1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2022 Intel Corporation. */
3 
4 #include <linux/cpu.h>
5 #include <linux/delay.h>
6 #include <linux/fs.h>
7 #include <linux/semaphore.h>
8 #include <linux/slab.h>
9 
10 #include "ifs.h"
11 
12 /*
13  * Protects against simultaneous tests on multiple cores, or
14  * reloading can file while a test is in progress
15  */
16 DEFINE_SEMAPHORE(ifs_sem);
17 
18 /*
19  * The sysfs interface to check additional details of last test
20  * cat /sys/devices/system/platform/ifs/details
21  */
22 static ssize_t details_show(struct device *dev,
23 			    struct device_attribute *attr,
24 			    char *buf)
25 {
26 	struct ifs_data *ifsd = ifs_get_data(dev);
27 
28 	return sysfs_emit(buf, "%#llx\n", ifsd->scan_details);
29 }
30 
31 static DEVICE_ATTR_RO(details);
32 
33 static const char * const status_msg[] = {
34 	[SCAN_NOT_TESTED] = "untested",
35 	[SCAN_TEST_PASS] = "pass",
36 	[SCAN_TEST_FAIL] = "fail"
37 };
38 
39 /*
40  * The sysfs interface to check the test status:
41  * To check the status of last test
42  * cat /sys/devices/platform/ifs/status
43  */
44 static ssize_t status_show(struct device *dev,
45 			   struct device_attribute *attr,
46 			   char *buf)
47 {
48 	struct ifs_data *ifsd = ifs_get_data(dev);
49 
50 	return sysfs_emit(buf, "%s\n", status_msg[ifsd->status]);
51 }
52 
53 static DEVICE_ATTR_RO(status);
54 
55 /*
56  * The sysfs interface for single core testing
57  * To start test, for example, cpu5
58  * echo 5 > /sys/devices/platform/ifs/run_test
59  * To check the result:
60  * cat /sys/devices/platform/ifs/result
61  * The sibling core gets tested at the same time.
62  */
63 static ssize_t run_test_store(struct device *dev,
64 			      struct device_attribute *attr,
65 			      const char *buf, size_t count)
66 {
67 	struct ifs_data *ifsd = ifs_get_data(dev);
68 	unsigned int cpu;
69 	int rc;
70 
71 	rc = kstrtouint(buf, 0, &cpu);
72 	if (rc < 0 || cpu >= nr_cpu_ids)
73 		return -EINVAL;
74 
75 	if (down_interruptible(&ifs_sem))
76 		return -EINTR;
77 
78 	if (!ifsd->loaded)
79 		rc = -EPERM;
80 	else
81 		rc = do_core_test(cpu, dev);
82 
83 	up(&ifs_sem);
84 
85 	return rc ? rc : count;
86 }
87 
88 static DEVICE_ATTR_WO(run_test);
89 
90 /*
91  * Reload the IFS image. When user wants to install new IFS image
92  */
93 static ssize_t reload_store(struct device *dev,
94 			    struct device_attribute *attr,
95 			    const char *buf, size_t count)
96 {
97 	struct ifs_data *ifsd = ifs_get_data(dev);
98 	bool res;
99 
100 
101 	if (kstrtobool(buf, &res))
102 		return -EINVAL;
103 	if (!res)
104 		return count;
105 
106 	if (down_interruptible(&ifs_sem))
107 		return -EINTR;
108 
109 	ifs_load_firmware(dev);
110 
111 	up(&ifs_sem);
112 
113 	return ifsd->loaded ? count : -ENODEV;
114 }
115 
116 static DEVICE_ATTR_WO(reload);
117 
118 /*
119  * Display currently loaded IFS image version.
120  */
121 static ssize_t image_version_show(struct device *dev,
122 				  struct device_attribute *attr, char *buf)
123 {
124 	struct ifs_data *ifsd = ifs_get_data(dev);
125 
126 	if (!ifsd->loaded)
127 		return sysfs_emit(buf, "%s\n", "none");
128 	else
129 		return sysfs_emit(buf, "%#x\n", ifsd->loaded_version);
130 }
131 
132 static DEVICE_ATTR_RO(image_version);
133 
134 /* global scan sysfs attributes */
135 static struct attribute *plat_ifs_attrs[] = {
136 	&dev_attr_details.attr,
137 	&dev_attr_status.attr,
138 	&dev_attr_run_test.attr,
139 	&dev_attr_reload.attr,
140 	&dev_attr_image_version.attr,
141 	NULL
142 };
143 
144 ATTRIBUTE_GROUPS(plat_ifs);
145 
146 const struct attribute_group **ifs_get_groups(void)
147 {
148 	return plat_ifs_groups;
149 }
150