drm/amdgpu: restrict debugfs register access under SR-IOV

Under bare metal, there is no more else to take
care of the GPU register access through MMIO.
Under Virtualization, to access GPU register is
implemented through KIQ during run-time due to
world-switch.

Therefore, under SR-IOV user can only access
debugfs to r/w GPU registers when meets all
three conditions below.
- amdgpu_gpu_recovery=0
- TDR happened
- in_gpu_reset=0

v2: merge amdgpu_virt_can_access_debugfs() into
    amdgpu_virt_enable_access_debugfs()

v3: drop ret variable in amdgpu_virt_enable_access_debugfs()
    and directly return result

Signed-off-by: Yintian Tao <yttao@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c

@@ -152,11 +152,16 @@ static int  amdgpu_debugfs_process_reg_op(bool read, struct file *f,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	if (use_bank) {
 		if ((sh_bank != 0xFFFFFFFF && sh_bank >= adev->gfx.config.max_sh_per_se) ||
 		    (se_bank != 0xFFFFFFFF && se_bank >= adev->gfx.config.max_shader_engines)) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return -EINVAL;
 		}
 		mutex_lock(&adev->grbm_idx_mutex);
@@ -207,6 +212,7 @@ end:
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -255,6 +261,10 @@ static ssize_t amdgpu_debugfs_regs_pcie_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -263,6 +273,7 @@ static ssize_t amdgpu_debugfs_regs_pcie_read(struct file *f, char __user *buf,
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -275,6 +286,7 @@ static ssize_t amdgpu_debugfs_regs_pcie_read(struct file *f, char __user *buf,
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -304,6 +316,10 @@ static ssize_t amdgpu_debugfs_regs_pcie_write(struct file *f, const char __user
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -311,6 +327,7 @@ static ssize_t amdgpu_debugfs_regs_pcie_write(struct file *f, const char __user
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -325,6 +342,7 @@ static ssize_t amdgpu_debugfs_regs_pcie_write(struct file *f, const char __user
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -354,6 +372,10 @@ static ssize_t amdgpu_debugfs_regs_didt_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -362,6 +384,7 @@ static ssize_t amdgpu_debugfs_regs_didt_read(struct file *f, char __user *buf,
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -374,6 +397,7 @@ static ssize_t amdgpu_debugfs_regs_didt_read(struct file *f, char __user *buf,
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -403,6 +427,10 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -410,6 +438,7 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -424,6 +453,7 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -453,6 +483,10 @@ static ssize_t amdgpu_debugfs_regs_smc_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -461,6 +495,7 @@ static ssize_t amdgpu_debugfs_regs_smc_read(struct file *f, char __user *buf,
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -473,6 +508,7 @@ static ssize_t amdgpu_debugfs_regs_smc_read(struct file *f, char __user *buf,
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -502,6 +538,10 @@ static ssize_t amdgpu_debugfs_regs_smc_write(struct file *f, const char __user *
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	while (size) {
 		uint32_t value;
 
@@ -509,6 +549,7 @@ static ssize_t amdgpu_debugfs_regs_smc_write(struct file *f, const char __user *
 		if (r) {
 			pm_runtime_mark_last_busy(adev->ddev->dev);
 			pm_runtime_put_autosuspend(adev->ddev->dev);
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
 		}
 
@@ -523,6 +564,7 @@ static ssize_t amdgpu_debugfs_regs_smc_write(struct file *f, const char __user *
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -651,16 +693,24 @@ static ssize_t amdgpu_debugfs_sensor_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	r = amdgpu_dpm_read_sensor(adev, idx, &values[0], &valuesize);
 
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
-	if (r)
+	if (r) {
+		amdgpu_virt_disable_access_debugfs(adev);
 		return r;
+	}
 
-	if (size > valuesize)
+	if (size > valuesize) {
+		amdgpu_virt_disable_access_debugfs(adev);
 		return -EINVAL;
+	}
 
 	outsize = 0;
 	x = 0;
@@ -673,6 +723,7 @@ static ssize_t amdgpu_debugfs_sensor_read(struct file *f, char __user *buf,
 		}
 	}
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return !r ? outsize : r;
 }
 
@@ -720,6 +771,10 @@ static ssize_t amdgpu_debugfs_wave_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	/* switch to the specific se/sh/cu */
 	mutex_lock(&adev->grbm_idx_mutex);
 	amdgpu_gfx_select_se_sh(adev, se, sh, cu);
@@ -734,16 +789,20 @@ static ssize_t amdgpu_debugfs_wave_read(struct file *f, char __user *buf,
 	pm_runtime_mark_last_busy(adev->ddev->dev);
 	pm_runtime_put_autosuspend(adev->ddev->dev);
 
-	if (!x)
+	if (!x) {
+		amdgpu_virt_disable_access_debugfs(adev);
 		return -EINVAL;
+	}
 
 	while (size && (offset < x * 4)) {
 		uint32_t value;
 
 		value = data[offset >> 2];
 		r = put_user(value, (uint32_t *)buf);
-		if (r)
+		if (r) {
+			amdgpu_virt_disable_access_debugfs(adev);
 			return r;
+		}
 
 		result += 4;
 		buf += 4;
@@ -751,6 +810,7 @@ static ssize_t amdgpu_debugfs_wave_read(struct file *f, char __user *buf,
 		size -= 4;
 	}
 
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }
 
@@ -805,6 +865,10 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
 	if (r < 0)
 		return r;
 
+	r = amdgpu_virt_enable_access_debugfs(adev);
+	if (r < 0)
+		return r;
+
 	/* switch to the specific se/sh/cu */
 	mutex_lock(&adev->grbm_idx_mutex);
 	amdgpu_gfx_select_se_sh(adev, se, sh, cu);
@@ -840,6 +904,7 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
 
 err:
 	kfree(data);
+	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
 }