[PATCH v4 0/7] PCI: Consolidate TLP Log reading and printing

[PATCH v4 0/7] PCI: Consolidate TLP Log reading and printing

[Ilpo Järvinen]

This series has the remaining patches of the AER & DPC TLP Log handling
consolidation and now includes a few minor improvements to the earlier
accepted TLP Logging code.

v4:
- Added patches:
	- Remove EXPORT of pcie_read_tlp_log()
	- Moved code to pcie/tlp.c and build only with AER enabled
	- Match variables in prototype and function
	- int -> unsigned int conversion
	- eetlp_prefix_max into own patch
- struct pcie_tlp_log param consistently called "log" within tlp.c
- Moved function prototypes into drivers/pci/pci.h
- Describe AER/DPC differences more clearly in one commit message

v3:
- Small rewording in a commit message

v2:
- Don't add EXPORT()s
- Don't include igxbe changes
- Don't use pr_cont() as it's incompatible with pci_err() and according
  to Andy Shevchenko should not be used in the first place

Ilpo Järvinen (7):
  PCI: Don't expose pcie_read_tlp_log() outside of PCI subsystem
  PCI: Move TLP Log handling to own file
  PCI: Make pcie_read_tlp_log() signature same
  PCI: Use unsigned int i in pcie_read_tlp_log()
  PCI: Store # of supported End-End TLP Prefixes
  PCI: Add TLP Prefix reading into pcie_read_tlp_log()
  PCI: Create helper to print TLP Header and Prefix Log

 drivers/pci/ats.c             |   2 +-
 drivers/pci/pci.c             |  28 ---------
 drivers/pci/pci.h             |   9 +++
 drivers/pci/pcie/Makefile     |   2 +-
 drivers/pci/pcie/aer.c        |  14 ++---
 drivers/pci/pcie/dpc.c        |  14 ++---
 drivers/pci/pcie/tlp.c        | 107 ++++++++++++++++++++++++++++++++++
 drivers/pci/probe.c           |  14 +++--
 include/linux/aer.h           |   3 +-
 include/linux/pci.h           |   2 +-
 include/uapi/linux/pci_regs.h |   2 +
 11 files changed, 141 insertions(+), 56 deletions(-)
 create mode 100644 drivers/pci/pcie/tlp.c

-- 
2.39.2

[PATCH v4 1/7] PCI: Don't expose pcie_read_tlp_log() outside of PCI subsystem

[Ilpo Järvinen]

pcie_read_tlp_log() was exposed by the commit 0a5a46a6a61b ("PCI/AER:
Generalize TLP Header Log reading") but this is now considered a
mistake. No drivers outside of PCI subsystem should build their own
diagnostic logging but should rely on PCI core doing it for them.

There's currently one driver (ixgbe) doing it independently which was
the initial reason why the export was added but it was decided by the
PCI maintainer that it's something that should be eliminated.

Remove the unwanted EXPORT of pcie_read_tlp_log() and remove it from
include/linux/aer.h.

Link: https://lore.kernel.org/all/20240322193011.GA701027@bhelgaas/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.c   | 1 -
 drivers/pci/pci.h   | 4 ++++
 include/linux/aer.h | 2 --
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e5f243dd4288..54ab1d6b8e53 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1092,7 +1092,6 @@ int pcie_read_tlp_log(struct pci_dev *dev, int where,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(pcie_read_tlp_log);
 
 /**
  * pci_restore_bars - restore a device's BAR values (e.g. after wake-up)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 17fed1846847..9c968df86a92 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -4,6 +4,8 @@
 
 #include <linux/pci.h>
 
+struct pcie_tlp_log;
+
 /* Number of possible devfns: 0.0 to 1f.7 inclusive */
 #define MAX_NR_DEVFNS 256
 
@@ -419,6 +421,8 @@ 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);
+
 #ifdef CONFIG_PCIEPORTBUS
 /* Cached RCEC Endpoint Association */
 struct rcec_ea {
diff --git a/include/linux/aer.h b/include/linux/aer.h
index 4b97f38f3fcf..190a0a2061cd 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -37,8 +37,6 @@ struct aer_capability_regs {
 	u16 uncor_err_source;
 };
 
