drm/rockchip: gem: support secure memory

Change-Id: I91dfbbfbf5d13983edfb79585e9beb980566f784
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Jianqun Xu <xjq@rock-chips.com>
Signed-off-by: Sandy Huang <hjc@rock-chips.com>

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -9,8 +9,10 @@
 #include <linux/dma-buf.h>
 #include <linux/dma-mapping.h>
 #include <linux/dma-iommu.h>
+#include <linux/genalloc.h>
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
+#include <linux/of_address.h>
 #include <linux/of_graph.h>
 #include <linux/of_platform.h>
 #include <linux/component.h>
@@ -528,6 +530,46 @@ err_unlock:
 	drm_modeset_unlock_all(drm);
 }
 
+static int rockchip_gem_pool_init(struct drm_device *drm)
+{
+	struct rockchip_drm_private *private = drm->dev_private;
+	struct device_node *np = drm->dev->of_node;
+	struct device_node *node;
+	phys_addr_t start, size;
+	struct resource res;
+	int ret;
+
+	node = of_parse_phandle(np, "secure-memory-region", 0);
+	if (!node)
+		return -ENXIO;
+
+	ret = of_address_to_resource(node, 0, &res);
+	if (ret)
+		return ret;
+	start = res.start;
+	size = resource_size(&res);
+	if (!size)
+		return -ENOMEM;
+
+	private->secure_buffer_pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!private->secure_buffer_pool)
+		return -ENOMEM;
+
+	gen_pool_add(private->secure_buffer_pool, start, size, -1);
+
+	return 0;
+}
+
+static void rockchip_gem_pool_destroy(struct drm_device *drm)
+{
+	struct rockchip_drm_private *private = drm->dev_private;
+
+	if (!private->secure_buffer_pool)
+		return;
+
+	gen_pool_destroy(private->secure_buffer_pool);
+}
+
 static int rockchip_drm_bind(struct device *dev)
 {
 	struct drm_device *drm_dev;
@@ -587,12 +629,15 @@ static int rockchip_drm_bind(struct device *dev)
 	/* init kms poll for handling hpd */
 	drm_kms_helper_poll_init(drm_dev);
 
+	rockchip_gem_pool_init(drm_dev);
+
 	ret = drm_dev_register(drm_dev, 0);
 	if (ret)
 		goto err_kms_helper_poll_fini;
 
 	return 0;
 err_kms_helper_poll_fini:
+	rockchip_gem_pool_destroy(drm_dev);
 	drm_kms_helper_poll_fini(drm_dev);
 	rockchip_drm_fbdev_fini(drm_dev);
 err_unbind_all:
@@ -611,6 +656,7 @@ static void rockchip_drm_unbind(struct device *dev)
 	drm_dev_unregister(drm_dev);
 
 	rockchip_drm_fbdev_fini(drm_dev);
+	rockchip_gem_pool_destroy(drm_dev);
 	drm_kms_helper_poll_fini(drm_dev);
 
 	drm_atomic_helper_shutdown(drm_dev);

drivers/gpu/drm/rockchip/rockchip_drm_drv.h

@@ -165,6 +165,7 @@ struct rockchip_drm_private {
 	struct drm_fb_helper *fbdev_helper;
 	struct drm_gem_object *fbdev_bo;
 	struct iommu_domain *domain;
+	struct gen_pool *secure_buffer_pool;
 	struct mutex mm_lock;
 	struct drm_mm mm;
 	struct list_head psr_list;

drivers/gpu/drm/rockchip/rockchip_drm_gem.c

@@ -13,6 +13,12 @@
 #include <drm/drm_prime.h>
 #include <drm/drm_vma_manager.h>
 
+#include <linux/dma-buf.h>
+#include <linux/genalloc.h>
+#include <linux/iommu.h>
+#include <linux/pagemap.h>
+#include <linux/vmalloc.h>
+
 #include "rockchip_drm_drv.h"
 #include "rockchip_drm_gem.h"
 
@@ -287,6 +293,91 @@ static int rockchip_gem_alloc_dma(struct rockchip_gem_object *rk_obj,
 	return 0;
 }
 
