1 files changed, 458 insertions, 0 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c b/drivers/gpu/drm/exynos/exynos_drm_gem.c
new file mode 100644
index 000000000..3e493f48e
--- /dev/null
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* exynos_drm_gem.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ * Author: Inki Dae <inki.dae@samsung.com>
+ */
+
+
+#include <linux/dma-buf.h>
+#include <linux/pfn_t.h>
+#include <linux/shmem_fs.h>
+#include <linux/module.h>
+
+#include <drm/drm_prime.h>
+#include <drm/drm_vma_manager.h>
+#include <drm/exynos_drm.h>
+
+#include "exynos_drm_drv.h"
+#include "exynos_drm_gem.h"
+
+MODULE_IMPORT_NS(DMA_BUF);
+
+static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
+
+static int exynos_drm_alloc_buf(struct exynos_drm_gem *exynos_gem, bool kvmap)
+{
+	struct drm_device *dev = exynos_gem->base.dev;
+	unsigned long attr = 0;
+
+	if (exynos_gem->dma_addr) {
+		DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "already allocated.\n");
+		return 0;
+	}
+
+	/*
+	 * if EXYNOS_BO_CONTIG, fully physically contiguous memory
+	 * region will be allocated else physically contiguous
+	 * as possible.
+	 */
+	if (!(exynos_gem->flags & EXYNOS_BO_NONCONTIG))
+		attr |= DMA_ATTR_FORCE_CONTIGUOUS;
+
+	/*
+	 * if EXYNOS_BO_WC or EXYNOS_BO_NONCACHABLE, writecombine mapping
+	 * else cachable mapping.
+	 */
+	if (exynos_gem->flags & EXYNOS_BO_WC ||
+			!(exynos_gem->flags & EXYNOS_BO_CACHABLE))
+		attr |= DMA_ATTR_WRITE_COMBINE;
+
+	/* FBDev emulation requires kernel mapping */
+	if (!kvmap)
+		attr |= DMA_ATTR_NO_KERNEL_MAPPING;
+
+	exynos_gem->dma_attrs = attr;
+	exynos_gem->cookie = dma_alloc_attrs(to_dma_dev(dev), exynos_gem->size,
+					     &exynos_gem->dma_addr, GFP_KERNEL,
+					     exynos_gem->dma_attrs);
+	if (!exynos_gem->cookie) {
+		DRM_DEV_ERROR(to_dma_dev(dev), "failed to allocate buffer.\n");
+		return -ENOMEM;
+	}
+
+	if (kvmap)
+		exynos_gem->kvaddr = exynos_gem->cookie;
+
+	DRM_DEV_DEBUG_KMS(to_dma_dev(dev), "dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
+	return 0;
+}
+
+static void exynos_drm_free_buf(struct exynos_drm_gem *exynos_gem)
+{
+	struct drm_device *dev = exynos_gem->base.dev;
+
+	if (!exynos_gem->dma_addr) {
+		DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr is invalid.\n");
+		return;
+	}
+
+	DRM_DEV_DEBUG_KMS(dev->dev, "dma_addr(0x%lx), size(0x%lx)\n",
+			(unsigned long)exynos_gem->dma_addr, exynos_gem->size);
+
+	dma_free_attrs(to_dma_dev(dev), exynos_gem->size, exynos_gem->cookie,
+			(dma_addr_t)exynos_gem->dma_addr,
+			exynos_gem->dma_attrs);
+}
+
+static int exynos_drm_gem_handle_create(struct drm_gem_object *obj,
+					struct drm_file *file_priv,
+					unsigned int *handle)
+{
+	int ret;
+
+	/*
+	 * allocate a id of idr table where the obj is registered
+	 * and handle has the id what user can see.
+	 */
+	ret = drm_gem_handle_create(file_priv, obj, handle);
+	if (ret)
+		return ret;
+
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "gem handle = 0x%x\n", *handle);
+
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_put(obj);
+
+	return 0;
+}
+
+void exynos_drm_gem_destroy(struct exynos_drm_gem *exynos_gem)
+{
+	struct drm_gem_object *obj = &exynos_gem->base;
+
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "handle count = %d\n",
+			  obj->handle_count);
+
+	/*
+	 * do not release memory region from exporter.
+	 *
+	 * the region will be released by exporter
+	 * once dmabuf's refcount becomes 0.
+	 */
+	if (obj->import_attach)
+		drm_prime_gem_destroy(obj, exynos_gem->sgt);
+	else
+		exynos_drm_free_buf(exynos_gem);
+
+	/* release file pointer to gem object. */
+	drm_gem_object_release(obj);
+
+	kfree(exynos_gem);
+}
+
+static const struct vm_operations_struct exynos_drm_gem_vm_ops = {
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+static const struct drm_gem_object_funcs exynos_drm_gem_object_funcs = {
+	.free = exynos_drm_gem_free_object,
+	.get_sg_table = exynos_drm_gem_prime_get_sg_table,
+	.mmap = exynos_drm_gem_mmap,
+	.vm_ops = &exynos_drm_gem_vm_ops,
+};
+
+static struct exynos_drm_gem *exynos_drm_gem_init(struct drm_device *dev,
+						  unsigned long size)
+{
+	struct exynos_drm_gem *exynos_gem;
+	struct drm_gem_object *obj;
+	int ret;
+
+	exynos_gem = kzalloc(sizeof(*exynos_gem), GFP_KERNEL);
+	if (!exynos_gem)
+		return ERR_PTR(-ENOMEM);
+
+	exynos_gem->size = size;
+	obj = &exynos_gem->base;
+
+	obj->funcs = &exynos_drm_gem_object_funcs;
+
+	ret = drm_gem_object_init(dev, obj, size);
+	if (ret < 0) {
+		DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
+	}
+
+	ret = drm_gem_create_mmap_offset(obj);
+	if (ret < 0) {
+		drm_gem_object_release(obj);
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
+	}
+
+	DRM_DEV_DEBUG_KMS(dev->dev, "created file object = %pK\n", obj->filp);
+
+	return exynos_gem;
+}
+
+struct exynos_drm_gem *exynos_drm_gem_create(struct drm_device *dev,
+					     unsigned int flags,
+					     unsigned long size,
+					     bool kvmap)
+{
+	struct exynos_drm_gem *exynos_gem;
+	int ret;
+
+	if (flags & ~(EXYNOS_BO_MASK)) {
+		DRM_DEV_ERROR(dev->dev,
+			      "invalid GEM buffer flags: %u\n", flags);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!size) {
+		DRM_DEV_ERROR(dev->dev, "invalid GEM buffer size: %lu\n", size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	size = roundup(size, PAGE_SIZE);
+
+	exynos_gem = exynos_drm_gem_init(dev, size);
+	if (IS_ERR(exynos_gem))
+		return exynos_gem;
+
+	if (!is_drm_iommu_supported(dev) && (flags & EXYNOS_BO_NONCONTIG)) {
+		/*
+		 * when no IOMMU is available, all allocated buffers are
+		 * contiguous anyway, so drop EXYNOS_BO_NONCONTIG flag
+		 */
+		flags &= ~EXYNOS_BO_NONCONTIG;
+		DRM_WARN("Non-contiguous allocation is not supported without IOMMU, falling back to contiguous buffer\n");
+	}
+
+	/* set memory type and cache attribute from user side. */
+	exynos_gem->flags = flags;
+
+	ret = exynos_drm_alloc_buf(exynos_gem, kvmap);
+	if (ret < 0) {
+		drm_gem_object_release(&exynos_gem->base);
+		kfree(exynos_gem);
+		return ERR_PTR(ret);
+	}
+
+	return exynos_gem;
+}
+
+int exynos_drm_gem_create_ioctl(struct drm_device *dev, void *data,
+				struct drm_file *file_priv)
+{
+	struct drm_exynos_gem_create *args = data;
+	struct exynos_drm_gem *exynos_gem;
+	int ret;
+
+	exynos_gem = exynos_drm_gem_create(dev, args->flags, args->size, false);
+	if (IS_ERR(exynos_gem))
+		return PTR_ERR(exynos_gem);
+
+	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
+					   &args->handle);
+	if (ret) {
+		exynos_drm_gem_destroy(exynos_gem);
+		return ret;
+	}
+
+	return 0;
+}
+
+int exynos_drm_gem_map_ioctl(struct drm_device *dev, void *data,
+			     struct drm_file *file_priv)
+{
+	struct drm_exynos_gem_map *args = data;
+
+	return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
+				       &args->offset);
+}
+
+struct exynos_drm_gem *exynos_drm_gem_get(struct drm_file *filp,
+					  unsigned int gem_handle)
+{
+	struct drm_gem_object *obj;
+
+	obj = drm_gem_object_lookup(filp, gem_handle);
+	if (!obj)
+		return NULL;
+	return to_exynos_gem(obj);
+}
+
+static int exynos_drm_gem_mmap_buffer(struct exynos_drm_gem *exynos_gem,
+				      struct vm_area_struct *vma)
+{
+	struct drm_device *drm_dev = exynos_gem->base.dev;
+	unsigned long vm_size;
+	int ret;
+
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_pgoff = 0;
+
+	vm_size = vma->vm_end - vma->vm_start;
+
+	/* check if user-requested size is valid. */
+	if (vm_size > exynos_gem->size)
+		return -EINVAL;
+
+	ret = dma_mmap_attrs(to_dma_dev(drm_dev), vma, exynos_gem->cookie,
+			     exynos_gem->dma_addr, exynos_gem->size,
+			     exynos_gem->dma_attrs);
+	if (ret < 0) {
+		DRM_ERROR("failed to mmap.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+int exynos_drm_gem_get_ioctl(struct drm_device *dev, void *data,
+				      struct drm_file *file_priv)
+{
+	struct exynos_drm_gem *exynos_gem;
+	struct drm_exynos_gem_info *args = data;
+	struct drm_gem_object *obj;
+
+	obj = drm_gem_object_lookup(file_priv, args->handle);
+	if (!obj) {
+		DRM_DEV_ERROR(dev->dev, "failed to lookup gem object.\n");
+		return -EINVAL;
+	}
+
+	exynos_gem = to_exynos_gem(obj);
+
+	args->flags = exynos_gem->flags;
+	args->size = exynos_gem->size;
+
+	drm_gem_object_put(obj);
+
+	return 0;
+}
+
+void exynos_drm_gem_free_object(struct drm_gem_object *obj)
+{
+	exynos_drm_gem_destroy(to_exynos_gem(obj));
+}
+
+int exynos_drm_gem_dumb_create(struct drm_file *file_priv,
+			       struct drm_device *dev,
+			       struct drm_mode_create_dumb *args)
+{
+	struct exynos_drm_gem *exynos_gem;
+	unsigned int flags;
+	int ret;
+
+	/*
+	 * allocate memory to be used for framebuffer.
