1 files changed, 74 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index b4c8459deb7b..f9e750217f18 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -57,6 +57,7 @@
 #include "i915_memcpy.h"
 #include "i915_reg.h"
 #include "i915_scatterlist.h"
+#include "i915_sysfs.h"
 #include "i915_utils.h"
 
 #define ALLOW_FAIL (__GFP_KSWAPD_RECLAIM | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
@@ -2208,7 +2209,7 @@ void i915_capture_error_state(struct intel_gt *gt,
 	i915_gpu_coredump_put(error);
 }
 
-struct i915_gpu_coredump *
+static struct i915_gpu_coredump *
 i915_first_error_state(struct drm_i915_private *i915)
 {
 	struct i915_gpu_coredump *error;
@@ -2484,3 +2485,75 @@ void i915_gpu_error_debugfs_register(struct drm_i915_private *i915)
 	debugfs_create_file("i915_gpu_info", 0644, minor->debugfs_root, i915,
 			    &i915_gpu_info_fops);
 }
+
+static ssize_t error_state_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *attr, char *buf,
+				loff_t off, size_t count)
+{
+
+	struct device *kdev = kobj_to_dev(kobj);
+	struct drm_i915_private *i915 = kdev_minor_to_i915(kdev);
+	struct i915_gpu_coredump *gpu;
+	ssize_t ret = 0;
+
+	/*
+	 * FIXME: Concurrent clients triggering resets and reading + clearing
+	 * dumps can cause inconsistent sysfs reads when a user calls in with a
+	 * non-zero offset to complete a prior partial read but the
+	 * gpu_coredump has been cleared or replaced.
+	 */
+
+	gpu = i915_first_error_state(i915);
+	if (IS_ERR(gpu)) {
+		ret = PTR_ERR(gpu);
+	} else if (gpu) {
+		ret = i915_gpu_coredump_copy_to_buffer(gpu, buf, off, count);
+		i915_gpu_coredump_put(gpu);
+	} else {
+		const char *str = "No error state collected\n";
+		size_t len = strlen(str);
+
+		if (off < len) {
+			ret = min_t(size_t, count, len - off);
+			memcpy(buf, str + off, ret);
+		}
+	}
+
+	return ret;
+}
+
+static ssize_t error_state_write(struct file *file, struct kobject *kobj,
+				 struct bin_attribute *attr, char *buf,
+				 loff_t off, size_t count)
+{
+	struct device *kdev = kobj_to_dev(kobj);
+	struct drm_i915_private *dev_priv = kdev_minor_to_i915(kdev);
+
+	drm_dbg(&dev_priv->drm, "Resetting error state\n");
+	i915_reset_error_state(dev_priv);
+
+	return count;
+}
+
+static const struct bin_attribute error_state_attr = {
+	.attr.name = "error",
+	.attr.mode = S_IRUSR | S_IWUSR,
+	.size = 0,
+	.read = error_state_read,
+	.write = error_state_write,
+};
+
+void i915_gpu_error_sysfs_setup(struct drm_i915_private *i915)
+{
+	struct device *kdev = i915->drm.primary->kdev;
+
+	if (sysfs_create_bin_file(&kdev->kobj, &error_state_attr))
+		drm_err(&i915->drm, "error_state sysfs setup failed\n");
+}
+
+void i915_gpu_error_sysfs_teardown(struct drm_i915_private *i915)
+{
+	struct device *kdev = i915->drm.primary->kdev;
+
+	sysfs_remove_bin_file(&kdev->kobj, &error_state_attr);
+}