[PATCH v2 1/2] drm/amdgpu: Remove debugfs amdgpu_reset_dump_register_list

[Christian König]

Am 30.07.24 um 08:44 schrieb Sunil Khatri:
> There are some problem with existing amdgpu_reset_dump_register_list
> debugfs node. It is supposed to read a list of registers but there
> could be cases when the IP is not in correct power state. Register
> read in such cases could lead to more problems.

You could be a bit more specific here, e.g. "could lead to ASIC hangs.".

>
> We are taking care of all such power states in devcoredump and
> dumping the registers of need for debugging. So cleaning this code
> and we dont need this functionality via debugfs anymore.
>
> Signed-off-by: Sunil Khatri <sunil.khatri at amd.com>

This patch and #2 in the series could potentially be squashed together, 
but either way is fine with me.

Reviewed-by: Christian König <christian.koenig at amd.com> for both patches.

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 96 ---------------------
>   1 file changed, 96 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> index 0e1a11b6b989..cbef720de779 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
> @@ -2026,100 +2026,6 @@ 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[12];
> -	int i, ret, len = 0;
> -
> -	if (*pos)
> -		return 0;
> -
> -	memset(reg_offset, 0, 12);
> -	ret = down_read_killable(&adev->reset_domain->sem);
> -	if (ret)
> -		return ret;
> -
> -	for (i = 0; i < adev->reset_info.num_regs; i++) {
> -		sprintf(reg_offset, "0x%x\n", adev->reset_info.reset_dump_reg_list[i]);
> -		up_read(&adev->reset_domain->sem);
> -		if (copy_to_user(buf + len, reg_offset, strlen(reg_offset)))
> -			return -EFAULT;
> -
> -		len += strlen(reg_offset);
> -		ret = down_read_killable(&adev->reset_domain->sem);
> -		if (ret)
> -			return ret;
> -	}
> -
> -	up_read(&adev->reset_domain->sem);
> -	*pos += len;
> -
> -	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[11];
> -	uint32_t *new = NULL, *tmp = NULL;
> -	unsigned int len = 0;
> -	int ret, i = 0;
> -
> -	do {
> -		memset(reg_offset, 0, 11);
> -		if (copy_from_user(reg_offset, buf + len,
> -					min(10, (size-len)))) {
> -			ret = -EFAULT;
> -			goto error_free;
> -		}
> -
> -		new = krealloc_array(tmp, i + 1, sizeof(uint32_t), GFP_KERNEL);
> -		if (!new) {
> -			ret = -ENOMEM;
> -			goto error_free;
> -		}
> -		tmp = new;
> -		if (sscanf(reg_offset, "%X %n", &tmp[i], &ret) != 1) {
> -			ret = -EINVAL;
> -			goto error_free;
> -		}
> -
> -		len += ret;
> -		i++;
> -	} while (len < size);
> -
> -	new = kmalloc_array(i, sizeof(uint32_t), GFP_KERNEL);
> -	if (!new) {
> -		ret = -ENOMEM;
> -		goto error_free;
> -	}
> -	ret = down_write_killable(&adev->reset_domain->sem);
> -	if (ret)
> -		goto error_free;
> -
> -	swap(adev->reset_info.reset_dump_reg_list, tmp);
> -	swap(adev->reset_info.reset_dump_reg_value, new);
> -	adev->reset_info.num_regs = i;
> -	up_write(&adev->reset_domain->sem);
> -	ret = size;
> -
> -error_free:
> -	if (tmp != new)
> -		kfree(tmp);
> -	kfree(new);
> -	return ret;
> -}
> -
> -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;
> @@ -2204,8 +2110,6 @@ int amdgpu_debugfs_init(struct amdgpu_device *adev)
>   			    &amdgpu_debugfs_vm_info_fops);
>   	debugfs_create_file("amdgpu_benchmark", 0200, root, adev,
>   			    &amdgpu_benchmark_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;