drm: make drm_get_format_name thread-safe

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
[danvet: Clarify that the returned pointer must be freed with
kfree().]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/amd/amdgpu/dce_v10_0.c

@@ -2071,6 +2071,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
 	u32 tmp, viewport_w, viewport_h;
 	int r;
 	bool bypass_lut = false;
+	const char *format_name;
 
 	/* no fb bound */
 	if (!atomic && !crtc->primary->fb) {
@@ -2182,8 +2183,9 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
 		bypass_lut = true;
 		break;
 	default:
-		DRM_ERROR("Unsupported screen format %s\n",
-			drm_get_format_name(target_fb->pixel_format));
+		format_name = drm_get_format_name(target_fb->pixel_format);
+		DRM_ERROR("Unsupported screen format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 

drivers/gpu/drm/amd/amdgpu/dce_v11_0.c

@@ -2046,6 +2046,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
 	u32 tmp, viewport_w, viewport_h;
 	int r;
 	bool bypass_lut = false;
+	const char *format_name;
 
 	/* no fb bound */
 	if (!atomic && !crtc->primary->fb) {
@@ -2157,8 +2158,9 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
 		bypass_lut = true;
 		break;
 	default:
-		DRM_ERROR("Unsupported screen format %s\n",
-			drm_get_format_name(target_fb->pixel_format));
+		format_name = drm_get_format_name(target_fb->pixel_format);
+		DRM_ERROR("Unsupported screen format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 

drivers/gpu/drm/amd/amdgpu/dce_v8_0.c

@@ -1952,6 +1952,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
 	u32 viewport_w, viewport_h;
 	int r;
 	bool bypass_lut = false;
+	const char *format_name;
 
 	/* no fb bound */
 	if (!atomic && !crtc->primary->fb) {
@@ -2056,8 +2057,9 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
 		bypass_lut = true;
 		break;
 	default:
-		DRM_ERROR("Unsupported screen format %s\n",
-			  drm_get_format_name(target_fb->pixel_format));
+		format_name = drm_get_format_name(target_fb->pixel_format);
+		DRM_ERROR("Unsupported screen format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 

drivers/gpu/drm/drm_atomic.c

@@ -837,8 +837,9 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
 	/* Check whether this plane supports the fb pixel format. */
 	ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
 	if (ret) {
-		DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
-				 drm_get_format_name(state->fb->pixel_format));
+		const char *format_name = drm_get_format_name(state->fb->pixel_format);
+		DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
+		kfree(format_name);
 		return ret;
 	}
 

drivers/gpu/drm/drm_crtc.c

@@ -2592,8 +2592,9 @@ static int __setplane_internal(struct drm_plane *plane,
 	/* Check whether this plane supports the fb pixel format. */
 	ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
 	if (ret) {
-		DRM_DEBUG_KMS("Invalid pixel format %s\n",
-			      drm_get_format_name(fb->pixel_format));
+		const char *format_name = drm_get_format_name(fb->pixel_format);
+		DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+		kfree(format_name);
 		goto out;
 	}
 
@@ -2902,8 +2903,9 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
 			ret = drm_plane_check_pixel_format(crtc->primary,
 							   fb->pixel_format);
 			if (ret) {
-				DRM_DEBUG_KMS("Invalid pixel format %s\n",
-					drm_get_format_name(fb->pixel_format));
+				const char *format_name = drm_get_format_name(fb->pixel_format);
+				DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
+				kfree(format_name);
 				goto out;
 			}
 		}
@@ -3279,6 +3281,7 @@ int drm_mode_addfb(struct drm_device *dev,
 static int format_check(const struct drm_mode_fb_cmd2 *r)
 {
 	uint32_t format = r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN;
+	const char *format_name;
 
 	switch (format) {
 	case DRM_FORMAT_C8:
@@ -3343,8 +3346,9 @@ static int format_check(const struct drm_mode_fb_cmd2 *r)
 	case DRM_FORMAT_YVU444:
 		return 0;
 	default:
-		DRM_DEBUG_KMS("invalid pixel format %s\n",
-			      drm_get_format_name(r->pixel_format));
+		format_name = drm_get_format_name(r->pixel_format);
+		DRM_DEBUG_KMS("invalid pixel format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 }
@@ -3355,8 +3359,9 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
 
 	ret = format_check(r);
 	if (ret) {
-		DRM_DEBUG_KMS("bad framebuffer format %s\n",
-			      drm_get_format_name(r->pixel_format));
+		const char *format_name = drm_get_format_name(r->pixel_format);
+		DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
+		kfree(format_name);
 		return ret;
 	}
 

drivers/gpu/drm/drm_fourcc.c

@@ -39,16 +39,14 @@ static char printable_char(int c)
  * drm_get_format_name - return a string for drm fourcc format
  * @format: format to compute name of
  *
- * Note that the buffer used by this function is globally shared and owned by
- * the function itself.
- *
- * FIXME: This isn't really multithreading safe.
+ * Note that the buffer returned by this function is owned by the caller
+ * and will need to be freed using kfree().
  */
 const char *drm_get_format_name(uint32_t format)
 {
-	static char buf[32];
+	char *buf = kmalloc(32, GFP_KERNEL);
 
