PCI endpoint fixes and improvements

This series fixes several issues with the PCI endpoint code and endpoint test drivers (RC side and EP side).

The first 2 patches address an issue with the use of configfs to create an endpoint driver type attributes group, preventing a potential crash if the user creates a directory multiple times for the driver type attributes.

The following patches are fixes and improvements for the endpoint test drivers, EP side and RC side.

This is all tested using a Pine Rockpro64 board, with the rockchip ep driver fixed using Rick Wertenbroek <[email protected]> patches [1].

[1] https://lore.kernel.org/linux-pci/[email protected]/

Changes from v4:
- Addressed Bjorn comments on the commit messages (typos, text clarity)
- Changed patch 1 to use dev_err() instead of pr_err().
- Add print of invalid command value in patch 10
- Chnaged all patches author and Signed-off-by tag to use my kernel.org email address
- Added Mani's review tags

Changes from v3:
- Corrected patch 7 and 12 title
- Added patch 11

Changes from v2:
- Add updates of the ntb and vntb function driver documentation in patch 1 to reflect the patch changes.
- Removed unnecessary WARN_ON() call in patch 4
- Added missing cc: stable tags
- Added review tags

Changes from v1:
- Improved patch 1 commit message
- Modified patch 2 to not have to add an internal header file
- Split former patch 3 into patch 3, 4 and 5
- Removed former patch 4 introducing volatile casts and replaced it with patch 9
- Added patch 6, 7, 8 and 10
- Added Reviewed-by tags in patches not modified

Damien Le Moal (17):
PCI: endpoint: Automatically create a function specific attributes
group
PCI: endpoint: Move pci_epf_type_add_cfs() code
PCI: epf-test: Fix DMA transfer completion initialization
PCI: epf-test: Fix DMA transfer completion detection
PCI: epf-test: Use dmaengine_submit() to initiate DMA transfer
PCI: epf-test: Simplify read/write/copy test functions
PCI: epf-test: Simplify pci_epf_test_raise_irq()
PCI: epf-test: Simplify IRQ test commands execution
PCI: epf-test: Improve handling of command and status registers
PCI: epf-test: Cleanup pci_epf_test_cmd_handler()
PCI: epf-test: Cleanup request result handling
PCI: epf-test: Simplify DMA support checks
PCI: epf-test: Simplify transfers result print
misc: pci_endpoint_test: Free IRQs before removing the device
misc: pci_endpoint_test: Re-init completion for every test
misc: pci_endpoint_test: Do not write status in IRQ handler
misc: pci_endpoint_test: Simplify pci_endpoint_test_msi_irq()

 Documentation/PCI/endpoint/pci-ntb-howto.rst  |  11 +-
 Documentation/PCI/endpoint/pci-vntb-howto.rst |  13 +-
 drivers/misc/pci_endpoint_test.c              |  25 +-
 drivers/pci/endpoint/functions/pci-epf-test.c | 266 ++++++++----------
 drivers/pci/endpoint/pci-ep-cfs.c             |  54 ++--
 drivers/pci/endpoint/pci-epf-core.c           |  32 ---
 include/linux/pci-epf.h                       |   2 -
 7 files changed, 175 insertions(+), 228 deletions(-)

2.39.2