forked from Minki/linux
drm/vgem: use shmem helpers
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_PFNMAP, 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)
v4: I got tricked by 0cf2ef46c6 ("drm/shmem-helper: Use cached
mappings by default"), and we need WC in vgem because vgem doesn't
have explicit begin/end cpu access ioctls.
Also add a comment why exactly vgem has to use wc.
v5: Don't set obj->base.funcs, it will default to drm_gem_shmem_funcs
(Thomas)
v6: vgem also needs an MMU for remapping
v7: I absolutely butchered the rebases over the vgem mmap change and
revert and broke the patch. Actually go back to v6 from before the
vgem mmap changes.
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Melissa Wen <melissa.srw@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20210812131412.2487363-4-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter
parent
804b6e5ee6
commit
45d9c8dde4
@ -272,7 +272,8 @@ source "drivers/gpu/drm/kmb/Kconfig"
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config DRM_VGEM
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tristate "Virtual GEM provider"
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depends on DRM
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depends on DRM && MMU
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select DRM_GEM_SHMEM_HELPER
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help
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Choose this option to get a virtual graphics memory manager,
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as used by Mesa's software renderer for enhanced performance.
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@ -280,7 +281,7 @@ config DRM_VGEM
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config DRM_VKMS
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tristate "Virtual KMS (EXPERIMENTAL)"
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depends on DRM
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depends on DRM && MMU
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select DRM_KMS_HELPER
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select DRM_GEM_SHMEM_HELPER
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select CRC32
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@ -38,6 +38,7 @@
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#include <drm/drm_drv.h>
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#include <drm/drm_file.h>
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#include <drm/drm_gem_shmem_helper.h>
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#include <drm/drm_ioctl.h>
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#include <drm/drm_managed.h>
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#include <drm/drm_prime.h>
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@ -50,87 +51,11 @@
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#define DRIVER_MAJOR 1
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#define DRIVER_MINOR 0
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static const struct drm_gem_object_funcs vgem_gem_object_funcs;
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static struct vgem_device {
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struct drm_device drm;
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struct platform_device *platform;
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} *vgem_device;
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static void vgem_gem_free_object(struct drm_gem_object *obj)
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{
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struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
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kvfree(vgem_obj->pages);
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mutex_destroy(&vgem_obj->pages_lock);
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if (obj->import_attach)
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drm_prime_gem_destroy(obj, vgem_obj->table);
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drm_gem_object_release(obj);
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kfree(vgem_obj);
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}
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static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct drm_vgem_gem_object *obj = vma->vm_private_data;
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/* We don't use vmf->pgoff since that has the fake offset */
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unsigned long vaddr = vmf->address;
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vm_fault_t ret = VM_FAULT_SIGBUS;
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loff_t num_pages;
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pgoff_t page_offset;
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page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
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num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
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if (page_offset >= num_pages)
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return VM_FAULT_SIGBUS;
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mutex_lock(&obj->pages_lock);
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if (obj->pages) {
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get_page(obj->pages[page_offset]);
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vmf->page = obj->pages[page_offset];
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ret = 0;
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}
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mutex_unlock(&obj->pages_lock);
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if (ret) {
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struct page *page;
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page = shmem_read_mapping_page(
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file_inode(obj->base.filp)->i_mapping,
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page_offset);
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if (!IS_ERR(page)) {
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vmf->page = page;
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ret = 0;
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} else switch (PTR_ERR(page)) {
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case -ENOSPC:
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case -ENOMEM:
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ret = VM_FAULT_OOM;
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break;
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case -EBUSY:
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ret = VM_FAULT_RETRY;
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break;
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case -EFAULT:
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case -EINVAL:
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ret = VM_FAULT_SIGBUS;
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break;
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default:
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WARN_ON(PTR_ERR(page));
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ret = VM_FAULT_SIGBUS;
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break;
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}
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}
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return ret;
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}
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static const struct vm_operations_struct vgem_gem_vm_ops = {
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.fault = vgem_gem_fault,
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.open = drm_gem_vm_open,
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.close = drm_gem_vm_close,
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};
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static int vgem_open(struct drm_device *dev, struct drm_file *file)
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{
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struct vgem_file *vfile;
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@ -159,266 +84,30 @@ static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
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kfree(vfile);
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}
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static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
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unsigned long size)
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{
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struct drm_vgem_gem_object *obj;
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int ret;
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obj = kzalloc(sizeof(*obj), GFP_KERNEL);
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if (!obj)
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return ERR_PTR(-ENOMEM);
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obj->base.funcs = &vgem_gem_object_funcs;
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ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
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if (ret) {
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kfree(obj);
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return ERR_PTR(ret);
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}
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mutex_init(&obj->pages_lock);
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return obj;
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}
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static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
