drm/i915/region: support contiguous allocations

Some kernel internal objects may need to be allocated as a contiguous
block, also thinking ahead the various kernel io_mapping interfaces seem
to expect it, although this is purely a limitation in the kernel
API...so perhaps something to be improved.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Michael J Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191008160116.18379-3-matthew.auld@intel.com

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 086a9bf..dfd16d6 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -140,6 +140,12 @@ i915_gem_object_is_readonly(const struct drm_i915_gem_object *obj)
 }
 
 static inline bool
+i915_gem_object_is_contiguous(const struct drm_i915_gem_object *obj)
+{
+       return obj->flags & I915_BO_ALLOC_CONTIGUOUS;
+}
+
+static inline bool
 i915_gem_object_type_has(const struct drm_i915_gem_object *obj,
                         unsigned long flags)
 {

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 1139058..c6a712c 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -119,6 +119,10 @@ struct drm_i915_gem_object {
 
        I915_SELFTEST_DECLARE(struct list_head st_link);
 
+       unsigned long flags;
+#define I915_BO_ALLOC_CONTIGUOUS BIT(0)
+#define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS)
+
        /*
         * Is the object to be mapped as read-only to the GPU
         * Only honoured if hardware has relevant pte bit

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index 6588e3c..d94914a 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -23,10 +23,10 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
 {
        struct intel_memory_region *mem = obj->mm.region;
        struct list_head *blocks = &obj->mm.blocks;
-       unsigned int flags = I915_ALLOC_MIN_PAGE_SIZE;
        resource_size_t size = obj->base.size;
        resource_size_t prev_end;
        struct i915_buddy_block *block;
+       unsigned int flags;
        struct sg_table *st;
        struct scatterlist *sg;
        unsigned int sg_page_sizes;
@@ -41,6 +41,10 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
                return -ENOMEM;
        }
 
+       flags = I915_ALLOC_MIN_PAGE_SIZE;
+       if (obj->flags & I915_BO_ALLOC_CONTIGUOUS)
+               flags |= I915_ALLOC_CONTIGUOUS;
+
        ret = __intel_memory_region_get_pages_buddy(mem, size, flags, blocks);
        if (ret)
                goto err_free_sg;
@@ -55,7 +59,8 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
        list_for_each_entry(block, blocks, link) {
                u64 block_size, offset;
 
-               block_size = i915_buddy_block_size(&mem->mm, block);
+               block_size = min_t(u64, size,
+                                  i915_buddy_block_size(&mem->mm, block));
                offset = i915_buddy_block_offset(block);
 
                GEM_BUG_ON(overflows_type(block_size, sg->length));
@@ -96,10 +101,12 @@ err_free_sg:
 }
 
 void i915_gem_object_init_memory_region(struct drm_i915_gem_object *obj,
-                                       struct intel_memory_region *mem)
+                                       struct intel_memory_region *mem,
+                                       unsigned long flags)
 {
        INIT_LIST_HEAD(&obj->mm.blocks);
        obj->mm.region = intel_memory_region_get(mem);
+       obj->flags |= flags;
 }
 
 void i915_gem_object_release_memory_region(struct drm_i915_gem_object *obj)
@@ -120,6 +127,8 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
         * future.
         */
 
+       GEM_BUG_ON(flags & ~I915_BO_ALLOC_FLAGS);
+
        if (!mem)
                return ERR_PTR(-ENODEV);
 