+	 * - this callback would be called by user application
+	 *	with DRM_IOCTL_MODE_CREATE_DUMB command.
+	 */
+
+	args->pitch = args->width * ((args->bpp + 7) / 8);
+	args->size = args->pitch * args->height;
+
+	if (is_drm_iommu_supported(dev))
+		flags = EXYNOS_BO_NONCONTIG | EXYNOS_BO_WC;
+	else
+		flags = EXYNOS_BO_CONTIG | EXYNOS_BO_WC;
+
+	exynos_gem = exynos_drm_gem_create(dev, flags, args->size, false);
+	if (IS_ERR(exynos_gem)) {
+		dev_warn(dev->dev, "FB allocation failed.\n");
+		return PTR_ERR(exynos_gem);
+	}
+
+	ret = exynos_drm_gem_handle_create(&exynos_gem->base, file_priv,
+					   &args->handle);
+	if (ret) {
+		exynos_drm_gem_destroy(exynos_gem);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int exynos_drm_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
+{
+	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
+	int ret;
+
+	if (obj->import_attach)
+		return dma_buf_mmap(obj->dma_buf, vma, 0);
+
+	vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
+
+	DRM_DEV_DEBUG_KMS(to_dma_dev(obj->dev), "flags = 0x%x\n",
+			  exynos_gem->flags);
+
+	/* non-cachable as default. */
+	if (exynos_gem->flags & EXYNOS_BO_CACHABLE)
+		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+	else if (exynos_gem->flags & EXYNOS_BO_WC)
+		vma->vm_page_prot =
+			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+	else
+		vma->vm_page_prot =
+			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
+
+	ret = exynos_drm_gem_mmap_buffer(exynos_gem, vma);
+	if (ret)
+		goto err_close_vm;
+
+	return ret;
+
+err_close_vm:
+	drm_gem_vm_close(vma);
+
+	return ret;
+}
+
+/* low-level interface prime helpers */
+struct drm_gem_object *exynos_drm_gem_prime_import(struct drm_device *dev,
+					    struct dma_buf *dma_buf)
+{
+	return drm_gem_prime_import_dev(dev, dma_buf, to_dma_dev(dev));
+}
+
+struct sg_table *exynos_drm_gem_prime_get_sg_table(struct drm_gem_object *obj)
+{
+	struct exynos_drm_gem *exynos_gem = to_exynos_gem(obj);
+	struct drm_device *drm_dev = obj->dev;
+	struct sg_table *sgt;
+	int ret;
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	ret = dma_get_sgtable_attrs(to_dma_dev(drm_dev), sgt, exynos_gem->cookie,
+				    exynos_gem->dma_addr, exynos_gem->size,
+				    exynos_gem->dma_attrs);
+	if (ret) {
+		DRM_ERROR("failed to get sgtable, %d\n", ret);
+		kfree(sgt);
+		return ERR_PTR(ret);
+	}
+
+	return sgt;
+}
+
+struct drm_gem_object *
+exynos_drm_gem_prime_import_sg_table(struct drm_device *dev,
+				     struct dma_buf_attachment *attach,
+				     struct sg_table *sgt)
+{
+	struct exynos_drm_gem *exynos_gem;
+
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size) {
+		DRM_ERROR("buffer chunks must be mapped contiguously");
+		return ERR_PTR(-EINVAL);
+	}
+
+	exynos_gem = exynos_drm_gem_init(dev, attach->dmabuf->size);
+	if (IS_ERR(exynos_gem))
+		return ERR_CAST(exynos_gem);
+
+	/*
+	 * Buffer has been mapped as contiguous into DMA address space,
+	 * but if there is IOMMU, it can be either CONTIG or NONCONTIG.
+	 * We assume a simplified logic below:
+	 */
+	if (is_drm_iommu_supported(dev))
+		exynos_gem->flags |= EXYNOS_BO_NONCONTIG;
+	else
+		exynos_gem->flags |= EXYNOS_BO_CONTIG;
+
+	exynos_gem->dma_addr = sg_dma_address(sgt->sgl);
+	exynos_gem->sgt = sgt;
+	return &exynos_gem->base;
+}