New subject: [Intel-gfx] [PATCH] drm/i915: Wean off drm_pci_alloc/drm_pci_free

2 Feb 2020

drm_pci_alloc and drm_pci_free are just very thin wrappers around
dma_alloc_coherent, with a note that we should be removing them.
Furthermore since
commit de09d31dd38a50fdce106c15abd68432eebbd014
Author: Kirill A. Shutemov kirill.shutemov@linux.intel.com
Date:   Fri Jan 15 16:51:42 2016 -0800
page-flags: define PG_reserved behavior on compound pages
As far as I can see there's no users of PG_reserved on compound pages.
    Let's use PF_NO_COMPOUND here.
drm_pci_alloc has been declared broken since it mixes GFP_COMP and
SetPageReserved. Avoid this conflict by weaning ourselves off using the
abstraction and using the dma functions directly.
Reported-by: Taketo Kabe
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1027
Fixes: de09d31dd38a ("page-flags: define PG_reserved behavior on compound pages")
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk
Cc: stable@vger.kernel.org # v4.5+
---
 drivers/gpu/drm/i915/display/intel_display.c  |  2 +-
 .../gpu/drm/i915/gem/i915_gem_object_types.h  |  3 -
 drivers/gpu/drm/i915/gem/i915_gem_phys.c      | 98 ++++++++++---------
 drivers/gpu/drm/i915/i915_gem.c               |  8 +-
 4 files changed, 55 insertions(+), 56 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index b0af37fb6d4a..1f584263aa97 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -11234,7 +11234,7 @@ static u32 intel_cursor_base(const struct intel_plane_state *plane_state)
    u32 base;
if (INTEL_INFO(dev_priv)->display.cursor_needs_physical)
-		base = obj->phys_handle->busaddr;
+		base = sg_dma_address(obj->mm.pages->sgl);
    else
    	base = intel_plane_ggtt_offset(plane_state);
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 f64ad77e6b1e..c2174da35bb0 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -285,9 +285,6 @@ struct drm_i915_gem_object {
void *gvt_info;
    };
-
-	/** for phys allocated objects */
-	struct drm_dma_handle *phys_handle;
 };
static inline struct drm_i915_gem_object *
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_phys.c b/drivers/gpu/drm/i915/gem/i915_gem_phys.c
index b1b7c1b3038a..b07bb40edd5a 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_phys.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_phys.c
@@ -22,88 +22,87 @@
 static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
 {
    struct address_space *mapping = obj->base.filp->f_mapping;
-	struct drm_dma_handle *phys;
-	struct sg_table *st;
    struct scatterlist *sg;
-	char *vaddr;
+	struct sg_table *st;
+	dma_addr_t dma;
+	void *vaddr;
+	void *dst;
    int i;
-	int err;
if (WARN_ON(i915_gem_object_needs_bit17_swizzle(obj)))
    	return -EINVAL;
-	/* Always aligning to the object size, allows a single allocation
+	/*
+	 * Always aligning to the object size, allows a single allocation
     * to handle all possible callers, and given typical object sizes,
     * the alignment of the buddy allocation will naturally match.
     */
-	phys = drm_pci_alloc(obj->base.dev,
-			     roundup_pow_of_two(obj->base.size),
-			     roundup_pow_of_two(obj->base.size));
-	if (!phys)
+	vaddr = dma_alloc_coherent(&obj->base.dev->pdev->dev,
+				   roundup_pow_of_two(obj->base.size),
+				   &dma, GFP_KERNEL);
+	if (!vaddr)
    	return -ENOMEM;
-	vaddr = phys->vaddr;
+	st = kmalloc(sizeof(*st), GFP_KERNEL);
+	if (!st)
+		goto err_pci;
+
+	if (sg_alloc_table(st, 1, GFP_KERNEL))
+		goto err_st;
+
+	sg = st->sgl;
+	sg->offset = 0;
+	sg->length = obj->base.size;
+
+	sg_assign_page(sg, (struct page *)vaddr);
