- Use pci_host_bridge.windows list directly instead of splicing in a
temporary list for cadence, mvebu, host-common (Rob Herring)
- Use pci_host_probe() instead of open-coding all the pieces for altera,
brcmstb, iproc, mobiveil, rcar, rockchip, tegra, v3, versatile, xgene,
xilinx, xilinx-nwl (Rob Herring)
- Convert to devm_platform_ioremap_resource_byname() instead of open-coding
platform_get_resource_byname() and devm_ioremap_resource() for altera,
cadence, mediatek, rockchip, tegra, xgene (Dejin Zheng)
- Convert to devm_platform_ioremap_resource() instead of open-coding
platform_get_resource() and devm_ioremap_resource() for aardvark,
brcmstb, exynos, ftpci100, versatile (Dejin Zheng)
- Remove redundant error messages from devm_pci_remap_cfg_resource()
callers (Dejin Zheng)
- Drop useless PCI_ENABLE_PROC_DOMAINS from versatile driver (Rob Herring)
- Default host bridge parent device to the platform device (Rob Herring)
- Drop unnecessary zeroing of host bridge fields (Rob Herring)
- Use pci_is_root_bus() instead of tracking root bus number separately in
aardvark, designware (imx6, keystone, designware-host), mobiveil,
xilinx-nwl, xilinx, rockchip, rcar (Rob Herring)
- Set host bridge bus number in pci_scan_root_bus_bridge() instead of each
driver for aardvark, designware-host, host-common, mediatek, rcar, tegra,
v3-semi (Rob Herring)
- Use bridge resources instead of parsing DT 'ranges' again for cadence
(Rob Herring)
- Remove private bus number and range from cadence (Rob Herring)
- Use devm_pci_alloc_host_bridge() to simplify rcar (Rob Herring)
- Use struct pci_host_bridge.windows list directly rather than a temporary
(Rob Herring)
- Reduce OF "missing non-prefetchable window" from error to warning message
(Rob Herring)
- Convert rcar-gen2 from old Arm-specific pci_common_init_dev() to new
arch-independent interfaces (Rob Herring)
- Move DT resource setup into devm_pci_alloc_host_bridge() (Rob Herring)
- Set bridge map_irq and swizzle_irq to default functions; drivers that
don't support legacy IRQs (iproc) need to undo this (Rob Herring)
* pci/host-probe-refactor:
PCI: Set bridge map_irq and swizzle_irq to default functions
PCI: Move DT resource setup into devm_pci_alloc_host_bridge()
PCI: rcar-gen2: Convert to use modern host bridge probe functions
PCI: of: Reduce missing non-prefetchable memory region to a warning
PCI: rcar: Use struct pci_host_bridge.windows list directly
PCI: rcar: Use devm_pci_alloc_host_bridge()
PCI: cadence: Remove private bus number and range storage
PCI: cadence: Use bridge resources for outbound window setup
PCI: Move setting pci_host_bridge.busnr out of host drivers
PCI: rcar: Use pci_is_root_bus() to check if bus is root bus
PCI: rockchip: Use pci_is_root_bus() to check if bus is root bus
PCI: xilinx: Use pci_is_root_bus() to check if bus is root bus
PCI: xilinx-nwl: Use pci_is_root_bus() to check if bus is root bus
PCI: mobiveil: Use pci_is_root_bus() to check if bus is root bus
PCI: designware: Use pci_is_root_bus() to check if bus is root bus
PCI: aardvark: Use pci_is_root_bus() to check if bus is root bus
PCI: Drop unnecessary zeroing of bridge fields
PCI: Set default bridge parent device
PCI: versatile: Drop flag PCI_ENABLE_PROC_DOMAINS
PCI: controller: Remove duplicate error message
PCI: controller: Convert to devm_platform_ioremap_resource()
PCI: controller: Convert to devm_platform_ioremap_resource_byname()
PCI: xilinx: Use pci_host_probe() to register host
PCI: xilinx-nwl: Use pci_host_probe() to register host
PCI: rockchip: Use pci_host_probe() to register host
