1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/pci/pcie/tlp.c b/drivers/pci/pcie/tlp.c
new file mode 100644
index 000000000000..890d5391d7f5
--- /dev/null
+++ b/drivers/pci/pcie/tlp.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe TLP Log handling
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+
+#include <linux/aer.h>
+#include <linux/array_size.h>
+#include <linux/bitfield.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+
+#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)
+{
+	if (aercc & PCI_ERR_CAP_TLP_LOG_FLIT)
+		return FIELD_GET(PCI_ERR_CAP_TLP_LOG_SIZE, 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)
+ * @flit: TLP Logged in Flit mode
+ * @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, int where2,
+		      unsigned int tlp_len, bool flit, struct pcie_tlp_log *log)
+{
+	unsigned int i;
+	int off, ret;
+
+	if (tlp_len > ARRAY_SIZE(log->dw))
+		tlp_len = ARRAY_SIZE(log->dw);
+
+	memset(log, 0, sizeof(*log));
+
+	for (i = 0; i < tlp_len; i++) {
+		if (i < PCIE_STD_NUM_TLP_HEADERLOG)
+			off = where + i * 4;
+		else
+			off = where2 + (i - PCIE_STD_NUM_TLP_HEADERLOG) * 4;
+
+		ret = pci_read_config_dword(dev, off, &log->dw[i]);
+		if (ret)
+			return pcibios_err_to_errno(ret);
+	}
+
+	/*
+	 * Hard-code non-Flit mode to 4 DWORDs, for now. The exact length
+	 * can only be known if the TLP is parsed.
+	 */
+	log->header_len = flit ? tlp_len : 4;
+	log->flit = flit;
+
+	return 0;
+}
+
+#define EE_PREFIX_STR " E-E Prefixes:"
+
+/**
+ * pcie_print_tlp_log - Print TLP Header / Prefix Log contents
+ * @dev: PCIe device
+ * @log: TLP Log structure
+ * @pfx: String prefix
+ *
+ * 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)
+{
+	/* EE_PREFIX_STR fits the extended DW space needed for the Flit mode */
+	char buf[11 * PCIE_STD_MAX_TLP_HEADERLOG + 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->flit) {
+		for (i = PCIE_STD_NUM_TLP_HEADERLOG; i < log->header_len; i++) {
+			len += scnprintf(buf + len, sizeof(buf) - len,
+					 " %#010x", log->dw[i]);
+		}
+	} else {
+		if (log->prefix[0])
+			len += scnprintf(buf + len, sizeof(buf) - len,
+					 EE_PREFIX_STR);
+		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: %s\n", pfx,
+		log->flit ? " (Flit)" : "", buf);
+}