-int pcie_read_tlp_log(struct pci_dev *dev, int where, struct pcie_tlp_log *log);
-
 #if defined(CONFIG_PCIEAER)
 int pci_aer_clear_nonfatal_status(struct pci_dev *dev);
 int pcie_aer_is_native(struct pci_dev *dev);
-- 
2.39.2

[PATCH v4 2/7] PCI: Move TLP Log handling to own file

[Ilpo Järvinen]

TLP Log is 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 own file under pcie/ subdirectory and
include it only when AER is enabled.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.c         | 27 ---------------------------
 drivers/pci/pci.h         |  2 +-
 drivers/pci/pcie/Makefile |  2 +-
 drivers/pci/pcie/tlp.c    | 39 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 29 deletions(-)
 create mode 100644 drivers/pci/pcie/tlp.c

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 54ab1d6b8e53..2cc875f60fef 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1066,33 +1066,6 @@ static void pci_enable_acs(struct pci_dev *dev)
 	pci_disable_acs_redir(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 9c968df86a92..0e9917f8bf3f 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -419,9 +419,9 @@ 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 6461aa93fe76..591ef3177777 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
 
 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;
+}
-- 
2.39.2

[PATCH v4 3/7] PCI: Make pcie_read_tlp_log() signature same

[Ilpo Järvinen]

pcie_read_tlp_log()'s prototype and function signature diverged due to
changes made while applying.

Make the parameters of pcie_read_tlp_log() named identically.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pcie/tlp.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
index 3f053cc62290..2bf15749cd31 100644
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c
@@ -15,22 +15,21 @@
  * 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
+ * @log: TLP Log structure to fill
  *
- * Fill @tlp_log from TLP Header Log registers, e.g., AER or DPC.
+ * 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 *tlp_log)
+		      struct pcie_tlp_log *log)
 {
 	int i, ret;
 
-	memset(tlp_log, 0, sizeof(*tlp_log));
+	memset(log, 0, sizeof(*log));
 
 	for (i = 0; i < 4; i++) {
-		ret = pci_read_config_dword(dev, where + i * 4,
-					    &tlp_log->dw[i]);
+		ret = pci_read_config_dword(dev, where + i * 4, &log->dw[i]);
 		if (ret)
 			return pcibios_err_to_errno(ret);
 	}
-- 
2.39.2

[PATCH v4 4/7] PCI: Use unsigned int i in pcie_read_tlp_log()

[Ilpo Järvinen]

Loop variable i counting from 0 upwards does not need to be signed so
make it unsigned int.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pcie/tlp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
index 2bf15749cd31..65ac7b5d8a87 100644
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c
@@ -24,7 +24,8 @@
 int pcie_read_tlp_log(struct pci_dev *dev, int where,
 		      struct pcie_tlp_log *log)
 {
-	int i, ret;
+	unsigned int i;
+	int ret;
 
 	memset(log, 0, sizeof(*log));
 
-- 
2.39.2

[PATCH v4 5/7] PCI: Store # of supported End-End TLP Prefixes

[Ilpo Järvinen]

eetlp_prefix_path in the struct pci_dev tells if End-End TLP Prefixes
are supported by the path or not, the value is only calculated if
CONFIG_PCI_PASID is set.

The Max End-End TLP Prefixes field in the Device Capabilities Register
2 also tells how many (1-4) End-End TLP Prefixes are supported (PCIe r6
sec 7.5.3.15). The number of supported End-End Prefixes is useful for
reading correct number of DWORDs from TLP Prefix Log register in AER
capability (PCIe r6 sec 7.8.4.12).

