[PATCH 0/4] PCI: dwc: Add PTM sysfs support
Manivannan Sadhasivam via B4 Relay
devnull+manivannan.sadhasivam.linaro.org at kernel.org
Tue Feb 18 06:36:39 PST 2025
Hi,
This series adds sysfs support for PCIe PTM in Synopsys Designware IPs.
First patch moves the common DWC struct definitions (dwc_pcie_vsec_id) to
include/pci/pcie-dwc.h from dwc-pcie-pmu driver. This allows reusing the same
definitions in pcie-designware-sysfs driver introduced in this series and also
in the debugfs series by Shradha [1].
Second patch adds support for searching the Vendor Specific Extended Capability
(VSEC) in the pcie-designware driver. This patch was originally based on
Shradha's patch [2], but modified to accept 'struct dwc_pcie_vsec_id' to avoid
iterating through the vsec_ids in the driver.
Third patch adds the actual sysfs support for PTM in a new file
pcie-designware-sysfs.c built along with pcie-designware.c.
Finally, fourth patch masks the PTM_UPDATING interrupt in the pcie-qcom-ep
driver to avoid processing the interrupt for each PTM context update.
Testing
=======
This series is tested on Qcom SA8775p Ride Mx platform where one SA8775p acts as
RC and another as EP with following instructions:
RC
--
$ echo 1 > /sys/devices/platform/1c10000.pcie/dwc/ptm/ptm_context_valid
EP
--
$ echo auto > /sys/devices/platform/1c10000.pcie-ep/dwc/ptm/ptm_context_update
$ cat /sys/devices/platform/1c10000.pcie-ep/dwc/ptm/ptm_local_clock
159612570424
$ cat /sys/devices/platform/1c10000.pcie-ep/dwc/ptm/ptm_master_clock
159609466232
$ cat /sys/devices/platform/1c10000.pcie-ep/dwc/ptm/ptm_t1
159609466112
$ cat /sys/devices/platform/1c10000.pcie-ep/dwc/ptm/ptm_t4
159609466518
NOTE: To make use of the PTM feature, the host PCIe client driver has to call
'pci_enable_ptm()' API during probe. This series was tested with enabling PTM in
the MHI host driver with a local change (which will be upstreamed later).
Technically, PTM could also be enabled in the pci_endpoint_test driver, but I
didn't add the change as I'm not sure we'd want to add random PCIe features in
the test driver without corresponding code in pci-epf-test driver.
Merging Strategy
================
I'd like to have an ACK from the perf maintainers to take the whole series
through PCI tree.
[1] https://lore.kernel.org/linux-pci/20250214105007.97582-1-shradha.t@samsung.com
[2] https://lore.kernel.org/linux-pci/20250214105007.97582-2-shradha.t@samsung.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
---
Manivannan Sadhasivam (4):
perf/dwc_pcie: Move common DWC struct definitions to 'pcie-dwc.h'
PCI: dwc: Add helper to find the Vendor Specific Extended Capability (VSEC)
PCI: dwc: Add sysfs support for PTM
PCI: qcom-ep: Mask PTM_UPDATING interrupt
Documentation/ABI/testing/sysfs-platform-dwc-pcie | 70 ++++++
MAINTAINERS | 2 +
drivers/pci/controller/dwc/Makefile | 2 +-
drivers/pci/controller/dwc/pcie-designware-ep.c | 3 +
drivers/pci/controller/dwc/pcie-designware-host.c | 4 +
drivers/pci/controller/dwc/pcie-designware-sysfs.c | 278 +++++++++++++++++++++
drivers/pci/controller/dwc/pcie-designware.c | 46 ++++
drivers/pci/controller/dwc/pcie-designware.h | 22 ++
drivers/pci/controller/dwc/pcie-qcom-ep.c | 8 +
drivers/perf/dwc_pcie_pmu.c | 23 +-
include/linux/pcie-dwc.h | 42 ++++
11 files changed, 478 insertions(+), 22 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20250218-pcie-qcom-ptm-bf6952f5c4e5
Best regards,
--
Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
More information about the linux-arm-kernel
mailing list