Initial import

1 files changed, 543 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
new file mode 100644
index 000000000..e419eedf7
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -0,0 +1,543 @@
+/*
+ * drm gem CMA (contiguous memory allocator) helper functions
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ *
+ * Based on Samsung Exynos code
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/export.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_vma_manager.h>
+
+/**
+ * DOC: cma helpers
+ *
+ * The Contiguous Memory Allocator reserves a pool of memory at early boot
+ * that is used to service requests for large blocks of contiguous memory.
+ *
+ * The DRM GEM/CMA helpers use this allocator as a means to provide buffer
+ * objects that are physically contiguous in memory. This is useful for
+ * display drivers that are unable to map scattered buffers via an IOMMU.
+ */
+
+/**
+ * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
+ * @drm: DRM device
+ * @size: size of the object to allocate
+ *
+ * This function creates and initializes a GEM CMA object of the given size,
+ * but doesn't allocate any memory to back the object.
+ *
+ * Returns:
+ * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+static struct drm_gem_cma_object *
+__drm_gem_cma_create(struct drm_device *drm, size_t size)
+{
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_gem_object *gem_obj;
+	int ret;
+
+	cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
+	if (!cma_obj)
+		return ERR_PTR(-ENOMEM);
+
+	gem_obj = &cma_obj->base;
+
+	ret = drm_gem_object_init(drm, gem_obj, size);
+	if (ret)
+		goto error;
+
+	ret = drm_gem_create_mmap_offset(gem_obj);
+	if (ret) {
+		drm_gem_object_release(gem_obj);
+		goto error;
+	}
+
+	return cma_obj;
+
+error:
+	kfree(cma_obj);
+	return ERR_PTR(ret);
+}
+
+/**
+ * drm_gem_cma_create - allocate an object with the given size
+ * @drm: DRM device
+ * @size: size of the object to allocate
+ *
+ * This function creates a CMA GEM object and allocates a contiguous chunk of
+ * memory as backing store. The backing memory has the writecombine attribute
+ * set.
+ *
+ * Returns:
+ * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
+					      size_t size)
+{
+	struct drm_gem_cma_object *cma_obj;
+	int ret;
+
+	size = round_up(size, PAGE_SIZE);
+
+	cma_obj = __drm_gem_cma_create(drm, size);
+	if (IS_ERR(cma_obj))
+		return cma_obj;
+
+	cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
+			&cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
+	if (!cma_obj->vaddr) {
+		dev_err(drm->dev, "failed to allocate buffer with size %d\n",
+			size);
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	return cma_obj;
+
+error:
+	drm_gem_cma_free_object(&cma_obj->base);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_create);
+
+/**
+ * drm_gem_cma_create_with_handle - allocate an object with the given size and
+ *     return a GEM handle to it
+ * @file_priv: DRM file-private structure to register the handle for
+ * @drm: DRM device
+ * @size: size of the object to allocate
+ * @handle: return location for the GEM handle
+ *
+ * This function creates a CMA GEM object, allocating a physically contiguous
+ * chunk of memory as backing store. The GEM object is then added to the list
+ * of object associated with the given file and a handle to it is returned.
+ *
+ * Returns:
+ * A struct drm_gem_cma_object * on success or an ERR_PTR()-encoded negative
+ * error code on failure.
+ */
+static struct drm_gem_cma_object *
+drm_gem_cma_create_with_handle(struct drm_file *file_priv,
+			       struct drm_device *drm, size_t size,
+			       uint32_t *handle)
+{
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_gem_object *gem_obj;
+	int ret;
+
+	cma_obj = drm_gem_cma_create(drm, size);
+	if (IS_ERR(cma_obj))
+		return cma_obj;
+
+	gem_obj = &cma_obj->base;
+
+	/*
+	 * 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, gem_obj, handle);
+	if (ret)
+		goto err_handle_create;
+
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_unreference_unlocked(gem_obj);
+
+	return cma_obj;
+
+err_handle_create:
+	drm_gem_cma_free_object(gem_obj);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * drm_gem_cma_free_object - free resources associated with a CMA GEM object
+ * @gem_obj: GEM object to free
+ *
+ * This function frees the backing memory of the CMA GEM object, cleans up the
+ * GEM object state and frees the memory used to store the object itself.
+ * Drivers using the CMA helpers should set this as their DRM driver's
+ * ->gem_free_object() callback.
