drm/exynos: add iommu support for exynos drm framework

Changelog v4:
- fix condition to drm_iommu_detach_device funtion.

Changelog v3:
- add dma_parms->max_segment_size setting of drm_device->dev.
- use devm_kzalloc instead of kzalloc.

Changelog v2:
- fix iommu attach condition.
  . check archdata.dma_ops of drm device instead of
    subdrv device's one.
- code clean to exynos_drm_iommu.c file.
  . remove '#ifdef CONFIG_ARM_DMA_USE_IOMMU' from exynos_drm_iommu.c
    and add it to driver/gpu/drm/exynos/Kconfig.

Changelog v1:
This patch adds iommu support for exynos drm framework with dma mapping
api. In this patch, we used dma mapping api to allocate physical memory
and maps it with iommu table and removed some existing codes and added
new some codes for iommu support.

GEM allocation requires one device object to use dma mapping api so
this patch uses one iommu mapping for all sub drivers. In other words,
all sub drivers have same iommu mapping.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>

1 files changed, 15 insertions, 195 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index d2545560664f..08d0218d5ba6 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -83,61 +83,12 @@ static void update_vm_cache_attr(struct exynos_drm_gem_obj *obj,
 
 static unsigned long roundup_gem_size(unsigned long size, unsigned int flags)
 {
-	if (!IS_NONCONTIG_BUFFER(flags)) {
-		if (size >= SZ_1M)
-			return roundup(size, SECTION_SIZE);
-		else if (size >= SZ_64K)
-			return roundup(size, SZ_64K);
-		else
-			goto out;
-	}
-out:
-	return roundup(size, PAGE_SIZE);
-}
-
-struct page **exynos_gem_get_pages(struct drm_gem_object *obj,
-						gfp_t gfpmask)
-{
-	struct page *p, **pages;
-	int i, npages;
-
-	npages = obj->size >> PAGE_SHIFT;
-
-	pages = drm_malloc_ab(npages, sizeof(struct page *));
-	if (pages == NULL)
-		return ERR_PTR(-ENOMEM);
-
-	for (i = 0; i < npages; i++) {
-		p = alloc_page(gfpmask);
-		if (IS_ERR(p))
-			goto fail;
-		pages[i] = p;
-	}
-
-	return pages;
-
-fail:
-	while (--i)
-		__free_page(pages[i]);
-
-	drm_free_large(pages);
-	return ERR_CAST(p);
-}
-
-static void exynos_gem_put_pages(struct drm_gem_object *obj,
-					struct page **pages)
-{
-	int npages;
+	/* TODO */
 
-	npages = obj->size >> PAGE_SHIFT;
-
-	while (--npages >= 0)
-		__free_page(pages[npages]);
-
-	drm_free_large(pages);
+	return roundup(size, PAGE_SIZE);
 }
 
-static int exynos_drm_gem_map_pages(struct drm_gem_object *obj,
+static int exynos_drm_gem_map_buf(struct drm_gem_object *obj,
 					struct vm_area_struct *vma,
 					unsigned long f_vaddr,
 					pgoff_t page_offset)
@@ -157,85 +108,6 @@ static int exynos_drm_gem_map_pages(struct drm_gem_object *obj,
 	return vm_insert_mixed(vma, f_vaddr, pfn);
 }
 
-static int exynos_drm_gem_get_pages(struct drm_gem_object *obj)
-{
-	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
-	struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
-	struct scatterlist *sgl;
-	struct page **pages;
-	unsigned int npages, i = 0;
-	int ret;
-
-	if (buf->pages) {
-		DRM_DEBUG_KMS("already allocated.\n");
-		return -EINVAL;
-	}
-
-	pages = exynos_gem_get_pages(obj, GFP_HIGHUSER_MOVABLE);
-	if (IS_ERR(pages)) {
-		DRM_ERROR("failed to get pages.\n");
-		return PTR_ERR(pages);
-	}
-
-	npages = obj->size >> PAGE_SHIFT;
-	buf->page_size = PAGE_SIZE;
-
-	buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
-	if (!buf->sgt) {
-		DRM_ERROR("failed to allocate sg table.\n");
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	ret = sg_alloc_table(buf->sgt, npages, GFP_KERNEL);
-	if (ret < 0) {
-		DRM_ERROR("failed to initialize sg table.\n");
-		ret = -EFAULT;
-		goto err1;
-	}
-
-	sgl = buf->sgt->sgl;
-
-	/* set all pages to sg list. */
-	while (i < npages) {
-		sg_set_page(sgl, pages[i], PAGE_SIZE, 0);
-		sg_dma_address(sgl) = page_to_phys(pages[i]);
-		i++;
-		sgl = sg_next(sgl);
-	}
-
-	/* add some codes for UNCACHED type here. TODO */
-
-	buf->pages = pages;
-	return ret;
-err1:
-	kfree(buf->sgt);
-	buf->sgt = NULL;
-err:
-	exynos_gem_put_pages(obj, pages);
-	return ret;
-
-}
-
-static void exynos_drm_gem_put_pages(struct drm_gem_object *obj)
-{
-	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
-	struct exynos_drm_gem_buf *buf = exynos_gem_obj->buffer;
-
-	/*
-	 * if buffer typs is EXYNOS_BO_NONCONTIG then release all pages
-	 * allocated at gem fault handler.
-	 */
-	sg_free_table(buf->sgt);
-	kfree(buf->sgt);
-	buf->sgt = NULL;
-
-	exynos_gem_put_pages(obj, buf->pages);
-	buf->pages = NULL;
-
-	/* add some codes for UNCACHED type here. TODO */
-}
-
 static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
 					struct drm_file *file_priv,
 					unsigned int *handle)
@@ -270,9 +142,6 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
 
