Re: [PATCH v6 6/8] PCI: Add TLP Prefix reading into pcie_read_tlp_log()
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: 2024-12-11 16:49:09
Also in:
linux-pci, lkml
On Fri, 13 Sep 2024 17:36:30 +0300 Ilpo Järvinen [off-list ref] wrote:
pcie_read_tlp_log() handles only 4 Header Log DWORDs but TLP Prefix Log (PCIe r6.1 secs 7.8.4.12 & 7.9.14.13) may also be present. Generalize pcie_read_tlp_log() and struct pcie_tlp_log to handle also TLP Prefix Log. The relevant registers are formatted identically in AER and DPC Capability, but has these variations: a) The offsets of TLP Prefix Log registers vary. b) DPC RP PIO TLP Prefix Log register can be < 4 DWORDs. Therefore callers must pass the offset of the TLP Prefix Log register and the entire length to pcie_read_tlp_log() to be able to read the correct number of TLP Prefix DWORDs from the correct offset. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Trivial comments below Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Would have been nice if they'd just made the formats have the same sized holes etc!
quoted hunk ↗ jump to hunk
diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c index 65ac7b5d8a87..def9dd7b73e8 100644 --- a/drivers/pci/pcie/tlp.c +++ b/drivers/pci/pcie/tlp.c@@ -11,26 +11,65 @@
/** * pcie_read_tlp_log - read TLP Header Log
Maybe update this to read TLP Header and Prefix Logs
* @dev: PCIe device * @where: PCI Config offset of TLP Header Log + * @where2: PCI Config offset of TLP Prefix Log
Is it worth giving it a more specific name than where2? Possibly renaming where as well!
+ * @tlp_len: TLP Log length (Header Log + TLP Prefix Log in DWORDs)
* @log: TLP Log structure to fill
*
* Fill @log from TLP Header Log registers, e.g., AER or DPC.
*
* Return: 0 on success and filled TLP Log structure, <0 on error.
*/
-int pcie_read_tlp_log(struct pci_dev *dev, int where,
- struct pcie_tlp_log *log)
+int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
+ unsigned int tlp_len, struct pcie_tlp_log *log)
{