-	snprintf(buf, sizeof(buf),
+	snprintf(buf, 32,
 		 "%c%c%c%c %s-endian (0x%08x)",
 		 printable_char(format & 0xff),
 		 printable_char((format >> 8) & 0xff),
@@ -73,6 +71,8 @@ EXPORT_SYMBOL(drm_get_format_name);
 void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 			  int *bpp)
 {
+	const char *format_name;
+
 	switch (format) {
 	case DRM_FORMAT_C8:
 	case DRM_FORMAT_RGB332:
@@ -127,8 +127,9 @@ void drm_fb_get_bpp_depth(uint32_t format, unsigned int *depth,
 		*bpp = 32;
 		break;
 	default:
-		DRM_DEBUG_KMS("unsupported pixel format %s\n",
-			      drm_get_format_name(format));
+		format_name = drm_get_format_name(format);
+		DRM_DEBUG_KMS("unsupported pixel format %s\n", format_name);
+		kfree(format_name);
 		*depth = 0;
 		*bpp = 0;
 		break;

drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c

@@ -608,15 +608,17 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
 			 u32 ch, u32 y, u32 in_h, u32 fmt)
 {
 	struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
+	const char *format_name;
 	u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
 	u32 stride = fb->pitches[0];
 	u32 addr = (u32)obj->paddr + y * stride;
 
 	DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
 			 ch + 1, y, in_h, stride, (u32)obj->paddr);
+	format_name = drm_get_format_name(fb->pixel_format);
 	DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
-			 addr, fb->width, fb->height, fmt,
-			 drm_get_format_name(fb->pixel_format));
+			 addr, fb->width, fb->height, fmt, format_name);
+	kfree(format_name);
 
 	/* get reg offset */
 	reg_ctrl = RD_CH_CTRL(ch);

drivers/gpu/drm/i915/i915_debugfs.c

@@ -3113,6 +3113,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
 	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
 		struct drm_plane_state *state;
 		struct drm_plane *plane = &intel_plane->base;
+		const char *format_name;
 
 		if (!plane->state) {
 			seq_puts(m, "plane->state is NULL!\n");
@@ -3121,6 +3122,12 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
 
 		state = plane->state;
 
+		if (state->fb) {
+			format_name = drm_get_format_name(state->fb->pixel_format);
+		} else {
+			format_name = kstrdup("N/A", GFP_KERNEL);
+		}
+
 		seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
 			   plane->base.id,
 			   plane_type(intel_plane->base.type),
@@ -3134,8 +3141,10 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
 			   ((state->src_w & 0xffff) * 15625) >> 10,
 			   (state->src_h >> 16),
 			   ((state->src_h & 0xffff) * 15625) >> 10,
-			   state->fb ? drm_get_format_name(state->fb->pixel_format) : "N/A",
+			   format_name,
 			   plane_rotation(state->rotation));
+
+		kfree(format_name);
 	}
 }
 

drivers/gpu/drm/i915/intel_atomic_plane.c

@@ -143,6 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
 		crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
 
 	if (state->fb && intel_rotation_90_or_270(state->rotation)) {
+		const char *format_name;
 		if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
 			state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
 			DRM_DEBUG_KMS("Y/Yf tiling required for 90/270!\n");
@@ -157,8 +158,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
 		switch (state->fb->pixel_format) {
 		case DRM_FORMAT_C8:
 		case DRM_FORMAT_RGB565:
-			DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
-					drm_get_format_name(state->fb->pixel_format));
+			format_name = drm_get_format_name(state->fb->pixel_format);
+			DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 
 		default:

drivers/gpu/drm/i915/intel_display.c

@@ -12258,6 +12258,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 
 	DRM_DEBUG_KMS("planes on this crtc\n");
 	list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
+		const char *format_name;
 		intel_plane = to_intel_plane(plane);
 		if (intel_plane->pipe != crtc->pipe)
 			continue;
@@ -12270,11 +12271,12 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 			continue;
 		}
 