+static inline void *drm_calloc_large(size_t nmemb, size_t size)
+{
+	if (size != 0 && nmemb > SIZE_MAX / size)
+		return NULL;
+
+	if (size * nmemb <= PAGE_SIZE)
+		return kcalloc(nmemb, size, GFP_KERNEL);
+
+	return __vmalloc(size * nmemb,
+			 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+}
+
+static inline void drm_free_large(void *ptr)
+{
+	kvfree(ptr);
+}
+
+static int rockchip_gem_alloc_secure(struct rockchip_gem_object *rk_obj)
+{
+	struct drm_gem_object *obj = &rk_obj->base;
+	struct drm_device *drm = obj->dev;
+	struct rockchip_drm_private *private = drm->dev_private;
+	unsigned long paddr;
+	struct sg_table *sgt;
+	int ret = 0, i;
+
+	if (!private->secure_buffer_pool) {
+		DRM_ERROR("No secure buffer pool found\n");
+		return -ENOMEM;
+	}
+
+	paddr = gen_pool_alloc(private->secure_buffer_pool, rk_obj->base.size);
+	if (!paddr) {
+		DRM_ERROR("failed to allocate secure buffer\n");
+		return -ENOMEM;
+	}
+
+	rk_obj->dma_handle = paddr;
+	rk_obj->num_pages = rk_obj->base.size >> PAGE_SHIFT;
+
+	rk_obj->pages = drm_calloc_large(rk_obj->num_pages,
+					 sizeof(*rk_obj->pages));
+	if (!rk_obj->pages) {
+		DRM_ERROR("failed to allocate pages.\n");
+		ret = -ENOMEM;
+		goto err_buf_free;
+	}
+
+	i = 0;
+	while (i < rk_obj->num_pages) {
+		rk_obj->pages[i] = phys_to_page(paddr);
+		paddr += PAGE_SIZE;
+		i++;
+	}
+	sgt = drm_prime_pages_to_sg(obj->dev, rk_obj->pages, rk_obj->num_pages);
+	if (IS_ERR(sgt)) {
+		ret = PTR_ERR(sgt);
+		goto err_free_pages;
+	}
+
+	rk_obj->sgt = sgt;
+
+	return 0;
+
+err_free_pages:
+	drm_free_large(rk_obj->pages);
+err_buf_free:
+	gen_pool_free(private->secure_buffer_pool, paddr, rk_obj->base.size);
+
+	return ret;
+}
+
+static void rockchip_gem_free_secure(struct rockchip_gem_object *rk_obj)
+{
+	struct drm_gem_object *obj = &rk_obj->base;
+	struct drm_device *drm = obj->dev;
+	struct rockchip_drm_private *private = drm->dev_private;
+
+	drm_free_large(rk_obj->pages);
+	sg_free_table(rk_obj->sgt);
+	kfree(rk_obj->sgt);
+	gen_pool_free(private->secure_buffer_pool, rk_obj->dma_handle,
+		      rk_obj->base.size);
+}
+
 static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
 				  bool alloc_kmap)
 {
@@ -294,10 +385,24 @@ static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
 	struct drm_device *drm = obj->dev;
 	struct rockchip_drm_private *private = drm->dev_private;
 
-	if (private->domain)
-		return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
-	else
+	if (!private->domain)
+		rk_obj->flags |= ROCKCHIP_BO_CONTIG;
+
+	if (rk_obj->flags & ROCKCHIP_BO_SECURE) {
+		rk_obj->buf_type = ROCKCHIP_GEM_BUF_TYPE_SECURE;
+		rk_obj->flags |= ROCKCHIP_BO_CONTIG;
+		if (alloc_kmap) {
+			DRM_ERROR("Not allow alloc secure buffer with kmap\n");
+			return -EINVAL;
+		}
+		return rockchip_gem_alloc_secure(rk_obj);
+	} else if (rk_obj->flags & ROCKCHIP_BO_CONTIG) {
+		rk_obj->buf_type = ROCKCHIP_GEM_BUF_TYPE_CMA;
 		return rockchip_gem_alloc_dma(rk_obj, alloc_kmap);
+	} else {
+		rk_obj->buf_type = ROCKCHIP_GEM_BUF_TYPE_SHMEM;
+		return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
+	}
 }
 
 static void rockchip_gem_free_iommu(struct rockchip_gem_object *rk_obj)
@@ -318,7 +423,9 @@ static void rockchip_gem_free_dma(struct rockchip_gem_object *rk_obj)
 
 static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
 {
-	if (rk_obj->pages)
+	if (rk_obj->buf_type == ROCKCHIP_GEM_BUF_TYPE_SECURE)
+		rockchip_gem_free_secure(rk_obj);
+	else if (rk_obj->pages)
 		rockchip_gem_free_iommu(rk_obj);
 	else
 		rockchip_gem_free_dma(rk_obj);
@@ -359,10 +466,14 @@ static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
 	 */
 	vma->vm_flags &= ~VM_PFNMAP;
 
-	if (rk_obj->pages)
+	if (rk_obj->buf_type == ROCKCHIP_GEM_BUF_TYPE_SECURE) {
+		DRM_ERROR("Disallow mmap for secure buffer\n");
+		ret = -EINVAL;
+	} else if (rk_obj->pages) {
 		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
-	else
+	} else {
 		ret = rockchip_drm_gem_object_mmap_dma(obj, vma);
+	}
 
 	if (ret)
 		drm_gem_vm_close(vma);

drivers/gpu/drm/rockchip/rockchip_drm_gem.h

@@ -11,12 +11,20 @@
 
 #define to_rockchip_obj(x) container_of(x, struct rockchip_gem_object, base)
 
+enum rockchip_gem_buf_type {
+	ROCKCHIP_GEM_BUF_TYPE_CMA,
+	ROCKCHIP_GEM_BUF_TYPE_SHMEM,
+	ROCKCHIP_GEM_BUF_TYPE_SECURE,
+};
+
 struct rockchip_gem_object {
 	struct drm_gem_object base;
 	unsigned int flags;
+	enum rockchip_gem_buf_type buf_type;
 
 	void *kvaddr;
-	dma_addr_t dma_addr;
+	dma_addr_t dma_addr;	/* iova if iommu enable, otherwise physical address */
+	dma_addr_t dma_handle;	/* physical address */
 	/* Used when IOMMU is disabled */
 	unsigned long dma_attrs;