Re: [PATCH v8 1/2] drm/amdgpu: add debugfs for reset registers list

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





Am 21.02.22 um 08:15 schrieb Somalapuram Amaranath:
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 | 114 ++++++++++++++++++++
  2 files changed, 118 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index b85b67a88a3d..6e35f2c4c869 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                             num_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..14ad9610f805 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1609,6 +1609,118 @@ 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];
+	uint32_t num_regs;
+	int i, ret, len = 0;
+
+	if (*pos)
+		return 0;
+
+	ret = down_read_killable(&adev->reset_sem);
+
+	if (ret)
+		return ret;
+
+	num_regs = adev->num_regs;
+
+	up_read(&adev->reset_sem);
+
+	if (num_regs == 0)
+		return 0;

I think we should drop that cause it just avoids the final \n.

+
+	for (i = 0; i < num_regs; i++) {

That's pretty close, but one problem is still that it is possible that the number of register becomes much smaller while this loop runs.

Try it like this instead:

down_read_killable(...)
for (i = 0; i < adev->num_regs; ++i) {
    sprintf(...)
    up_read(...);

    copy_to_user(

    down_read_killable(...)
}
up_read().

+
+		ret = down_read_killable(&adev->reset_sem);
+
+		if (ret)
+			return ret;
+
+		sprintf(reg_offset, "0x%x ", adev->reset_dump_reg_list[i]);
+
+		up_read(&adev->reset_sem);
+
+		ret = copy_to_user(buf + len, reg_offset, strlen(reg_offset));
+
+		if (ret)
+			return -EFAULT;
+
+		len += strlen(reg_offset);
+	}
+
+	ret = copy_to_user(buf + len, "\n", 1);
+
+	if (ret)
+		return -EFAULT;
+
+	len++;
+	*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, *reg, reg_temp[11];
+	uint32_t *tmp_list;
+	int ret, i = 0, len = 0;
+
+	do {
+		reg_offset = reg_temp;
+		memset(reg_offset, 0, 11);
+		ret = copy_from_user(reg_offset, buf + len, min(11, ((int)size-len)));
+
+		if (ret) {
+			kfree(tmp_list);
+			return -EFAULT;
+		}
+
+		reg = strsep(&reg_offset, " ");
+		tmp_list = krealloc_array(tmp_list,
+					1, sizeof(uint32_t), GFP_KERNEL);
+		ret = kstrtouint(reg, 16, &tmp_list[i]);
+
+		if (ret) {
+			kfree(tmp_list);
+			return -EFAULT;
+		}
+
+		len += strlen(reg) + 1;
+		i++;
+
+	} while (len < size);
+
+	ret = down_read_killable(&adev->reset_sem);
+
+	if (ret) {
+		kfree(tmp_list);
+		return ret;
+	}
+
+	kfree(adev->reset_dump_reg_list);
+
+	swap(adev->reset_dump_reg_list, tmp_list);

Just an assignment is sufficient here if you do the kfree before since tmp_list isn't used after that.

+	adev->num_regs = i;
+
+	up_read(&adev->reset_sem);

This should be a down_write_killable() and up_write() to avoid concurrent reads.

Apart from that the write function now looks clean.

Regards,
Christian.

+
+	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 +1784,8 @@ 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;




[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux