[PATCH 2/3] drm/amdgpu: add debug fs for AMD GPU reset register dumps

[Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>]

Implementation of debug fs “amdgpu_reset_reg_dumps”
to capture reset register status

Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 64 +++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 164d6a9e9fbb..c56d7b451aea 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1609,6 +1609,68 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ib_preempt, NULL,
 DEFINE_DEBUGFS_ATTRIBUTE(fops_sclk_set, NULL,
 			amdgpu_debugfs_sclk_set, "%llu\n");
 
+static DECLARE_RWSEM(reset_reg_dumps);
+
+static void seq_reg_dump(struct seq_file *m,
+			 uint32_t (*dump)[2], uint32_t n_regs, char **names)
+{
+	uint32_t i, count;
+
+	for (i = 0, count = 0; i < n_regs; i++) {
+		if (count == 0 ||
+		    dump[i-1][0] + sizeof(uint32_t) != dump[i][0]) {
+			seq_printf(m, "%s%s:	%08x: %08x",
+				   i ? "\n" : "", names[i],
+				   dump[i][0], dump[i][1]);
+			count = 7;
+		} else {
+			seq_printf(m, " %08x", dump[i][1]);
+			count--;
+		}
+	}
+
+	seq_puts(m, "\n");
+}
+
+int amdgpu_debugfs_reset_reg_dumps_show(struct seq_file *m, void *unused)
+{
+	struct amdgpu_device *adev = (struct amdgpu_device *)m->private;
+	uint32_t (*dump)[2], n_regs = 0;
+	int r = 0, i;
+	char **reg_names;
+
+	down_read(&reset_reg_dumps);
+
+	for (i = 0; i < adev->num_ip_blocks; i++) {
+		if (!adev->ip_blocks[i].status.valid)
+			continue;
+		if (!adev->ip_blocks[i].version->funcs->reset_reg_dumps)
+			continue;
+		r = adev->ip_blocks[i].version->funcs->reset_reg_dumps(
+				adev, &dump, &n_regs, &reg_names);
+
+		if (r)
+			DRM_ERROR("reset_reg_dumps of IP block <%s> failed %d\n",
+				  adev->ip_blocks[i].version->funcs->name, r);
+
+		if (!r) {
+			seq_reg_dump(m, dump, n_regs, reg_names);
+			kfree(dump);
+		}
+	}
+
+	up_read(&reset_reg_dumps);
+
+	for (i = 0; i < n_regs; i++)
+		kfree(reg_names[i]);
+
+	kfree(reg_names);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(amdgpu_debugfs_reset_reg_dumps);
+
 int amdgpu_debugfs_init(struct amdgpu_device *adev)
 {
 	struct dentry *root = adev_to_drm(adev)->primary->debugfs_root;
@@ -1672,6 +1734,8 @@ 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_reg_dumps", S_IFREG | 0444, root,
+			    adev, &amdgpu_debugfs_reset_reg_dumps_fops);
 
 	adev->debugfs_vbios_blob.data = adev->bios;
 	adev->debugfs_vbios_blob.size = adev->bios_size;
-- 
2.25.1