Replace eetlp_prefix_path with eetlp_prefix_max and determine the
number of supported End-End Prefixes regardless of CONFIG_PCI_PASID so
that an upcoming commit generalizing TLP Prefix Log register reading
does not have to read extra DWORDs for End-End Prefixes that never will
be there.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/ats.c             |  2 +-
 drivers/pci/probe.c           | 14 +++++++++-----
 include/linux/pci.h           |  2 +-
 include/uapi/linux/pci_regs.h |  1 +
 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index c570892b2090..e13433dcfc82 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -377,7 +377,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
 	if (WARN_ON(pdev->pasid_enabled))
 		return -EBUSY;
 
-	if (!pdev->eetlp_prefix_path && !pdev->pasid_no_tlp)
+	if (!pdev->eetlp_prefix_max && !pdev->pasid_no_tlp)
 		return -EINVAL;
 
 	if (!pasid)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1325fbae2f28..02035b005a53 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2211,8 +2211,8 @@ static void pci_configure_relaxed_ordering(struct pci_dev *dev)
 
 static void pci_configure_eetlp_prefix(struct pci_dev *dev)
 {
-#ifdef CONFIG_PCI_PASID
 	struct pci_dev *bridge;
+	unsigned int eetlp_max;
 	int pcie_type;
 	u32 cap;
 
@@ -2224,15 +2224,19 @@ static void pci_configure_eetlp_prefix(struct pci_dev *dev)
 		return;
 
 	pcie_type = pci_pcie_type(dev);
+
+	eetlp_max = FIELD_GET(PCI_EXP_DEVCAP2_EE_PREFIX_MAX, cap);
+	/* 00b means 4 */
+	eetlp_max = eetlp_max ?: 4;
+
 	if (pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
 	    pcie_type == PCI_EXP_TYPE_RC_END)
-		dev->eetlp_prefix_path = 1;
+		dev->eetlp_prefix_max = eetlp_max;
 	else {
 		bridge = pci_upstream_bridge(dev);
-		if (bridge && bridge->eetlp_prefix_path)
-			dev->eetlp_prefix_path = 1;
+		if (bridge && bridge->eetlp_prefix_max)
+			dev->eetlp_prefix_max = eetlp_max;
 	}
-#endif
 }
 
 static void pci_configure_serr(struct pci_dev *dev)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 16493426a04f..29c51325b1d9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -397,7 +397,7 @@ struct pci_dev {
 					   supported from root to here */
 #endif
 	unsigned int	pasid_no_tlp:1;		/* PASID works without TLP Prefix */
-	unsigned int	eetlp_prefix_path:1;	/* End-to-End TLP Prefix */
+	unsigned int	eetlp_prefix_max:3;	/* Max # of End-End TLP Prefixes, 0=not supported */
 
 	pci_channel_state_t error_state;	/* Current connectivity state */
 	struct device	dev;			/* Generic device interface */
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index a39193213ff2..09e0c300c952 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -661,6 +661,7 @@
 #define  PCI_EXP_DEVCAP2_OBFF_MSG	0x00040000 /* New message signaling */
 #define  PCI_EXP_DEVCAP2_OBFF_WAKE	0x00080000 /* Re-use WAKE# for OBFF */
 #define  PCI_EXP_DEVCAP2_EE_PREFIX	0x00200000 /* End-End TLP Prefix */
+#define  PCI_EXP_DEVCAP2_EE_PREFIX_MAX	0x00c00000 /* Max End-End TLP Prefixes */
 #define PCI_EXP_DEVCTL2		0x28	/* Device Control 2 */
 #define  PCI_EXP_DEVCTL2_COMP_TIMEOUT	0x000f	/* Completion Timeout Value */
 #define  PCI_EXP_DEVCTL2_COMP_TMOUT_DIS	0x0010	/* Completion Timeout Disable */
-- 
2.39.2

[PATCH v4 6/7] PCI: Add TLP Prefix reading into pcie_read_tlp_log()

[Ilpo Järvinen]

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>
---
 drivers/pci/pci.h             |  5 +++-
 drivers/pci/pcie/aer.c        |  4 ++-
 drivers/pci/pcie/dpc.c        | 13 +++++-----
 drivers/pci/pcie/tlp.c        | 47 +++++++++++++++++++++++++++++++----
 include/linux/aer.h           |  1 +
 include/uapi/linux/pci_regs.h |  1 +
 6 files changed, 57 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 0e9917f8bf3f..3d9034d89be8 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -420,7 +420,10 @@ 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);
 
-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);
+unsigned int aer_tlp_log_len(struct pci_dev *dev);
+unsigned int dpc_tlp_log_len(struct pci_dev *dev);
 #endif	/* CONFIG_PCIEAER */
 
