[RFC PATCH 017/162] drm/i915: Rework struct phys attachment handling
Matthew Auld
matthew.auld at intel.com
Fri Nov 27 12:04:53 UTC 2020
From: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Instead of creating a separate object type, we make changes to
the shmem type, to clear struct page backing. This will allow us to
ensure we never run into a race when we exchange obj->ops with other
function pointers.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_object.h | 8 ++
drivers/gpu/drm/i915/gem/i915_gem_phys.c | 102 +++++++++---------
drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 22 +++-
.../drm/i915/gem/selftests/i915_gem_phys.c | 6 --
4 files changed, 78 insertions(+), 60 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 16608bf7a4e9..e549b88693a2 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -37,7 +37,15 @@ void __i915_gem_object_release_shmem(struct drm_i915_gem_object *obj,
struct sg_table *pages,
bool needs_clflush);
+int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_pwrite *args);
+int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_pread *args);
+
int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align);
+void i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
+ struct sg_table *pages);
+
void i915_gem_flush_free_objects(struct drm_i915_private *i915);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c
index 965590d3a570..4bdd0429c08b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c
@@ -76,6 +76,8 @@ static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
intel_gt_chipset_flush(&to_i915(obj->base.dev)->gt);
+ /* We're no longer struct page backed */
+ obj->flags &= ~I915_BO_ALLOC_STRUCT_PAGE;
__i915_gem_object_set_pages(obj, st, sg->length);
return 0;
@@ -89,7 +91,7 @@ static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
return -ENOMEM;
}
-static void
+void
i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
struct sg_table *pages)
{
@@ -134,9 +136,8 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
vaddr, dma);
}
-static int
-phys_pwrite(struct drm_i915_gem_object *obj,
- const struct drm_i915_gem_pwrite *args)
+int i915_gem_object_pwrite_phys(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_pwrite *args)
{
void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
char __user *user_data = u64_to_user_ptr(args->data_ptr);
@@ -165,9 +166,8 @@ phys_pwrite(struct drm_i915_gem_object *obj,
return 0;
}
-static int
-phys_pread(struct drm_i915_gem_object *obj,
- const struct drm_i915_gem_pread *args)
+int i915_gem_object_pread_phys(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_pread *args)
{
void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
char __user *user_data = u64_to_user_ptr(args->data_ptr);
@@ -186,86 +186,82 @@ phys_pread(struct drm_i915_gem_object *obj,
return 0;
}
-static void phys_release(struct drm_i915_gem_object *obj)
+static int i915_gem_object_shmem_to_phys(struct drm_i915_gem_object *obj)
{
- fput(obj->base.filp);
-}
+ struct sg_table *pages;
+ int err;
-static const struct drm_i915_gem_object_ops i915_gem_phys_ops = {
- .name = "i915_gem_object_phys",
- .get_pages = i915_gem_object_get_pages_phys,
- .put_pages = i915_gem_object_put_pages_phys,
+ pages = __i915_gem_object_unset_pages(obj);
+
+ err = i915_gem_object_get_pages_phys(obj);
+ if (err)
+ goto err_xfer;
- .pread = phys_pread,
- .pwrite = phys_pwrite,
+ /* Perma-pin (until release) the physical set of pages */
+ __i915_gem_object_pin_pages(obj);
- .release = phys_release,
-};
+ if (!IS_ERR_OR_NULL(pages))
+ i915_gem_shmem_ops.put_pages(obj, pages);
+
+ i915_gem_object_release_memory_region(obj);
+ return 0;
+
+err_xfer:
+ if (!IS_ERR_OR_NULL(pages)) {
+ unsigned int sg_page_sizes = i915_sg_page_sizes(pages->sgl);
+
+ __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
+ }
+ return err;
+}