 	DRM_DEBUG_KMS("handle count = %d\n", atomic_read(&obj->handle_count));
 
-	if (!buf->pages)
-		return;
-
 	/*
 	 * do not release memory region from exporter.
 	 *
@@ -282,10 +151,7 @@ void exynos_drm_gem_destroy(struct exynos_drm_gem_obj *exynos_gem_obj)
 	if (obj->import_attach)
 		goto out;
 
-	if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG)
-		exynos_drm_gem_put_pages(obj);
-	else
-		exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
+	exynos_drm_free_buf(obj->dev, exynos_gem_obj->flags, buf);
 
 out:
 	exynos_drm_fini_buf(obj->dev, buf);
@@ -364,22 +230,10 @@ struct exynos_drm_gem_obj *exynos_drm_gem_create(struct drm_device *dev,
 	/* set memory type and cache attribute from user side. */
 	exynos_gem_obj->flags = flags;
 
-	/*
-	 * allocate all pages as desired size if user wants to allocate
-	 * physically non-continuous memory.
-	 */
-	if (flags & EXYNOS_BO_NONCONTIG) {
-		ret = exynos_drm_gem_get_pages(&exynos_gem_obj->base);
-		if (ret < 0) {
-			drm_gem_object_release(&exynos_gem_obj->base);
-			goto err_fini_buf;
-		}
-	} else {
-		ret = exynos_drm_alloc_buf(dev, buf, flags);
-		if (ret < 0) {
-			drm_gem_object_release(&exynos_gem_obj->base);
-			goto err_fini_buf;
-		}
+	ret = exynos_drm_alloc_buf(dev, buf, flags);
+	if (ret < 0) {
+		drm_gem_object_release(&exynos_gem_obj->base);
+		goto err_fini_buf;
 	}
 
 	return exynos_gem_obj;
@@ -495,8 +349,7 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp,
 	struct drm_gem_object *obj = filp->private_data;
 	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
 	struct exynos_drm_gem_buf *buffer;
-	unsigned long pfn, vm_size, usize, uaddr = vma->vm_start;
-	int ret;
+	unsigned long vm_size;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
@@ -504,7 +357,7 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp,
 
 	update_vm_cache_attr(exynos_gem_obj, vma);
 
-	vm_size = usize = vma->vm_end - vma->vm_start;
+	vm_size = vma->vm_end - vma->vm_start;
 
 	/*
 	 * a buffer contains information to physically continuous memory
@@ -516,42 +369,9 @@ static int exynos_drm_gem_mmap_buffer(struct file *filp,
 	if (vm_size > buffer->size)
 		return -EINVAL;
 
-	if (exynos_gem_obj->flags & EXYNOS_BO_NONCONTIG) {
-		int i = 0;
-
-		if (!buffer->pages)
-			return -EINVAL;
-
-		vma->vm_flags |= VM_MIXEDMAP;
-
-		do {
-			ret = vm_insert_page(vma, uaddr, buffer->pages[i++]);
-			if (ret) {
-				DRM_ERROR("failed to remap user space.\n");
-				return ret;
-			}
-
-			uaddr += PAGE_SIZE;
-			usize -= PAGE_SIZE;
-		} while (usize > 0);
-	} else {
-		/*
-		 * get page frame number to physical memory to be mapped
-		 * to user space.
-		 */
-		pfn = ((unsigned long)exynos_gem_obj->buffer->dma_addr) >>
-								PAGE_SHIFT;
-
-		DRM_DEBUG_KMS("pfn = 0x%lx\n", pfn);
-
-		if (remap_pfn_range(vma, vma->vm_start, pfn, vm_size,
-					vma->vm_page_prot)) {
-			DRM_ERROR("failed to remap pfn range.\n");
-			return -EAGAIN;
-		}
-	}
-
-	return 0;
+	return dma_mmap_attrs(obj->dev->dev, vma, buffer->kvaddr,
+				buffer->dma_addr, buffer->size,
+				&buffer->dma_attrs);
 }
 
 static const struct file_operations exynos_drm_gem_fops = {
@@ -753,9 +573,9 @@ int exynos_drm_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 	mutex_lock(&dev->struct_mutex);
 
-	ret = exynos_drm_gem_map_pages(obj, vma, f_vaddr, page_offset);
+	ret = exynos_drm_gem_map_buf(obj, vma, f_vaddr, page_offset);
 	if (ret < 0)
-		DRM_ERROR("failed to map pages.\n");
+		DRM_ERROR("failed to map a buffer with user.\n");
 
 	mutex_unlock(&dev->struct_mutex);