[Intel-gfx] [RFC] drm/i915: Introduce i915_alloc_sg_table
Tvrtko Ursulin
tursulin at ursulin.net
Mon Oct 10 10:53:18 UTC 2016
From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
There are currently two places in the code which build the
sg table for the object backing store and in the future there
will be one more.
Consolidate that into a single helper which takes a caller
defined context and callbacks.
!!! Compile tested only. !!!
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_gem.c | 162 ++++++++++++++++----------------
drivers/gpu/drm/i915/i915_gem_gtt.c | 84 +++++++++++++++++
drivers/gpu/drm/i915/i915_gem_gtt.h | 14 +++
drivers/gpu/drm/i915/i915_gem_userptr.c | 54 ++++-------
4 files changed, 198 insertions(+), 116 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a89a88922448..79dcd912759f 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2208,19 +2208,69 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
return 0;
}
+struct i915_gem_get_pages_gtt_ctx {
+ struct drm_i915_private *dev_priv;
+ gfp_t gfp;
+ struct address_space *mapping;
+ unsigned int page_count;
+ bool shrunk_all;
+};
+
+static struct page *
+i915_gem_gtt_get_page(void *context, unsigned int page_num)
+{
+ struct i915_gem_get_pages_gtt_ctx *ctx = context;
+ struct page *page;
+
+ if (!ctx->shrunk_all)
+ page = shmem_read_mapping_page_gfp(ctx->mapping, page_num,
+ ctx->gfp);
+ else
+ page = shmem_read_mapping_page(ctx->mapping, page_num);
+
+ /* Check that the i965g/gm workaround works. */
+ WARN_ON(page && !IS_ERR(page) && (ctx->gfp & __GFP_DMA32) &&
+ (page_to_pfn(page) >= 0x00100000UL));
+
+ return page;
+}
+
+static bool
+i915_gem_gtt_get_page_failed(void *context, unsigned int page_num,
+ unsigned int err_cnt, int err)
+{
+ struct i915_gem_get_pages_gtt_ctx *ctx = context;
+
+ if (err_cnt > 1)
+ return true;
+
+ if (err_cnt == 0) {
+ i915_gem_shrink(ctx->dev_priv, ctx->page_count,
+ I915_SHRINK_BOUND | I915_SHRINK_UNBOUND |
+ I915_SHRINK_PURGEABLE);
+ } else {
+ i915_gem_shrink_all(ctx->dev_priv);
+ ctx->shrunk_all = true;
+ }
+
+ return false;
+}
+
+static void
+i915_gem_gtt_put_page(void *context, struct page *page)
+{
+ put_page(page);
+}
+
static int
i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
- int page_count, i;
- struct address_space *mapping;
+ struct i915_gem_get_pages_gtt_ctx ctx;
struct sg_table *st;
- struct scatterlist *sg;
struct sgt_iter sgt_iter;
struct page *page;
- unsigned long last_pfn = 0; /* suppress gcc warning */
int ret;
- gfp_t gfp;
/* Assert that the object is not currently in any GPU domain. As it
* wasn't in the GTT, there shouldn't be any way it could have been in
@@ -2229,78 +2279,44 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
- st = kmalloc(sizeof(*st), GFP_KERNEL);
- if (st == NULL)
- return -ENOMEM;
-
- page_count = obj->base.size / PAGE_SIZE;
- if (sg_alloc_table(st, page_count, GFP_KERNEL)) {
- kfree(st);
- return -ENOMEM;
- }
+ ctx.dev_priv = dev_priv;
+ ctx.page_count = obj->base.size / PAGE_SIZE;
+ ctx.shrunk_all = false;
/* Get the list of pages out of our struct file. They'll be pinned
* at this point until we release them.
*
* Fail silently without starting the shrinker
*/
- mapping = obj->base.filp->f_mapping;
- gfp = mapping_gfp_constraint(mapping, ~(__GFP_IO | __GFP_RECLAIM));
- gfp |= __GFP_NORETRY | __GFP_NOWARN;
- sg = st->sgl;
- st->nents = 0;
- for (i = 0; i < page_count; i++) {
- page = shmem_read_mapping_page_gfp(mapping, i, gfp);
- if (IS_ERR(page)) {
- i915_gem_shrink(dev_priv,
- page_count,
- I915_SHRINK_BOUND |
- I915_SHRINK_UNBOUND |
- I915_SHRINK_PURGEABLE);
- page = shmem_read_mapping_page_gfp(mapping, i, gfp);
- }
- if (IS_ERR(page)) {
- /* We've tried hard to allocate the memory by reaping
- * our own buffer, now let the real VM do its job and
- * go down in flames if truly OOM.
