[PATCH v3] drm/vgem: implement virtual GEM
Rob Clark
robdclark at gmail.com
Wed Feb 18 12:58:36 PST 2015
On Tue, Feb 10, 2015 at 3:46 PM, Zach Reizner <zachr at google.com> wrote:
> This patch implements the virtual GEM driver with PRIME sharing which
> allows vgem to import a gem object from other drivers for the purpose
> of mmap-ing them to userspace. The mmap is done using the mmap
> operation exported by other drivers.
>
> v2: remove platform_device and do not attach to dma bufs
> v3: use drm helpers for get/put pages
>
> Reviewed-by: Rob Clark <robdclark at gmail.com>
Re-Reviewed-by: Rob Clark <robdclark at gmail.com>
(well, just the get/put_pages bits, but that was all that changed)
> Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
> Signed-off-by: Adam Jackson <ajax at redhat.com>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> Signed-off-by: Zach Reizner <zachr at google.com>
> ---
> drivers/gpu/drm/Kconfig | 9 +
> drivers/gpu/drm/Makefile | 1 +
> drivers/gpu/drm/vgem/Makefile | 4 +
> drivers/gpu/drm/vgem/vgem_dma_buf.c | 94 ++++++++++
> drivers/gpu/drm/vgem/vgem_drv.c | 363 ++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/vgem/vgem_drv.h | 57 ++++++
> 6 files changed, 528 insertions(+)
> create mode 100644 drivers/gpu/drm/vgem/Makefile
> create mode 100644 drivers/gpu/drm/vgem/vgem_dma_buf.c
> create mode 100644 drivers/gpu/drm/vgem/vgem_drv.c
> create mode 100644 drivers/gpu/drm/vgem/vgem_drv.h
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 308c104..b58f667 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -164,6 +164,15 @@ config DRM_SAVAGE
> Choose this option if you have a Savage3D/4/SuperSavage/Pro/Twister
> chipset. If M is selected the module will be called savage.
>
> +config DRM_VGEM
> + tristate "Virtual GEM provider"
> + depends on DRM
> + help
> + Choose this option to get a virtual graphics memory manager,
> + as used by Mesa's software renderer for enhanced performance.
> + If M is selected the module will be called vgem.
> +
> +
> source "drivers/gpu/drm/exynos/Kconfig"
>
> source "drivers/gpu/drm/rockchip/Kconfig"
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 2c239b9..7d4944e 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -48,6 +48,7 @@ obj-$(CONFIG_DRM_SIS) += sis/
> obj-$(CONFIG_DRM_SAVAGE)+= savage/
> obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
> obj-$(CONFIG_DRM_VIA) +=via/
> +obj-$(CONFIG_DRM_VGEM) += vgem/
> obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
> obj-$(CONFIG_DRM_EXYNOS) +=exynos/
> obj-$(CONFIG_DRM_ROCKCHIP) +=rockchip/
> diff --git a/drivers/gpu/drm/vgem/Makefile b/drivers/gpu/drm/vgem/Makefile
> new file mode 100644
> index 0000000..1055cb7
> --- /dev/null
> +++ b/drivers/gpu/drm/vgem/Makefile
> @@ -0,0 +1,4 @@
> +ccflags-y := -Iinclude/drm
> +vgem-y := vgem_drv.o vgem_dma_buf.o
> +
> +obj-$(CONFIG_DRM_VGEM) += vgem.o
> diff --git a/drivers/gpu/drm/vgem/vgem_dma_buf.c b/drivers/gpu/drm/vgem/vgem_dma_buf.c
> new file mode 100644
> index 0000000..0254438
> --- /dev/null
> +++ b/drivers/gpu/drm/vgem/vgem_dma_buf.c
> @@ -0,0 +1,94 @@
> +/*
> + * Copyright © 2012 Intel Corporation
> + * Copyright © 2014 The Chromium OS Authors
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + * Ben Widawsky <ben at bwidawsk.net>
> + *
> + */
> +
> +#include <linux/dma-buf.h>
> +#include "vgem_drv.h"
> +
> +struct sg_table *vgem_gem_prime_get_sg_table(struct drm_gem_object *gobj)
> +{
> + struct drm_vgem_gem_object *obj = to_vgem_bo(gobj);
> + BUG_ON(obj->pages == NULL);
> +
> + return drm_prime_pages_to_sg(obj->pages, obj->base.size / PAGE_SIZE);
> +}
> +
> +int vgem_gem_prime_pin(struct drm_gem_object *gobj)
> +{
> + struct drm_vgem_gem_object *obj = to_vgem_bo(gobj);
> + return vgem_gem_get_pages(obj);
> +}
> +
> +void vgem_gem_prime_unpin(struct drm_gem_object *gobj)
> +{
