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, 32 insertions, 56 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_buf.c b/drivers/gpu/drm/exynos/exynos_drm_buf.c
index 118c117b3226..48c589661cbe 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_buf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_buf.c
@@ -33,71 +33,58 @@
 static int lowlevel_buffer_allocate(struct drm_device *dev,
 		unsigned int flags, struct exynos_drm_gem_buf *buf)
 {
-	dma_addr_t start_addr;
+	int ret = 0;
 	unsigned int npages, i = 0;
 	struct scatterlist *sgl;
-	int ret = 0;
+	enum dma_attr attr = DMA_ATTR_FORCE_CONTIGUOUS;
 
 	DRM_DEBUG_KMS("%s\n", __FILE__);
 
-	if (IS_NONCONTIG_BUFFER(flags)) {
-		DRM_DEBUG_KMS("not support allocation type.\n");
-		return -EINVAL;
-	}
-
 	if (buf->dma_addr) {
 		DRM_DEBUG_KMS("already allocated.\n");
 		return 0;
 	}
 
-	if (buf->size >= SZ_1M) {
-		npages = buf->size >> SECTION_SHIFT;
-		buf->page_size = SECTION_SIZE;
-	} else if (buf->size >= SZ_64K) {
-		npages = buf->size >> 16;
-		buf->page_size = SZ_64K;
-	} else {
-		npages = buf->size >> PAGE_SHIFT;
-		buf->page_size = PAGE_SIZE;
+	init_dma_attrs(&buf->dma_attrs);
+
+	if (flags & EXYNOS_BO_NONCONTIG)
+		attr = DMA_ATTR_WRITE_COMBINE;
+
+	dma_set_attr(attr, &buf->dma_attrs);
+
+	buf->kvaddr = dma_alloc_attrs(dev->dev, buf->size,
+			&buf->dma_addr, GFP_KERNEL, &buf->dma_attrs);
+	if (!buf->kvaddr) {
+		DRM_ERROR("failed to allocate buffer.\n");
+		return -ENOMEM;
 	}
 
 	buf->sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
 	if (!buf->sgt) {
 		DRM_ERROR("failed to allocate sg table.\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_free_attrs;
 	}
 
-	ret = sg_alloc_table(buf->sgt, npages, GFP_KERNEL);
+	ret = dma_get_sgtable(dev->dev, buf->sgt, buf->kvaddr, buf->dma_addr,
+			buf->size);
 	if (ret < 0) {
-		DRM_ERROR("failed to initialize sg table.\n");
-		kfree(buf->sgt);
-		buf->sgt = NULL;
-		return -ENOMEM;
+		DRM_ERROR("failed to get sgtable.\n");
+		goto err_free_sgt;
 	}
 
-	buf->kvaddr = dma_alloc_writecombine(dev->dev, buf->size,
-			&buf->dma_addr, GFP_KERNEL);
-	if (!buf->kvaddr) {
-		DRM_ERROR("failed to allocate buffer.\n");
-		ret = -ENOMEM;
-		goto err1;
-	}
+	npages = buf->sgt->nents;
 
 	buf->pages = kzalloc(sizeof(struct page) * npages, GFP_KERNEL);
 	if (!buf->pages) {
 		DRM_ERROR("failed to allocate pages.\n");
 		ret = -ENOMEM;
-		goto err2;
+		goto err_free_table;
 	}
 
 	sgl = buf->sgt->sgl;
-	start_addr = buf->dma_addr;
-
 	while (i < npages) {
-		buf->pages[i] = phys_to_page(start_addr);
-		sg_set_page(sgl, buf->pages[i], buf->page_size, 0);
-		sg_dma_address(sgl) = start_addr;
-		start_addr += buf->page_size;
+		buf->pages[i] = sg_page(sgl);
 		sgl = sg_next(sgl);
 		i++;
 	}
@@ -108,14 +95,16 @@ static int lowlevel_buffer_allocate(struct drm_device *dev,
 			buf->size);
 
 	return ret;
-err2:
-	dma_free_writecombine(dev->dev, buf->size, buf->kvaddr,
-			(dma_addr_t)buf->dma_addr);
-	buf->dma_addr = (dma_addr_t)NULL;
-err1:
+
+err_free_table:
 	sg_free_table(buf->sgt);
+err_free_sgt:
 	kfree(buf->sgt);
 	buf->sgt = NULL;
+err_free_attrs:
+	dma_free_attrs(dev->dev, buf->size, buf->kvaddr,
+			(dma_addr_t)buf->dma_addr, &buf->dma_attrs);
+	buf->dma_addr = (dma_addr_t)NULL;
 
 	return ret;
 }
@@ -125,16 +114,6 @@ static void lowlevel_buffer_deallocate(struct drm_device *dev,
 {
 	DRM_DEBUG_KMS("%s.\n", __FILE__);
 
-	/*
-	 * release only physically continuous memory and
-	 * non-continuous memory would be released by exynos
-	 * gem framework.
-	 */
-	if (IS_NONCONTIG_BUFFER(flags)) {
-		DRM_DEBUG_KMS("not support allocation type.\n");
-		return;
-	}
-
 	if (!buf->dma_addr) {
 		DRM_DEBUG_KMS("dma_addr is invalid.\n");
 		return;
@@ -150,11 +129,8 @@ static void lowlevel_buffer_deallocate(struct drm_device *dev,
 	kfree(buf->sgt);
 	buf->sgt = NULL;
 
-	kfree(buf->pages);
-	buf->pages = NULL;
-
-	dma_free_writecombine(dev->dev, buf->size, buf->kvaddr,
-				(dma_addr_t)buf->dma_addr);
+	dma_free_attrs(dev->dev, buf->size, buf->kvaddr,
+				(dma_addr_t)buf->dma_addr, &buf->dma_attrs);
 	buf->dma_addr = (dma_addr_t)NULL;
 }