PCI/AER: Generalize TLP Header Log reading

Both AER and DPC RP PIO provide TLP Header Log registers (PCIe r6.1 secs
7.8.4 & 7.9.14) to convey error diagnostics but the struct is named after
AER as the struct aer_header_log_regs. Also, not all places that handle TLP
Header Log use the struct and the struct members are named individually.

Generalize the struct name and members, and use it consistently where TLP
Header Log is being handled so that a pcie_read_tlp_log() helper can be
easily added.

Link: https://lore.kernel.org/r/20240206135717.8565-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: drop ixgbe changes for now, tidy whitespace]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

4 files changed, 36 insertions, 22 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d8f11a078924c..a0af94cfcf7dc 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1068,6 +1068,34 @@ disable_acs_redir:
 }
 
 /**
+ * pcie_read_tlp_log - read TLP Header Log
+ * @dev: PCIe device
+ * @where: PCI Config offset of TLP Header Log
+ * @tlp_log: TLP Log structure to fill
+ *
+ * Fill @tlp_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 *tlp_log)
+{
+	int i, ret;
+
+	memset(tlp_log, 0, sizeof(*tlp_log));
+
+	for (i = 0; i < 4; i++) {
+		ret = pci_read_config_dword(dev, where + i * 4,
+					    &tlp_log->dw[i]);
+		if (ret)
+			return pcibios_err_to_errno(ret);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pcie_read_tlp_log);
+
+/**
  * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
  * @dev: PCI device to have its BARs restored
  *
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 2336a8d1edab2..a59ba6fde2a08 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -409,7 +409,7 @@ struct aer_err_info {
 
 	unsigned int status;		/* COR/UNCOR Error Status */
 	unsigned int mask;		/* COR/UNCOR Error Mask */
-	struct aer_header_log_regs tlp;	/* TLP Header */
+	struct pcie_tlp_log tlp;	/* TLP Header */
 };
 
 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index e31e6a9a77732..ac6293c249766 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -664,11 +664,10 @@ static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
 	}
 }
 
-static void __print_tlp_header(struct pci_dev *dev,
-			       struct aer_header_log_regs *t)
+static void __print_tlp_header(struct pci_dev *dev, struct pcie_tlp_log *t)
 {
 	pci_err(dev, "  TLP Header: %08x %08x %08x %08x\n",
-		t->dw0, t->dw1, t->dw2, t->dw3);
+		t->dw[0], t->dw[1], t->dw[2], t->dw[3]);
 }
 
 static void __aer_print_error(struct pci_dev *dev,
@@ -1246,14 +1245,7 @@ int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
 
 		if (info->status & AER_LOG_TLP_MASKS) {
 			info->tlp_header_valid = 1;
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
-			pci_read_config_dword(dev,
-				aer + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
+			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG, &info->tlp);
 		}
 	}
 
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 94111e4382413..c197bc7f7f2cb 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -190,7 +190,8 @@ out:
 static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 {
 	u16 cap = pdev->dpc_cap, dpc_status, first_error;
-	u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix;
+	u32 status, mask, sev, syserr, exc, log, prefix;
+	struct pcie_tlp_log tlp_log;
 	int i;
 
 	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, &status);
@@ -216,16 +217,9 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 
 	if (pdev->dpc_rp_log_size < 4)
 		goto clear_status;
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
-			      &dw0);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 4,
-			      &dw1);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 8,
-			      &dw2);
-	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG + 12,
-			      &dw3);
+	pcie_read_tlp_log(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG, &tlp_log);
 	pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n",
-		dw0, dw1, dw2, dw3);
+		tlp_log.dw[0], tlp_log.dw[1], tlp_log.dw[2], tlp_log.dw[3]);
 
 	if (pdev->dpc_rp_log_size < 5)
 		goto clear_status;