kernel/linux.git/Documentation/PCI, branch v6.1.168

Documentation: PCI: endpoint: Fix ntb/vntb copy & paste errors

2026-03-04T12:19:38+00:00

[ Upstream commit ad0c6da5be901f5c181490f683d22b416059bccb ] Fix copy & paste errors by changing the references from 'ntb' to 'vntb'. Fixes: 4ac8c8e52cd9 ("Documentation: PCI: Add specification for the PCI vNTB function device") Signed-off-by: Baruch Siach [mani: squashed the patches and fixed more errors] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Reviewed-by: Frank Li Link: https://patch.msgid.link/b51c2a69ffdbfa2c359f5cf33f3ad2acc3db87e4.1762154911.git.baruch@tkos.co.il Signed-off-by: Sasha Levin

PCI: endpoint: Automatically create a function specific attributes group

2026-02-19T15:25:16+00:00

[ Upstream commit 70b3740f2c1941e2006d61539131b70d20cba9a6 ] A PCI endpoint function driver can define function specific attributes under its function configfs directory using the add_cfs() endpoint driver operation. This is done by tying up the mkdir operation for the function configfs directory to a call to the add_cfs() operation. However, there are no checks preventing the user from repeatedly creating function specific attribute directories with different names, resulting in the same endpoint specific attributes group being added multiple times, which also result in an invalid reference counting for the attribute groups. E.g., using the pci-epf-ntb function driver as an example, the user creates the function as follows: $ modprobe pci-epf-ntb $ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb $ mkdir func0 $ tree func0 func0/ |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid $ mkdir func0/attrs $ tree func0 func0/ |-- attrs | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid At this point, the function can be started by linking the EP controller. However, if the user mistakenly creates again a directory: $ mkdir func0/attrs2 $ tree func0 func0/ |-- attrs | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- attrs2 | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid The endpoint function specific attributes are duplicated and cause a crash when the endpoint function device is torn down: refcount_t: addition on 0; use-after-free. WARNING: CPU: 2 PID: 834 at lib/refcount.c:25 refcount_warn_saturate+0xc8/0x144 CPU: 2 PID: 834 Comm: rmdir Not tainted 6.3.0-rc1 #1 Hardware name: Pine64 RockPro64 v2.1 (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) ... Call trace: refcount_warn_saturate+0xc8/0x144 config_item_get+0x7c/0x80 configfs_rmdir+0x17c/0x30c vfs_rmdir+0x8c/0x204 do_rmdir+0x158/0x184 __arm64_sys_unlinkat+0x64/0x80 invoke_syscall+0x48/0x114 ... Fix this by modifying pci_epf_cfs_work() to execute the new function pci_ep_cfs_add_type_group() which itself calls pci_epf_type_add_cfs() to obtain the function specific attribute group and the group name (directory name) from the endpoint function driver. If the function driver defines an attribute group, pci_ep_cfs_add_type_group() then proceeds to register this group using configfs_register_group(), thus automatically exposing the function type specific configfs attributes to the user. E.g.: $ modprobe pci-epf-ntb $ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb $ mkdir func0 $ tree func0 func0/ |-- baseclass_code |-- cache_line_size |-- ... |-- pci_epf_ntb.0 | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- primary |-- ... `-- vendorid With this change, there is no need for the user to create or delete directories in the endpoint function attributes directory. The pci_epf_type_group_ops group operations are thus removed. Also update the documentation for the pci-epf-ntb and pci-epf-vntb function drivers to reflect this change, removing the explanations showing the need to manually create the sub-directory for the function specific attributes. Link: https://lore.kernel.org/r/20230415023542.77601-2-dlemoal@kernel.org Signed-off-by: Damien Le Moal Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam Stable-dep-of: 7c5c7d06bd1f ("PCI: endpoint: Avoid creating sub-groups asynchronously") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Merge tag 'ntb-5.20' of https://github.com/jonmason/ntb

2022-08-13T21:00:45+00:00

Pull NTB updates from Jon Mason: "Non-Transparent Bridge updates. Fix of heap data and clang warnings, support for a new Intel NTB device, and NTB EndPoint Function (EPF) support and the various fixes for that" * tag 'ntb-5.20' of https://github.com/jonmason/ntb: MAINTAINERS: add PCI Endpoint NTB drivers to NTB files NTB: EPF: Tidy up some bounds checks NTB: EPF: Fix error code in epf_ntb_bind() PCI: endpoint: pci-epf-vntb: reduce several globals to statics PCI: endpoint: pci-epf-vntb: fix error handle in epf_ntb_mw_bar_init() PCI: endpoint: Fix Kconfig dependency NTB: EPF: set pointer addr to null using NULL rather than 0 Documentation: PCI: extend subheading underline for "lspci output" section Documentation: PCI: Use code-block block for scratchpad registers diagram Documentation: PCI: Add specification for the PCI vNTB function device PCI: endpoint: Support NTB transfer between RC and EP NTB: epf: Allow more flexibility in the memory BAR map method PCI: designware-ep: Allow pci_epc_set_bar() update inbound map address ntb: intel: add GNR support for Intel PCIe gen5 NTB NTB: ntb_tool: uninitialized heap data in tool_fn_write() ntb: idt: fix clang -Wformat warnings