PCI: rcar: Use pci_host_probe() to register host
PCI: iproc: Use pci_host_probe() to register host
PCI: altera: Use pci_host_probe() to register host
PCI: xgene: Use pci_host_probe() to register host
PCI: versatile: Use pci_host_probe() to register host
PCI: v3: Use pci_host_probe() to register host
PCI: tegra: Use pci_host_probe() to register host
PCI: mobiveil: Use pci_host_probe() to register host
PCI: brcmstb: Use pci_host_probe() to register host
PCI: host-common: Use struct pci_host_bridge.windows list directly
PCI: mvebu: Use struct pci_host_bridge.windows list directly
PCI: cadence: Use struct pci_host_bridge.windows list directly
# Conflicts:
# drivers/pci/controller/cadence/pcie-cadence-host.c
- Use pci_channel_state_t instead of enum pci_channel_state (Luc Van
Oostenryck)
- Simplify __aer_print_error() (Bjorn Helgaas)
- Log AER correctable errors as warning, not error (Matt Jolly)
- Rename pci_aer_clear_device_status() to pcie_clear_device_status() (Bjorn
Helgaas)
- Clear PCIe Device Status errors only if OS owns AER (Jonathan Cameron)
* pci/error:
PCI/ERR: Clear PCIe Device Status errors only if OS owns AER
PCI/ERR: Rename pci_aer_clear_device_status() to pcie_clear_device_status()
PCI/AER: Log correctable errors as warning, not error
PCI/AER: Simplify __aer_print_error()
PCI: Use 'pci_channel_state_t' instead of 'enum pci_channel_state'
The method struct pci_error_handlers.error_detected() is defined and
documented as taking an 'enum pci_channel_state' for the second argument,
but most drivers use 'pci_channel_state_t' instead.
This 'pci_channel_state_t' is not a typedef for the enum but a typedef for
a bitwise type in order to have better/stricter typechecking.
Consolidate everything by using 'pci_channel_state_t' in the method's
definition, in the related helpers and in the drivers.
Enforce use of 'pci_channel_state_t' by replacing 'enum pci_channel_state'
with an anonymous 'enum'.
Note: Currently, from a typechecking point of view this patch changes
nothing because only the constants defined by the enum are bitwise, not the
enum itself (sparse doesn't have the notion of 'bitwise enum'). This may
change in some not too far future, hence the patch.
[bhelgaas: squash in
https://lore.kernel.org/r/20200702162651.49526-3-luc.vanoostenryck@gmail.comhttps://lore.kernel.org/r/20200702162651.49526-4-luc.vanoostenryck@gmail.com]
Link: https://lore.kernel.org/r/20200702162651.49526-2-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Commit 6ae72bfa65 ("PCI: Unify pcie_find_root_port() and
pci_find_pcie_root_port()") broke acpi_pci_bridge_d3() because calling
pcie_find_root_port() on a Root Port returned NULL when it should return
the Root Port, which in turn broke power management of PCIe hierarchies.
Rework pcie_find_root_port() so it returns its argument when it is already
a Root Port.
[bhelgaas: test device only once, test for PCIe]
Fixes: 6ae72bfa65 ("PCI: Unify pcie_find_root_port() and pci_find_pcie_root_port()")
Link: https://lore.kernel.org/r/20200622161248.51099-1-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull s390 updates from Vasily Gorbik:
- Add support for multi-function devices in pci code.
- Enable PF-VF linking for architectures using the pdev->no_vf_scan
flag (currently just s390).
- Add reipl from NVMe support.
- Get rid of critical section cleanup in entry.S.
- Refactor PNSO CHSC (perform network subchannel operation) in cio and
qeth.
- QDIO interrupts and error handling fixes and improvements, more
refactoring changes.
- Align ioremap() with generic code.
- Accept requests without the prefetch bit set in vfio-ccw.
