4 files changed, 302 insertions, 0 deletions

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 0cbdc458011f..2df146dd0c85 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -54,6 +54,12 @@ config DRM_TTM
           GPU memory types. Will be enabled automatically if a device driver
           uses it.
 
+config DRM_GEM_CMA_HELPER
+        bool
+        depends on DRM
+        help
+          Choose this if you need the GEM CMA helper functions
+
 config DRM_TDFX
         tristate "3dfx Banshee/Voodoo3+"
         depends on DRM && PCI
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index f65f65ed0ddf..2fcedbb7d638 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -15,6 +15,7 @@ drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
                 drm_trace_points.o drm_global.o drm_prime.o
 
 drm-$(CONFIG_COMPAT) += drm_ioc32.o
+drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
 
 drm-usb-y   := drm_usb.o
 
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 000000000000..1aa8fee1e865
--- /dev/null
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -0,0 +1,251 @@
+/*
+ * 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-mapping.h>
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+#include <drm/drm_gem_cma_helper.h>
+
+static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj)
+{
+        return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT;
+}
+
+static void drm_gem_cma_buf_destroy(struct drm_device *drm,
+                struct drm_gem_cma_object *cma_obj)
+{
+        dma_free_writecombine(drm->dev, cma_obj->base.size, cma_obj->vaddr,
+                        cma_obj->paddr);
+}
+
+/*
+ * drm_gem_cma_create - allocate an object with the given size
+ *
+ * returns a struct drm_gem_cma_object* on success or ERR_PTR values
+ * on failure.
+ */
+struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
+                unsigned int size)
+{
+        struct drm_gem_cma_object *cma_obj;
+        struct drm_gem_object *gem_obj;
+        int ret;
+
+        size = round_up(size, PAGE_SIZE);
+
+        cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
+        if (!cma_obj)
+                return ERR_PTR(-ENOMEM);
+
+        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 err_dma_alloc;
+        }
+
+        gem_obj = &cma_obj->base;
+
+        ret = drm_gem_object_init(drm, gem_obj, size);
+        if (ret)
+                goto err_obj_init;
+
+        ret = drm_gem_create_mmap_offset(gem_obj);
+        if (ret)
+                goto err_create_mmap_offset;
+
+        return cma_obj;
+
+err_create_mmap_offset:
+        drm_gem_object_release(gem_obj);
+
+err_obj_init:
+        drm_gem_cma_buf_destroy(drm, cma_obj);
+
+err_dma_alloc:
+        kfree(cma_obj);
+
+        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 create a gem handle on it
+ *
+ * returns a struct drm_gem_cma_object* on success or ERR_PTR values
+ * on failure.
+ */
+static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
+                struct drm_file *file_priv,
+                struct drm_device *drm, unsigned int size,
+                unsigned int *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 - (struct drm_driver)->gem_free_object callback
+ * function
+ */
+void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
+{
+        struct drm_gem_cma_object *cma_obj;
+
+        if (gem_obj->map_list.map)
+                drm_gem_free_mmap_offset(gem_obj);
+
+        drm_gem_object_release(gem_obj);
+
+        cma_obj = to_drm_gem_cma_obj(gem_obj);
+
+        drm_gem_cma_buf_destroy(gem_obj->dev, cma_obj);
+
+        kfree(cma_obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
+
+/*
+ * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
+ * function
+ *
+ * This aligns the pitch and size arguments to the minimum required. wrap
+ * this into your own function if you need bigger alignment.
+ */
+int drm_gem_cma_dumb_create(struct drm_file *file_priv,
+                struct drm_device *dev, struct drm_mode_create_dumb *args)
+{
+        struct drm_gem_cma_object *cma_obj;
+        int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+
+        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, dev,
+                        args->size, &args->handle);
+        if (IS_ERR(cma_obj))
+                return PTR_ERR(cma_obj);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
+
+/*
+ * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
+ * function
+ */
+int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
+                struct drm_device *drm, uint32_t handle, uint64_t *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 = get_gem_mmap_offset(gem_obj);
+
+        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);
+
+/*
+ * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
+ */
+int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+        struct drm_gem_object *gem_obj;
+        struct drm_gem_cma_object *cma_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);
+
+        ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
+                        vma->vm_end - vma->vm_start, vma->vm_page_prot);
+        if (ret)
+                drm_gem_vm_close(vma);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
+
+/*
+ * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
+ */
+int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
+                struct drm_device *drm, unsigned int handle)
+{
+        return drm_gem_handle_delete(file_priv, handle);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
new file mode 100644
index 000000000000..f0f6b1af25ad
--- /dev/null
+++ b/include/drm/drm_gem_cma_helper.h
@@ -0,0 +1,44 @@
+#ifndef __DRM_GEM_CMA_HELPER_H__
+#define __DRM_GEM_CMA_HELPER_H__
+
+struct drm_gem_cma_object {
+        struct drm_gem_object base;
+        dma_addr_t paddr;
+        void *vaddr;
+};
+
+static inline struct drm_gem_cma_object *
+to_drm_gem_cma_obj(struct drm_gem_object *gem_obj)
+{
+        return container_of(gem_obj, struct drm_gem_cma_object, base);
+}
+
+/* free gem object. */
+void drm_gem_cma_free_object(struct drm_gem_object *gem_obj);
+
+/* create memory region for drm framebuffer. */
+int drm_gem_cma_dumb_create(struct drm_file *file_priv,
+                struct drm_device *drm, struct drm_mode_create_dumb *args);
+
+/* map memory region for drm framebuffer to user space. */
+int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
+                struct drm_device *drm, uint32_t handle, uint64_t *offset);
+
+/* set vm_flags and we can change the vm attribute to other one at here. */
+int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma);
+
+/*
+ * destroy memory region allocated.
+ *      - a gem handle and physical memory region pointed by a gem object
+ *      would be released by drm_gem_handle_delete().
+ */
+int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
+                struct drm_device *drm, unsigned int handle);
+
+/* allocate physical memory. */
+struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
+                unsigned int size);
+
+extern const struct vm_operations_struct drm_gem_cma_vm_ops;
+
+#endif /* __DRM_GEM_CMA_HELPER_H__ */