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| author | Breno Leitao <leitao@debian.org> | 2026-08-05 07:52:36 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2026-08-10 11:47:20 -1000 |
| commit | a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656 (patch) | |
| tree | 39f5b258386e1127d253d293194e9a2991bf3c34 /Documentation/PCI/endpoint/pci-test-function.rst | |
| download | linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.tar.gz linux-stable-a5bde5d8fde8a8cb28e59a672d5ddc5b9c1e7656.zip | |
workqueue: skip the node_nr_active update for non-unbound workqueuesgrafted
apply_wqattrs_commit() updates node_nr_active->max unconditionally.
wq->node_nr_active[] is only allocated for unbound workqueues, so guard
the call before per-cpu workqueues start using this path.
No functional change: only unbound workqueues reach apply_wqattrs_*()
today.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'Documentation/PCI/endpoint/pci-test-function.rst')
| -rw-r--r-- | Documentation/PCI/endpoint/pci-test-function.rst | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/Documentation/PCI/endpoint/pci-test-function.rst b/Documentation/PCI/endpoint/pci-test-function.rst new file mode 100644 index 000000000..3c8521d7a --- /dev/null +++ b/Documentation/PCI/endpoint/pci-test-function.rst @@ -0,0 +1,103 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +PCI Test Function +================= + +:Author: Kishon Vijay Abraham I <kishon@ti.com> + +Traditionally PCI RC has always been validated by using standard +PCI cards like ethernet PCI cards or USB PCI cards or SATA PCI cards. +However with the addition of EP-core in linux kernel, it is possible +to configure a PCI controller that can operate in EP mode to work as +a test device. + +The PCI endpoint test device is a virtual device (defined in software) +used to test the endpoint functionality and serve as a sample driver +for other PCI endpoint devices (to use the EP framework). + +The PCI endpoint test device has the following registers: + + 1) PCI_ENDPOINT_TEST_MAGIC + 2) PCI_ENDPOINT_TEST_COMMAND + 3) PCI_ENDPOINT_TEST_STATUS + 4) PCI_ENDPOINT_TEST_SRC_ADDR + 5) PCI_ENDPOINT_TEST_DST_ADDR + 6) PCI_ENDPOINT_TEST_SIZE + 7) PCI_ENDPOINT_TEST_CHECKSUM + 8) PCI_ENDPOINT_TEST_IRQ_TYPE + 9) PCI_ENDPOINT_TEST_IRQ_NUMBER + +* PCI_ENDPOINT_TEST_MAGIC + +This register will be used to test BAR0. A known pattern will be written +and read back from MAGIC register to verify BAR0. + +* PCI_ENDPOINT_TEST_COMMAND + +This register will be used by the host driver to indicate the function +that the endpoint device must perform. + +======== ================================================================ +Bitfield Description +======== ================================================================ +Bit 0 raise legacy IRQ +Bit 1 raise MSI IRQ +Bit 2 raise MSI-X IRQ +Bit 3 read command (read data from RC buffer) +Bit 4 write command (write data to RC buffer) +Bit 5 copy command (copy data from one RC buffer to another RC buffer) +======== ================================================================ + +* PCI_ENDPOINT_TEST_STATUS + +This register reflects the status of the PCI endpoint device. + +======== ============================== +Bitfield Description +======== ============================== +Bit 0 read success +Bit 1 read fail +Bit 2 write success +Bit 3 write fail +Bit 4 copy success +Bit 5 copy fail +Bit 6 IRQ raised +Bit 7 source address is invalid +Bit 8 destination address is invalid +======== ============================== + +* PCI_ENDPOINT_TEST_SRC_ADDR + +This register contains the source address (RC buffer address) for the +COPY/READ command. + +* PCI_ENDPOINT_TEST_DST_ADDR + +This register contains the destination address (RC buffer address) for +the COPY/WRITE command. + +* PCI_ENDPOINT_TEST_IRQ_TYPE + +This register contains the interrupt type (Legacy/MSI) triggered +for the READ/WRITE/COPY and raise IRQ (Legacy/MSI) commands. + +Possible types: + +====== == +Legacy 0 +MSI 1 +MSI-X 2 +====== == + +* PCI_ENDPOINT_TEST_IRQ_NUMBER + +This register contains the triggered ID interrupt. + +Admissible values: + +====== =========== +Legacy 0 +MSI [1 .. 32] +MSI-X [1 .. 2048] +====== =========== |