Documentation: PCI: extend subheading underline for "lspci output" section

2022-08-09T21:54:22+00:00

The underline syntax for "lspci output..." section is off-by-one less than the section heading's length, hence triggers the warning: Documentation/PCI/endpoint/pci-vntb-howto.rst:131: WARNING: Title underline too short. Extend the underline by one to match the heading length. Link: https://lore.kernel.org/linux-next/20220621200235.211b2e32@canb.auug.org.au/ Fixes: 0c4b285d9636cc ("Documentation: PCI: Add specification for the PCI vNTB function device") Reported-by: Stephen Rothwell Cc: Kishon Vijay Abraham I Cc: Lorenzo Pieralisi Cc: "Krzysztof Wilczyński" Cc: Bjorn Helgaas Cc: Jonathan Corbet Cc: Frank Li Cc: linux-pci@vger.kernel.org Cc: linux-next@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Bagas Sanjaya Signed-off-by: Jon Mason

Documentation: PCI: Use code-block block for scratchpad registers diagram

2022-08-09T21:54:12+00:00

The diagram in "Scratchpad Registers" isn't formatted inside code block, hence triggers indentation warning: Documentation/PCI/endpoint/pci-vntb-function.rst:82: WARNING: Unexpected indentation. Fix the warning by using code-block directive to format the diagram inside code block, as in other diagrams in Documentation/. While at it, unindent the preceeding text. Link: https://lore.kernel.org/linux-next/20220621200235.211b2e32@canb.auug.org.au/ Fixes: 0c4b285d9636cc ("Documentation: PCI: Add specification for the PCI vNTB function device") Reported-by: Stephen Rothwell Cc: Kishon Vijay Abraham I Cc: Lorenzo Pieralisi Cc: "Krzysztof Wilczyński" Cc: Bjorn Helgaas Cc: Jonathan Corbet Cc: Frank Li Cc: linux-pci@vger.kernel.org Cc: linux-next@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Bagas Sanjaya Signed-off-by: Jon Mason

Documentation: PCI: Add specification for the PCI vNTB function device

2022-08-09T21:54:10+00:00

Add specification for the PCI vNTB function device. The endpoint function driver and the host PCI driver should be created based on this specification. Signed-off-by: Frank Li Signed-off-by: Jon Mason

Merge branch 'pci/resource'

2022-08-04T16:41:52+00:00

- Replace sparc pci_mmap_page_range() wrapper. This still leaves a sparc-specific pci_mmap_resource_range(), but it's only one interface instead of two (Arnd Bergmann) - Remove sparc-specific pci_mmap_resource_range() by implementing pci_iobar_pfn(). This removes the ability to map the entire PCI I/O space using /proc/bus/pci, but we believe that's already been broken since v2.6.28 (Arnd Bergmann) * pci/resource: sparc: Use generic pci_mmap_resource_range() PCI: Remove pci_mmap_page_range() wrapper

PCI: Remove pci_mmap_page_range() wrapper

2022-07-29T17:08:44+00:00

The ARCH_GENERIC_PCI_MMAP_RESOURCE symbol came up in a recent discussion, and I noticed that this was left behind by an unfinished cleanup from 2017. The only architecture that still relies on providing its own pci_mmap_page_range() helper instead of using the generic pci_mmap_resource_range() is sparc. Presumably the reasons for this have not changed, but at least this can be simplified by converting sparc to use the same interface as the others. The only difference between the two is the device-specific offset that gets added to or subtracted from vma->vm_pgoff. Change the only caller of pci_mmap_page_range() in common code to subtract this offset and call the modern interface, while adding it back in the sparc implementation to preserve the existing behavior. This removes the complexities of the dual interfaces from the common code, and keeps it all specific to the sparc architecture code. According to David Miller, the sparc code lets user space poke into the VGA I/O port registers by mmapping the I/O space of the parent bridge device, which is something that the generic pci_mmap_resource_range() code apparently does not. Link: https://lore.kernel.org/lkml/1519887203.622.3.camel@infradead.org/t/ Link: https://lore.kernel.org/lkml/20220714214657.2402250-3-shorne@gmail.com/ Link: https://lore.kernel.org/r/20220715153617.3393420-1-arnd@kernel.org Signed-off-by: Arnd Bergmann Signed-off-by: Bjorn Helgaas Cc: David Woodhouse Cc: David S. Miller Cc: Stafford Horne

PCI/doc: Convert examples to generic power management

2022-07-11T23:17:29+00:00

PCI-specific power management (pci_driver.suspend and pci_driver.resume) is deprecated. Convert sample code to the generic power management framework. Link: https://lore.kernel.org/r/20220607232946.355987-1-helgaas@kernel.org Signed-off-by: Bjorn Helgaas Signed-off-by: Bjorn Helgaas

PCI/doc: Update obsolete pci_set_dma_mask() references

2022-04-21T17:10:44+00:00

The function is dma_set_mask(), fix a missed instance of the old pci_set_dma_mask() and a reference to a function that doesn't exist. Fixes: 05b0ebd06ae6 ("PCI/doc: cleanup references to the legacy PCI DMA API") Link: https://lore.kernel.org/r/165048747271.2959320.13475081883467312497.stgit@omen Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Reviewed-by: Christoph Hellwig