drm/amdgpu: Add reg_state sysfs attribute

Add reg_state attribute to fetch the register snapshot of different
IPs like XGMI, WAFL,PCIE and USR. To get a snapshot for a particular IP
	1) Open the sysfs file
	2) Seek to the offset as defined in amdgpu_sysfs_reg_offset
	3) Read
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -162,6 +162,65 @@ static ssize_t amdgpu_device_get_pcie_replay_count(struct device *dev,
 static DEVICE_ATTR(pcie_replay_count, 0444,
 		amdgpu_device_get_pcie_replay_count, NULL);
 
+static ssize_t amdgpu_sysfs_reg_state_get(struct file *f, struct kobject *kobj,
+					  struct bin_attribute *attr, char *buf,
+					  loff_t ppos, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct amdgpu_device *adev = drm_to_adev(ddev);
+	ssize_t bytes_read;
+
+	switch (ppos) {
+	case AMDGPU_SYS_REG_STATE_XGMI:
+		bytes_read = amdgpu_asic_get_reg_state(
+			adev, AMDGPU_REG_STATE_TYPE_XGMI, buf, count);
+		break;
+	case AMDGPU_SYS_REG_STATE_WAFL:
+		bytes_read = amdgpu_asic_get_reg_state(
+			adev, AMDGPU_REG_STATE_TYPE_WAFL, buf, count);
+		break;
+	case AMDGPU_SYS_REG_STATE_PCIE:
+		bytes_read = amdgpu_asic_get_reg_state(
+			adev, AMDGPU_REG_STATE_TYPE_PCIE, buf, count);
+		break;
+	case AMDGPU_SYS_REG_STATE_USR:
+		bytes_read = amdgpu_asic_get_reg_state(
+			adev, AMDGPU_REG_STATE_TYPE_USR, buf, count);
+		break;
+	case AMDGPU_SYS_REG_STATE_USR_1:
+		bytes_read = amdgpu_asic_get_reg_state(
+			adev, AMDGPU_REG_STATE_TYPE_USR_1, buf, count);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return bytes_read;
+}
+
+BIN_ATTR(reg_state, 0444, amdgpu_sysfs_reg_state_get, NULL,
+	 AMDGPU_SYS_REG_STATE_END);
+
+int amdgpu_reg_state_sysfs_init(struct amdgpu_device *adev)
+{
+	int ret;
+
+	if (!amdgpu_asic_get_reg_state_supported(adev))
+		return 0;
+
+	ret = sysfs_create_bin_file(&adev->dev->kobj, &bin_attr_reg_state);
+
+	return ret;
+}
+
+void amdgpu_reg_state_sysfs_fini(struct amdgpu_device *adev)
+{
+	if (!amdgpu_asic_get_reg_state_supported(adev))
+		return;
+	sysfs_remove_bin_file(&adev->dev->kobj, &bin_attr_reg_state);
+}
+
 /**
  * DOC: board_info
  *
@@ -4233,6 +4292,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 			"Could not create amdgpu board attributes\n");
 
 	amdgpu_fru_sysfs_init(adev);
+	amdgpu_reg_state_sysfs_init(adev);
 
 	if (IS_ENABLED(CONFIG_PERF_EVENTS))
 		r = amdgpu_pmu_init(adev);
@@ -4355,6 +4415,8 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
 	sysfs_remove_files(&adev->dev->kobj, amdgpu_dev_attributes);
 	amdgpu_fru_sysfs_fini(adev);
 
+	amdgpu_reg_state_sysfs_fini(adev);
+
 	/* disable ras feature must before hw fini */
 	amdgpu_ras_pre_fini(adev);
 

drivers/gpu/drm/amd/include/amdgpu_reg_state.h

@@ -34,6 +34,15 @@ enum amdgpu_reg_state {
 	AMDGPU_REG_STATE_TYPE_USR_1	= 5
 };
 
+enum amdgpu_sysfs_reg_offset {
+	AMDGPU_SYS_REG_STATE_XGMI	= 0x0000,
+	AMDGPU_SYS_REG_STATE_WAFL	= 0x1000,
+	AMDGPU_SYS_REG_STATE_PCIE	= 0x2000,
+	AMDGPU_SYS_REG_STATE_USR	= 0x3000,
+	AMDGPU_SYS_REG_STATE_USR_1	= 0x4000,
+	AMDGPU_SYS_REG_STATE_END	= 0x5000,
+};
+
 struct amdgpu_reg_state_header {
 	uint16_t		structure_size;
 	uint8_t			format_revision;
@@ -137,4 +146,8 @@ static inline size_t amdgpu_reginst_size(uint16_t num_inst, size_t inst_size,
 						   (size)) :               \
 		 0)
 
+
+int amdgpu_reg_state_sysfs_init(struct amdgpu_device *adev);
+void amdgpu_reg_state_sysfs_fini(struct amdgpu_device *adev);
+
 #endif