diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2024-05-02 09:57:32 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-05-08 13:25:36 -0500 |
| commit | b1956e2d0713e210a56ae65ad3488ae36f833e76 (patch) | |
| tree | 7a1fe4631df85458c10d92d26d16555c84079fca /include | |
| parent | 7e89efc6e9e402839643cb297bab14055c547f07 (diff) | |
PCI/CXL: Fail bus reset if upstream CXL Port has SBR masked
Per CXL spec r3.1, sec 8.1.5.2, the Secondary Bus Reset (SBR) bit in the
Bridge Control register of a CXL port has no effect unless the "Unmask SBR"
bit is set.
Return -ENOTTY if we attempt a bus reset on a device below a CXL Port where
"Unmask SBR" is 0. Otherwise, the bus reset would appear to have succeeded
even though setting the bridge SBR bit had no effect.
Link: https://lore.kernel.org/linux-cxl/20240220203956.GA1502351@bhelgaas/
Link: https://lore.kernel.org/r/20240502165851.1948523-4-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
[bhelgaas: simplify commit log and comments]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/pci_regs.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index a39193213ff2..6024eb2e9a2f 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -1148,4 +1148,9 @@ #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL 0x00ff0000 #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX 0xff000000 +/* Compute Express Link (CXL r3.1, sec 8.1.5) */ +#define PCI_DVSEC_CXL_PORT 3 +#define PCI_DVSEC_CXL_PORT_CTL 0x0c +#define PCI_DVSEC_CXL_PORT_CTL_UNMASK_SBR 0x00000001 + #endif /* LINUX_PCI_REGS_H */ |