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.h b/drivers/gpu/drm/i915/gem/i915_gem_region.h
index ebddc86..f2ff6f8 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.h
@@ -17,7 +17,8 @@ void i915_gem_object_put_pages_buddy(struct drm_i915_gem_object *obj,
                                     struct sg_table *pages);
 
 void i915_gem_object_init_memory_region(struct drm_i915_gem_object *obj,
-                                       struct intel_memory_region *mem);
+                                       struct intel_memory_region *mem,
+                                       unsigned long flags);
 void i915_gem_object_release_memory_region(struct drm_i915_gem_object *obj);
 
 struct drm_i915_gem_object *

diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
index b4c390e..63a4743 100644 (file)
--- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
+++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c
@@ -456,6 +456,7 @@ out_device:
 
 static int igt_mock_memory_region_huge_pages(void *arg)
 {
+       const unsigned int flags[] = { 0, I915_BO_ALLOC_CONTIGUOUS };
        struct i915_ppgtt *ppgtt = arg;
        struct drm_i915_private *i915 = ppgtt->vm.i915;
        unsigned long supported = INTEL_INFO(i915)->page_sizes;
@@ -474,46 +475,52 @@ static int igt_mock_memory_region_huge_pages(void *arg)
        for_each_set_bit(bit, &supported, ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) {
                unsigned int page_size = BIT(bit);
                resource_size_t phys;
+               int i;
 
-               obj = i915_gem_object_create_region(mem, page_size, 0);
-               if (IS_ERR(obj)) {
-                       err = PTR_ERR(obj);
-                       goto out_region;
-               }
+               for (i = 0; i < ARRAY_SIZE(flags); ++i) {
+                       obj = i915_gem_object_create_region(mem, page_size,
+                                                           flags[i]);
+                       if (IS_ERR(obj)) {
+                               err = PTR_ERR(obj);
+                               goto out_region;
+                       }
 
-               vma = i915_vma_instance(obj, &ppgtt->vm, NULL);
-               if (IS_ERR(vma)) {
-                       err = PTR_ERR(vma);
-                       goto out_put;
-               }
+                       vma = i915_vma_instance(obj, &ppgtt->vm, NULL);
+                       if (IS_ERR(vma)) {
+                               err = PTR_ERR(vma);
+                               goto out_put;
+                       }
 
-               err = i915_vma_pin(vma, 0, 0, PIN_USER);
-               if (err)
-                       goto out_close;
+                       err = i915_vma_pin(vma, 0, 0, PIN_USER);
+                       if (err)
+                               goto out_close;
 
-               err = igt_check_page_sizes(vma);
-               if (err)
-                       goto out_unpin;
+                       err = igt_check_page_sizes(vma);
+                       if (err)
+                               goto out_unpin;
 
-               phys = i915_gem_object_get_dma_address(obj, 0);
-               if (!IS_ALIGNED(phys, page_size)) {
-                       pr_err("%s addr misaligned(%pa) page_size=%u\n",
-                              __func__, &phys, page_size);
-                       err = -EINVAL;
-                       goto out_unpin;
-               }
+                       phys = i915_gem_object_get_dma_address(obj, 0);
+                       if (!IS_ALIGNED(phys, page_size)) {
+                               pr_err("%s addr misaligned(%pa) page_size=%u\n",
+                                      __func__, &phys, page_size);
+                               err = -EINVAL;
+                               goto out_unpin;
+                       }
 
-               if (vma->page_sizes.gtt != page_size) {
-                       pr_err("%s page_sizes.gtt=%u, expected=%u\n",
-                              __func__, vma->page_sizes.gtt, page_size);
-                       err = -EINVAL;
-                       goto out_unpin;
-               }
+                       if (vma->page_sizes.gtt != page_size) {
+                               pr_err("%s page_sizes.gtt=%u, expected=%u\n",
+                                      __func__, vma->page_sizes.gtt,
+                                      page_size);
+                               err = -EINVAL;
+                               goto out_unpin;
+                       }
 
-               i915_vma_unpin(vma);
-               i915_vma_close(vma);
+                       i915_vma_unpin(vma);
+                       i915_vma_close(vma);
 