- */
- i915_gem_shrink_all(dev_priv);
- page = shmem_read_mapping_page(mapping, i);
- if (IS_ERR(page)) {
- ret = PTR_ERR(page);
- goto err_pages;
- }
- }
-#ifdef CONFIG_SWIOTLB
- if (swiotlb_nr_tbl()) {
- st->nents++;
- sg_set_page(sg, page, PAGE_SIZE, 0);
- sg = sg_next(sg);
- continue;
- }
-#endif
- if (!i || page_to_pfn(page) != last_pfn + 1) {
- if (i)
- sg = sg_next(sg);
- st->nents++;
- sg_set_page(sg, page, PAGE_SIZE, 0);
- } else {
- sg->length += PAGE_SIZE;
- }
- last_pfn = page_to_pfn(page);
-
- /* Check that the i965g/gm workaround works. */
- WARN_ON((gfp & __GFP_DMA32) && (last_pfn >= 0x00100000UL));
+ ctx.mapping = obj->base.filp->f_mapping;
+ ctx.gfp = mapping_gfp_constraint(ctx.mapping,
+ ~(__GFP_IO | __GFP_RECLAIM));
+ ctx.gfp |= __GFP_NORETRY | __GFP_NOWARN;
+
+ st = i915_alloc_sg_table(ctx.page_count, &ctx,
+ i915_gem_gtt_get_page,
+ i915_gem_gtt_get_page_failed,
+ i915_gem_gtt_put_page);
+ if (IS_ERR(st)) {
+ ret = PTR_ERR(st);
+ /* shmemfs first checks if there is enough memory to allocate
+ * the page and reports ENOSPC should there be insufficient,
+ * along with the usual ENOMEM for a genuine allocation failure.
+ *
+ * We use ENOSPC in our driver to mean that we have run out of
+ * aperture space and so want to translate the error from
+ * shmemfs back to our usual understanding of ENOMEM.
+ */
+ if (ret == -ENOSPC)
+ ret = -ENOMEM;
+ return ret;
}
-#ifdef CONFIG_SWIOTLB
- if (!swiotlb_nr_tbl())
-#endif
- sg_mark_end(sg);
+
obj->pages = st;
ret = i915_gem_gtt_prepare_object(obj);
if (ret)
- goto err_pages;
+ goto err;
if (i915_gem_object_needs_bit17_swizzle(obj))
i915_gem_object_do_bit_17_swizzle(obj);
@@ -2311,24 +2327,12 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
return 0;
-err_pages:
- sg_mark_end(sg);
+err:
for_each_sgt_page(page, sgt_iter, st)
put_page(page);
sg_free_table(st);
kfree(st);
- /* shmemfs first checks if there is enough memory to allocate the page
- * and reports ENOSPC should there be insufficient, along with the usual
- * ENOMEM for a genuine allocation failure.
- *
- * We use ENOSPC in our driver to mean that we have run out of aperture
- * space and so want to translate the error from shmemfs back to our
- * usual understanding of ENOMEM.
