Since kmap allows us to block we can pin the pages and use our normal
page lookup routine making the implementation simple.
Testcase: igt/drv_selftest/dmabuf
Testcase: igt/prime_rw
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_dmabuf.c | 24 ++++++
drivers/gpu/drm/i915/selftests/i915_gem_dmabuf.c | 105 +++++++++++++++++++++++
2 files changed, 129 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 11898cd97596..0710319b8223 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -122,12 +122,36 @@ static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long
}
static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
{
+ struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
+ struct page *page;
+
+ if (page_num >= obj->base.size >> PAGE_SHIFT)
+ return NULL;
+
+ if (!i915_gem_object_has_struct_page(obj))
+ return NULL;
+
+ if (i915_gem_object_pin_pages(obj))
+ return NULL;
+
+ /* Synchronisation with GPU? mandatory set-domain? */
+ page = i915_gem_object_get_page(obj, page_num);
+ if (IS_ERR(page))
+ goto err_unpin;
+
+ return kmap(page);
+
+err_unpin:
+ i915_gem_object_unpin_pages(obj);
return NULL;
}
static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
{
+ struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
+ kunmap(virt_to_page(addr));
+ i915_gem_object_unpin_pages(obj);
}
static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/selftests/i915_gem_dmabuf.c
index 817bef74bbcb..c41e79f85caa 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_dmabuf.c
@@ -271,6 +271,110 @@ static int igt_dmabuf_export_vmap(void *arg)
return err;
}
+static int igt_dmabuf_export_kmap(void *arg)
+{
+ struct drm_i915_private *i915 = arg;
+ struct drm_i915_gem_object *obj;
+ struct dma_buf *dmabuf;
+ void *ptr;
+ int err;
+
+ obj = i915_gem_object_create(i915, 2*PAGE_SIZE);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+
+ dmabuf = i915_gem_prime_export(&i915->drm, &obj->base, 0);
+ if (IS_ERR(dmabuf)) {
+ pr_err("i915_gem_prime_export failed with err=%d\n",
+ (int)PTR_ERR(dmabuf));
+ err = PTR_ERR(dmabuf);
+ goto err_obj;
+ }
+ i915_gem_object_put(obj);
+
+ ptr = dma_buf_kmap(dmabuf, 0);
+ if (!ptr) {
+ pr_err("dma_buf_kmap failed\n");
+ err = -ENOMEM;
+ goto err;
+ }
+
+ if (memchr_inv(ptr, 0, PAGE_SIZE)) {
+ dma_buf_kunmap(dmabuf, 0, ptr);
+ pr_err("Exported page[0] not initialiased to zero!\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ memset(ptr, 0xc5, PAGE_SIZE);
+ dma_buf_kunmap(dmabuf, 0, ptr);
+
+ ptr = i915_gem_object_pin_map(obj, I915_MAP_WB);
+ if (IS_ERR(ptr)) {
+ err = PTR_ERR(ptr);
+ pr_err("i915_gem_object_pin_map failed with err=%d\n", err);
+ goto err;
+ }
+ memset(ptr + PAGE_SIZE, 0xaa, PAGE_SIZE);
+ i915_gem_object_unpin_map(obj);
+
+ ptr = dma_buf_kmap(dmabuf, 1);
+ if (!ptr) {
+ pr_err("dma_buf_kmap failed\n");
+ err = -ENOMEM;
+ goto err;
+ }
+
+ if (memchr_inv(ptr, 0xaa, PAGE_SIZE)) {
+ dma_buf_kunmap(dmabuf, 1, ptr);
+ pr_err("Exported page[1] not set to 0xaa!\n");
+ err = -EINVAL;
+ goto err;
+ }
+
+ memset(ptr, 0xc5, PAGE_SIZE);
+ dma_buf_kunmap(dmabuf, 1, ptr);
+
+ ptr = dma_buf_kmap(dmabuf, 0);
+ if (!ptr) {
+ pr_err("dma_buf_kmap failed\n");
+ err = -ENOMEM;
+ goto err;
+ }
+ if (memchr_inv(ptr, 0xc5, PAGE_SIZE)) {
+ dma_buf_kunmap(dmabuf, 0, ptr);
+ pr_err("Exported page[0] did not retain 0xc5!\n");
+ err = -EINVAL;
+ goto err;
+ }
+ dma_buf_kunmap(dmabuf, 0, ptr);
+
+ ptr = dma_buf_kmap(dmabuf, 2);
+ if (ptr) {
+ pr_err("Erroneously kmapped beyond the end of the object!\n");
+ dma_buf_kunmap(dmabuf, 2, ptr);
+ err = -EINVAL;
+ goto err;
+ }
+
+ ptr = dma_buf_kmap(dmabuf, -1);
+ if (ptr) {
+ pr_err("Erroneously kmapped before the start of the object!\n");
+ dma_buf_kunmap(dmabuf, -1, ptr);
+ err = -EINVAL;
+ goto err;
+ }
+
+ err = 0;
+err:
+ dma_buf_put(dmabuf);
+ return err;
+
+err_obj:
+ i915_gem_object_put(obj);
+ return err;
+}
+
int i915_gem_dmabuf_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
@@ -279,6 +383,7 @@ int i915_gem_dmabuf_mock_selftests(void)
SUBTEST(igt_dmabuf_import),
SUBTEST(igt_dmabuf_import_ownership),
SUBTEST(igt_dmabuf_export_vmap),
+ SUBTEST(igt_dmabuf_export_kmap),
};
struct drm_i915_private *i915;
int err;
--
2.11.0
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