PCI: Move TLP Log handling to its own file

TLP Log is a PCIe feature and is processed only by AER and DPC.
Configwise, DPC depends AER being enabled. In lack of better place, the TLP
Log handling code was initially placed into pci.c but it can be easily
placed in a separate file.

Move TLP Log handling code to its own file under pcie/ subdirectory and
include it only when AER is enabled.

Link: https://lore.kernel.org/r/20250114170840.1633-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>

4 files changed, 41 insertions, 29 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e0fdc9d10f91..02cd4c7eb80b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1100,33 +1100,6 @@ static void pci_enable_acs(struct pci_dev *dev)
 }
 
 /**
- * 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;
-}
-
-/**
  * 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 8a60fc9e7786..55fcf3bac4f7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -549,9 +549,9 @@ struct aer_err_info {
 
 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
-#endif	/* CONFIG_PCIEAER */
 
 int pcie_read_tlp_log(struct pci_dev *dev, int where, struct pcie_tlp_log *log);
+#endif	/* CONFIG_PCIEAER */
 
 #ifdef CONFIG_PCIEPORTBUS
 /* Cached RCEC Endpoint Association */
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index 53ccab62314d..173829aa02e6 100644
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -7,7 +7,7 @@ pcieportdrv-y			:= portdrv.o rcec.o
 obj-$(CONFIG_PCIEPORTBUS)	+= pcieportdrv.o bwctrl.o
 
 obj-y				+= aspm.o
-obj-$(CONFIG_PCIEAER)		+= aer.o err.o
+obj-$(CONFIG_PCIEAER)		+= aer.o err.o tlp.o
 obj-$(CONFIG_PCIEAER_INJECT)	+= aer_inject.o
 obj-$(CONFIG_PCIE_PME)		+= pme.o
 obj-$(CONFIG_PCIE_DPC)		+= dpc.o
diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
new file mode 100644
index 000000000000..3f053cc62290
--- /dev/null
+++ b/drivers/pci/pcie/tlp.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe TLP Log handling
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+
+#include <linux/aer.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+
+#include "../pci.h"
+
+/**
+ * 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;
+}