 #ifdef CONFIG_PCIEPORTBUS
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ac6293c24976..ecc1dea5a208 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1245,7 +1245,9 @@ 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;
-			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG, &info->tlp);
+			pcie_read_tlp_log(dev, aer + PCI_ERR_HEADER_LOG,
+					  aer + PCI_ERR_PREFIX_LOG,
+					  aer_tlp_log_len(dev), &info->tlp);
 		}
 	}
 
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index a668820696dc..5056cc6961ec 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -190,7 +190,7 @@ pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
 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, log, prefix;
+	u32 status, mask, sev, syserr, exc, log;
 	struct pcie_tlp_log tlp_log;
 	int i;
 
@@ -217,20 +217,19 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 
 	if (pdev->dpc_rp_log_size < 4)
 		goto clear_status;
-	pcie_read_tlp_log(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG, &tlp_log);
+	pcie_read_tlp_log(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
+			  cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG,
+			  dpc_tlp_log_len(pdev), &tlp_log);
 	pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n",
 		tlp_log.dw[0], tlp_log.dw[1], tlp_log.dw[2], tlp_log.dw[3]);
+	for (i = 0; i < pdev->dpc_rp_log_size - 5; i++)
+		pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, tlp_log.prefix[i]);
 
 	if (pdev->dpc_rp_log_size < 5)
 		goto clear_status;
 	pci_read_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_IMPSPEC_LOG, &log);
 	pci_err(pdev, "RP PIO ImpSpec Log %#010x\n", log);
 
-	for (i = 0; i < pdev->dpc_rp_log_size - 5; i++) {
-		pci_read_config_dword(pdev,
-			cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG + i * 4, &prefix);
-		pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, prefix);
-	}
  clear_status:
 	pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS, status);
 }
diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
index 65ac7b5d8a87..3615ca520c9a 100644
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c
@@ -11,26 +11,63 @@
 
 #include "../pci.h"
 
+/**
+ * aer_tlp_log_len - Calculates AER Capability TLP Header/Prefix Log length
+ * @dev: PCIe device
+ *
+ * Return: TLP Header/Prefix Log length
+ */
+unsigned int aer_tlp_log_len(struct pci_dev *dev)
+{
+	return 4 + dev->eetlp_prefix_max;
+}
+
+/**
+ * dpc_tlp_log_len - Calculates DPC RP PIO TLP Header/Prefix Log length
+ * @dev: PCIe device
+ *
+ * Return: TLP Header/Prefix Log length
+ */
+unsigned int dpc_tlp_log_len(struct pci_dev *pdev)
+{
+	/* Remove ImpSpec Log register from the count */
+	if (pdev->dpc_rp_log_size >= 5)
+		return pdev->dpc_rp_log_size - 1;
+
+	return pdev->dpc_rp_log_size;
+}
+
 /**
  * pcie_read_tlp_log - read TLP Header Log
  * @dev: PCIe device
  * @where: PCI Config offset of TLP Header Log
+ * @where2: PCI Config offset of TLP Prefix Log
+ * @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)
 {
 	unsigned int i;
-	int ret;
+	int off, ret;
+	u32 *to;
 
 	memset(log, 0, sizeof(*log));
 
-	for (i = 0; i < 4; i++) {
-		ret = pci_read_config_dword(dev, where + i * 4, &log->dw[i]);
+	for (i = 0; i < tlp_len; i++) {
+		if (i < 4) {
+			off = where + i * 4;
+			to = &log->dw[i];
+		} else {
+			off = where2 + (i - 4) * 4;
+			to = &log->prefix[i - 4];
+		}
+
+		ret = pci_read_config_dword(dev, off, to);
 		if (ret)
 			return pcibios_err_to_errno(ret);
 	}
diff --git a/include/linux/aer.h b/include/linux/aer.h
index 190a0a2061cd..dc498adaa1c8 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -20,6 +20,7 @@ struct pci_dev;
 
 struct pcie_tlp_log {
 	u32 dw[4];
+	u32 prefix[4];
 };
 
 struct aer_capability_regs {
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 09e0c300c952..cf7a07fa4a3b 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -803,6 +803,7 @@
 #define  PCI_ERR_ROOT_FATAL_RCV		0x00000040 /* Fatal Received */
 #define  PCI_ERR_ROOT_AER_IRQ		0xf8000000 /* Advanced Error Interrupt Message Number */
 #define PCI_ERR_ROOT_ERR_SRC	0x34	/* Error Source Identification */
+#define PCI_ERR_PREFIX_LOG	0x38	/* TLP Prefix LOG Register (up to 16 bytes) */
 