int i915_gem_object_attach_phys(struct drm_i915_gem_object *obj, int align)
{
- struct sg_table *pages;
int err;
if (align > obj->base.size)
return -EINVAL;
- if (obj->ops == &i915_gem_phys_ops)
- return 0;
-
if (obj->ops != &i915_gem_shmem_ops)
return -EINVAL;
+ if (!i915_gem_object_has_struct_page(obj))
+ return 0;
+
err = i915_gem_object_unbind(obj, I915_GEM_OBJECT_UNBIND_ACTIVE);
if (err)
return err;
mutex_lock_nested(&obj->mm.lock, I915_MM_GET_PAGES);
+ if (unlikely(!i915_gem_object_has_struct_page(obj)))
+ goto out;
+
if (obj->mm.madv != I915_MADV_WILLNEED) {
err = -EFAULT;
- goto err_unlock;
+ goto out;
}
if (obj->mm.quirked) {
err = -EFAULT;
- goto err_unlock;
+ goto out;
}
- if (obj->mm.mapping) {
+ if (obj->mm.mapping || i915_gem_object_has_pinned_pages(obj)) {
err = -EBUSY;
- goto err_unlock;
+ goto out;
}
- pages = __i915_gem_object_unset_pages(obj);
-
- obj->ops = &i915_gem_phys_ops;
- obj->flags &= ~I915_BO_ALLOC_STRUCT_PAGE;
-
- err = ____i915_gem_object_get_pages(obj);
- if (err)
- goto err_xfer;
-
- /* Perma-pin (until release) the physical set of pages */
- __i915_gem_object_pin_pages(obj);
-
- if (!IS_ERR_OR_NULL(pages))
- i915_gem_shmem_ops.put_pages(obj, pages);
-
- i915_gem_object_release_memory_region(obj);
-
- mutex_unlock(&obj->mm.lock);
- return 0;
+ if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {
+ drm_dbg(obj->base.dev,
+ "Attempting to obtain a purgeable object\n");
+ err = -EFAULT;
+ goto out;
+ }
-err_xfer:
- obj->ops = &i915_gem_shmem_ops;
- obj->flags |= I915_BO_ALLOC_STRUCT_PAGE;
- if (!IS_ERR_OR_NULL(pages)) {
- unsigned int sg_page_sizes = i915_sg_page_sizes(pages->sgl);
+ err = i915_gem_object_shmem_to_phys(obj);
- __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
- }
-err_unlock:
+out:
mutex_unlock(&obj->mm.lock);
return err;
}
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 31c617a1115f..d590e0c3bd00 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
@@ -303,6 +303,11 @@ shmem_put_pages(struct drm_i915_gem_object *obj, struct sg_table *pages)
struct pagevec pvec;
struct page *page;
+ if (unlikely(!i915_gem_object_has_struct_page(obj))) {
+ i915_gem_object_put_pages_phys(obj, pages);
+ return;
+ }
+
__i915_gem_object_release_shmem(obj, pages, true);
i915_gem_gtt_finish_pages(obj, pages);
@@ -343,6 +348,9 @@ shmem_pwrite(struct drm_i915_gem_object *obj,
/* Caller already validated user args */
GEM_BUG_ON(!access_ok(user_data, arg->size));
+ if (!i915_gem_object_has_struct_page(obj))
+ return i915_gem_object_pwrite_phys(obj, arg);
+
/*
* Before we instantiate/pin the backing store for our use, we
* can prepopulate the shmemfs filp efficiently using a write into
@@ -421,9 +429,20 @@ shmem_pwrite(struct drm_i915_gem_object *obj,
return 0;
}
+static int
+shmem_pread(struct drm_i915_gem_object *obj,
+ const struct drm_i915_gem_pread *arg)
+{
+ if (!i915_gem_object_has_struct_page(obj))
+ return i915_gem_object_pread_phys(obj, arg);
+
+ return -ENODEV;
+}
+
static void shmem_release(struct drm_i915_gem_object *obj)
{
- i915_gem_object_release_memory_region(obj);
+ if (obj->flags & I915_BO_ALLOC_STRUCT_PAGE)
+ i915_gem_object_release_memory_region(obj);
fput(obj->base.filp);
}
@@ -438,6 +457,7 @@ const struct drm_i915_gem_object_ops i915_gem_shmem_ops = {
.writeback = shmem_writeback,
.pwrite = shmem_pwrite,
+ .pread = shmem_pread,
.release = shmem_release,
};
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
index fb6a17701310..0cfa082047fe 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_phys.c
@@ -38,12 +38,6 @@ static int mock_phys_object(void *arg)
}
if (i915_gem_object_has_struct_page(obj)) {
- err = -EINVAL;
- pr_err("shmem has a struct page\n");
- goto out_obj;
- }
-
- if (obj->ops != &i915_gem_phys_ops) {
pr_err("i915_gem_object_attach_phys did not create a phys object\n");
err = -EINVAL;
goto out_obj;
--
2.26.2
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