xref: /openbmc/linux/drivers/fpga/dfl-afu-error.c (revision 9e3bd0f6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for FPGA Accelerated Function Unit (AFU) Error Reporting
4  *
5  * Copyright 2019 Intel Corporation, Inc.
6  *
7  * Authors:
8  *   Wu Hao <hao.wu@linux.intel.com>
9  *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
10  *   Joseph Grecco <joe.grecco@intel.com>
11  *   Enno Luebbers <enno.luebbers@intel.com>
12  *   Tim Whisonant <tim.whisonant@intel.com>
13  *   Ananda Ravuri <ananda.ravuri@intel.com>
14  *   Mitchel Henry <henry.mitchel@intel.com>
15  */
16 
17 #include <linux/uaccess.h>
18 
19 #include "dfl-afu.h"
20 
21 #define PORT_ERROR_MASK		0x8
22 #define PORT_ERROR		0x10
23 #define PORT_FIRST_ERROR	0x18
24 #define PORT_MALFORMED_REQ0	0x20
25 #define PORT_MALFORMED_REQ1	0x28
26 
27 #define ERROR_MASK		GENMASK_ULL(63, 0)
28 
29 /* mask or unmask port errors by the error mask register. */
30 static void __afu_port_err_mask(struct device *dev, bool mask)
31 {
32 	void __iomem *base;
33 
34 	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
35 
36 	writeq(mask ? ERROR_MASK : 0, base + PORT_ERROR_MASK);
37 }
38 
39 static void afu_port_err_mask(struct device *dev, bool mask)
40 {
41 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
42 
43 	mutex_lock(&pdata->lock);
44 	__afu_port_err_mask(dev, mask);
45 	mutex_unlock(&pdata->lock);
46 }
47 
48 /* clear port errors. */
49 static int afu_port_err_clear(struct device *dev, u64 err)
50 {
51 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
52 	struct platform_device *pdev = to_platform_device(dev);
53 	void __iomem *base_err, *base_hdr;
54 	int ret = -EBUSY;
55 	u64 v;
56 
57 	base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
58 	base_hdr = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_HEADER);
59 
60 	mutex_lock(&pdata->lock);
61 
62 	/*
63 	 * clear Port Errors
64 	 *
65 	 * - Check for AP6 State
66 	 * - Halt Port by keeping Port in reset
67 	 * - Set PORT Error mask to all 1 to mask errors
68 	 * - Clear all errors
69 	 * - Set Port mask to all 0 to enable errors
70 	 * - All errors start capturing new errors
71 	 * - Enable Port by pulling the port out of reset
72 	 */
73 
74 	/* if device is still in AP6 power state, can not clear any error. */
75 	v = readq(base_hdr + PORT_HDR_STS);
76 	if (FIELD_GET(PORT_STS_PWR_STATE, v) == PORT_STS_PWR_STATE_AP6) {
77 		dev_err(dev, "Could not clear errors, device in AP6 state.\n");
78 		goto done;
79 	}
80 
81 	/* Halt Port by keeping Port in reset */
82 	ret = __afu_port_disable(pdev);
83 	if (ret)
84 		goto done;
85 
86 	/* Mask all errors */
87 	__afu_port_err_mask(dev, true);
88 
89 	/* Clear errors if err input matches with current port errors.*/
90 	v = readq(base_err + PORT_ERROR);
91 
92 	if (v == err) {
93 		writeq(v, base_err + PORT_ERROR);
94 
95 		v = readq(base_err + PORT_FIRST_ERROR);
96 		writeq(v, base_err + PORT_FIRST_ERROR);
97 	} else {
98 		ret = -EINVAL;
99 	}
100 
101 	/* Clear mask */
102 	__afu_port_err_mask(dev, false);
103 
104 	/* Enable the Port by clear the reset */
105 	__afu_port_enable(pdev);
106 
107 done:
108 	mutex_unlock(&pdata->lock);
109 	return ret;
110 }
111 
112 static ssize_t errors_show(struct device *dev, struct device_attribute *attr,
113 			   char *buf)
114 {
115 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
116 	void __iomem *base;
117 	u64 error;
118 
119 	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
120 
121 	mutex_lock(&pdata->lock);
122 	error = readq(base + PORT_ERROR);
123 	mutex_unlock(&pdata->lock);
124 
125 	return sprintf(buf, "0x%llx\n", (unsigned long long)error);
126 }
127 
128 static ssize_t errors_store(struct device *dev, struct device_attribute *attr,
129 			    const char *buff, size_t count)
130 {
131 	u64 value;
132 	int ret;
133 
134 	if (kstrtou64(buff, 0, &value))
135 		return -EINVAL;
136 
137 	ret = afu_port_err_clear(dev, value);
138 
139 	return ret ? ret : count;
140 }
141 static DEVICE_ATTR_RW(errors);
142 
143 static ssize_t first_error_show(struct device *dev,
144 				struct device_attribute *attr, char *buf)
145 {
146 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
147 	void __iomem *base;
148 	u64 error;
149 
150 	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
151 
152 	mutex_lock(&pdata->lock);
153 	error = readq(base + PORT_FIRST_ERROR);
154 	mutex_unlock(&pdata->lock);
155 
156 	return sprintf(buf, "0x%llx\n", (unsigned long long)error);
157 }
158 static DEVICE_ATTR_RO(first_error);
159 
160 static ssize_t first_malformed_req_show(struct device *dev,
161 					struct device_attribute *attr,
162 					char *buf)
163 {
164 	struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
165 	void __iomem *base;
166 	u64 req0, req1;
167 
168 	base = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR);
169 
170 	mutex_lock(&pdata->lock);
171 	req0 = readq(base + PORT_MALFORMED_REQ0);
172 	req1 = readq(base + PORT_MALFORMED_REQ1);
173 	mutex_unlock(&pdata->lock);
174 
175 	return sprintf(buf, "0x%016llx%016llx\n",
176 		       (unsigned long long)req1, (unsigned long long)req0);
177 }
178 static DEVICE_ATTR_RO(first_malformed_req);
179 
180 static struct attribute *port_err_attrs[] = {
181 	&dev_attr_errors.attr,
182 	&dev_attr_first_error.attr,
183 	&dev_attr_first_malformed_req.attr,
184 	NULL,
185 };
186 
187 static umode_t port_err_attrs_visible(struct kobject *kobj,
188 				      struct attribute *attr, int n)
189 {
190 	struct device *dev = kobj_to_dev(kobj);
191 
192 	/*
193 	 * sysfs entries are visible only if related private feature is
194 	 * enumerated.
195 	 */
196 	if (!dfl_get_feature_by_id(dev, PORT_FEATURE_ID_ERROR))
197 		return 0;
198 
199 	return attr->mode;
200 }
201 
202 const struct attribute_group port_err_group = {
203 	.name       = "errors",
204 	.attrs      = port_err_attrs,
205 	.is_visible = port_err_attrs_visible,
206 };
207 
208 static int port_err_init(struct platform_device *pdev,
209 			 struct dfl_feature *feature)
210 {
211 	afu_port_err_mask(&pdev->dev, false);
212 
213 	return 0;
214 }
215 
216 static void port_err_uinit(struct platform_device *pdev,
217 			   struct dfl_feature *feature)
218 {
219 	afu_port_err_mask(&pdev->dev, true);
220 }
221 
222 const struct dfl_feature_id port_err_id_table[] = {
223 	{.id = PORT_FEATURE_ID_ERROR,},
224 	{0,}
225 };
226 
227 const struct dfl_feature_ops port_err_ops = {
228 	.init = port_err_init,
229 	.uinit = port_err_uinit,
230 };
231