[Intel-gfx] [PATCH] drm/vgem: use shmem helpers
Thomas Zimmermann
tzimmermann at suse.de
Fri Feb 26 13:51:58 UTC 2021
Hi
Am 26.02.21 um 14:30 schrieb Daniel Vetter:
> On Fri, Feb 26, 2021 at 10:19 AM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>
>> Hi
>>
>> Am 25.02.21 um 11:23 schrieb Daniel Vetter:
>>> Aside from deleting lots of code the real motivation here is to switch
>>> the mmap over to VM_PFNMAP, to be more consistent with what real gpu
>>> drivers do. They're all VM_PFNMP, which means get_user_pages doesn't
>>> work, and even if you try and there's a struct page behind that,
>>> touching it and mucking around with its refcount can upset drivers
>>> real bad.
>>>
>>> v2: Review from Thomas:
>>> - sort #include
>>> - drop more dead code that I didn't spot somehow
>>>
>>> v3: select DRM_GEM_SHMEM_HELPER to make it build (intel-gfx-ci)
>>
>> Since you're working on it, could you move the config item into a
>> Kconfig file under vgem?
>
> We have a lot of drivers still without their own Kconfig. I thought
> we're only doing that for drivers which have multiple options, or
> otherwise would clutter up the main drm/Kconfig file?
>
> Not opposed to this, just feels like if we do this, should do it for
> all of them.
I didn't know that there was a rule for how to handle this. I just
didn't like to have driver config rules in the main Kconfig file.
But yeah, maybe let's change this consistently in a separate patchset.
Best regards
Thomas
> -Daniel
>
>
>>
>> Best regards
>> Thomas
>>
>>>
>>> Cc: Thomas Zimmermann <tzimmermann at suse.de>
>>> Acked-by: Thomas Zimmermann <tzimmermann at suse.de>
>>> Cc: John Stultz <john.stultz at linaro.org>
>>> Cc: Sumit Semwal <sumit.semwal at linaro.org>
>>> Cc: "Christian König" <christian.koenig at amd.com>
>>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>>> Cc: Melissa Wen <melissa.srw at gmail.com>
>>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>>> ---
>>> drivers/gpu/drm/Kconfig | 1 +
>>> drivers/gpu/drm/vgem/vgem_drv.c | 340 +-------------------------------
>>> 2 files changed, 4 insertions(+), 337 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>>> index 8e73311de583..94e4ac830283 100644
>>> --- a/drivers/gpu/drm/Kconfig
>>> +++ b/drivers/gpu/drm/Kconfig
>>> @@ -274,6 +274,7 @@ source "drivers/gpu/drm/kmb/Kconfig"
>>> config DRM_VGEM
>>> tristate "Virtual GEM provider"
>>> depends on DRM
>>> + select DRM_GEM_SHMEM_HELPER
>>> help
>>> Choose this option to get a virtual graphics memory manager,
>>> as used by Mesa's software renderer for enhanced performance.
