2024-04-12 13:37:36

by Ilpo Järvinen

[permalink] [raw]
Subject: [PATCH v3 2/2] PCI: Create helper to print TLP Header and Prefix Log

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() but 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 <[email protected]>
---
drivers/pci/pci.c | 32 ++++++++++++++++++++++++++++++++
drivers/pci/pcie/aer.c | 10 ++--------
drivers/pci/pcie/dpc.c | 5 +----
include/linux/aer.h | 2 ++
4 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index af230e6e5557..54d4872d14b8 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -9,6 +9,7 @@
*/

#include <linux/acpi.h>
+#include <linux/array_size.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/dmi.h>
@@ -1116,6 +1117,37 @@ int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
}
EXPORT_SYMBOL_GPL(pcie_read_tlp_log);

+/**
+ * pcie_print_tlp_log - Print TLP Header / Prefix Log contents
+ * @dev: PCIe device
+ * @tlp_log: TLP Log structure
+ * @pfx: Internal string prefix (for indentation)
+ *
+ * Prints TLP Header and Prefix Log information held by @tlp_log.
+ */
+void pcie_print_tlp_log(const struct pci_dev *dev,
+ const struct pcie_tlp_log *tlp_log, const char *pfx)
+{
+ char buf[(10 + 1) * (4 + ARRAY_SIZE(tlp_log->prefix)) + 14 + 1];
+ unsigned int i;
+ int len;
+
+ len = scnprintf(buf, sizeof(buf), "%#010x %#010x %#010x %#010x",
+ tlp_log->dw[0], tlp_log->dw[1], tlp_log->dw[2],
+ tlp_log->dw[3]);
+
+ if (tlp_log->prefix[0])
+ len += scnprintf(buf + len, sizeof(buf) - len, " E-E Prefixes:");
+ for (i = 0; i < ARRAY_SIZE(tlp_log->prefix); i++) {
+ if (!tlp_log->prefix[i])
+ break;
+ len += scnprintf(buf + len, sizeof(buf) - len,
+ " %#010x", tlp_log->prefix[i]);
+ }
+
+ pci_err(dev, "%sTLP Header: %s\n", pfx, buf);
+}
+
/**
* 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/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 80b1456f95fe..3f8e3b6c7948 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -229,10 +229,7 @@ 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/include/linux/aer.h b/include/linux/aer.h
index 2484056feb8d..1e8c61deca65 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -41,6 +41,8 @@ struct aer_capability_regs {
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);
+void pcie_print_tlp_log(const struct pci_dev *dev,
+ const struct pcie_tlp_log *tlp_log, const char *pfx);

#if defined(CONFIG_PCIEAER)
int pci_aer_clear_nonfatal_status(struct pci_dev *dev);
--
2.39.2