[v5,4/8] drm/i915/gem: Add i915_gem_object_panic_map()

Commit Message

Jocelyn Falempe Feb. 14, 2025, 9:21 a.m. UTC

Prepare the work for drm_panic support. This is used to map the
current framebuffer, so the CPU can overwrite it with the panic
message.

Signed-off-by: Jocelyn Falempe <[e-mail]>
---

v5:
 * Use iosys_map for intel_bo_panic_map().

 drivers/gpu/drm/i915/display/intel_bo.c    |  5 ++++
 drivers/gpu/drm/i915/display/intel_bo.h    |  1 +
 drivers/gpu/drm/i915/gem/i915_gem_object.h |  2 ++
 drivers/gpu/drm/i915/gem/i915_gem_pages.c  | 29 ++++++++++++++++++++++
 drivers/gpu/drm/xe/display/intel_bo.c      | 10 ++++++++
 5 files changed, 47 insertions(+)

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_bo.c b/drivers/gpu/drm/i915/display/intel_bo.c
index fbd16d7b58d95..ac904e9ec7d51 100644
--- a/drivers/gpu/drm/i915/display/intel_bo.c
+++ b/drivers/gpu/drm/i915/display/intel_bo.c
@@ -57,3 +57,8 @@  void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj)
 {
 	i915_debugfs_describe_obj(m, to_intel_bo(obj));
 }
+
+void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	i915_gem_object_panic_map(to_intel_bo(obj), map);
+}
diff --git a/drivers/gpu/drm/i915/display/intel_bo.h b/drivers/gpu/drm/i915/display/intel_bo.h
index ea7a2253aaa57..5b6c63d99786a 100644
--- a/drivers/gpu/drm/i915/display/intel_bo.h
+++ b/drivers/gpu/drm/i915/display/intel_bo.h
@@ -23,5 +23,6 @@  struct intel_frontbuffer *intel_bo_set_frontbuffer(struct drm_gem_object *obj,
 						   struct intel_frontbuffer *front);
 
 void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj);
+void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map);
 
 #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 a5f34542135ce..b16092707ea5a 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -692,6 +692,8 @@  i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
 int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj);
 int i915_gem_object_truncate(struct drm_i915_gem_object *obj);
 
+void i915_gem_object_panic_map(struct drm_i915_gem_object *obj, struct iosys_map *map);
+
 /**
  * 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 8780aa2431053..718bea6474d7f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -355,6 +355,35 @@  static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj,
 	return vaddr ?: ERR_PTR(-ENOMEM);
 }
 
+/* Map the current framebuffer for CPU access. Called from panic handler, so no
+ * need to pin or cleanup.
+ */
+void i915_gem_object_panic_map(struct drm_i915_gem_object *obj, struct iosys_map *map)
+{
+	enum i915_map_type has_type;
+	void *ptr;
+
+	ptr = page_unpack_bits(obj->mm.mapping, &has_type);
+
+
+	if (!ptr) {
+		if (i915_gem_object_has_struct_page(obj))
+			ptr = i915_gem_object_map_page(obj, I915_MAP_WB);
+		else
+			ptr = i915_gem_object_map_pfn(obj, I915_MAP_WB);
+
+		if (IS_ERR(ptr))
+			return;
+
+		obj->mm.mapping = page_pack_bits(ptr, I915_MAP_WB);
+	}
+
+	if (i915_gem_object_has_iomem(obj))
+		iosys_map_set_vaddr_iomem(map, (void __iomem *) ptr);
+	else
+		iosys_map_set_vaddr(map, ptr);
+}
+
 /* 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 b463f5bd4eed1..bde276bc896b1 100644
--- a/drivers/gpu/drm/xe/display/intel_bo.c
+++ b/drivers/gpu/drm/xe/display/intel_bo.c
@@ -59,3 +59,13 @@  void intel_bo_describe(struct seq_file *m, struct drm_gem_object *obj)
 {
 	/* FIXME */
 }
+
+void intel_bo_panic_map(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	struct xe_bo *bo = gem_to_xe_bo(obj);
+	int ret;
+
+	ret = ttm_bo_vmap(&bo->ttm, map);
+	if (ret)
+		iosys_map_clear(map);
+}