[RFC] drm/qxl: Add drm_panic support

[Ryosuke Yasuoka]

QXL supports the drm_panic module, which displays a message to the
screen when a kernel panic occurs.

Signed-off-by: Ryosuke Yasuoka <ryasuoka@xxxxxxxxxx>
---
 drivers/gpu/drm/qxl/qxl_cmd.c     | 29 ++++++++++
 drivers/gpu/drm/qxl/qxl_display.c | 94 +++++++++++++++++++++++++++++++
 drivers/gpu/drm/qxl/qxl_draw.c    | 57 ++++++++++++++++++-
 drivers/gpu/drm/qxl/qxl_drv.h     | 21 +++++++
 drivers/gpu/drm/qxl/qxl_image.c   | 27 +++++++++
 drivers/gpu/drm/qxl/qxl_object.c  | 62 ++++++++++++++++++++
 drivers/gpu/drm/qxl/qxl_object.h  |  4 ++
 7 files changed, 293 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/qxl/qxl_cmd.c b/drivers/gpu/drm/qxl/qxl_cmd.c
index d6ea01f3797b..c70041ce55c0 100644
--- a/drivers/gpu/drm/qxl/qxl_cmd.c
+++ b/drivers/gpu/drm/qxl/qxl_cmd.c
@@ -174,6 +174,35 @@ static bool qxl_ring_pop(struct qxl_ring *ring,
 	return true;
 }
 
+/* For drm panic */
+int
+qxl_push_command_ring_without_release(struct qxl_device *qdev,
+		struct qxl_bo *bo, uint32_t type, uint32_t offset)
+{
+	struct qxl_command cmd;
+	struct qxl_ring *ring = qdev->command_ring;
+	struct qxl_ring_header *header = &(ring->ring->header);
+	uint8_t *elt;
+	int idx;
+
+	cmd.type = type;
+	cmd.data = qxl_bo_physical_address(qdev, bo, offset);
+
+	idx = header->prod & (ring->n_elements - 1);
+	elt = ring->ring->elements + idx * ring->element_size;
+
+	memcpy((void *)elt, &cmd, ring->element_size);
+
+	header->prod++;
+
+	mb();
+
+	if (header->prod == header->notify_on_prod)
+		outb(0, ring->prod_notify);
+
+	return 0;
+}
+
 int
 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 			      uint32_t type, bool interruptible)
diff --git a/drivers/gpu/drm/qxl/qxl_display.c b/drivers/gpu/drm/qxl/qxl_display.c
index bc24af08dfcd..b5f2ddfe71a9 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -37,6 +37,7 @@
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
 #include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_panic.h>
 
 #include "qxl_drv.h"
 #include "qxl_object.h"
@@ -889,6 +890,97 @@ static void qxl_plane_cleanup_fb(struct drm_plane *plane,
 	}
 }
 