- */
- if (ret == -ENOSPC)
- ret = -ENOMEM;
-
return ret;
}
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 0bb4232f66bc..441910eafdea 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -3703,3 +3703,87 @@ void i915_vma_unpin_and_release(struct i915_vma **p_vma)
i915_vma_unpin(vma);
i915_vma_put(vma);
}
+
+struct sg_table *
+i915_alloc_sg_table(unsigned int page_count, void *context,
+ i915_page_alloc_f page_alloc,
+ i915_page_alloc_err_f page_alloc_error,
+ i915_page_put_f page_put)
+{
+ struct sg_table *st;
+ struct scatterlist *sg;
+ struct page *page;
+ struct sgt_iter sgt_iter;
+ unsigned long pfn;
+ unsigned long last_pfn = 0; /* suppress gcc warning */
+ unsigned int err_cnt = 0;
+ unsigned int i;
+ int err;
+
+ st = kmalloc(sizeof(*st), GFP_KERNEL);
+ if (st == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ if (sg_alloc_table(st, page_count, GFP_KERNEL)) {
+ kfree(st);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ sg = st->sgl;
+ st->nents = 0;
+
+ for (i = 0; i < page_count; i++) {
+retry:
+ page = page_alloc(context, i);
+ if (!page || IS_ERR(page)) {
+ err = page ? PTR_ERR(page) : -ENOMEM;
+
+ if (!page_alloc_error ||
+ page_alloc_error(context, i, err_cnt, err))
+ goto err_page_alloc;
+ else
+ goto retry;
+
+ err_cnt++;
+ }
+
+#ifdef CONFIG_SWIOTLB
+ if (swiotlb_nr_tbl()) {
+ st->nents++;
+ sg_set_page(sg, page, PAGE_SIZE, 0);
+ sg = sg_next(sg);
+ continue;
+ }
+#endif
+ pfn = page_to_pfn(page);
+
+ if (!i || pfn != last_pfn + 1) {
+ if (i)
+ sg = sg_next(sg);
+ st->nents++;
+ sg_set_page(sg, page, PAGE_SIZE, 0);
+ } else {
+ sg->length += PAGE_SIZE;
+ }
+
+ last_pfn = pfn;
+ }
+
+#ifdef CONFIG_SWIOTLB
+ if (!swiotlb_nr_tbl())
+#endif
+ sg_mark_end(sg);
+
+ return st;
+
+err_page_alloc:
+ sg_mark_end(sg);
+ if (page_put) {
+ for_each_sgt_page(page, sgt_iter, st)
+ page_put(context, page);
+ }
+ sg_free_table(st);
+ kfree(st);
+
+ return ERR_PTR(err);
+}
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index ec78be2f8c77..17768c99605e 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -730,4 +730,18 @@ static inline struct page *i915_vma_first_page(struct i915_vma *vma)
return sg_page(vma->pages->sgl);
}
+typedef struct page *
+(*i915_page_alloc_f)(void *context, unsigned int page_num);
+typedef bool
+(*i915_page_alloc_err_f)(void *context, unsigned int page_num,
+ unsigned int err_cnt, int err);
+typedef void
+(*i915_page_put_f)(void *context, struct page *page);
+
+struct sg_table *
+i915_alloc_sg_table(unsigned int page_count, void *context,
+ i915_page_alloc_f page_alloc,
+ i915_page_alloc_err_f page_alloc_error,
+ i915_page_put_f page_put);
+
#endif
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index e537930c64b5..cddebe50916a 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -397,54 +397,34 @@ struct get_pages_work {
struct task_struct *task;
};
-#if IS_ENABLED(CONFIG_SWIOTLB)
-#define swiotlb_active() swiotlb_nr_tbl()
-#else
-#define swiotlb_active() 0
-#endif
+struct i915_gem_get_pages_userptr_ctx {
+ struct page **pvec;
+};
-static int
-st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
+static struct page *
+i915_gem_userptr_get_page(void *context, unsigned int page_num)
{
- struct scatterlist *sg;
- int ret, n;
-
- *st = kmalloc(sizeof(**st), GFP_KERNEL);
- if (*st == NULL)
- return -ENOMEM;
+ struct i915_gem_get_pages_userptr_ctx *ctx = context;
- if (swiotlb_active()) {
- ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
- if (ret)
- goto err;
-
- for_each_sg((*st)->sgl, sg, num_pages, n)
- sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
- } else {
- ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
- 0, num_pages << PAGE_SHIFT,
- GFP_KERNEL);
- if (ret)
- goto err;
- }
-
- return 0;
-
-err:
- kfree(*st);
- *st = NULL;
- return ret;
+ return ctx->pvec[page_num];
}
static int
__i915_gem_userptr_set_pages(struct drm_i915_gem_object *obj,
struct page **pvec, int num_pages)
{
+ struct i915_gem_get_pages_userptr_ctx ctx;
+ struct sg_table *st;
int ret;
- ret = st_set_pages(&obj->pages, pvec, num_pages);
- if (ret)
- return ret;
+ ctx.pvec = pvec;
+ st = i915_alloc_sg_table(num_pages, &ctx,
+ i915_gem_userptr_get_page,
+ NULL, NULL);
+ if (IS_ERR(st))
+ return PTR_ERR(st);
+
+ obj->pages = st;
ret = i915_gem_gtt_prepare_object(obj);
if (ret) {
--
2.7.4
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