1 files changed, 142 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 7f83f8bdc8fb..c16a57160b26 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -4,8 +4,11 @@
  */
 
 #include <drm/drm_cache.h>
+#include <drm/drm_panic.h>
 #include <linux/vmalloc.h>
 
+#include "display/intel_fb.h"
+#include "display/intel_display_types.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_tlb.h"
 
@@ -354,6 +357,145 @@ static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj,
 	return vaddr ?: ERR_PTR(-ENOMEM);
 }
 
+struct i915_panic_data {
+	struct page **pages;
+	int page;
+	void *vaddr;
+};
+
+struct i915_framebuffer {
+	struct intel_framebuffer base;
+	struct i915_panic_data panic;
+};
+
+static inline struct i915_panic_data *to_i915_panic_data(struct intel_framebuffer *fb)
+{
+	return &container_of_const(fb, struct i915_framebuffer, base)->panic;
+}
+
+static void i915_panic_kunmap(struct i915_panic_data *panic)
+{
+	if (panic->vaddr) {
+		drm_clflush_virt_range(panic->vaddr, PAGE_SIZE);
+		kunmap_local(panic->vaddr);
+		panic->vaddr = NULL;
+	}
+}
+
+static struct page **i915_gem_object_panic_pages(struct drm_i915_gem_object *obj)
+{
+	unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
+	struct page *page;
+	struct page **pages;
+	struct sgt_iter iter;
+
+	/* For a 3840x2160 32 bits Framebuffer, this should require ~64K */
+	pages = kmalloc_array(n_pages, sizeof(*pages), GFP_ATOMIC);
+	if (!pages)
+		return NULL;
+
+	i = 0;
+	for_each_sgt_page(page, iter, obj->mm.pages)
+		pages[i++] = page;
+	return pages;
+}
+
+static void i915_gem_object_panic_map_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
+						unsigned int y, u32 color)
+{
+	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+	unsigned int offset = fb->panic_tiling(sb->width, x, y);
+
+	iosys_map_wr(&sb->map[0], offset, u32, color);
+}
+
+/*
+ * The scanout buffer pages are not mapped, so for each pixel,
+ * use kmap_local_page_try_from_panic() to map the page, and write the pixel.
+ * Try to keep the map from the previous pixel, to avoid too much map/unmap.
+ */
+static void i915_gem_object_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
+						 unsigned int y, u32 color)
+{
+	unsigned int new_page;
+	unsigned int offset;
+	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+	struct i915_panic_data *panic = to_i915_panic_data(fb);
+
+	if (fb->panic_tiling)
+		offset = fb->panic_tiling(sb->width, x, y);
+	else
+		offset = y * sb->pitch[0] + x * sb->format->cpp[0];
+
+	new_page = offset >> PAGE_SHIFT;
+	offset = offset % PAGE_SIZE;
+	if (new_page != panic->page) {
+		i915_panic_kunmap(panic);
+		panic->page = new_page;
+		panic->vaddr =
+			kmap_local_page_try_from_panic(panic->pages[panic->page]);
+	}
+	if (panic->vaddr) {
+		u32 *pix = panic->vaddr + offset;
+		*pix = color;
+	}
+}
+
+struct intel_framebuffer *i915_gem_object_alloc_framebuffer(void)
+{
+	struct i915_framebuffer *i915_fb;
+
+	i915_fb = kzalloc(sizeof(*i915_fb), GFP_KERNEL);
+	if (i915_fb)
+		return &i915_fb->base;
+	return NULL;
+}
+
+/*
+ * Setup the gem framebuffer for drm_panic access.
+ * Use current vaddr if it exists, or setup a list of pages.
+ * pfn is not supported yet.
+ */
+int i915_gem_object_panic_setup(struct drm_scanout_buffer *sb)
+{
+	enum i915_map_type has_type;
+	struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+	struct i915_panic_data *panic = to_i915_panic_data(fb);
+	struct drm_i915_gem_object *obj = to_intel_bo(intel_fb_bo(&fb->base));
+	void *ptr;
+
+	ptr = page_unpack_bits(obj->mm.mapping, &has_type);
+	if (ptr) {
+		if (i915_gem_object_has_iomem(obj))
+			iosys_map_set_vaddr_iomem(&sb->map[0], (void __iomem *)ptr);
+		else
+			iosys_map_set_vaddr(&sb->map[0], ptr);
+
+		if (fb->panic_tiling)
+			sb->set_pixel = i915_gem_object_panic_map_set_pixel;
+		return 0;
+	}
+	if (i915_gem_object_has_struct_page(obj)) {
+		panic->pages = i915_gem_object_panic_pages(obj);
+		if (!panic->pages)
+			return -ENOMEM;
+		panic->page = -1;
+		sb->set_pixel = i915_gem_object_panic_page_set_pixel;
+		return 0;
+	}
+	return -EOPNOTSUPP;
+}
+
+void i915_gem_object_panic_finish(struct intel_framebuffer *fb)
+{
+	struct i915_panic_data *panic = to_i915_panic_data(fb);
+
+	i915_panic_kunmap(panic);
+	panic->page = -1;
+	kfree(panic->pages);
+	panic->pages = NULL;
+}
+
 /* get, pin, and map the pages of the object into kernel space */
 void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
 			      enum i915_map_type type)