+static int qxl_primary_plane_helper_get_scanout_buffer(struct drm_plane *plane,
+							struct drm_scanout_buffer *sb)
+{
+	struct qxl_bo *bo;
+
+	if (!plane->state || !plane->state->fb)
+		return -ENODEV;
+
+	bo = gem_to_qxl_bo(plane->state->fb->obj[0]);
+
+	if (!bo->map.vaddr) {
+		int ret;
+
+		ret = qxl_bo_pin_and_vmap(bo, &sb->map[0]);
+		if (ret)
+			return ret;
+	} else {
+		iosys_map_set_vaddr(&sb->map[0], bo->map.vaddr);
+	}
+
+	sb->format = plane->state->fb->format;
+	sb->height = plane->state->fb->height;
+	sb->width = plane->state->fb->width;
+	sb->pitch[0] = plane->state->fb->pitches[0];
+	return 0;
+}
+
+static void qxl_panic_flush(struct drm_plane *plane)
+{
+	struct qxl_device *qdev = to_qxl(plane->dev);
+	struct qxl_bo *_bo = gem_to_qxl_bo(plane->state->fb->obj[0]);
+	uint8_t *surface_base = _bo->map.vaddr;
+	struct drm_clip_rect rect = {
+		.x1 = 0,
+		.y1 = 0,
+		.x2 = plane->state->fb->width,
+		.y2 = plane->state->fb->height
+	};
+	unsigned int num_clips = 1;
+	struct qxl_bo clips_bo = {};
+	struct qxl_bo image_bo = {};
+	struct qxl_bo chunk_bo = {};
+	struct qxl_drm_image dimage;
+	struct qxl_drm_chunk chunk;
+	int width = rect.x2;
+	int height = rect.y2;
+	int stride = plane->state->fb->pitches[0];
+	int depth = plane->state->fb->format->cpp[0] * 8;
+	struct qxl_rect *rects;
+	struct qxl_rect drawable_rect = {
+		.left = 0,
+		.right = width,
+		.top = 0,
+		.bottom = height,
+	};
+	int cur_idx = 0;
+	int size = 256;
+	struct qxl_bo *bo = qxl_bo_ref(qdev->current_release_bo[cur_idx]);
+	uint32_t offset = qdev->current_release_bo_offset[cur_idx] * size;
+	int ret;
+
+	qxl_panic_bo_create(qdev, sizeof(struct qxl_clip_rects) + sizeof(struct qxl_rect),
+			false, false, QXL_GEM_DOMAIN_VRAM, 0, NULL, &clips_bo);
+
+	ret = qxl_image_alloc_objects_without_release(qdev, &dimage, &chunk, &image_bo, &chunk_bo,
+			surface_base, width, height, depth, stride);
+	if (ret)
+		return;
+
+	ret = make_drawable_without_release(qdev, &drawable_rect, bo, &clips_bo,
+			&dimage, offset, height, width);
+	if (ret)
+		return;
+
+	rects = drawable_set_clipping(qdev, num_clips, &clips_bo);
+	if (!rects)
+		return;
+	rects[0].left = 0;
+	rects[0].right = width;
+	rects[0].top = 0;
+	rects[0].bottom = height;
+
+	qxl_push_command_ring_without_release(qdev, bo, QXL_CMD_DRAW, offset);
+
+	qxl_gem_object_free(&chunk_bo.tbo.base);
+	qxl_gem_object_free(&image_bo.tbo.base);
+
+	qxl_bo_vunmap_locked(&clips_bo);
+	qxl_gem_object_free(&clips_bo.tbo.base);
+}
+
 static const uint32_t qxl_cursor_plane_formats[] = {
 	DRM_FORMAT_ARGB8888,
 };
@@ -920,6 +1012,8 @@ static const struct drm_plane_helper_funcs primary_helper_funcs = {
 	.atomic_disable = qxl_primary_atomic_disable,
 	.prepare_fb = qxl_plane_prepare_fb,
 	.cleanup_fb = qxl_plane_cleanup_fb,
+	.get_scanout_buffer = qxl_primary_plane_helper_get_scanout_buffer,
+	.panic_flush = qxl_panic_flush,
 };
 
 static const struct drm_plane_funcs qxl_primary_plane_funcs = {
diff --git a/drivers/gpu/drm/qxl/qxl_draw.c b/drivers/gpu/drm/qxl/qxl_draw.c
index 3a3e127ce297..49fdc0162377 100644
--- a/drivers/gpu/drm/qxl/qxl_draw.c
+++ b/drivers/gpu/drm/qxl/qxl_draw.c
@@ -41,7 +41,8 @@ static int alloc_clips(struct qxl_device *qdev,
 /* returns a pointer to the already allocated qxl_rect array inside
  * the qxl_clip_rects. This is *not* the same as the memory allocated
  * on the device, it is offset to qxl_clip_rects.chunk.data */
-static struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
+
+struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
 					      unsigned int num_clips,
 					      struct qxl_bo *clips_bo)
 {
@@ -74,6 +75,60 @@ free_drawable(struct qxl_device *qdev, struct qxl_release *release)
 	qxl_release_free(qdev, release);
 }
 
