1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCIe TLP Log handling
4 *
5 * Copyright (C) 2024 Intel Corporation
6 */
7
8#include <linux/aer.h>
9#include <linux/array_size.h>
10#include <linux/bitfield.h>
11#include <linux/pci.h>
12#include <linux/string.h>
13
14#include "../pci.h"
15
16/**
17 * aer_tlp_log_len - Calculate AER Capability TLP Header/Prefix Log length
18 * @dev: PCIe device
19 * @aercc: AER Capabilities and Control register value
20 *
21 * Return: TLP Header/Prefix Log length
22 */
23unsigned int aer_tlp_log_len(struct pci_dev *dev, u32 aercc)
24{
25 if (aercc & PCI_ERR_CAP_TLP_LOG_FLIT)
26 return FIELD_GET(PCI_ERR_CAP_TLP_LOG_SIZE, aercc);
27
28 return PCIE_STD_NUM_TLP_HEADERLOG +
29 ((aercc & PCI_ERR_CAP_PREFIX_LOG_PRESENT) ?
30 dev->eetlp_prefix_max : 0);
31}
32
33#ifdef CONFIG_PCIE_DPC
34/**
35 * dpc_tlp_log_len - Calculate DPC RP PIO TLP Header/Prefix Log length
36 * @dev: PCIe device
37 *
38 * Return: TLP Header/Prefix Log length
39 */
40unsigned int dpc_tlp_log_len(struct pci_dev *dev)
41{
42 /* Remove ImpSpec Log register from the count */
43 if (dev->dpc_rp_log_size >= PCIE_STD_NUM_TLP_HEADERLOG + 1)
44 return dev->dpc_rp_log_size - 1;
45
46 return dev->dpc_rp_log_size;
47}
48#endif
49
50/**
51 * pcie_read_tlp_log - read TLP Header Log
52 * @dev: PCIe device
53 * @where: PCI Config offset of TLP Header Log
54 * @where2: PCI Config offset of TLP Prefix Log
55 * @tlp_len: TLP Log length (Header Log + TLP Prefix Log in DWORDs)
56 * @flit: TLP Logged in Flit mode
57 * @log: TLP Log structure to fill
58 *
59 * Fill @log from TLP Header Log registers, e.g., AER or DPC.
60 *
61 * Return: 0 on success and filled TLP Log structure, <0 on error.
62 */
63int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
64 unsigned int tlp_len, bool flit, struct pcie_tlp_log *log)
65{
66 unsigned int i;
67 int off, ret;
68
69 if (tlp_len > ARRAY_SIZE(log->dw))
70 tlp_len = ARRAY_SIZE(log->dw);
71
72 memset(log, 0, sizeof(*log));
73
74 for (i = 0; i < tlp_len; i++) {
75 if (i < PCIE_STD_NUM_TLP_HEADERLOG)
76 off = where + i * 4;
77 else
78 off = where2 + (i - PCIE_STD_NUM_TLP_HEADERLOG) * 4;
79
80 ret = pci_read_config_dword(dev, where: off, val: &log->dw[i]);
81 if (ret)
82 return pcibios_err_to_errno(err: ret);
83 }
84
85 /*
86 * Hard-code non-Flit mode to 4 DWORDs, for now. The exact length
87 * can only be known if the TLP is parsed.
88 */
89 log->header_len = flit ? tlp_len : 4;
90 log->flit = flit;
91
92 return 0;
93}
94
95#define EE_PREFIX_STR " E-E Prefixes:"
96
97/**
98 * pcie_print_tlp_log - Print TLP Header / Prefix Log contents
99 * @dev: PCIe device
100 * @log: TLP Log structure
101 * @level: Printk log level
102 * @pfx: String prefix
103 *
104 * Prints TLP Header and Prefix Log information held by @log.
105 */
106void pcie_print_tlp_log(const struct pci_dev *dev,
107 const struct pcie_tlp_log *log, const char *level,
108 const char *pfx)
109{
110 /* EE_PREFIX_STR fits the extended DW space needed for the Flit mode */
111 char buf[11 * PCIE_STD_MAX_TLP_HEADERLOG + 1];
112 unsigned int i;
113 int len;
114
115 len = scnprintf(buf, size: sizeof(buf), fmt: "%#010x %#010x %#010x %#010x",
116 log->dw[0], log->dw[1], log->dw[2], log->dw[3]);
117
118 if (log->flit) {
119 for (i = PCIE_STD_NUM_TLP_HEADERLOG; i < log->header_len; i++) {
120 len += scnprintf(buf: buf + len, size: sizeof(buf) - len,
121 fmt: " %#010x", log->dw[i]);
122 }
123 } else {
124 if (log->prefix[0])
125 len += scnprintf(buf: buf + len, size: sizeof(buf) - len,
126 EE_PREFIX_STR);
127 for (i = 0; i < ARRAY_SIZE(log->prefix); i++) {
128 if (!log->prefix[i])
129 break;
130 len += scnprintf(buf: buf + len, size: sizeof(buf) - len,
131 fmt: " %#010x", log->prefix[i]);
132 }
133 }
134
135 dev_printk(level, &dev->dev, "%sTLP Header%s: %s\n", pfx,
136 log->flit ? " (Flit)" : "", buf);
137}
138

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source code of linux/drivers/pci/pcie/tlp.c