>>> diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
>>> index a0e75f1d5d01..b1b3a5ffc542 100644
>>> --- a/drivers/gpu/drm/vgem/vgem_drv.c
>>> +++ b/drivers/gpu/drm/vgem/vgem_drv.c
>>> @@ -38,6 +38,7 @@
>>>
>>> #include <drm/drm_drv.h>
>>> #include <drm/drm_file.h>
>>> +#include <drm/drm_gem_shmem_helper.h>
>>> #include <drm/drm_ioctl.h>
>>> #include <drm/drm_managed.h>
>>> #include <drm/drm_prime.h>
>>> @@ -50,87 +51,11 @@
>>> #define DRIVER_MAJOR 1
>>> #define DRIVER_MINOR 0
>>>
>>> -static const struct drm_gem_object_funcs vgem_gem_object_funcs;
>>> -
>>> static struct vgem_device {
>>> struct drm_device drm;
>>> struct platform_device *platform;
>>> } *vgem_device;
>>>
>>> -static void vgem_gem_free_object(struct drm_gem_object *obj)
>>> -{
>>> - struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
>>> -
>>> - kvfree(vgem_obj->pages);
>>> - mutex_destroy(&vgem_obj->pages_lock);
>>> -
>>> - if (obj->import_attach)
>>> - drm_prime_gem_destroy(obj, vgem_obj->table);
>>> -
>>> - drm_gem_object_release(obj);
>>> - kfree(vgem_obj);
>>> -}
>>> -
>>> -static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
>>> -{
>>> - struct vm_area_struct *vma = vmf->vma;
>>> - struct drm_vgem_gem_object *obj = vma->vm_private_data;
>>> - /* We don't use vmf->pgoff since that has the fake offset */
>>> - unsigned long vaddr = vmf->address;
>>> - vm_fault_t ret = VM_FAULT_SIGBUS;
>>> - loff_t num_pages;
>>> - pgoff_t page_offset;
>>> - page_offset = (vaddr - 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(&obj->pages_lock);
>>> - if (obj->pages) {
>>> - get_page(obj->pages[page_offset]);
>>> - vmf->page = obj->pages[page_offset];
>>> - ret = 0;
>>> - }
>>> - mutex_unlock(&obj->pages_lock);
>>> - if (ret) {
>>> - struct page *page;
>>> -
>>> - page = shmem_read_mapping_page(
>>> - file_inode(obj->base.filp)->i_mapping,
>>> - page_offset);
>>> - if (!IS_ERR(page)) {
>>> - vmf->page = page;
>>> - ret = 0;
>>> - } else switch (PTR_ERR(page)) {
>>> - case -ENOSPC:
>>> - case -ENOMEM:
>>> - ret = VM_FAULT_OOM;
>>> - break;
>>> - case -EBUSY:
>>> - ret = VM_FAULT_RETRY;
>>> - break;
>>> - case -EFAULT:
>>> - case -EINVAL:
>>> - ret = VM_FAULT_SIGBUS;
>>> - break;
>>> - default:
>>> - WARN_ON(PTR_ERR(page));
>>> - ret = VM_FAULT_SIGBUS;
>>> - break;
>>> - }
>>> -
>>> - }
>>> - return ret;
>>> -}
>>> -
>>> -static const struct vm_operations_struct vgem_gem_vm_ops = {
>>> - .fault = vgem_gem_fault,
>>> - .open = drm_gem_vm_open,
>>> - .close = drm_gem_vm_close,
>>> -};
>>> -
>>> static int vgem_open(struct drm_device *dev, struct drm_file *file)
>>> {
>>> struct vgem_file *vfile;
>>> @@ -159,265 +84,12 @@ static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
>>> kfree(vfile);
>>> }
>>>
>>> -static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
>>> - unsigned long size)
>>> -{
>>> - struct drm_vgem_gem_object *obj;
>>> - int ret;
>>> -
>>> - obj = kzalloc(sizeof(*obj), GFP_KERNEL);
>>> - if (!obj)
>>> - return ERR_PTR(-ENOMEM);
>>> -
>>> - obj->base.funcs = &vgem_gem_object_funcs;
>>> -
>>> - ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
>>> - if (ret) {
>>> - kfree(obj);
>>> - return ERR_PTR(ret);
>>> - }
>>> -
>>> - mutex_init(&obj->pages_lock);
>>> -
>>> - return obj;
