[PATCH v4 1/2] drm/amdgpu: add debugfs for reset registers list

[Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>]

List of register populated for dump collection during the GPU reset.

Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h         |  4 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 89 +++++++++++++++++++++
 2 files changed, 93 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index b85b67a88a3d..2e8c2318276d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1097,6 +1097,10 @@ struct amdgpu_device {
 
 	struct amdgpu_reset_control     *reset_cntl;
 	uint32_t                        ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
+
+	/* reset dump register */
+	uint32_t			*reset_dump_reg_list;
+	int                             n_regs;
 };
 
 static inline struct amdgpu_device *drm_to_adev(struct drm_device *ddev)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 164d6a9e9fbb..edcb032bc1f3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1609,6 +1609,93 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ib_preempt, NULL,
 DEFINE_DEBUGFS_ATTRIBUTE(fops_sclk_set, NULL,
 			amdgpu_debugfs_sclk_set, "%llu\n");
 
+static ssize_t amdgpu_reset_dump_register_list_read(struct file *f,
+				char __user *buf, size_t size, loff_t *pos)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)file_inode(f)->i_private;
+	char reg_offset[11];
+	int i, r, len = 0;
+
+	if (adev->n_regs == 0)
+		return 0;
+
+	for (i = 0; i < adev->n_regs; i++) {
+		memset(reg_offset,  0, 11);
+		sprintf(reg_offset + strlen(reg_offset),
+				"0x%x ", adev->reset_dump_reg_list[i]);
+		r = copy_to_user(buf + len, reg_offset, strlen(reg_offset));
+		len += strlen(reg_offset);
+	}
+
+	r = copy_to_user(buf + len, "\n", 1);
+	len++;
+
+	if (*pos >= len)
+		return 0;
+
+	*pos += len - r;
+
+	return len;
+}
+
+static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
+			const char __user *buf, size_t size, loff_t *pos)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)file_inode(f)->i_private;
+	char *reg_offset, *reg, reg_temp[11];
+	int ret, i = 0, len = 0;
+
+	reg_offset = reg_temp;
+	memset(reg_offset,  0, 11);
+	ret = copy_from_user(reg_offset, buf, 11);
+
+	if (ret)
+		return -EFAULT;
+
+	if (adev->n_regs > 0) {
+		adev->n_regs = 0;
+		kfree(adev->reset_dump_reg_list);
+		adev->reset_dump_reg_list = NULL;
+	}
+
+	while (((reg = strsep(&reg_offset, " ")) != NULL) && len < size) {
+		adev->reset_dump_reg_list =  krealloc_array(
+						adev->reset_dump_reg_list, 1,
+						sizeof(uint32_t), GFP_KERNEL);
+		ret  = kstrtouint(reg, 16, &adev->reset_dump_reg_list[i]);
+
+		if (ret) {
+			kfree(adev->reset_dump_reg_list);
+			adev->reset_dump_reg_list = NULL;
+			return -EINVAL;
+		}
+
+		len += strlen(reg) + 1;
+		reg_offset = reg_temp;
+		memset(reg_offset,  0, 11);
+		ret = copy_from_user(reg_offset, buf + len, 11);
+
+		if (ret) {
+			kfree(adev->reset_dump_reg_list);
+			adev->reset_dump_reg_list = NULL;
+			return -EFAULT;
+		}
+
+		i++;
+	}
+
+	adev->n_regs = i;
+
+	return size;
+}
+
+static const struct file_operations amdgpu_reset_dump_register_list = {
+	.owner = THIS_MODULE,
+	.read = amdgpu_reset_dump_register_list_read,
+	.write = amdgpu_reset_dump_register_list_write,
+	.llseek = default_llseek
+};
+
 int amdgpu_debugfs_init(struct amdgpu_device *adev)
 {
 	struct dentry *root = adev_to_drm(adev)->primary->debugfs_root;
@@ -1672,6 +1759,8 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
 			    &amdgpu_debugfs_test_ib_fops);
 	debugfs_create_file("amdgpu_vm_info", 0444, root, adev,
 			    &amdgpu_debugfs_vm_info_fops);
+	debugfs_create_file("amdgpu_reset_dump_register_list", 0644, root, adev,
+			    &amdgpu_reset_dump_register_list);
 
 	adev->debugfs_vbios_blob.data = adev->bios;
 	adev->debugfs_vbios_blob.size = adev->bios_size;
-- 
2.25.1