> + struct drm_vgem_gem_object *obj = to_vgem_bo(gobj);
> + vgem_gem_put_pages(obj);
> +}
> +
> +void *vgem_gem_prime_vmap(struct drm_gem_object *gobj)
> +{
> + struct drm_vgem_gem_object *obj = to_vgem_bo(gobj);
> + BUG_ON(obj->pages == NULL);
> +
> + return vmap(obj->pages, obj->base.size / PAGE_SIZE, 0, PAGE_KERNEL);
> +}
> +
> +void vgem_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
> +{
> + vunmap(vaddr);
> +}
> +
> +struct drm_gem_object *vgem_gem_prime_import(struct drm_device *dev,
> + struct dma_buf *dma_buf)
> +{
> + struct drm_vgem_gem_object *obj = NULL;
> + int ret;
> +
> + obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> + if (obj == NULL) {
> + ret = -ENOMEM;
> + goto fail;
> + }
> +
> + ret = drm_gem_object_init(dev, &obj->base, dma_buf->size);
> + if (ret) {
> + ret = -ENOMEM;
> + goto fail_free;
> + }
> +
> + get_dma_buf(dma_buf);
> +
> + obj->base.dma_buf = dma_buf;
> + obj->use_dma_buf = true;
> +
> + return &obj->base;
> +
> +fail_free:
> + kfree(obj);
> +fail:
> + return ERR_PTR(ret);
> +}
> diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
> new file mode 100644
> index 0000000..8b0cc10
> --- /dev/null
> +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> @@ -0,0 +1,363 @@
> +/*
> + * Copyright 2011 Red Hat, Inc.
> + * Copyright © 2014 The Chromium OS Authors
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software")
> + * to deal in the software without restriction, including without limitation
> + * on the rights to use, copy, modify, merge, publish, distribute, sub
> + * license, and/or sell copies of the Software, and to permit persons to whom
> + * them Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTIBILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY, WHETHER
> + * IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM, OUT OF OR IN
> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> + *
> + * Authors:
> + * Adam Jackson <ajax at redhat.com>
> + * Ben Widawsky <ben at bwidawsk.net>
> + */
> +
> +/**
> + * This is vgem, a (non-hardware-backed) GEM service. This is used by Mesa's
> + * software renderer and the X server for efficient buffer sharing.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/ramfs.h>
> +#include <linux/shmem_fs.h>
> +#include <linux/dma-buf.h>
> +#include "vgem_drv.h"
> +
> +#define DRIVER_NAME "vgem"
> +#define DRIVER_DESC "Virtual GEM provider"
> +#define DRIVER_DATE "20120112"
> +#define DRIVER_MAJOR 1
> +#define DRIVER_MINOR 0
> +
> +void vgem_gem_put_pages(struct drm_vgem_gem_object *obj)
> +{
> + drm_gem_put_pages(&obj->base, obj->pages, false, false);
> + obj->pages = NULL;
> +}
> +
> +static void vgem_gem_free_object(struct drm_gem_object *obj)
> +{
> + struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
> +
> + drm_gem_free_mmap_offset(obj);
> +
> + if (vgem_obj->use_dma_buf && obj->dma_buf) {
> + dma_buf_put(obj->dma_buf);
> + obj->dma_buf = NULL;
> + }
> +
> + drm_gem_object_release(obj);
> +
> + if (vgem_obj->pages)
> + vgem_gem_put_pages(vgem_obj);
> +
> + vgem_obj->pages = NULL;
> +
> + kfree(vgem_obj);
> +}
> +
> +int vgem_gem_get_pages(struct drm_vgem_gem_object *obj)
> +{
> + struct page **pages;
> +
> + if (obj->pages || obj->use_dma_buf)
> + return 0;
> +
> + pages = drm_gem_get_pages(&obj->base);
> + if (IS_ERR(pages)) {
> + return PTR_ERR(pages);
> + }
> +
> + obj->pages = pages;
> +
> + return 0;
> +}
> +
> +static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> +{
> + struct drm_vgem_gem_object *obj = vma->vm_private_data;
> + struct drm_device *dev = obj->base.dev;
> + loff_t num_pages;
> + pgoff_t page_offset;
> + int ret;
> +
> + /* We don't use vmf->pgoff since that has the fake offset */
> + page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
> + PAGE_SHIFT;
> +
> + num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