>>> -}
>>> -
>>> -static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
>>> -{
>>> - drm_gem_object_release(&obj->base);
>>> - kfree(obj);
>>> -}
>>> -
>>> -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;
>>> - int ret;
>>> -
>>> - obj = __vgem_gem_create(dev, size);
>>> - if (IS_ERR(obj))
>>> - return ERR_CAST(obj);
>>> -
>>> - ret = drm_gem_handle_create(file, &obj->base, handle);
>>> - if (ret) {
>>> - drm_gem_object_put(&obj->base);
>>> - return ERR_PTR(ret);
>>> - }
>>> -
>>> - return &obj->base;
>>> -}
>>> -
>>> -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;
>>> - u64 pitch, size;
>>> -
>>> - pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
>>> - size = args->height * pitch;
>>> - if (size == 0)
>>> - return -EINVAL;
>>> -
>>> - gem_object = vgem_gem_create(dev, file, &args->handle, size);
>>> - if (IS_ERR(gem_object))
>>> - return PTR_ERR(gem_object);
>>> -
>>> - args->size = gem_object->size;
>>> - args->pitch = pitch;
>>> -
>>> - drm_gem_object_put(gem_object);
>>> -
>>> - DRM_DEBUG("Created object of size %llu\n", args->size);
>>> -
>>> - return 0;
>>> -}
>>> -
>>> static struct drm_ioctl_desc vgem_ioctls[] = {
>>> DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_RENDER_ALLOW),
>>> DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
>>> };
>>>
>>> -static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
>>> -{
>>> - unsigned long flags = vma->vm_flags;
>>> - int ret;
>>> -
>>> - ret = drm_gem_mmap(filp, vma);
>>> - if (ret)
>>> - return ret;
>>> -
>>> - /* Keep the WC mmaping set by drm_gem_mmap() but our pages
>>> - * are ordinary and not special.
>>> - */
>>> - vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
>>> - return 0;
>>> -}
>>> -
>>> -static const struct file_operations vgem_driver_fops = {
>>> - .owner = THIS_MODULE,
>>> - .open = drm_open,
>>> - .mmap = vgem_mmap,
>>> - .poll = drm_poll,
>>> - .read = drm_read,
>>> - .unlocked_ioctl = drm_ioctl,
>>> - .compat_ioctl = drm_compat_ioctl,
>>> - .release = drm_release,
>>> -};
>>> -
>>> -static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
>>> -{
>>> - mutex_lock(&bo->pages_lock);
>>> - if (bo->pages_pin_count++ == 0) {
>>> - struct page **pages;
>>> -
>>> - pages = drm_gem_get_pages(&bo->base);
>>> - if (IS_ERR(pages)) {
>>> - bo->pages_pin_count--;
>>> - mutex_unlock(&bo->pages_lock);
>>> - return pages;
>>> - }
>>> -
>>> - bo->pages = pages;
>>> - }
>>> - mutex_unlock(&bo->pages_lock);
>>> -
>>> - return bo->pages;
>>> -}
>>> -
>>> -static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
>>> -{
>>> - mutex_lock(&bo->pages_lock);
>>> - if (--bo->pages_pin_count == 0) {
>>> - drm_gem_put_pages(&bo->base, bo->pages, true, true);
>>> - bo->pages = NULL;
>>> - }
>>> - mutex_unlock(&bo->pages_lock);
>>> -}
>>> -
>>> -static int vgem_prime_pin(struct drm_gem_object *obj)
>>> -{
>>> - struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
>>> - long n_pages = obj->size >> PAGE_SHIFT;
>>> - struct page **pages;
>>> -
>>> - pages = vgem_pin_pages(bo);
>>> - if (IS_ERR(pages))
>>> - return PTR_ERR(pages);
>>> -
>>> - /* Flush the object from the CPU cache so that importers can rely
>>> - * on coherent indirect access via the exported dma-address.