+/* For drm panic */
+int
+make_drawable_without_release(struct qxl_device *qdev,
+		struct qxl_rect *drawable_rect,
+		struct qxl_bo *bo,
+		struct qxl_bo *clips_bo,
+		struct qxl_drm_image *dimage,
+		uint32_t offset, int height, int width)
+{
+	struct qxl_drawable *drawable;
+	union qxl_release_info *info;
+	void *ptr;
+	int i;
+
+	ptr = qxl_bo_kmap_atomic_page(qdev, bo, offset & PAGE_MASK);
+	if (!ptr)
+		return -ENOMEM;
+	drawable = ptr + (offset & ~PAGE_MASK);
+
+	drawable->type = QXL_DRAW_COPY;
+	drawable->surface_id = 0;
+	drawable->effect = QXL_EFFECT_OPAQUE;
+	drawable->self_bitmap = 0;
+	drawable->self_bitmap_area.top = 0;
+	drawable->self_bitmap_area.left = 0;
+	drawable->self_bitmap_area.bottom = 0;
+	drawable->self_bitmap_area.right = 0;
+
+	for (i = 0; i < 3; ++i)
+		drawable->surfaces_dest[i] = -1;
+
+	drawable->bbox = *drawable_rect;
+	drawable->mm_time = qdev->rom->mm_clock;
+	drawable->clip.type = SPICE_CLIP_TYPE_RECTS;
+	drawable->clip.data = qxl_bo_physical_address(qdev, clips_bo, 0);
+	drawable->u.copy.src_area.top = 0;
+	drawable->u.copy.src_area.bottom = height;
+	drawable->u.copy.src_area.left = 0;
+	drawable->u.copy.src_area.right = width;
+	drawable->u.copy.rop_descriptor = SPICE_ROPD_OP_PUT;
+	drawable->u.copy.scale_mode = 0;
+	drawable->u.copy.mask.flags = 0;
+	drawable->u.copy.mask.pos.x = 0;
+	drawable->u.copy.mask.pos.y = 0;
+	drawable->u.copy.mask.bitmap = 0;
+	drawable->u.copy.src_bitmap = qxl_bo_physical_address(qdev, dimage->bo, 0);
+
+	info = &drawable->release_info;
+	ptr = ((void *)info) - (offset & ~PAGE_MASK);
+	qxl_bo_kunmap_atomic_page(qdev, bo, ptr);
+
+	return 0;
+}
+
 /* release needs to be reserved at this point */
 static int
 make_drawable(struct qxl_device *qdev, int surface, uint8_t type,
diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
index 32069acd93f8..93dd0de06c23 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.h
+++ b/drivers/gpu/drm/qxl/qxl_drv.h
@@ -334,6 +334,13 @@ int qxl_image_init(struct qxl_device *qdev,
 		   const uint8_t *data,
 		   int x, int y, int width, int height,
 		   int depth, int stride);
+
+int qxl_image_alloc_objects_without_release(struct qxl_device *qdev,
+		struct qxl_drm_image *image, struct qxl_drm_chunk *chunk,
+		struct qxl_bo *image_bo, struct qxl_bo *chunk_bo,
+		uint8_t *surface_base, int width,
+		int height, int depth, int stride);
+
 int
 qxl_image_alloc_objects(struct qxl_device *qdev,
 			struct qxl_release *release,
@@ -376,6 +383,9 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
 			       int type, struct qxl_release **release,
 			       struct qxl_bo **rbo);
 
+int qxl_push_command_ring_without_release(struct qxl_device *qdev,
+		struct qxl_bo *bo, uint32_t type, uint32_t offset);
+
 int
 qxl_push_command_ring_release(struct qxl_device *qdev, struct qxl_release *release,
 			      uint32_t type, bool interruptible);
@@ -387,6 +397,9 @@ int qxl_alloc_bo_reserved(struct qxl_device *qdev,
 			  unsigned long size,
 			  struct qxl_bo **_bo);
 /* qxl drawing commands */
+struct qxl_rect *drawable_set_clipping(struct qxl_device *qdev,
+					      unsigned int num_clips,
+					      struct qxl_bo *clips_bo);
 
 void qxl_draw_dirty_fb(struct qxl_device *qdev,
 		       struct drm_framebuffer *fb,
@@ -399,6 +412,14 @@ void qxl_draw_dirty_fb(struct qxl_device *qdev,
 void qxl_release_free(struct qxl_device *qdev,
 		      struct qxl_release *release);
 
+int
+make_drawable_without_release(struct qxl_device *qdev,
+		struct qxl_rect *drawable_rect,
+		struct qxl_bo *bo,
+		struct qxl_bo *clips_bo,
+		struct qxl_drm_image *dimage,
+		uint32_t offset, int height, int width);
+
 /* used by qxl_debugfs_release */
 struct qxl_release *qxl_release_from_id_locked(struct qxl_device *qdev,
 						   uint64_t id);
diff --git a/drivers/gpu/drm/qxl/qxl_image.c b/drivers/gpu/drm/qxl/qxl_image.c
index ffff54e5fb31..2efe0cf133a6 100644
--- a/drivers/gpu/drm/qxl/qxl_image.c
+++ b/drivers/gpu/drm/qxl/qxl_image.c
@@ -52,6 +52,33 @@ qxl_allocate_chunk(struct qxl_device *qdev,
 	return 0;
 }
 
