce3c65f04a@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Use unaligned access helpers to simplify the code.

Link: https://lore.kernel.org/r/0f1c7e21-5330-72ab-139d-f5ce3c65f04a@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Clean up public VPD defines and inline functions 2021-08-31T21:10:18+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:57:01+00:00 06e1913d457121a98ee276179734c34dab30f388 After recent introduction of new VPD API functions and user migration these defines and inline functions aren't used outside VPD core any longer. Link: https://lore.kernel.org/r/d33e06bf-bc5e-ece7-bf35-7245ae224d1b@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
After recent introduction of new VPD API functions and user migration
these defines and inline functions aren't used outside VPD core any
longer.

Link: https://lore.kernel.org/r/d33e06bf-bc5e-ece7-bf35-7245ae224d1b@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Add pci_vpd_find_id_string() 2021-08-31T21:08:15+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:55:43+00:00 acfbb1b8a494d7bfd316dfb363a820e6df637e8d Add a pci_vpd_find_id_string() API function to retrieve the ID string from VPD. This way callers don't need pci_vpd_lrdt_size() any longer, and it can be made private to the VPD core. Link: https://lore.kernel.org/r/c5225bf6-8d29-970d-e271-0d7b52252630@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Add a pci_vpd_find_id_string() API function to retrieve the ID string from
VPD.

This way callers don't need pci_vpd_lrdt_size() any longer, and it can be
made private to the VPD core.

Link: https://lore.kernel.org/r/c5225bf6-8d29-970d-e271-0d7b52252630@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Include post-processing in pci_vpd_find_tag() 2021-08-31T21:04:05+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:55:07+00:00 46a347835cc50b04da0996a070939ed8927d69bd Move pci_vpd_find_tag() post-processing from pci_vpd_find_ro_info_keyword() to pci_vpd_find_tag(). This simplifies function pci_vpd_find_id_string() that will be added in a subsequent patch. Link: https://lore.kernel.org/r/fb15393f-d3b2-e140-2643-570d3abd7382@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Move pci_vpd_find_tag() post-processing from pci_vpd_find_ro_info_keyword()
to pci_vpd_find_tag(). This simplifies function pci_vpd_find_id_string()
that will be added in a subsequent patch.

Link: https://lore.kernel.org/r/fb15393f-d3b2-e140-2643-570d3abd7382@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Stop exporting pci_vpd_find_info_keyword() 2021-08-31T21:04:05+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:54:23+00:00 59b83b29bb5532bbff54a271e0b4f321e28b954f Now that the last users have been migrated to pci_vpd_find_ro_keyword() we can stop exporting this function. It's still used in VPD core code. Link: https://lore.kernel.org/r/96ca2a56-383e-9b61-9cba-4f1e5611dc15@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Now that the last users have been migrated to pci_vpd_find_ro_keyword()
we can stop exporting this function. It's still used in VPD core code.

Link: https://lore.kernel.org/r/96ca2a56-383e-9b61-9cba-4f1e5611dc15@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCI/VPD: Stop exporting pci_vpd_find_tag() 2021-08-31T21:04:05+00:00 Heiner Kallweit hkallweit1@gmail.com 2021-08-26T18:53:42+00:00 a61590892ef097c180144fa469abe2256b9ae715 Now that the last users have been migrated to pci_vpd_find_ro_keyword() we can stop exporting this function. It's still used in VPD core code. Link: https://lore.kernel.org/r/71131eca-0502-7878-365f-30b6614161cf@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 
Now that the last users have been migrated to pci_vpd_find_ro_keyword()
we can stop exporting this function. It's still used in VPD core code.

Link: https://lore.kernel.org/r/71131eca-0502-7878-365f-30b6614161cf@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>