+ */
+void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
+{
+	struct drm_gem_cma_object *cma_obj;
+
+	cma_obj = to_drm_gem_cma_obj(gem_obj);
+
+	if (cma_obj->vaddr) {
+		dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
+				      cma_obj->vaddr, cma_obj->paddr);
+	} else if (gem_obj->import_attach) {
+		drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
+	}
+
+	drm_gem_object_release(gem_obj);
+
+	kfree(cma_obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
+
+/**
+ * drm_gem_cma_dumb_create_internal - create a dumb buffer object
+ * @file_priv: DRM file-private structure to create the dumb buffer for
+ * @drm: DRM device
+ * @args: IOCTL data
+ *
+ * This aligns the pitch and size arguments to the minimum required. This is
+ * an internal helper that can be wrapped by a driver to account for hardware
+ * with more specific alignment requirements. It should not be used directly
+ * as the ->dumb_create() callback in a DRM driver.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_dumb_create_internal(struct drm_file *file_priv,
+				     struct drm_device *drm,
+				     struct drm_mode_create_dumb *args)
+{
+	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+	struct drm_gem_cma_object *cma_obj;
+
+	if (args->pitch < min_pitch)
+		args->pitch = min_pitch;
+
+	if (args->size < args->pitch * args->height)
+		args->size = args->pitch * args->height;
+
+	cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size,
+						 &args->handle);
+	return PTR_ERR_OR_ZERO(cma_obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create_internal);
+
+/**
+ * drm_gem_cma_dumb_create - create a dumb buffer object
+ * @file_priv: DRM file-private structure to create the dumb buffer for
+ * @drm: DRM device
+ * @args: IOCTL data
+ *
+ * This function computes the pitch of the dumb buffer and rounds it up to an
+ * integer number of bytes per pixel. Drivers for hardware that doesn't have
+ * any additional restrictions on the pitch can directly use this function as
+ * their ->dumb_create() callback.
+ *
+ * For hardware with additional restrictions, drivers can adjust the fields
+ * set up by userspace and pass the IOCTL data along to the
+ * drm_gem_cma_dumb_create_internal() function.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_dumb_create(struct drm_file *file_priv,
+			    struct drm_device *drm,
+			    struct drm_mode_create_dumb *args)
+{
+	struct drm_gem_cma_object *cma_obj;
+
+	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+	args->size = args->pitch * args->height;
+
+	cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size,
+						 &args->handle);
+	return PTR_ERR_OR_ZERO(cma_obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
+
+/**
+ * drm_gem_cma_dumb_map_offset - return the fake mmap offset for a CMA GEM
+ *     object
+ * @file_priv: DRM file-private structure containing the GEM object
+ * @drm: DRM device
+ * @handle: GEM object handle
+ * @offset: return location for the fake mmap offset
+ *
+ * This function look up an object by its handle and returns the fake mmap
+ * offset associated with it. Drivers using the CMA helpers should set this
+ * as their DRM driver's ->dumb_map_offset() callback.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
+				struct drm_device *drm, u32 handle,
+				u64 *offset)
+{
+	struct drm_gem_object *gem_obj;
+
+	mutex_lock(&drm->struct_mutex);
+
+	gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
+	if (!gem_obj) {
+		dev_err(drm->dev, "failed to lookup GEM object\n");
+		mutex_unlock(&drm->struct_mutex);
+		return -EINVAL;
+	}
+
+	*offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
+
+	drm_gem_object_unreference(gem_obj);
+
+	mutex_unlock(&drm->struct_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
+
+const struct vm_operations_struct drm_gem_cma_vm_ops = {
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
+
+static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj,
+				struct vm_area_struct *vma)
+{
+	int ret;
+
+	/*
+	 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
+	 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
+	 * the whole buffer.
+	 */
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_pgoff = 0;
+
+	ret = dma_mmap_writecombine(cma_obj->base.dev->dev, vma,
+				    cma_obj->vaddr, cma_obj->paddr,
+				    vma->vm_end - vma->vm_start);
+	if (ret)
+		drm_gem_vm_close(vma);
+
+	return ret;
+}
+
+/**
+ * drm_gem_cma_mmap - memory-map a CMA GEM object
+ * @filp: file object
+ * @vma: VMA for the area to be mapped
+ *
+ * This function implements an augmented version of the GEM DRM file mmap
+ * operation for CMA objects: In addition to the usual GEM VMA setup it
+ * immediately faults in the entire object instead of using on-demaind
+ * faulting. Drivers which employ the CMA helpers should use this function
+ * as their ->mmap() handler in the DRM device file's file_operations
+ * structure.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_gem_object *gem_obj;
+	int ret;
+
+	ret = drm_gem_mmap(filp, vma);
+	if (ret)
+		return ret;
+
+	gem_obj = vma->vm_private_data;
+	cma_obj = to_drm_gem_cma_obj(gem_obj);
+
+	return drm_gem_cma_mmap_obj(cma_obj, vma);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
+
+#ifdef CONFIG_DEBUG_FS
+/**
+ * drm_gem_cma_describe - describe a CMA GEM object for debugfs
+ * @cma_obj: CMA GEM object
+ * @m: debugfs file handle
+ *
+ * This function can be used to dump a human-readable representation of the
+ * CMA GEM object into a synthetic file.