-               i915_gem_object_put(obj);
+                       __i915_gem_object_put_pages(obj, I915_MM_NORMAL);
+                       i915_gem_object_put(obj);
+               }
        }
 
        goto out_region;

diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 2ef67c3..9800661 100644 (file)
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -47,8 +47,8 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
                                      unsigned int flags,
                                      struct list_head *blocks)
 {
-       unsigned long n_pages = size >> ilog2(mem->mm.chunk_size);
        unsigned int min_order = 0;
+       unsigned long n_pages;
 
        GEM_BUG_ON(!IS_ALIGNED(size, mem->mm.chunk_size));
        GEM_BUG_ON(!list_empty(blocks));
@@ -58,6 +58,13 @@ __intel_memory_region_get_pages_buddy(struct intel_memory_region *mem,
                            ilog2(mem->mm.chunk_size);
        }
 
+       if (flags & I915_ALLOC_CONTIGUOUS) {
+               size = roundup_pow_of_two(size);
+               min_order = ilog2(size) - ilog2(mem->mm.chunk_size);
+       }
+
+       n_pages = size >> ilog2(mem->mm.chunk_size);
+
        mutex_lock(&mem->mm_lock);
 
        do {

diff --git a/drivers/gpu/drm/i915/intel_memory_region.h b/drivers/gpu/drm/i915/intel_memory_region.h
index 2ea17d6..29b86ca 100644 (file)
--- a/drivers/gpu/drm/i915/intel_memory_region.h
+++ b/drivers/gpu/drm/i915/intel_memory_region.h
@@ -18,7 +18,8 @@ struct drm_i915_gem_object;
 struct intel_memory_region;
 struct sg_table;
 
-#define I915_ALLOC_MIN_PAGE_SIZE   BIT(0)
+#define I915_ALLOC_MIN_PAGE_SIZE  BIT(0)
+#define I915_ALLOC_CONTIGUOUS     BIT(1)
 
 struct intel_memory_region_ops {
        unsigned int flags;

diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 89eaa41..4e44c81 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -13,6 +13,7 @@
 
 #include "gem/i915_gem_region.h"
 #include "gem/selftests/mock_context.h"
+#include "selftests/i915_random.h"
 
 static void close_objects(struct intel_memory_region *mem,
                          struct list_head *objects)
@@ -86,10 +87,174 @@ static int igt_mock_fill(void *arg)
        return err;
 }
 