>>> - */
>>> - drm_clflush_pages(pages, n_pages);
>>> -
>>> - return 0;
>>> -}
>>> -
>>> -static void vgem_prime_unpin(struct drm_gem_object *obj)
>>> -{
>>> - struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
>>> -
>>> - vgem_unpin_pages(bo);
>>> -}
>>> -
>>> -static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
>>> -{
>>> - struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
>>> -
>>> - return drm_prime_pages_to_sg(obj->dev, bo->pages, bo->base.size >> PAGE_SHIFT);
>>> -}
>>> -
>>> -static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
>>> - struct dma_buf *dma_buf)
>>> -{
>>> - struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
>>> -
>>> - return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
>>> -}
>>> -
>>> -static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
>>> - struct dma_buf_attachment *attach, struct sg_table *sg)
>>> -{
>>> - struct drm_vgem_gem_object *obj;
>>> - int npages;
>>> -
>>> - obj = __vgem_gem_create(dev, attach->dmabuf->size);
>>> - if (IS_ERR(obj))
>>> - return ERR_CAST(obj);
>>> -
>>> - npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
>>> -
>>> - obj->table = sg;
>>> - obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
>>> - if (!obj->pages) {
>>> - __vgem_gem_destroy(obj);
>>> - return ERR_PTR(-ENOMEM);
>>> - }
>>> -
>>> - obj->pages_pin_count++; /* perma-pinned */
>>> - drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
>>> - return &obj->base;
>>> -}
>>> -
>>> -static int vgem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
>>> -{
>>> - struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
>>> - long n_pages = obj->size >> PAGE_SHIFT;
>>> - struct page **pages;
>>> - void *vaddr;
>>> -
>>> - pages = vgem_pin_pages(bo);
>>> - if (IS_ERR(pages))
>>> - return PTR_ERR(pages);
>>> -
>>> - vaddr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
>>> - if (!vaddr)
>>> - return -ENOMEM;
>>> - dma_buf_map_set_vaddr(map, vaddr);
>>> -
>>> - return 0;
>>> -}
>>> -
>>> -static void vgem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
>>> -{
>>> - struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
>>> -
>>> - vunmap(map->vaddr);
>>> - vgem_unpin_pages(bo);
>>> -}
>>> -
>>> -static int vgem_prime_mmap(struct drm_gem_object *obj,
>>> - struct vm_area_struct *vma)
>>> -{
>>> - int ret;
>>> -
>>> - if (obj->size < vma->vm_end - vma->vm_start)
>>> - return -EINVAL;
>>> -
>>> - if (!obj->filp)
>>> - return -ENODEV;
>>> -
>>> - ret = call_mmap(obj->filp, vma);
>>> - if (ret)
>>> - return ret;
>>> -
>>> - vma_set_file(vma, obj->filp);
>>> - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
>>> - vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
>>> -
>>> - return 0;
>>> -}
>>> -
>>> -static const struct drm_gem_object_funcs vgem_gem_object_funcs = {
>>> - .free = vgem_gem_free_object,
>>> - .pin = vgem_prime_pin,
>>> - .unpin = vgem_prime_unpin,
>>> - .get_sg_table = vgem_prime_get_sg_table,
>>> - .vmap = vgem_prime_vmap,
>>> - .vunmap = vgem_prime_vunmap,
>>> - .vm_ops = &vgem_gem_vm_ops,
>>> -};
>>> +DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
>>>
>>> static const struct drm_driver vgem_driver = {
>>> .driver_features = DRIVER_GEM | DRIVER_RENDER,
>>> @@ -427,13 +99,7 @@ static const struct drm_driver vgem_driver = {
>>> .num_ioctls = ARRAY_SIZE(vgem_ioctls),
>>> .fops = &vgem_driver_fops,
>>>
>>> - .dumb_create = vgem_gem_dumb_create,
>>> -
>>> - .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
>>> - .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
>>> - .gem_prime_import = vgem_prime_import,
>>> - .gem_prime_import_sg_table = vgem_prime_import_sg_table,
>>> - .gem_prime_mmap = vgem_prime_mmap,
>>> + DRM_GEM_SHMEM_DRIVER_OPS,
>>>
>>> .name = DRIVER_NAME,
>>> .desc = DRIVER_DESC,
>>>
>>
>> --
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Maxfeldstr. 5, 90409 Nürnberg, Germany
>> (HRB 36809, AG Nürnberg)
>> Geschäftsführer: Felix Imendörffer
>>
>
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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