[V10,0/8] PCI: Enable 10-Bit tag support for PCIe devices

10-Bit Tag capability, introduced in PCIe-4.0 increases the total Tag
field size from 8 bits to 10 bits.

This patchset is to enable 10-Bit tag for PCIe EP devices (include VF).

V9->V10:
- Rebased on V5.15-rc4.
- Fix some commets suggested by Krzysztof.

V8->V9:
- Rebased on V5.15-rc2.
- Rename pcie_devcap to devcap, pcie_devcap2 to devcap2 to keep the same
  style with commit 691392448065 ("PCI: Cache PCIe Device Capabilities
  register").

V7->V8:
- Add a kernel parameter pcie_tag_peer2peer to disable 10-bit tags.
- Provide sysfs file to enable 10-bit tags.
- Remove [PATCH V7 6/9] PCI: Enable 10-Bit Tag support for PCIe RP devices.
- Rebased on v5.14-rc6.
- Fix some other comments. Thanks to Bjorn who gave a lot of review
  comments.

V6->V7:
- Rebased on v5.14-rc3.
- Change the "pci=disable_10bit_tag=" parameter to sysfs file to disable
  10-Bit Tag Requester when need for p2pdma suggested by Leon.
- Fix comment for p2pdma 10-bit tag check.

V5->V6:
- Rebased on v5.14-rc2.
- Add Reviewed-by: Christoph Hellwig <hch@lst.de> in [PATCH V6 2/8].
- PCI: Add "pci=disable_10bit_tag=" parameter for peer-to-peer support.
- Add a 10-bit tag check in P2PDMA.
- Simplified implementation in [PATCH V6 6/8].
- Fix some comments in [PATCH V6 4/8].

V4->V5:
- Fix warning variable 'capa' is uninitialized.
- Fix warning unused variable 'pchild'.

V3->V4:
- Get the value of pcie_devcap2 in set_pcie_port_type().
- Add Reviewed-by: Christoph Hellwig <hch@lst.de> in [PATCH V4 1/6],
  [PATCH V4 3/6], [PATCH V4 4/6], [PATCH V4 5/6].
- Fix some code style.
- Rebased on v5.13-rc6.

V2->V3:
- Use cached Device Capabilities Register suggested by Christoph.
- Fix code style to avoid > 80 char lines.
- Rename devcap2 to pcie_devcap2.

V1->V2: Fix some comments by Christoph.
- Store the devcap2 value in the pci_dev instead of reading it multiple
  times.
- Change pci_info to pci_dbg to avoid the noisy log.
- Rename ext_10bit_tag_comp_path to ext_10bit_tag.
- Fix the compile error.
- Rebased on v5.13-rc1.

Dongdong Liu (8):
  PCI: Use cached devcap in more places
  PCI: Cache Device Capabilities 2 Register
  PCI: Add 10-Bit Tag register definitions
  PCI/sysfs: Add a 10-Bit Tag sysfs file PCIe Endpoint devices
  PCI/IOV: Add 10-Bit Tag sysfs files for VF devices
  PCI/P2PDMA: Add a 10-Bit Tag check in P2PDMA
  PCI: Enable 10-Bit Tag support for PCIe Endpoint device
  PCI/IOV: Enable 10-Bit Tag support for PCIe VF devices

 Documentation/ABI/testing/sysfs-bus-pci       | 41 +++++++++-
 .../admin-guide/kernel-parameters.txt         |  5 ++
 drivers/media/pci/cobalt/cobalt-driver.c      |  4 +-
 .../net/ethernet/chelsio/cxgb4/cxgb4_main.c   |  4 +-
 drivers/pci/iov.c                             | 69 ++++++++++++++++
 drivers/pci/p2pdma.c                          | 48 +++++++++++
 drivers/pci/pci-sysfs.c                       | 81 +++++++++++++++++++
 drivers/pci/pci.c                             | 12 +--
 drivers/pci/pci.h                             |  9 +++
 drivers/pci/pcie/aspm.c                       | 11 +--
 drivers/pci/probe.c                           | 75 ++++++++++++++---
 drivers/pci/quirks.c                          |  3 +-
 include/linux/pci.h                           |  1 +
 include/uapi/linux/pci_regs.h                 |  5 ++
 14 files changed, 336 insertions(+), 32 deletions(-)

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2.22.0