- Enable path handling via two new regions in vfio-ccw.
- Other small fixes and improvements all over the code.
* tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits)
vfio-ccw: make vfio_ccw_regops variables declarations static
vfio-ccw: Add trace for CRW event
vfio-ccw: Wire up the CRW irq and CRW region
vfio-ccw: Introduce a new CRW region
vfio-ccw: Refactor IRQ handlers
vfio-ccw: Introduce a new schib region
vfio-ccw: Refactor the unregister of the async regions
vfio-ccw: Register a chp_event callback for vfio-ccw
vfio-ccw: Introduce new helper functions to free/destroy regions
vfio-ccw: document possible errors
vfio-ccw: Enable transparent CCW IPL from DASD
s390/pci: Log new handle in clp_disable_fh()
s390/cio, s390/qeth: cleanup PNSO CHSC
s390/qdio: remove q->first_to_kick
s390/qdio: fix up qdio_start_irq() kerneldoc
s390: remove critical section cleanup from entry.S
s390: add machine check SIGP
s390/pci: ioremap() align with generic code
s390/ap: introduce new ap function ap_get_qdev()
Documentation/s390: Update / remove developerWorks web links
...
- Clarify that platform_get_irq() should never return 0 (Bjorn Helgaas)
- Check for platform_get_irq() failure consistently (Bjorn Helgaas)
- Replace zero-length array with flexible-array (Gustavo A. R. Silva)
- Unify pcie_find_root_port() and pci_find_pcie_root_port() (Yicong Yang)
- Quirk Intel C620 MROMs, which have non-BARs in BAR locations (Xiaochun
Lee)
- Fix pcie_pme_resume() and pcie_pme_remove() kernel-doc (Jay Fang)
- Rename _DSM constants to align with spec (Krzysztof Wilczyński)
* pci/misc:
PCI: Rename _DSM constants to align with spec
PCI/PME: Fix kernel-doc of pcie_pme_resume() and pcie_pme_remove()
x86/PCI: Mark Intel C620 MROMs as having non-compliant BARs
PCI: Unify pcie_find_root_port() and pci_find_pcie_root_port()
PCI: Replace zero-length array with flexible-array
PCI: Check for platform_get_irq() failure consistently
driver core: platform: Clarify that IRQ 0 is invalid
- Log only ACPI_NOTIFY_DISCONNECT_RECOVER events for EDR, not all ACPI
SYSTEM-level events (Kuppuswamy Sathyanarayanan)
- Rely only on _OSC (not _OSC + HEST FIRMWARE_FIRST) to negotiate AER
Capability ownership (Alexandru Gagniuc)
- Remove HEST/FIRMWARE_FIRST parsing that was previously used to help
intuit AER Capability ownership (Kuppuswamy Sathyanarayanan)
- Remove redundant pci_is_pcie() and dev->aer_cap checks (Kuppuswamy
Sathyanarayanan)
- Print IRQ number used by DPC (Yicong Yang)
* pci/error:
PCI/DPC: Print IRQ number used by port
PCI/AER: Use "aer" variable for capability offset
PCI/AER: Remove redundant dev->aer_cap checks
PCI/AER: Remove redundant pci_is_pcie() checks
PCI/AER: Remove HEST/FIRMWARE_FIRST parsing for AER ownership
PCI/AER: Use only _OSC to determine AER ownership
PCI/EDR: Log only ACPI_NOTIFY_DISCONNECT_RECOVER events
Commit c100beb9cc ("PCI/AER: Use only _OSC to determine AER ownership")
removed the use of HEST in determining AER ownership, but the AER driver
still used HEST to verify AER ownership in some of its APIs.
Per the ACPI spec v6.3, sec 18.3.2.4, some HEST table entries contain a
FIRMWARE_FIRST bit, but that bit does not tell us anything about ownership
of the AER capability.
Remove parsing of HEST to look for FIRMWARE_FIRST.