> +
> + if (page_offset > num_pages)
> + return VM_FAULT_SIGBUS;
> +
> + mutex_lock(&dev->struct_mutex);
> +
> + ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
> + obj->pages[page_offset]);
> +
> + mutex_unlock(&dev->struct_mutex);
> + switch (ret) {
> + case 0:
> + return VM_FAULT_NOPAGE;
> + case -ENOMEM:
> + return VM_FAULT_OOM;
> + case -EBUSY:
> + return VM_FAULT_RETRY;
> + case -EFAULT:
> + case -EINVAL:
> + return VM_FAULT_SIGBUS;
> + default:
> + WARN_ON(1);
> + return VM_FAULT_SIGBUS;
> + }
> +}
> +
> +static struct vm_operations_struct vgem_gem_vm_ops = {
> + .fault = vgem_gem_fault,
> + .open = drm_gem_vm_open,
> + .close = drm_gem_vm_close,
> +};
> +
> +/* ioctls */
> +
> +static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
> + struct drm_file *file,
> + unsigned int *handle,
> + unsigned long size)
> +{
> + struct drm_vgem_gem_object *obj;
> + struct drm_gem_object *gem_object;
> + int err;
> +
> + size = roundup(size, PAGE_SIZE);
> +
> + obj = kzalloc(sizeof(*obj), GFP_KERNEL);
> + if (!obj)
> + return ERR_PTR(-ENOMEM);
> +
> + gem_object = &obj->base;
> +
> + err = drm_gem_object_init(dev, gem_object, size);
> + if (err)
> + goto out;
> +
> + err = drm_gem_handle_create(file, gem_object, handle);
> + if (err)
> + goto handle_out;
> +
> + drm_gem_object_unreference_unlocked(gem_object);
> +
> + return gem_object;
> +
> +handle_out:
> + drm_gem_object_release(gem_object);
> +out:
> + kfree(obj);
> + return ERR_PTR(err);
> +}
> +
> +static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
> + struct drm_mode_create_dumb *args)
> +{
> + struct drm_gem_object *gem_object;
> + uint64_t size;
> +
> + size = args->height * args->width * DIV_ROUND_UP(args->bpp, 8);
> + if (size == 0)
> + return -EINVAL;
> +
> + gem_object = vgem_gem_create(dev, file, &args->handle, size);
> +
> + if (IS_ERR(gem_object)) {
> + DRM_DEBUG_DRIVER("object creation failed\n");
> + return PTR_ERR(gem_object);
> + }
> +
> + args->size = gem_object->size;
> + args->pitch = args->width;
> +
> + DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
> +
> + return 0;
> +}
> +
> +int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
> + uint32_t handle, uint64_t *offset)
> +{
> + int ret = 0;
> + struct drm_gem_object *obj;
> +
> + mutex_lock(&dev->struct_mutex);
> + obj = drm_gem_object_lookup(dev, file, handle);
> + if (!obj) {
> + ret = -ENOENT;
> + goto unlock;
> + }
> +
> + if (!drm_vma_node_has_offset(&obj->vma_node)) {
> + ret = drm_gem_create_mmap_offset(obj);
> + if (ret)
> + goto unref;
> + }
> +
> + BUG_ON(!obj->filp);
> +
> + obj->filp->private_data = obj;
> +
> + ret = vgem_gem_get_pages(to_vgem_bo(obj));
> + if (ret)
> + goto fail_get_pages;
> +
> + *offset = drm_vma_node_offset_addr(&obj->vma_node);
> +
> + goto unref;
> +
> +fail_get_pages:
> + drm_gem_free_mmap_offset(obj);
> +unref:
> + drm_gem_object_unreference(obj);
> +unlock:
> + mutex_unlock(&dev->struct_mutex);
> + return ret;
> +}
> +
> +int vgem_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
> +{
> + struct drm_file *priv = filp->private_data;
> + struct drm_device *dev = priv->minor->dev;
> + struct drm_vma_offset_node *node;
> + struct drm_gem_object *obj;
> + struct drm_vgem_gem_object *vgem_obj;
> + int ret = 0;
> +
> + mutex_lock(&dev->struct_mutex);
> +
> + node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
> + vma->vm_pgoff,
> + vma_pages(vma));
> + if (!node) {
> + ret = -EINVAL;
> + goto out_unlock;
> + } else if (!drm_vma_node_is_allowed(node, filp)) {
> + ret = -EACCES;
> + goto out_unlock;
> + }
> +
> + obj = container_of(node, struct drm_gem_object, vma_node);
> +
> + vgem_obj = to_vgem_bo(obj);
> +
> + if (obj->dma_buf && vgem_obj->use_dma_buf) {
> + ret = dma_buf_mmap(obj->dma_buf, vma, 0);
> + goto out_unlock;
> + }
> +
> + if (!obj->dev->driver->gem_vm_ops) {
