PCI: Add TLP Prefix reading to pcie_read_tlp_log()

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 also handle 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.

  c) AER TLP Prefix Log Present (PCIe r6.1 sec 7.8.4.7) can indicate Prefix
     Log is not present.

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.

Link: https://lore.kernel.org/r/20250114170840.1633-8-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: squash ternary fix from
https://lore.kernel.org/r/20250116172019.88116-1-colin.i.king@gmail.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 55fcf3bac4f7e4d4f210d24d7d42e4b891a0f49d..7797b2544d00dc0ad18979a99803244fc4c45832 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -550,7 +550,9 @@ 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);
 
-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, u32 aercc);
 #endif /* CONFIG_PCIEAER */
 
 #ifdef CONFIG_PCIEPORTBUS
@@ -569,6 +571,7 @@ void pci_dpc_init(struct pci_dev *pdev);
 void dpc_process_error(struct pci_dev *pdev);
 pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);
 bool pci_dpc_recovered(struct pci_dev *pdev);
+unsigned int dpc_tlp_log_len(struct pci_dev *dev);
 #else
 static inline void pci_save_dpc_state(struct pci_dev *dev) { }
 static inline void pci_restore_dpc_state(struct pci_dev *dev) { }

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 80c5ba8d829625a947044e03bd121688ccd0db56..656dbf1ac45b6ca505373e185bd71c186c67b899 100644 (file)
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1248,7 +1248,10 @@ 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, aercc),
+                                         &info->tlp);
                }
        }
 

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 0674d8c89bfa943c4bfc6ef1e3ec46984858d4fc..0aa20bc58697723031d61767c2c4d03df3e8bb3b 100644 (file)
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -190,7 +190,7 @@ 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, 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 < PCIE_STD_NUM_TLP_HEADERLOG)
                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 - PCIE_STD_NUM_TLP_HEADERLOG - 1; i++)
+               pci_err(pdev, "TLP Prefix Header: dw%d, %#010x\n", i, tlp_log.prefix[i]);
 
        if (pdev->dpc_rp_log_size < PCIE_STD_NUM_TLP_HEADERLOG + 1)
                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 - PCIE_STD_NUM_TLP_HEADERLOG - 1; 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 d7ad99f466b9b9e4ae653ec91ee5c6c3eaae9e4e..0071ea8903ed81ac0882dd8cfb4f7b94350f32c2 100644 (file)
--- a/drivers/pci/pcie/tlp.c
+++ b/drivers/pci/pcie/tlp.c
@@ -11,26 +11,68 @@
 
 #include "../pci.h"
 
+/**
+ * aer_tlp_log_len - Calculate AER Capability TLP Header/Prefix Log length
+ * @dev: PCIe device
+ * @aercc: AER Capabilities and Control register value
+ *
+ * Return: TLP Header/Prefix Log length
+ */
+unsigned int aer_tlp_log_len(struct pci_dev *dev, u32 aercc)
+{
+       return PCIE_STD_NUM_TLP_HEADERLOG +
+              ((aercc & PCI_ERR_CAP_PREFIX_LOG_PRESENT) ?
+               dev->eetlp_prefix_max : 0);
+}
+
+#ifdef CONFIG_PCIE_DPC
+/**
+ * dpc_tlp_log_len - Calculate 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 *dev)
+{
+       /* Remove ImpSpec Log register from the count */
+       if (dev->dpc_rp_log_size >= PCIE_STD_NUM_TLP_HEADERLOG + 1)
+               return dev->dpc_rp_log_size - 1;
+
+       return dev->dpc_rp_log_size;
+}
+#endif
+
 /**
  * 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 < PCIE_STD_NUM_TLP_HEADERLOG; i++) {
-               ret = pci_read_config_dword(dev, where + i * 4, &log->dw[i]);
+       for (i = 0; i < tlp_len; i++) {
+               if (i < PCIE_STD_NUM_TLP_HEADERLOG) {
+                       off = where + i * 4;
+                       to = &log->dw[i];
+               } else {
+                       off = where2 + (i - PCIE_STD_NUM_TLP_HEADERLOG) * 4;
+                       to = &log->prefix[i - PCIE_STD_NUM_TLP_HEADERLOG];
+               }
+
+               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 4ef6515c320598fef90200503fd68e54f60ae1a5..947b63091902a80963758406cdeecd33725cf8e6 100644 (file)
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -27,6 +27,7 @@ struct pci_dev;
 
 struct pcie_tlp_log {
        u32 dw[PCIE_STD_NUM_TLP_HEADERLOG];
+       u32 prefix[PCIE_STD_MAX_TLP_PREFIXLOG];
 };
 
 struct aer_capability_regs {

diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index 14a6306c4ce183bb6d473e00e23f64f0e6f9735f..82866ac0bda734c8562d85cf3b4bc222e3b957d5 100644 (file)
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -790,10 +790,11 @@
        /* Same bits as above */
 #define PCI_ERR_CAP            0x18    /* Advanced Error Capabilities & Ctrl*/
 #define  PCI_ERR_CAP_FEP(x)    ((x) & 0x1f)    /* First Error Pointer */
-#define  PCI_ERR_CAP_ECRC_GENC 0x00000020      /* ECRC Generation Capable */
-#define  PCI_ERR_CAP_ECRC_GENE 0x00000040      /* ECRC Generation Enable */
-#define  PCI_ERR_CAP_ECRC_CHKC 0x00000080      /* ECRC Check Capable */
-#define  PCI_ERR_CAP_ECRC_CHKE 0x00000100      /* ECRC Check Enable */
+#define  PCI_ERR_CAP_ECRC_GENC         0x00000020 /* ECRC Generation Capable */
+#define  PCI_ERR_CAP_ECRC_GENE         0x00000040 /* ECRC Generation Enable */
+#define  PCI_ERR_CAP_ECRC_CHKC         0x00000080 /* ECRC Check Capable */
+#define  PCI_ERR_CAP_ECRC_CHKE         0x00000100 /* ECRC Check Enable */
+#define  PCI_ERR_CAP_PREFIX_LOG_PRESENT        0x00000800 /* TLP Prefix Log Present */
 #define PCI_ERR_HEADER_LOG     0x1c    /* Header Log Register (16 bytes) */
 #define PCI_ERR_ROOT_COMMAND   0x2c    /* Root Error Command */
 #define  PCI_ERR_ROOT_CMD_COR_EN       0x00000001 /* Correctable Err Reporting Enable */
@@ -809,6 +810,7 @@
 #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