drivers/platform/x86/intel/ifs/sysfs.c

   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 }