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> +
> + vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
> + vma->vm_ops = obj->dev->driver->gem_vm_ops;
> + vma->vm_private_data = vgem_obj;
> + vma->vm_page_prot =
> + pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
> +
> + mutex_unlock(&dev->struct_mutex);
> + drm_gem_vm_open(vma);
> + return ret;
> +
> +out_unlock:
> + mutex_unlock(&dev->struct_mutex);
> +
> + return ret;
> +}
> +
> +
> +static struct drm_ioctl_desc vgem_ioctls[] = {
> +};
> +
> +static const struct file_operations vgem_driver_fops = {
> + .owner = THIS_MODULE,
> + .open = drm_open,
> + .mmap = vgem_drm_gem_mmap,
> + .poll = drm_poll,
> + .read = drm_read,
> + .unlocked_ioctl = drm_ioctl,
> + .release = drm_release,
> +};
> +
> +static struct drm_driver vgem_driver = {
> + .driver_features = DRIVER_GEM | DRIVER_PRIME,
> + .gem_free_object = vgem_gem_free_object,
> + .gem_vm_ops = &vgem_gem_vm_ops,
> + .ioctls = vgem_ioctls,
> + .fops = &vgem_driver_fops,
> + .dumb_create = vgem_gem_dumb_create,
> + .dumb_map_offset = vgem_gem_dumb_map,
> + .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
> + .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
> + .gem_prime_export = drm_gem_prime_export,
> + .gem_prime_import = vgem_gem_prime_import,
> + .gem_prime_pin = vgem_gem_prime_pin,
> + .gem_prime_unpin = vgem_gem_prime_unpin,
> + .gem_prime_get_sg_table = vgem_gem_prime_get_sg_table,
> + .gem_prime_vmap = vgem_gem_prime_vmap,
> + .gem_prime_vunmap = vgem_gem_prime_vunmap,
> + .name = DRIVER_NAME,
> + .desc = DRIVER_DESC,
> + .date = DRIVER_DATE,
> + .major = DRIVER_MAJOR,
> + .minor = DRIVER_MINOR,
> +};
> +
> +struct drm_device *vgem_device;
> +
> +static int __init vgem_init(void)
> +{
> + int ret;
> +
> + vgem_device = drm_dev_alloc(&vgem_driver, NULL);
> + if (!vgem_device) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + ret = drm_dev_register(vgem_device, 0);
> +
> + if (ret)
> + goto out_unref;
> +
> + return 0;
> +
> +out_unref:
> + drm_dev_unref(vgem_device);
> +out:
> + return ret;
> +}
> +
> +static void __exit vgem_exit(void)
> +{
> + drm_dev_unregister(vgem_device);
> + drm_dev_unref(vgem_device);
> +}
> +
> +module_init(vgem_init);
> +module_exit(vgem_exit);
> +
> +MODULE_AUTHOR("Red Hat, Inc.");
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL and additional rights");
> diff --git a/drivers/gpu/drm/vgem/vgem_drv.h b/drivers/gpu/drm/vgem/vgem_drv.h
> new file mode 100644
> index 0000000..57ab4d8
> --- /dev/null
> +++ b/drivers/gpu/drm/vgem/vgem_drv.h
> @@ -0,0 +1,57 @@
> +/*
> + * Copyright © 2012 Intel Corporation
> + * Copyright © 2014 The Chromium OS Authors
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + * Ben Widawsky <ben at bwidawsk.net>
> + *
> + */
> +
> +#ifndef _VGEM_DRV_H_
> +#define _VGEM_DRV_H_
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_gem.h>
> +
> +#define to_vgem_bo(x) container_of(x, struct drm_vgem_gem_object, base)
> +struct drm_vgem_gem_object {
> + struct drm_gem_object base;
> + struct page **pages;
> + bool use_dma_buf;
> +};
> +
> +/* vgem_drv.c */
> +extern void vgem_gem_put_pages(struct drm_vgem_gem_object *obj);
> +extern int vgem_gem_get_pages(struct drm_vgem_gem_object *obj);
> +
> +/* vgem_dma_buf.c */
> +extern struct sg_table *vgem_gem_prime_get_sg_table(
> + struct drm_gem_object *gobj);
> +extern int vgem_gem_prime_pin(struct drm_gem_object *gobj);
> +extern void vgem_gem_prime_unpin(struct drm_gem_object *gobj);
> +extern void *vgem_gem_prime_vmap(struct drm_gem_object *gobj);
> +extern void vgem_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);
> +extern struct drm_gem_object *vgem_gem_prime_import(struct drm_device *dev,
> + struct dma_buf *dma_buf);
> +
> +
> +#endif
> --
> 2.2.0.rc0.207.ga3a616c
>
More information about the dri-devel
mailing list