+	sg_dma_address(sg) = dma;
+	sg_dma_len(sg) = obj->base.size;
+
+	dst = vaddr;
    for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
    	struct page *page;
-		char *src;
+		void *src;
page = shmem_read_mapping_page(mapping, i);
-		if (IS_ERR(page)) {
-			err = PTR_ERR(page);
-			goto err_phys;
-		}
+		if (IS_ERR(page))
+			goto err_st;
src = kmap_atomic(page);
-		memcpy(vaddr, src, PAGE_SIZE);
-		drm_clflush_virt_range(vaddr, PAGE_SIZE);
+		memcpy(dst, src, PAGE_SIZE);
+		drm_clflush_virt_range(dst, PAGE_SIZE);
    	kunmap_atomic(src);
put_page(page);
-		vaddr += PAGE_SIZE;
+		dst += PAGE_SIZE;
    }
intel_gt_chipset_flush(&to_i915(obj->base.dev)->gt);
-	st = kmalloc(sizeof(*st), GFP_KERNEL);
-	if (!st) {
-		err = -ENOMEM;
-		goto err_phys;
-	}
-
-	if (sg_alloc_table(st, 1, GFP_KERNEL)) {
-		kfree(st);
-		err = -ENOMEM;
-		goto err_phys;
-	}
-
-	sg = st->sgl;
-	sg->offset = 0;
-	sg->length = obj->base.size;
-
-	sg_dma_address(sg) = phys->busaddr;
-	sg_dma_len(sg) = obj->base.size;
-
-	obj->phys_handle = phys;
-
    __i915_gem_object_set_pages(obj, st, sg->length);
return 0;
-err_phys:
-	drm_pci_free(obj->base.dev, phys);
-
-	return err;
+err_st:
+	kfree(st);
+err_pci:
+	dma_free_coherent(&obj->base.dev->pdev->dev,
+			  roundup_pow_of_two(obj->base.size),
+			  vaddr, dma);
+	return -ENOMEM;
 }
static void
 i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
    		       struct sg_table *pages)
 {
+	dma_addr_t dma = sg_dma_address(pages->sgl);
+	void *vaddr = sg_page(pages->sgl);
+
    __i915_gem_object_release_shmem(obj, pages, false);
if (obj->mm.dirty) {
    	struct address_space *mapping = obj->base.filp->f_mapping;
-		char *vaddr = obj->phys_handle->vaddr;
+		void *src = vaddr;
    	int i;
for (i = 0; i < obj->base.size / PAGE_SIZE; i++) {
@@ -115,15 +114,16 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
    			continue;
dst = kmap_atomic(page);
-			drm_clflush_virt_range(vaddr, PAGE_SIZE);
-			memcpy(dst, vaddr, PAGE_SIZE);
+			drm_clflush_virt_range(src, PAGE_SIZE);
+			memcpy(dst, src, PAGE_SIZE);
    		kunmap_atomic(dst);
set_page_dirty(page);
    		if (obj->mm.madv == I915_MADV_WILLNEED)
    			mark_page_accessed(page);
    		put_page(page);
-			vaddr += PAGE_SIZE;
+
+			src += PAGE_SIZE;
    	}
    	obj->mm.dirty = false;
    }
@@ -131,7 +131,9 @@ i915_gem_object_put_pages_phys(struct drm_i915_gem_object *obj,
    sg_free_table(pages);
    kfree(pages);
-	drm_pci_free(obj->base.dev, obj->phys_handle);
+	dma_free_coherent(&obj->base.dev->pdev->dev,
+			  roundup_pow_of_two(obj->base.size),
+			  vaddr, dma);
 }
static void phys_release(struct drm_i915_gem_object *obj)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7245e056ce77..a712e60b016a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -180,7 +180,7 @@ i915_gem_phys_pwrite(struct drm_i915_gem_object *obj,
    	     struct drm_i915_gem_pwrite *args,
    	     struct drm_file *file)
 {
-	void *vaddr = obj->phys_handle->vaddr + args->offset;
+	void *vaddr = sg_page(obj->mm.pages->sgl) + args->offset;
    char __user *user_data = u64_to_user_ptr(args->data_ptr);
/*
@@ -844,10 +844,10 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
    	ret = i915_gem_gtt_pwrite_fast(obj, args);
if (ret == -EFAULT || ret == -ENOSPC) {
-		if (obj->phys_handle)
-			ret = i915_gem_phys_pwrite(obj, args, file);
-		else
+		if (i915_gem_object_has_struct_page(obj))
    		ret = i915_gem_shmem_pwrite(obj, args);
+		else
+			ret = i915_gem_phys_pwrite(obj, args, file);
    }
i915_gem_object_unpin_pages(obj);
-- 
2.25.0


    