drm/i915: Add intel_bo_panic_setup() and intel_bo_panic_finish()

Implement both functions for i915 and xe, they prepare the work for
drm_panic support.
They both use kmap_try_from_panic(), and map one page at a time, to
write the panic screen on the framebuffer.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250624091501.257661-8-jfalempe@redhat.com
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

diff --git a/drivers/gpu/drm/i915/display/intel_bo.c b/drivers/gpu/drm/i915/display/intel_bo.c
index bcf2eded7469fc411e3e66fd313cfa80ec3cf85e..65d64f79a4bd1d41d7a48c251e77b98014f1a7dc 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bo.c
+++ b/drivers/gpu/drm/i915/display/intel_bo.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 /* Copyright © 2024 Intel Corporation */
 
+#include <drm/drm_panic.h>
 #include "display/intel_display_types.h"
 #include "gem/i915_gem_mman.h"
 #include "gem/i915_gem_object.h"
@@ -63,3 +64,13 @@ struct intel_framebuffer *intel_bo_alloc_framebuffer(void)
 {
        return i915_gem_object_alloc_framebuffer();
 }
+
+int intel_bo_panic_setup(struct drm_scanout_buffer *sb)
+{
+       return i915_gem_object_panic_setup(sb);
+}
+
+void intel_bo_panic_finish(struct intel_framebuffer *fb)
+{
+       return i915_gem_object_panic_finish(fb);
+}

diff --git a/drivers/gpu/drm/i915/display/intel_bo.h b/drivers/gpu/drm/i915/display/intel_bo.h
index 315a81768c73dba49e615e868765c9601f150aa8..97087a64d23b547453abf4d5b3c86d4cd18f060a 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bo.h
+++ b/drivers/gpu/drm/i915/display/intel_bo.h
@@ -7,6 +7,7 @@
 #include <linux/types.h>
 
 struct drm_gem_object;
+struct drm_scanout_buffer;
 struct intel_framebuffer;
 struct seq_file;
 struct vm_area_struct;
@@ -25,5 +26,7 @@ struct intel_frontbuffer *intel_bo_set_frontbuffer(struct drm_gem_object *obj,
 
 void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj);
 struct intel_framebuffer *intel_bo_alloc_framebuffer(void);
+int intel_bo_panic_setup(struct drm_scanout_buffer *sb);
+void intel_bo_panic_finish(struct intel_framebuffer *fb);
 
 #endif /* __INTEL_BO__ */

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 364941444a0a9e095c8e940912f1288630a9c7bc..565f8fa330db6f1e19670fc5d13d253f16f27f02 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -16,6 +16,7 @@
 #include "i915_gem_ww.h"
 #include "i915_vma_types.h"
 
+struct drm_scanout_buffer;
 enum intel_region_id;
 struct intel_framebuffer;
 
@@ -693,6 +694,9 @@ int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj);
 int i915_gem_object_truncate(struct drm_i915_gem_object *obj);
 
 struct intel_framebuffer *i915_gem_object_alloc_framebuffer(void);
+int i915_gem_object_panic_setup(struct drm_scanout_buffer *sb);
+void i915_gem_object_panic_finish(struct intel_framebuffer *fb);
+
 /**
  * i915_gem_object_pin_map - return a contiguous mapping of the entire object
  * @obj: the object to map into kernel address space

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 10b84970f17ffe78068f3029847f4efe2826437c..91c7549e6ff2fa691b9ad75ee765ea5f875e5c4d 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -4,8 +4,10 @@
  */
 
 #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"
@@ -366,6 +368,67 @@ struct i915_framebuffer {
        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;
+}
+
+/*
+ * 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);
+
+       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;
@@ -376,6 +439,49 @@ struct intel_framebuffer *i915_gem_object_alloc_framebuffer(void)
        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);
+
+               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)

diff --git a/drivers/gpu/drm/xe/display/intel_bo.c b/drivers/gpu/drm/xe/display/intel_bo.c
index 926fcd9c86e1dcc4c830bb501cad2942ec52644d..bbb504f8e242987b74819d72022518a12ff00161 100644 (file)
--- a/drivers/gpu/drm/xe/display/intel_bo.c
+++ b/drivers/gpu/drm/xe/display/intel_bo.c
@@ -1,8 +1,11 @@
 // SPDX-License-Identifier: MIT
 /* Copyright © 2024 Intel Corporation */
 
+#include <drm/drm_cache.h>
 #include <drm/drm_gem.h>
+#include <drm/drm_panic.h>
 
+#include "intel_fb.h"
 #include "intel_display_types.h"
 
 #include "xe_bo.h"
@@ -73,6 +76,50 @@ struct xe_framebuffer {
        struct xe_panic_data panic;
 };
 
+static inline struct xe_panic_data *to_xe_panic_data(struct intel_framebuffer *fb)
+{
+       return &container_of_const(fb, struct xe_framebuffer, base)->panic;
+}
+
+static void xe_panic_kunmap(struct xe_panic_data *panic)
+{
+       if (panic->vaddr) {
+               drm_clflush_virt_range(panic->vaddr, PAGE_SIZE);
+               kunmap_local(panic->vaddr);
+               panic->vaddr = NULL;
+       }
+}
+
+/*
+ * 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 xe_panic_page_set_pixel(struct drm_scanout_buffer *sb, unsigned int x,
+                                   unsigned int y, u32 color)
+{
+       struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+       struct xe_panic_data *panic = to_xe_panic_data(fb);
+       struct xe_bo *bo = gem_to_xe_bo(intel_fb_bo(&fb->base));
+       unsigned int new_page;
+       unsigned int offset;
+
+       offset = y * sb->pitch[0] + x * sb->format->cpp[0];
+
+       new_page = offset >> PAGE_SHIFT;
+       offset = offset % PAGE_SIZE;
+       if (new_page != panic->page) {
+               xe_panic_kunmap(panic);
+               panic->page = new_page;
+               panic->vaddr = ttm_bo_kmap_try_from_panic(&bo->ttm,
+                                                         panic->page);
+       }
+       if (panic->vaddr) {
+               u32 *pix = panic->vaddr + offset;
+               *pix = color;
+       }
+}
+
 struct intel_framebuffer *intel_bo_alloc_framebuffer(void)
 {
        struct xe_framebuffer *xe_fb;
@@ -83,3 +130,20 @@ struct intel_framebuffer *intel_bo_alloc_framebuffer(void)
        return NULL;
 }
 
+int intel_bo_panic_setup(struct drm_scanout_buffer *sb)
+{
+       struct intel_framebuffer *fb = (struct intel_framebuffer *)sb->private;
+       struct xe_panic_data *panic = to_xe_panic_data(fb);
+
+       panic->page = -1;
+       sb->set_pixel = xe_panic_page_set_pixel;
+       return 0;
+}
+
+void intel_bo_panic_finish(struct intel_framebuffer *fb)
+{
+       struct xe_panic_data *panic = to_xe_panic_data(fb);
+
+       xe_panic_kunmap(panic);
+       panic->page = -1;
+}