 /* Virtual Channel */
 #define PCI_VC_PORT_CAP1	0x04
-- 
2.39.2

[PATCH v4 7/7] PCI: Create helper to print TLP Header and Prefix Log

[Ilpo Järvinen]

Add pcie_print_tlp_log() helper to print TLP Header and Prefix Log.
Print End-End Prefixes only if they are non-zero.

Consolidate the few places which currently print TLP using custom
formatting.

The first attempt used pr_cont() instead of building a string first but
it turns out pr_cont() is not compatible with pci_err() and prints on a
separate line. When I asked about this, Andy Shevchenko suggested
pr_cont() should not be used in the first place (to eventually get rid
of it) so pr_cont() is now replaced with building the string first.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
 drivers/pci/pci.h      |  2 ++
 drivers/pci/pcie/aer.c | 10 ++--------
 drivers/pci/pcie/dpc.c |  5 +----
 drivers/pci/pcie/tlp.c | 31 +++++++++++++++++++++++++++++++
 4 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 3d9034d89be8..bf13d2fc4bb7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -424,6 +424,8 @@ int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
 		      unsigned int tlp_len, struct pcie_tlp_log *log);
 unsigned int aer_tlp_log_len(struct pci_dev *dev);
 unsigned int dpc_tlp_log_len(struct pci_dev *dev);
+void pcie_print_tlp_log(const struct pci_dev *dev,
+			const struct pcie_tlp_log *log, const char *pfx);
 #endif	/* CONFIG_PCIEAER */
 
 #ifdef CONFIG_PCIEPORTBUS
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ecc1dea5a208..efb9e728fe94 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -664,12 +664,6 @@ static void pci_rootport_aer_stats_incr(struct pci_dev *pdev,
 	}
 }
 
-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->dw[0], t->dw[1], t->dw[2], t->dw[3]);
-}
-
 static void __aer_print_error(struct pci_dev *dev,
 			      struct aer_err_info *info)
 {
@@ -724,7 +718,7 @@ void aer_print_error(struct pci_dev *dev, struct aer_err_info *info)
 	__aer_print_error(dev, info);
 
 	if (info->tlp_header_valid)
-		__print_tlp_header(dev, &info->tlp);
+		pcie_print_tlp_log(dev, &info->tlp, "  ");
 
 out:
 	if (info->id && info->error_dev_num > 1 && info->id == id)
@@ -796,7 +790,7 @@ void pci_print_aer(struct pci_dev *dev, int aer_severity,
 			aer->uncor_severity);
 
 	if (tlp_header_valid)
-		__print_tlp_header(dev, &aer->header_log);
+		pcie_print_tlp_log(dev, &aer->header_log, "  ");
 
 	trace_aer_event(dev_name(&dev->dev), (status & ~mask),
 			aer_severity, tlp_header_valid, &aer->header_log);
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 5056cc6961ec..598f74384471 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -220,10 +220,7 @@ static void dpc_process_rp_pio_error(struct pci_dev *pdev)
 	pcie_read_tlp_log(pdev, cap + PCI_EXP_DPC_RP_PIO_HEADER_LOG,
 			  cap + PCI_EXP_DPC_RP_PIO_TLPPREFIX_LOG,
 			  dpc_tlp_log_len(pdev), &tlp_log);
-	pci_err(pdev, "TLP Header: %#010x %#010x %#010x %#010x\n",
-		tlp_log.dw[0], tlp_log.dw[1], tlp_log.dw[2], tlp_log.dw[3]);
-	for (i = 0; i < pdev->dpc_rp_log_size - 5; i++)
-		pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, tlp_log.prefix[i]);
+	pcie_print_tlp_log(pdev, &tlp_log, "");
 
 	if (pdev->dpc_rp_log_size < 5)
 		goto clear_status;
diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
index 3615ca520c9a..59a28485696f 100644
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/aer.h>
+#include <linux/array_size.h>
 #include <linux/pci.h>
 #include <linux/string.h>
 
