xref: /openbmc/linux/drivers/hwmon/occ/p9_sbe.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright IBM Corp 2019
3 
4 #include <linux/device.h>
5 #include <linux/errno.h>
6 #include <linux/slab.h>
7 #include <linux/fsi-occ.h>
8 #include <linux/mm.h>
9 #include <linux/module.h>
10 #include <linux/mutex.h>
11 #include <linux/platform_device.h>
12 #include <linux/string.h>
13 #include <linux/sysfs.h>
14 
15 #include "common.h"
16 
17 struct p9_sbe_occ {
18 	struct occ occ;
19 	bool sbe_error;
20 	void *ffdc;
21 	size_t ffdc_len;
22 	size_t ffdc_size;
23 	struct mutex sbe_error_lock;	/* lock access to ffdc data */
24 	struct device *sbe;
25 };
26 
27 #define to_p9_sbe_occ(x)	container_of((x), struct p9_sbe_occ, occ)
28 
29 static ssize_t ffdc_read(struct file *filp, struct kobject *kobj,
30 			 struct bin_attribute *battr, char *buf, loff_t pos,
31 			 size_t count)
32 {
33 	ssize_t rc = 0;
34 	struct occ *occ = dev_get_drvdata(kobj_to_dev(kobj));
35 	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
36 
37 	mutex_lock(&ctx->sbe_error_lock);
38 	if (ctx->sbe_error) {
39 		rc = memory_read_from_buffer(buf, count, &pos, ctx->ffdc,
40 					     ctx->ffdc_len);
41 		if (pos >= ctx->ffdc_len)
42 			ctx->sbe_error = false;
43 	}
44 	mutex_unlock(&ctx->sbe_error_lock);
45 
46 	return rc;
47 }
48 static BIN_ATTR_RO(ffdc, OCC_MAX_RESP_WORDS * 4);
49 
50 static bool p9_sbe_occ_save_ffdc(struct p9_sbe_occ *ctx, const void *resp,
51 				 size_t resp_len)
52 {
53 	bool notify = false;
54 
55 	mutex_lock(&ctx->sbe_error_lock);
56 	if (!ctx->sbe_error) {
57 		if (resp_len > ctx->ffdc_size) {
58 			if (ctx->ffdc)
59 				kvfree(ctx->ffdc);
60 			ctx->ffdc = kvmalloc(resp_len, GFP_KERNEL);
61 			if (!ctx->ffdc) {
62 				ctx->ffdc_len = 0;
63 				ctx->ffdc_size = 0;
64 				goto done;
65 			}
66 
67 			ctx->ffdc_size = resp_len;
68 		}
69 
70 		notify = true;
71 		ctx->sbe_error = true;
72 		ctx->ffdc_len = resp_len;
73 		memcpy(ctx->ffdc, resp, resp_len);
74 	}
75 
76 done:
77 	mutex_unlock(&ctx->sbe_error_lock);
78 	return notify;
79 }
80 
81 static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd, size_t len)
82 {
83 	struct occ_response *resp = &occ->resp;
84 	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
85 	size_t resp_len = sizeof(*resp);
86 	int rc;
87 
88 	rc = fsi_occ_submit(ctx->sbe, cmd, len, resp, &resp_len);
89 	if (rc < 0) {
90 		if (resp_len) {
91 			if (p9_sbe_occ_save_ffdc(ctx, resp, resp_len))
92 				sysfs_notify(&occ->bus_dev->kobj, NULL,
93 					     bin_attr_ffdc.attr.name);
94 		}
95 
96 		return rc;
97 	}
98 
99 	switch (resp->return_status) {
100 	case OCC_RESP_CMD_IN_PRG:
101 		rc = -ETIMEDOUT;
102 		break;
103 	case OCC_RESP_SUCCESS:
104 		rc = 0;
105 		break;
106 	case OCC_RESP_CMD_INVAL:
107 	case OCC_RESP_CMD_LEN_INVAL:
108 	case OCC_RESP_DATA_INVAL:
109 	case OCC_RESP_CHKSUM_ERR:
110 		rc = -EINVAL;
111 		break;
112 	case OCC_RESP_INT_ERR:
113 	case OCC_RESP_BAD_STATE:
114 	case OCC_RESP_CRIT_EXCEPT:
115 	case OCC_RESP_CRIT_INIT:
116 	case OCC_RESP_CRIT_WATCHDOG:
117 	case OCC_RESP_CRIT_OCB:
118 	case OCC_RESP_CRIT_HW:
119 		rc = -EREMOTEIO;
120 		break;
121 	default:
122 		rc = -EPROTO;
123 	}
124 
125 	return rc;
126 }
127 
128 static int p9_sbe_occ_probe(struct platform_device *pdev)
129 {
130 	int rc;
131 	struct occ *occ;
132 	struct p9_sbe_occ *ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx),
133 					      GFP_KERNEL);
134 	if (!ctx)
135 		return -ENOMEM;
136 
137 	mutex_init(&ctx->sbe_error_lock);
138 
139 	ctx->sbe = pdev->dev.parent;
140 	occ = &ctx->occ;
141 	occ->bus_dev = &pdev->dev;
142 	platform_set_drvdata(pdev, occ);
143 
144 	occ->powr_sample_time_us = 500;
145 	occ->poll_cmd_data = 0x20;		/* P9 OCC poll data */
146 	occ->send_cmd = p9_sbe_occ_send_cmd;
147 
148 	rc = occ_setup(occ);
149 	if (rc == -ESHUTDOWN)
150 		rc = -ENODEV;	/* Host is shutdown, don't spew errors */
151 
152 	if (!rc) {
153 		rc = device_create_bin_file(occ->bus_dev, &bin_attr_ffdc);
154 		if (rc) {
155 			dev_warn(occ->bus_dev,
156 				 "failed to create SBE error ffdc file\n");
157 			rc = 0;
158 		}
159 	}
160 
161 	return rc;
162 }
163 
164 static int p9_sbe_occ_remove(struct platform_device *pdev)
165 {
166 	struct occ *occ = platform_get_drvdata(pdev);
167 	struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
168 
169 	device_remove_bin_file(occ->bus_dev, &bin_attr_ffdc);
170 
171 	ctx->sbe = NULL;
172 	occ_shutdown(occ);
173 
174 	if (ctx->ffdc)
175 		kvfree(ctx->ffdc);
176 
177 	return 0;
178 }
179 
180 static struct platform_driver p9_sbe_occ_driver = {
181 	.driver = {
182 		.name = "occ-hwmon",
183 	},
184 	.probe	= p9_sbe_occ_probe,
185 	.remove = p9_sbe_occ_remove,
186 };
187 
188 module_platform_driver(p9_sbe_occ_driver);
189 
190 MODULE_AUTHOR("Eddie James <eajames@linux.ibm.com>");
191 MODULE_DESCRIPTION("BMC P9 OCC hwmon driver");
192 MODULE_LICENSE("GPL");
193