drm/i915: mark GEM object pages dirty when mapped & written by the CPU
In various places, a single page of a (regular) GEM object is mapped into
CPU address space and updated. In each such case, either the page or the
the object should be marked dirty, to ensure that the modifications are
not discarded if the object is evicted under memory pressure.
The typical sequence is:
va = kmap_atomic(i915_gem_object_get_page(obj, pageno));
*(va+offset) = ...
kunmap_atomic(va);
Here we introduce i915_gem_object_get_dirty_page(), which performs the
same operation as i915_gem_object_get_page() but with the side-effect
of marking the returned page dirty in the pagecache. This will ensure
that if the object is subsequently evicted (due to memory pressure),
the changes are written to backing store rather than discarded.
Note that it works only for regular (shmfs-backed) GEM objects, but (at
least for now) those are the only ones that are updated in this way --
the objects in question are contexts and batchbuffers, which are always
shmfs-backed.
Separate patches deal with the cases where whole objects are (or may
be) dirtied.
v3: Mark two more pages dirty in the page-boundary-crossing
cases of the execbuffer relocation code [Chris Wilson]
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1449773486-30822-2-git-send-email-david.s.gordon@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 13fb681..4c611b5 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2907,6 +2907,9 @@
return sg->length >> PAGE_SHIFT;
}
+struct page *
+i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n);
+
static inline struct page *
i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n)
{
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 26eba87..1592c54 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5185,6 +5185,21 @@
return false;
}
+/* Like i915_gem_object_get_page(), but mark the returned page dirty */
+struct page *
+i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n)
+{
+ struct page *page;
+
+ /* Only default objects have per-page dirty tracking */
+ if (WARN_ON(obj->ops != &i915_gem_object_ops))
+ return NULL;
+
+ page = i915_gem_object_get_page(obj, n);
+ set_page_dirty(page);
+ return page;
+}
+
/* Allocate a new GEM object and fill it with the supplied data */
struct drm_i915_gem_object *
i915_gem_object_create_from_data(struct drm_device *dev,
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 48ec484..5d01ea6 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -264,7 +264,7 @@
if (ret)
return ret;
- vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+ vaddr = kmap_atomic(i915_gem_object_get_dirty_page(obj,
reloc->offset >> PAGE_SHIFT));
*(uint32_t *)(vaddr + page_offset) = lower_32_bits(delta);
@@ -273,7 +273,7 @@
if (page_offset == 0) {
kunmap_atomic(vaddr);
- vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+ vaddr = kmap_atomic(i915_gem_object_get_dirty_page(obj,
(reloc->offset + sizeof(uint32_t)) >> PAGE_SHIFT));
}
@@ -355,7 +355,7 @@
if (ret)
return ret;
- vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+ vaddr = kmap_atomic(i915_gem_object_get_dirty_page(obj,
reloc->offset >> PAGE_SHIFT));
clflush_write32(vaddr + page_offset, lower_32_bits(delta));
@@ -364,7 +364,7 @@
if (page_offset == 0) {
kunmap_atomic(vaddr);
- vaddr = kmap_atomic(i915_gem_object_get_page(obj,
+ vaddr = kmap_atomic(i915_gem_object_get_dirty_page(obj,
(reloc->offset + sizeof(uint32_t)) >> PAGE_SHIFT));
}
diff --git a/drivers/gpu/drm/i915/i915_gem_render_state.c b/drivers/gpu/drm/i915/i915_gem_render_state.c
index 5026a62..fc7e6d5 100644
--- a/drivers/gpu/drm/i915/i915_gem_render_state.c
+++ b/drivers/gpu/drm/i915/i915_gem_render_state.c
@@ -103,7 +103,7 @@
if (ret)
return ret;
- page = sg_page(so->obj->pages->sgl);
+ page = i915_gem_object_get_dirty_page(so->obj, 0);
d = kmap(page);
while (i < rodata->batch_items) {
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 0d23785b..05aa7e6 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -568,7 +568,7 @@
WARN_ON(!i915_gem_obj_is_pinned(ctx_obj));
WARN_ON(!i915_gem_obj_is_pinned(rb_obj));
- page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
+ page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
reg_state = kmap_atomic(page);
reg_state[CTX_RING_BUFFER_START+1] = i915_gem_obj_ggtt_offset(rb_obj);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7644c48..3aa6147 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -372,7 +372,7 @@
WARN_ON(!i915_gem_obj_is_pinned(ctx_obj));
WARN_ON(!i915_gem_obj_is_pinned(rb_obj));
- page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
+ page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
reg_state = kmap_atomic(page);
reg_state[CTX_RING_TAIL+1] = rq->tail;
@@ -1425,7 +1425,7 @@
return ret;
}
- page = i915_gem_object_get_page(wa_ctx->obj, 0);
+ page = i915_gem_object_get_dirty_page(wa_ctx->obj, 0);
batch = kmap_atomic(page);
offset = 0;
@@ -2264,7 +2264,7 @@
/* The second page of the context object contains some fields which must
* be set up prior to the first execution. */
- page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
+ page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
reg_state = kmap_atomic(page);
/* A context is actually a big batch buffer with several MI_LOAD_REGISTER_IMM
@@ -2350,9 +2350,6 @@
}
kunmap_atomic(reg_state);
-
- ctx_obj->dirty = 1;
- set_page_dirty(page);
i915_gem_object_unpin_pages(ctx_obj);
return 0;
@@ -2536,7 +2533,7 @@
WARN(1, "Failed get_pages for context obj\n");
continue;
}
- page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
+ page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN);
reg_state = kmap_atomic(page);
reg_state[CTX_RING_HEAD+1] = 0;