Add pcie_aer_is_native() for the places that need to know whether the OS
owns the AER capability.
[bhelgaas: commit log, reorder patch, remove unused __aer_firmware_first]
Link: https://lore.kernel.org/r/9a37f53a4e6ff4942ff8e18dbb20b00e16c47341.1590534843.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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 <schnelle@linux.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Link: https://lore.kernel.org/r/20200506154139.90609-1-schnelle@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare variable-length
types such as these as a flexible array member [1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that dynamic memory allocations won't be affected by this
change:
Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero. [1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type [1]. There are some instances of code in which
the sizeof() operator is being incorrectly/erroneously applied to
zero-length arrays, and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also help
to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Link: https://lore.kernel.org/r/20200507190544.GA15633@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Pull pci updates from Bjorn Helgaas:
"Enumeration:
- Revert sysfs "rescan" renames that broke apps (Kelsey Skunberg)
- Add more 32 GT/s link speed decoding and improve the implementation
(Yicong Yang)
Resource management:
- Add support for sizing programmable host bridge apertures and fix a
related alpha Nautilus regression (Ivan Kokshaysky)
Interrupts:
- Add boot interrupt quirk mechanism for Xeon chipsets and document
boot interrupts (Sean V Kelley)
PCIe native device hotplug:
- When possible, disable in-band presence detect and use PDS
(Alexandru Gagniuc)
- Add DMI table for devices that don't use in-band presence detection
but don't advertise that correctly (Stuart Hayes)
- Fix hang when powering slots up/down via sysfs (Lukas Wunner)
- Fix an MSI interrupt race (Stuart Hayes)
Virtualization:
- Add ACS quirks for Zhaoxin devices (Raymond Pang)
Error handling:
- Add Error Disconnect Recover (EDR) support so firmware can report
devices disconnected via DPC and we can try to recover (Kuppuswamy
Sathyanarayanan)
Peer-to-peer DMA:
- Add Intel Sky Lake-E Root Ports B, C, D to the whitelist (Andrew
Maier)
ASPM:
- Reduce severity of common clock config message (Chris Packham)
- Clear the correct bits when enabling L1 substates, so we don't go
to the wrong state (Yicong Yang)
Endpoint framework:
- Replace EPF linkup ops with notifier call chain and improve locking
(Kishon Vijay Abraham I)
- Fix concurrent memory allocation in OB address region (Kishon Vijay
Abraham I)
- Move PF function number assignment to EPC core to support multiple
function creation methods (Kishon Vijay Abraham I)
- Fix issue with clearing configfs "start" entry (Kunihiko Hayashi)
- Fix issue with endpoint MSI-X ignoring BAR Indicator and Table
Offset (Kishon Vijay Abraham I)
- Add support for testing DMA transfers (Kishon Vijay Abraham I)
- Add support for testing > 10 endpoint devices (Kishon Vijay Abraham I)
- Add support for tests to clear IRQ (Kishon Vijay Abraham I)
- Add common DT schema for endpoint controllers (Kishon Vijay Abraham I)
Amlogic Meson PCIe controller driver:
- Add DT bindings for AXG PCIe PHY, shared MIPI/PCIe analog PHY (Remi
Pommarel)
- Add Amlogic AXG PCIe PHY, AXG MIPI/PCIe analog PHY drivers (Remi
Pommarel)
Cadence PCIe controller driver:
- Add Root Complex/Endpoint DT schema for Cadence PCIe (Kishon Vijay
Abraham I)
Intel VMD host bridge driver:
- Add two VMD Device IDs that require bus restriction mode (Sushma
Kalakota)
Mobiveil PCIe controller driver:
- Refactor and modularize mobiveil driver (Hou Zhiqiang)
- Add support for Mobiveil GPEX Gen4 host (Hou Zhiqiang)
Microsoft Hyper-V host bridge driver:
- Add support for Hyper-V PCI protocol version 1.3 and
PCI_BUS_RELATIONS2 (Long Li)
- Refactor to prepare for virtual PCI on non-x86 architectures (Boqun
Feng)
- Fix memory leak in hv_pci_probe()'s error path (Dexuan Cui)
NVIDIA Tegra PCIe controller driver:
- Use pci_parse_request_of_pci_ranges() (Rob Herring)
- Add support for endpoint mode and related DT updates (Vidya Sagar)
- Reduce -EPROBE_DEFER error message log level (Thierry Reding)
Qualcomm PCIe controller driver:
- Restrict class fixup to specific Qualcomm devices (Bjorn Andersson)
Synopsys DesignWare PCIe controller driver:
- Refactor core initialization code for endpoint mode (Vidya Sagar)
- Fix endpoint MSI-X to use correct table address (Kishon Vijay
Abraham I)
TI DRA7xx PCIe controller driver:
- Fix MSI IRQ handling (Vignesh Raghavendra)
TI Keystone PCIe controller driver:
- Allow AM654 endpoint to raise MSI-X interrupt (Kishon Vijay Abraham I)
Miscellaneous:
- Quirk ASMedia XHCI USB to avoid "PME# from D0" defect (Kai-Heng
Feng)
- Use ioremap(), not phys_to_virt(), for platform ROM to fix video
ROM mapping with CONFIG_HIGHMEM (Mikel Rychliski)"
* tag 'pci-v5.7-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (96 commits)
misc: pci_endpoint_test: remove duplicate macro PCI_ENDPOINT_TEST_STATUS
PCI: tegra: Print -EPROBE_DEFER error message at debug level
misc: pci_endpoint_test: Use full pci-endpoint-test name in request_irq()
misc: pci_endpoint_test: Fix to support > 10 pci-endpoint-test devices
tools: PCI: Add 'e' to clear IRQ
misc: pci_endpoint_test: Add ioctl to clear IRQ
misc: pci_endpoint_test: Avoid using module parameter to determine irqtype
PCI: keystone: Allow AM654 PCIe Endpoint to raise MSI-X interrupt
PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table address
PCI: endpoint: Fix ->set_msix() to take BIR and offset as arguments
misc: pci_endpoint_test: Add support to get DMA option from userspace
tools: PCI: Add 'd' command line option to support DMA
misc: pci_endpoint_test: Use streaming DMA APIs for buffer allocation
PCI: endpoint: functions/pci-epf-test: Print throughput information
PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer data
PCI: pciehp: Fix MSI interrupt race
PCI: pciehp: Fix indefinite wait on sysfs requests
PCI: endpoint: Fix clearing start entry in configfs
PCI: tegra: Add support for PCIe endpoint mode in Tegra194
PCI: sysfs: Revert "rescan" file renames
...
- Use ioremap(), not phys_to_virt() for platform ROM, to fix video ROM
mapping with CONFIG_HIGHMEM (Mikel Rychliski)
- Add support for root bus sizing so we don't have to assume host bridge
windows are known a priori (Ivan Kokshaysky)
- Fix alpha Nautilus PCI setup, which has been broken since we started
enforcing window limits in resource allocation (Ivan Kokshaysky)
* pci/resource:
alpha: Fix nautilus PCI setup
PCI: Add support for root bus sizing
PCI: Use ioremap(), not phys_to_virt() for platform ROM
In certain cases we should be able to enumerate IO and MEM ranges of all
PCI devices installed in the system, and then set respective host bridge
apertures basing on calculated size and alignment. Particularly when
firmware is broken and fails to assign bridge windows properly, like on
Alpha UP1500 platform.
Actually, almost everything is already in place, and required changes are
minimal:
- add "size_windows" flag to struct pci_host_bridge: when set, it
instructs __pci_bus_size_bridges() to continue with the root bus;
- in the __pci_bus_size_bridges() path: add checks for bus->self,
as it can legitimately be null for the root bus.
