xref: /linux/drivers/edac/loongson_edac.c (revision 0763dd892855aca05c4b45bc3a5da439d5f009ae)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2024 Loongson Technology Corporation Limited.
4  */
5 
6 #include <linux/acpi.h>
7 #include <linux/edac.h>
8 #include <linux/init.h>
9 #include <linux/io-64-nonatomic-lo-hi.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include "edac_module.h"
13 
14 #define ECC_CS_COUNT_REG	0x18
15 
16 struct loongson_edac_pvt {
17 	void __iomem *ecc_base;
18 
19 	/*
20 	 * The ECC register in this controller records the number of errors
21 	 * encountered since reset and cannot be zeroed so in order to be able
22 	 * to report the error count at each check, this records the previous
23 	 * register state.
24 	 */
25 	int last_ce_count;
26 };
27 
28 static int read_ecc(struct mem_ctl_info *mci)
29 {
30 	struct loongson_edac_pvt *pvt = mci->pvt_info;
31 	u64 ecc;
32 	int cs;
33 
34 	ecc = readq(pvt->ecc_base + ECC_CS_COUNT_REG);
35 	/* cs0 -- cs3 */
36 	cs = ecc & 0xff;
37 	cs += (ecc >> 8) & 0xff;
38 	cs += (ecc >> 16) & 0xff;
39 	cs += (ecc >> 24) & 0xff;
40 
41 	return cs;
42 }
43 
44 static void edac_check(struct mem_ctl_info *mci)
45 {
46 	struct loongson_edac_pvt *pvt = mci->pvt_info;
47 	int new, add;
48 
49 	new = read_ecc(mci);
50 	add = new - pvt->last_ce_count;
51 	pvt->last_ce_count = new;
52 	if (add <= 0)
53 		return;
54 
55 	edac_mc_handle_error(HW_EVENT_ERR_CORRECTED, mci, add,
56 			     0, 0, 0, 0, 0, -1, "error", "");
57 }
58 
59 static void dimm_config_init(struct mem_ctl_info *mci)
60 {
61 	struct dimm_info *dimm;
62 	u32 size, npages;
63 
64 	/* size not used */
65 	size = -1;
66 	npages = MiB_TO_PAGES(size);
67 
68 	dimm = edac_get_dimm(mci, 0, 0, 0);
69 	dimm->nr_pages = npages;
70 	snprintf(dimm->label, sizeof(dimm->label),
71 		 "MC#%uChannel#%u_DIMM#%u", mci->mc_idx, 0, 0);
72 	dimm->grain = 8;
73 }
74 
75 static void pvt_init(struct mem_ctl_info *mci, void __iomem *vbase)
76 {
77 	struct loongson_edac_pvt *pvt = mci->pvt_info;
78 
79 	pvt->ecc_base = vbase;
80 	pvt->last_ce_count = read_ecc(mci);
81 }
82 
83 static int edac_probe(struct platform_device *pdev)
84 {
85 	struct edac_mc_layer layers[2];
86 	struct mem_ctl_info *mci;
87 	void __iomem *vbase;
88 	int ret;
89 
90 	vbase = devm_platform_ioremap_resource(pdev, 0);
91 	if (IS_ERR(vbase))
92 		return PTR_ERR(vbase);
93 
94 	layers[0].type = EDAC_MC_LAYER_CHANNEL;
95 	layers[0].size = 1;
96 	layers[0].is_virt_csrow = false;
97 	layers[1].type = EDAC_MC_LAYER_SLOT;
98 	layers[1].size = 1;
99 	layers[1].is_virt_csrow = true;
100 	mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers,
101 			    sizeof(struct loongson_edac_pvt));
102 	if (mci == NULL)
103 		return -ENOMEM;
104 
105 	mci->mc_idx = edac_device_alloc_index();
106 	mci->mtype_cap = MEM_FLAG_RDDR4;
107 	mci->edac_ctl_cap = EDAC_FLAG_NONE;
108 	mci->edac_cap = EDAC_FLAG_NONE;
109 	mci->mod_name = "loongson_edac.c";
110 	mci->ctl_name = "loongson_edac_ctl";
111 	mci->dev_name = "loongson_edac_dev";
112 	mci->ctl_page_to_phys = NULL;
113 	mci->pdev = &pdev->dev;
114 	mci->error_desc.grain = 8;
115 	mci->edac_check = edac_check;
116 
117 	pvt_init(mci, vbase);
118 	dimm_config_init(mci);
119 
120 	ret = edac_mc_add_mc(mci);
121 	if (ret) {
122 		edac_dbg(0, "MC: failed edac_mc_add_mc()\n");
123 		edac_mc_free(mci);
124 		return ret;
125 	}
126 	edac_op_state = EDAC_OPSTATE_POLL;
127 
128 	return 0;
129 }
130 
131 static void edac_remove(struct platform_device *pdev)
132 {
133 	struct mem_ctl_info *mci = edac_mc_del_mc(&pdev->dev);
134 
135 	if (mci)
136 		edac_mc_free(mci);
137 }
138 
139 static const struct acpi_device_id loongson_edac_acpi_match[] = {
140 	{"LOON0010", 0},
141 	{}
142 };
143 MODULE_DEVICE_TABLE(acpi, loongson_edac_acpi_match);
144 
145 static struct platform_driver loongson_edac_driver = {
146 	.probe		= edac_probe,
147 	.remove		= edac_remove,
148 	.driver		= {
149 		.name	= "loongson-mc-edac",
150 		.acpi_match_table = loongson_edac_acpi_match,
151 	},
152 };
153 module_platform_driver(loongson_edac_driver);
154 
155 MODULE_LICENSE("GPL");
156 MODULE_AUTHOR("Zhao Qunqin <zhaoqunqin@loongson.cn>");
157 MODULE_DESCRIPTION("EDAC driver for loongson memory controller");
158