+/* For drm panic */
+int
+qxl_image_alloc_objects_without_release(struct qxl_device *qdev,
+		struct qxl_drm_image *image, struct qxl_drm_chunk *chunk,
+		struct qxl_bo *image_bo, struct qxl_bo *chunk_bo,
+		uint8_t *surface_base, int width, int height,
+		int depth, int stride)
+{
+	int ret;
+	unsigned int chunk_size = sizeof(struct qxl_data_chunk) + stride * height;
+
+	INIT_LIST_HEAD(&image->chunk_list);
+	qxl_panic_bo_create(qdev, sizeof(struct qxl_image), false, false,
+			QXL_GEM_DOMAIN_VRAM, 0, NULL, image_bo);
+	image->bo = image_bo;
+
+	qxl_panic_bo_create(qdev, chunk_size, false, false,
+			QXL_GEM_DOMAIN_VRAM, 0, NULL, chunk_bo);
+	chunk->bo = chunk_bo;
+	list_add_tail(&chunk->head, &image->chunk_list);
+
+	ret = qxl_image_init(qdev, NULL, image, surface_base,
+			     0, 0, width, height, depth, stride);
+	return ret;
+
+}
+
 int
 qxl_image_alloc_objects(struct qxl_device *qdev,
 			struct qxl_release *release,
diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 66635c55cf85..9e00700f8f03 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -29,6 +29,23 @@
 #include "qxl_drv.h"
 #include "qxl_object.h"
 
+/* for drm panic */
+static void qxl_panic_ttm_bo_destroy(struct ttm_buffer_object *tbo)
+{
+	struct qxl_bo *bo;
+	struct qxl_device *qdev;
+
+	bo = to_qxl_bo(tbo);
+	qdev = to_qxl(bo->tbo.base.dev);
+
+	qxl_surface_evict(qdev, bo, false);
+	WARN_ON_ONCE(bo->map_count > 0);
+	mutex_lock(&qdev->gem.mutex);
+	list_del_init(&bo->list);
+	mutex_unlock(&qdev->gem.mutex);
+	drm_gem_object_release(&bo->tbo.base);
+}
+
 static void qxl_ttm_bo_destroy(struct ttm_buffer_object *tbo)
 {
 	struct qxl_bo *bo;
@@ -101,6 +118,51 @@ static const struct drm_gem_object_funcs qxl_object_funcs = {
 	.print_info = drm_gem_ttm_print_info,
 };
 
+/* for drm_panic */
+int qxl_panic_bo_create(struct qxl_device *qdev, unsigned long size,
+		  bool kernel, bool pinned, u32 domain, u32 priority,
+		  struct qxl_surface *surf, struct qxl_bo *bo)
+{
+	struct ttm_operation_ctx ctx = { !kernel, false };
+	enum ttm_bo_type type;
+	int r;
+
+	if (kernel)
+		type = ttm_bo_type_kernel;
+	else
+		type = ttm_bo_type_device;
+
+	size = roundup(size, PAGE_SIZE);
+	r = drm_gem_object_init(&qdev->ddev, &bo->tbo.base, size);
+	if (unlikely(r))
+		return r;
+	bo->tbo.base.funcs = &qxl_object_funcs;
+	bo->type = domain;
+	bo->surface_id = 0;
+	INIT_LIST_HEAD(&bo->list);
+
+	if (surf)
+		bo->surf = *surf;
+
+	qxl_ttm_placement_from_domain(bo, domain);
+
+	bo->tbo.priority = priority;
+	r = ttm_bo_init_reserved(&qdev->mman.bdev, &bo->tbo, type,
+				 &bo->placement, 0, &ctx, NULL, NULL,
+				 &qxl_panic_ttm_bo_destroy);
+	if (unlikely(r != 0)) {
+		if (r != -ERESTARTSYS)
+			dev_err(qdev->ddev.dev,
+				"object_init failed for (%lu, 0x%08X)\n",
+				size, domain);
+		return r;
+	}
+	if (pinned)
+		ttm_bo_pin(&bo->tbo);
+	ttm_bo_unreserve(&bo->tbo);
+	return 0;
+}
+
 int qxl_bo_create(struct qxl_device *qdev, unsigned long size,
 		  bool kernel, bool pinned, u32 domain, u32 priority,
 		  struct qxl_surface *surf,
diff --git a/drivers/gpu/drm/qxl/qxl_object.h b/drivers/gpu/drm/qxl/qxl_object.h
index 875f63221074..4debb8ce6d08 100644
--- a/drivers/gpu/drm/qxl/qxl_object.h
+++ b/drivers/gpu/drm/qxl/qxl_object.h
@@ -53,6 +53,10 @@ static inline unsigned long qxl_bo_size(struct qxl_bo *bo)
 	return bo->tbo.base.size;
 }
 
+extern int qxl_panic_bo_create(struct qxl_device *qdev, unsigned long size,
+		  bool kernel, bool pinned, u32 domain, u32 priority,
+		  struct qxl_surface *surf,
+		  struct qxl_bo *bo);
 extern int qxl_bo_create(struct qxl_device *qdev,
 			 unsigned long size,
 			 bool kernel, bool pinned, u32 domain,
-- 
2.46.0