@@ -74,3 +75,33 @@ int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
 
 	return 0;
 }
+
+/**
+ * pcie_print_tlp_log - Print TLP Header / Prefix Log contents
+ * @dev: PCIe device
+ * @log: TLP Log structure
+ * @pfx: String prefix (for print out indentation)
+ *
+ * Prints TLP Header and Prefix Log information held by @log.
+ */
+void pcie_print_tlp_log(const struct pci_dev *dev,
+			const struct pcie_tlp_log *log, const char *pfx)
+{
+	char buf[(10 + 1) * (4 + ARRAY_SIZE(log->prefix)) + 14 + 1];
+	unsigned int i;
+	int len;
+
+	len = scnprintf(buf, sizeof(buf), "%#010x %#010x %#010x %#010x",
+			log->dw[0], log->dw[1], log->dw[2], log->dw[3]);
+
+	if (log->prefix[0])
+		len += scnprintf(buf + len, sizeof(buf) - len, " E-E Prefixes:");
+	for (i = 0; i < ARRAY_SIZE(log->prefix); i++) {
+		if (!log->prefix[i])
+			break;
+		len += scnprintf(buf + len, sizeof(buf) - len,
+				 " %#010x", log->prefix[i]);
+	}
+
+	pci_err(dev, "%sTLP Header: %s\n", pfx, buf);
+}
-- 
2.39.2

Re: [PATCH v4 6/7] PCI: Add TLP Prefix reading into pcie_read_tlp_log()

[Ilpo Järvinen]

[-- Attachment #1: Type: text/plain, Size: 2990 bytes --]

On Fri, 10 May 2024, Ilpo Järvinen 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>
> ---
>  drivers/pci/pci.h             |  5 +++-
>  drivers/pci/pcie/aer.c        |  4 ++-
>  drivers/pci/pcie/dpc.c        | 13 +++++-----
>  drivers/pci/pcie/tlp.c        | 47 +++++++++++++++++++++++++++++++----
>  include/linux/aer.h           |  1 +
>  include/uapi/linux/pci_regs.h |  1 +
>  6 files changed, 57 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 0e9917f8bf3f..3d9034d89be8 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -420,7 +420,10 @@ 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);
>  
> -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);
> +unsigned int aer_tlp_log_len(struct pci_dev *dev);
> +unsigned int dpc_tlp_log_len(struct pci_dev *dev);
>  #endif	/* CONFIG_PCIEAER */
>  
>  #ifdef CONFIG_PCIEPORTBUS
> diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
> index 65ac7b5d8a87..3615ca520c9a 100644
> --- a/drivers/pci/pcie/tlp.c
> +++ b/drivers/pci/pcie/tlp.c
> @@ -11,26 +11,63 @@
>  
>  #include "../pci.h"
>  
> +/**
> + * aer_tlp_log_len - Calculates AER Capability TLP Header/Prefix Log length
> + * @dev: PCIe device
> + *
> + * Return: TLP Header/Prefix Log length
> + */
> +unsigned int aer_tlp_log_len(struct pci_dev *dev)
> +{
> +	return 4 + dev->eetlp_prefix_max;
> +}
> +
> +/**
> + * dpc_tlp_log_len - Calculates DPC RP PIO TLP Header/Prefix Log length
> + * @dev: PCIe device
> + *
> + * Return: TLP Header/Prefix Log length
> + */
> +unsigned int dpc_tlp_log_len(struct pci_dev *pdev)
> +{
> +	/* Remove ImpSpec Log register from the count */
> +	if (pdev->dpc_rp_log_size >= 5)

Scratch this. LKP's randconfig build seems to have caught this failing to 
build when AER is enabled but DPC is not because this member doesn't exist 
w/o DPC.

> +		return pdev->dpc_rp_log_size - 1;
> +
> +	return pdev->dpc_rp_log_size;
> +}


-- 
 i.