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/pci.h>
11 #include <linux/string.h>
12 
13 #include "../pci.h"
14 
15 /**
16  * aer_tlp_log_len - Calculate AER Capability TLP Header/Prefix Log length
17  * @dev: PCIe device
18  * @aercc: AER Capabilities and Control register value
19  *
20  * Return: TLP Header/Prefix Log length
21  */
aer_tlp_log_len(struct pci_dev * dev,u32 aercc)22 unsigned int aer_tlp_log_len(struct pci_dev *dev, u32 aercc)
23 {
24 	return PCIE_STD_NUM_TLP_HEADERLOG +
25 	       ((aercc & PCI_ERR_CAP_PREFIX_LOG_PRESENT) ?
26 		dev->eetlp_prefix_max : 0);
27 }
28 
29 #ifdef CONFIG_PCIE_DPC
30 /**
31  * dpc_tlp_log_len - Calculate DPC RP PIO TLP Header/Prefix Log length
32  * @dev: PCIe device
33  *
34  * Return: TLP Header/Prefix Log length
35  */
dpc_tlp_log_len(struct pci_dev * dev)36 unsigned int dpc_tlp_log_len(struct pci_dev *dev)
37 {
38 	/* Remove ImpSpec Log register from the count */
39 	if (dev->dpc_rp_log_size >= PCIE_STD_NUM_TLP_HEADERLOG + 1)
40 		return dev->dpc_rp_log_size - 1;
41 
42 	return dev->dpc_rp_log_size;
43 }
44 #endif
45 
46 /**
47  * pcie_read_tlp_log - read TLP Header Log
48  * @dev: PCIe device
49  * @where: PCI Config offset of TLP Header Log
50  * @where2: PCI Config offset of TLP Prefix Log
51  * @tlp_len: TLP Log length (Header Log + TLP Prefix Log in DWORDs)
52  * @log: TLP Log structure to fill
53  *
54  * Fill @log from TLP Header Log registers, e.g., AER or DPC.
55  *
56  * Return: 0 on success and filled TLP Log structure, <0 on error.
57  */
pcie_read_tlp_log(struct pci_dev * dev,int where,int where2,unsigned int tlp_len,struct pcie_tlp_log * log)58 int pcie_read_tlp_log(struct pci_dev *dev, int where, int where2,
59 		      unsigned int tlp_len, struct pcie_tlp_log *log)
60 {
61 	unsigned int i;
62 	int off, ret;
63 	u32 *to;
64 
65 	memset(log, 0, sizeof(*log));
66 
67 	for (i = 0; i < tlp_len; i++) {
68 		if (i < PCIE_STD_NUM_TLP_HEADERLOG) {
69 			off = where + i * 4;
70 			to = &log->dw[i];
71 		} else {
72 			off = where2 + (i - PCIE_STD_NUM_TLP_HEADERLOG) * 4;
73 			to = &log->prefix[i - PCIE_STD_NUM_TLP_HEADERLOG];
74 		}
75 
76 		ret = pci_read_config_dword(dev, off, to);
77 		if (ret)
78 			return pcibios_err_to_errno(ret);
79 	}
80 
81 	return 0;
82 }
83 
84 #define EE_PREFIX_STR " E-E Prefixes:"
85 
86 /**
87  * pcie_print_tlp_log - Print TLP Header / Prefix Log contents
88  * @dev: PCIe device
89  * @log: TLP Log structure
90  * @pfx: String prefix
91  *
92  * Prints TLP Header and Prefix Log information held by @log.
93  */
pcie_print_tlp_log(const struct pci_dev * dev,const struct pcie_tlp_log * log,const char * pfx)94 void pcie_print_tlp_log(const struct pci_dev *dev,
95 			const struct pcie_tlp_log *log, const char *pfx)
96 {
97 	char buf[11 * (PCIE_STD_NUM_TLP_HEADERLOG + ARRAY_SIZE(log->prefix)) +
98 		 sizeof(EE_PREFIX_STR)];
99 	unsigned int i;
100 	int len;
101 
102 	len = scnprintf(buf, sizeof(buf), "%#010x %#010x %#010x %#010x",
103 			log->dw[0], log->dw[1], log->dw[2], log->dw[3]);
104 
105 	if (log->prefix[0])
106 		len += scnprintf(buf + len, sizeof(buf) - len, EE_PREFIX_STR);
107 	for (i = 0; i < ARRAY_SIZE(log->prefix); i++) {
108 		if (!log->prefix[i])
109 			break;
110 		len += scnprintf(buf + len, sizeof(buf) - len,
111 				 " %#010x", log->prefix[i]);
112 	}
113 
114 	pci_err(dev, "%sTLP Header: %s\n", pfx, buf);
115 }
116