+		format_name = drm_get_format_name(fb->pixel_format);
+
 		DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
 			      plane->base.id, plane->name);
 		DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
-			      fb->base.id, fb->width, fb->height,
-			      drm_get_format_name(fb->pixel_format));
+			      fb->base.id, fb->width, fb->height, format_name);
 		DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
 			      state->scaler_id,
 			      state->base.src.x1 >> 16,
@@ -12284,6 +12286,8 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 			      state->base.dst.x1, state->base.dst.y1,
 			      drm_rect_width(&state->base.dst),
 			      drm_rect_height(&state->base.dst));
+
+		kfree(format_name);
 	}
 }
 
@@ -14911,6 +14915,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
 	unsigned int aligned_height;
 	int ret;
 	u32 pitch_limit, stride_alignment;
+	const char *format_name;
 
 	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 
@@ -14985,16 +14990,18 @@ static int intel_framebuffer_init(struct drm_device *dev,
 		break;
 	case DRM_FORMAT_XRGB1555:
 		if (INTEL_INFO(dev)->gen > 3) {
-			DRM_DEBUG("unsupported pixel format: %s\n",
-				  drm_get_format_name(mode_cmd->pixel_format));
+			format_name = drm_get_format_name(mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 		}
 		break;
 	case DRM_FORMAT_ABGR8888:
 		if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev) &&
 		    INTEL_INFO(dev)->gen < 9) {
-			DRM_DEBUG("unsupported pixel format: %s\n",
-				  drm_get_format_name(mode_cmd->pixel_format));
+			format_name = drm_get_format_name(mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 		}
 		break;
@@ -15002,15 +15009,17 @@ static int intel_framebuffer_init(struct drm_device *dev,
 	case DRM_FORMAT_XRGB2101010:
 	case DRM_FORMAT_XBGR2101010:
 		if (INTEL_INFO(dev)->gen < 4) {
-			DRM_DEBUG("unsupported pixel format: %s\n",
-				  drm_get_format_name(mode_cmd->pixel_format));
+			format_name = drm_get_format_name(mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 		}
 		break;
 	case DRM_FORMAT_ABGR2101010:
 		if (!IS_VALLEYVIEW(dev) && !IS_CHERRYVIEW(dev)) {
-			DRM_DEBUG("unsupported pixel format: %s\n",
-				  drm_get_format_name(mode_cmd->pixel_format));
+			format_name = drm_get_format_name(mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 		}
 		break;
@@ -15019,14 +15028,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_VYUY:
 		if (INTEL_INFO(dev)->gen < 5) {
-			DRM_DEBUG("unsupported pixel format: %s\n",
-				  drm_get_format_name(mode_cmd->pixel_format));
+			format_name = drm_get_format_name(mode_cmd->pixel_format);
+			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+			kfree(format_name);
 			return -EINVAL;
 		}
 		break;
 	default:
-		DRM_DEBUG("unsupported pixel format: %s\n",
-			  drm_get_format_name(mode_cmd->pixel_format));
+		format_name = drm_get_format_name(mode_cmd->pixel_format);
+		DRM_DEBUG("unsupported pixel format: %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -1154,6 +1154,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
 	u32 tmp, viewport_w, viewport_h;
 	int r;
 	bool bypass_lut = false;
+	const char *format_name;
 
 	/* no fb bound */
 	if (!atomic && !crtc->primary->fb) {
@@ -1257,8 +1258,9 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
 		bypass_lut = true;
 		break;
 	default:
-		DRM_ERROR("Unsupported screen format %s\n",
-			  drm_get_format_name(target_fb->pixel_format));
+		format_name = drm_get_format_name(target_fb->pixel_format);
+		DRM_ERROR("Unsupported screen format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 
@@ -1469,6 +1471,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
 	u32 viewport_w, viewport_h;
 	int r;
 	bool bypass_lut = false;
+	const char *format_name;
 
 	/* no fb bound */
 	if (!atomic && !crtc->primary->fb) {
@@ -1558,8 +1561,9 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
 		bypass_lut = true;
 		break;
 	default:
-		DRM_ERROR("Unsupported screen format %s\n",
-			  drm_get_format_name(target_fb->pixel_format));
+		format_name = drm_get_format_name(target_fb->pixel_format);
+		DRM_ERROR("Unsupported screen format %s\n", format_name);
+		kfree(format_name);
 		return -EINVAL;
 	}
 

include/drm/drm_fourcc.h

@@ -32,6 +32,6 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
 int drm_format_vert_chroma_subsampling(uint32_t format);
 int drm_format_plane_width(int width, uint32_t format, int plane);
 int drm_format_plane_height(int height, uint32_t format, int plane);
-const char *drm_get_format_name(uint32_t format);
+const char *drm_get_format_name(uint32_t format) __malloc;
 
 #endif /* __DRM_FOURCC_H__ */