+static struct drm_i915_gem_object *
+igt_object_create(struct intel_memory_region *mem,
+                 struct list_head *objects,
+                 u64 size,
+                 unsigned int flags)
+{
+       struct drm_i915_gem_object *obj;
+       int err;
+
+       obj = i915_gem_object_create_region(mem, size, flags);
+       if (IS_ERR(obj))
+               return obj;
+
+       err = i915_gem_object_pin_pages(obj);
+       if (err)
+               goto put;
+
+       list_add(&obj->st_link, objects);
+       return obj;
+
+put:
+       i915_gem_object_put(obj);
+       return ERR_PTR(err);
+}
+
+static void igt_object_release(struct drm_i915_gem_object *obj)
+{
+       i915_gem_object_unpin_pages(obj);
+       __i915_gem_object_put_pages(obj, I915_MM_NORMAL);
+       list_del(&obj->st_link);
+       i915_gem_object_put(obj);
+}
+
+static int igt_mock_contiguous(void *arg)
+{
+       struct intel_memory_region *mem = arg;
+       struct drm_i915_gem_object *obj;
+       unsigned long n_objects;
+       LIST_HEAD(objects);
+       LIST_HEAD(holes);
+       I915_RND_STATE(prng);
+       resource_size_t target;
+       resource_size_t total;
+       resource_size_t min;
+       int err = 0;
+
+       total = resource_size(&mem->region);
+
+       /* Min size */
+       obj = igt_object_create(mem, &objects, mem->mm.chunk_size,
+                               I915_BO_ALLOC_CONTIGUOUS);
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);
+
+       if (obj->mm.pages->nents != 1) {
+               pr_err("%s min object spans multiple sg entries\n", __func__);
+               err = -EINVAL;
+               goto err_close_objects;
+       }
+
+       igt_object_release(obj);
+
+       /* Max size */
+       obj = igt_object_create(mem, &objects, total, I915_BO_ALLOC_CONTIGUOUS);
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);
+
+       if (obj->mm.pages->nents != 1) {
+               pr_err("%s max object spans multiple sg entries\n", __func__);
+               err = -EINVAL;
+               goto err_close_objects;
+       }
+
+       igt_object_release(obj);
+
+       /* Internal fragmentation should not bleed into the object size */
+       target = round_up(prandom_u32_state(&prng) % total, PAGE_SIZE);
+       target = max_t(u64, PAGE_SIZE, target);
+
+       obj = igt_object_create(mem, &objects, target,
+                               I915_BO_ALLOC_CONTIGUOUS);
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);
+
+       if (obj->base.size != target) {
+               pr_err("%s obj->base.size(%llx) != target(%llx)\n", __func__,
+                      (u64)obj->base.size, (u64)target);
+               err = -EINVAL;
+               goto err_close_objects;
+       }
+
+       if (obj->mm.pages->nents != 1) {
+               pr_err("%s object spans multiple sg entries\n", __func__);
+               err = -EINVAL;
+               goto err_close_objects;
+       }
+
+       igt_object_release(obj);
+
+       /*
+        * Try to fragment the address space, such that half of it is free, but
+        * the max contiguous block size is SZ_64K.
+        */
+
+       target = SZ_64K;
+       n_objects = div64_u64(total, target);
+
+       while (n_objects--) {
+               struct list_head *list;
+
+               if (n_objects % 2)
+                       list = &holes;
+               else
+                       list = &objects;
+
+               obj = igt_object_create(mem, list, target,
+                                       I915_BO_ALLOC_CONTIGUOUS);
+               if (IS_ERR(obj)) {
+                       err = PTR_ERR(obj);
+                       goto err_close_objects;
+               }
+       }
+
+       close_objects(mem, &holes);
+
+       min = target;
+       target = total >> 1;
+
+       /* Make sure we can still allocate all the fragmented space */
+       obj = igt_object_create(mem, &objects, target, 0);
+       if (IS_ERR(obj)) {
+               err = PTR_ERR(obj);
+               goto err_close_objects;
+       }
+
+       igt_object_release(obj);
+
+       /*
+        * Even though we have enough free space, we don't have a big enough
+        * contiguous block. Make sure that holds true.
+        */
+
+       do {
+               bool should_fail = target > min;
+
+               obj = igt_object_create(mem, &objects, target,
+                                       I915_BO_ALLOC_CONTIGUOUS);
+               if (should_fail != IS_ERR(obj)) {
+                       pr_err("%s target allocation(%llx) mismatch\n",
+                              __func__, (u64)target);
+                       err = -EINVAL;
+                       goto err_close_objects;
+               }
+
+               target >>= 1;
+       } while (target >= mem->mm.chunk_size);
+
+err_close_objects:
+       list_splice_tail(&holes, &objects);
+       close_objects(mem, &objects);
+       return err;
+}
+
 int intel_memory_region_mock_selftests(void)
 {
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_mock_fill),
+               SUBTEST(igt_mock_contiguous),
        };
        struct intel_memory_region *mem;
        struct drm_i915_private *i915;

diff --git a/drivers/gpu/drm/i915/selftests/mock_region.c b/drivers/gpu/drm/i915/selftests/mock_region.c
index 0e9a575..7b0c99d 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_region.c
+++ b/drivers/gpu/drm/i915/selftests/mock_region.c
@@ -36,7 +36,7 @@ mock_object_create(struct intel_memory_region *mem,
 
        i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE);
 
-       i915_gem_object_init_memory_region(obj, mem);
+       i915_gem_object_init_memory_region(obj, mem, flags);
 
        return obj;
 }