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

[Christian König]

Am 08.02.22 um 09:16 schrieb Somalapuram Amaranath:
List of register to be populated for dump collection during the GPU reset.
Signed-off-by: Somalapuram Amaranath <amaranath.somalapu...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu.h         |  3 ++
  drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 60 +++++++++++++++++++++
  2 files changed, 63 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index b85b67a88a3d..78fa46f959c5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1097,6 +1097,9 @@ struct amdgpu_device {
  
  	struct amdgpu_reset_control     *reset_cntl;
        uint32_t                        
ip_versions[HW_ID_MAX][HWIP_MAX_INSTANCE];
+
+       /* reset dump register */
+       long                    reset_dump_reg_list[128];

I don't have time for a full review, but using long here certainly makes 
no sense.

long is either 32bit or 64bit depending on the CPU architecture.

Regards,
Christian.

  };
  
  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..dad268e8a81a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1609,6 +1609,64 @@ 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;
+       int i, r, len;
+
+       reg_offset = kmalloc(2048, GFP_KERNEL);
+       memset(reg_offset,  0, 2048);
+       for (i = 0; adev->reset_dump_reg_list[i] != 0; i++)
+               sprintf(reg_offset + strlen(reg_offset), "0x%lx ", 
adev->reset_dump_reg_list[i]);
+
+       sprintf(reg_offset + strlen(reg_offset), "\n");
+       len = strlen(reg_offset);
+
+       if (*pos >=  len)
+               return 0;
+
+       r = copy_to_user(buf, reg_offset, len);
+       *pos += len - r;
+       kfree(reg_offset);
+
+       return len - r;
+}
+
+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;
+       int ret, i = 0;
+
+       reg_offset = kmalloc(size, GFP_KERNEL);
+       memset(reg_offset,  0, size);
+       ret = copy_from_user(reg_offset, buf, size);
+
+       if (ret)
+               return -EFAULT;
+
+       while ((reg = strsep(&reg_offset, " ")) != NULL) {
+               ret  = kstrtol(reg, 16, &adev->reset_dump_reg_list[i]);
+               if (ret)
+                       return -EINVAL;
+               i++;
+       }
+
+       kfree(reg_offset);
+
+       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 +1730,8 @@ 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;