Re: [PATCH v3] drm/vgem: implement virtual GEM

On Tue, Feb 10, 2015 at 3:46 PM, Zach Reizner zachr@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@gmail.com

Re-Reviewed-by: Rob Clark robdclark@gmail.com (well, just the get/put_pages bits, but that was all that changed)

Reviewed-by: Stéphane Marchesin marcheu@chromium.org Signed-off-by: Adam Jackson ajax@redhat.com Signed-off-by: Ben Widawsky ben@bwidawsk.net Signed-off-by: Zach Reizner zachr@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@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@redhat.com>
    

• • Ben Widawsky <ben@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@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