Link: https://lore.kernel.org/r/20200314194355.GA12510@mail.rc.ru
Tested-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
On some EFI systems, the video BIOS is provided by the EFI firmware. The
boot stub code stores the physical address of the ROM image in pdev->rom.
Currently we attempt to access this pointer using phys_to_virt(), which
doesn't work with CONFIG_HIGHMEM.
On these systems, attempting to load the radeon module on a x86_32 kernel
can result in the following:
BUG: unable to handle page fault for address: 3e8ed03c
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
*pde = 00000000
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 317 Comm: systemd-udevd Not tainted 5.6.0-rc3-next-20200228 #2
Hardware name: Apple Computer, Inc. MacPro1,1/Mac-F4208DC8, BIOS MP11.88Z.005C.B08.0707021221 07/02/07
EIP: radeon_get_bios+0x5ed/0xe50 [radeon]
Code: 00 00 84 c0 0f 85 12 fd ff ff c7 87 64 01 00 00 00 00 00 00 8b 47 08 8b 55 b0 e8 1e 83 e1 d6 85 c0 74 1a 8b 55 c0 85 d2 74 13 <80> 38 55 75 0e 80 78 01 aa 0f 84 a4 03 00 00 8d 74 26 00 68 dc 06
EAX: 3e8ed03c EBX: 00000000 ECX: 3e8ed03c EDX: 00010000
ESI: 00040000 EDI: eec04000 EBP: eef3fc60 ESP: eef3fbe0
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206
CR0: 80050033 CR2: 3e8ed03c CR3: 2ec77000 CR4: 000006d0
Call Trace:
r520_init+0x26/0x240 [radeon]
radeon_device_init+0x533/0xa50 [radeon]
radeon_driver_load_kms+0x80/0x220 [radeon]
drm_dev_register+0xa7/0x180 [drm]
radeon_pci_probe+0x10f/0x1a0 [radeon]
pci_device_probe+0xd4/0x140
Fix the issue by updating all drivers which can access a platform provided
ROM. Instead of calling the helper function pci_platform_rom() which uses
phys_to_virt(), call ioremap() directly on the pdev->rom.
radeon_read_platform_bios() previously directly accessed an __iomem
pointer. Avoid this by calling memcpy_fromio() instead of kmemdup().
pci_platform_rom() now has no remaining callers, so remove it.
Link: https://lore.kernel.org/r/20200319021623.5426-1-mikel@mikelr.com
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Error Disconnect Recover (EDR) is a feature that allows ACPI firmware to
notify OSPM that a device has been disconnected due to an error condition
(ACPI v6.3, sec 5.6.6). OSPM advertises its support for EDR on PCI devices
via _OSC (see [1], sec 4.5.1, table 4-4). The OSPM EDR notify handler
should invalidate software state associated with disconnected devices and
may attempt to recover them. OSPM communicates the status of recovery to
the firmware via _OST (sec 6.3.5.2).
For PCIe, firmware may use Downstream Port Containment (DPC) to support
EDR. Per [1], sec 4.5.1, table 4-6, even if firmware has retained control
of DPC, OSPM may read/write DPC control and status registers during the EDR
notification processing window, i.e., from the time it receives an EDR
notification until it clears the DPC Trigger Status.
Note that per [1], sec 4.5.1 and 4.5.2.4,
1. If the OS supports EDR, it should advertise that to firmware by
setting OSC_PCI_EDR_SUPPORT in _OSC Support.
2. If the OS sets OSC_PCI_EXPRESS_DPC_CONTROL in _OSC Control to request
control of the DPC capability, it must also set OSC_PCI_EDR_SUPPORT in
_OSC Support.
Add an EDR notify handler to attempt recovery.
[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
affecting PCI Firmware Specification, Rev. 3.2
https://members.pcisig.com/wg/PCI-SIG/document/12888
[bhelgaas: squash add/enable patches into one]
Link: https://lore.kernel.org/r/90f91fe6d25c13f9d2255d2ce97ca15be307e1bb.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