+ */
+void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj,
+			  struct seq_file *m)
+{
+	struct drm_gem_object *obj = &cma_obj->base;
+	struct drm_device *dev = obj->dev;
+	uint64_t off;
+
+	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
+	off = drm_vma_node_start(&obj->vma_node);
+
+	seq_printf(m, "%2d (%2d) %08llx %pad %p %d",
+			obj->name, obj->refcount.refcount.counter,
+			off, &cma_obj->paddr, cma_obj->vaddr, obj->size);
+
+	seq_printf(m, "\n");
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
+#endif
+
+/**
+ * drm_gem_cma_prime_get_sg_table - provide a scatter/gather table of pinned
+ *     pages for a CMA GEM object
+ * @obj: GEM object
+ *
+ * This function exports a scatter/gather table suitable for PRIME usage by
+ * calling the standard DMA mapping API. Drivers using the CMA helpers should
+ * set this as their DRM driver's ->gem_prime_get_sg_table() callback.
+ *
+ * Returns:
+ * A pointer to the scatter/gather table of pinned pages or NULL on failure.
+ */
+struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)
+{
+	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
+	struct sg_table *sgt;
+	int ret;
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return NULL;
+
+	ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
+			      cma_obj->paddr, obj->size);
+	if (ret < 0)
+		goto out;
+
+	return sgt;
+
+out:
+	kfree(sgt);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);
+
+/**
+ * drm_gem_cma_prime_import_sg_table - produce a CMA GEM object from another
+ *     driver's scatter/gather table of pinned pages
+ * @dev: device to import into
+ * @attach: DMA-BUF attachment
+ * @sgt: scatter/gather table of pinned pages
+ *
+ * This function imports a scatter/gather table exported via DMA-BUF by
+ * another driver. Imported buffers must be physically contiguous in memory
+ * (i.e. the scatter/gather table must contain a single entry). Drivers that
+ * use the CMA helpers should set this as their DRM driver's
+ * ->gem_prime_import_sg_table() callback.
+ *
+ * Returns:
+ * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_object *
+drm_gem_cma_prime_import_sg_table(struct drm_device *dev,
+				  struct dma_buf_attachment *attach,
+				  struct sg_table *sgt)
+{
+	struct drm_gem_cma_object *cma_obj;
+
+	if (sgt->nents != 1)
+		return ERR_PTR(-EINVAL);
+
+	/* Create a CMA GEM buffer. */
+	cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size);
+	if (IS_ERR(cma_obj))
+		return ERR_CAST(cma_obj);
+
+	cma_obj->paddr = sg_dma_address(sgt->sgl);
+	cma_obj->sgt = sgt;
+
+	DRM_DEBUG_PRIME("dma_addr = %pad, size = %zu\n", &cma_obj->paddr, attach->dmabuf->size);
+
+	return &cma_obj->base;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);
+
+/**
+ * drm_gem_cma_prime_mmap - memory-map an exported CMA GEM object
+ * @obj: GEM object
+ * @vma: VMA for the area to be mapped
+ *
+ * This function maps a buffer imported via DRM PRIME into a userspace
+ * process's address space. Drivers that use the CMA helpers should set this
+ * as their DRM driver's ->gem_prime_mmap() callback.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
+			   struct vm_area_struct *vma)
+{
+	struct drm_gem_cma_object *cma_obj;
+	struct drm_device *dev = obj->dev;
+	int ret;
+
+	mutex_lock(&dev->struct_mutex);
+	ret = drm_gem_mmap_obj(obj, obj->size, vma);
+	mutex_unlock(&dev->struct_mutex);
+	if (ret < 0)
+		return ret;
+
+	cma_obj = to_drm_gem_cma_obj(obj);
+	return drm_gem_cma_mmap_obj(cma_obj, vma);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
+
+/**
+ * drm_gem_cma_prime_vmap - map a CMA GEM object into the kernel's virtual
+ *     address space
+ * @obj: GEM object
+ *
+ * This function maps a buffer exported via DRM PRIME into the kernel's
+ * virtual address space. Since the CMA buffers are already mapped into the
+ * kernel virtual address space this simply returns the cached virtual
+ * address. Drivers using the CMA helpers should set this as their DRM
+ * driver's ->gem_prime_vmap() callback.
+ *
+ * Returns:
+ * The kernel virtual address of the CMA GEM object's backing store.
+ */
+void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
+{
+	struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
+
+	return cma_obj->vaddr;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
+
+/**
+ * drm_gem_cma_prime_vunmap - unmap a CMA GEM object from the kernel's virtual
+ *     address space
+ * @obj: GEM object
+ * @vaddr: kernel virtual address where the CMA GEM object was mapped
+ *
+ * This function removes a buffer exported via DRM PRIME from the kernel's
+ * virtual address space. This is a no-op because CMA buffers cannot be
+ * unmapped from kernel space. Drivers using the CMA helpers should set this
+ * as their DRM driver's ->gem_prime_vunmap() callback.
+ */
+void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+{
+	/* Nothing to do */
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);