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{
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drm_gem_object_release(&obj->base);
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kfree(obj);
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}
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static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
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struct drm_file *file,
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unsigned int *handle,
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unsigned long size)
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{
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struct drm_vgem_gem_object *obj;
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int ret;
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obj = __vgem_gem_create(dev, size);
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if (IS_ERR(obj))
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return ERR_CAST(obj);
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ret = drm_gem_handle_create(file, &obj->base, handle);
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if (ret) {
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drm_gem_object_put(&obj->base);
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return ERR_PTR(ret);
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}
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return &obj->base;
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}
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static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
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struct drm_mode_create_dumb *args)
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{
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struct drm_gem_object *gem_object;
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u64 pitch, size;
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pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
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size = args->height * pitch;
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if (size == 0)
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return -EINVAL;
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gem_object = vgem_gem_create(dev, file, &args->handle, size);
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if (IS_ERR(gem_object))
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return PTR_ERR(gem_object);
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args->size = gem_object->size;
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args->pitch = pitch;
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drm_gem_object_put(gem_object);
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DRM_DEBUG("Created object of size %llu\n", args->size);
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return 0;
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}
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static struct drm_ioctl_desc vgem_ioctls[] = {
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DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_RENDER_ALLOW),
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DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
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};
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static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
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DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
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static struct drm_gem_object *vgem_gem_create_object(struct drm_device *dev, size_t size)
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{
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unsigned long flags = vma->vm_flags;
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int ret;
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struct drm_gem_shmem_object *obj;
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ret = drm_gem_mmap(filp, vma);
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if (ret)
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return ret;
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obj = kzalloc(sizeof(*obj), GFP_KERNEL);
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if (!obj)
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return NULL;
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/* Keep the WC mmaping set by drm_gem_mmap() but our pages
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* are ordinary and not special.
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/*
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* vgem doesn't have any begin/end cpu access ioctls, therefore must use
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* coherent memory or dma-buf sharing just wont work.
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*/
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vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
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return 0;
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}
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obj->map_wc = true;
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static const struct file_operations vgem_driver_fops = {
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.owner = THIS_MODULE,
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.open = drm_open,
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.mmap = vgem_mmap,
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.poll = drm_poll,
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.read = drm_read,
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.unlocked_ioctl = drm_ioctl,
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.compat_ioctl = drm_compat_ioctl,
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.release = drm_release,
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};
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static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
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{
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mutex_lock(&bo->pages_lock);
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if (bo->pages_pin_count++ == 0) {
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struct page **pages;
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pages = drm_gem_get_pages(&bo->base);
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if (IS_ERR(pages)) {
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bo->pages_pin_count--;
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mutex_unlock(&bo->pages_lock);
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return pages;
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}
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bo->pages = pages;
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}
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mutex_unlock(&bo->pages_lock);
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return bo->pages;
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}
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static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
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{
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mutex_lock(&bo->pages_lock);
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if (--bo->pages_pin_count == 0) {
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drm_gem_put_pages(&bo->base, bo->pages, true, true);
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bo->pages = NULL;
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}
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mutex_unlock(&bo->pages_lock);
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}
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static int vgem_prime_pin(struct drm_gem_object *obj)
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{
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struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
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long n_pages = obj->size >> PAGE_SHIFT;
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struct page **pages;
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pages = vgem_pin_pages(bo);
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if (IS_ERR(pages))
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return PTR_ERR(pages);
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/* Flush the object from the CPU cache so that importers can rely
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* on coherent indirect access via the exported dma-address.
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*/
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drm_clflush_pages(pages, n_pages);
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return 0;
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}
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static void vgem_prime_unpin(struct drm_gem_object *obj)
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{
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struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
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vgem_unpin_pages(bo);
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}
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static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
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{
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struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
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return drm_prime_pages_to_sg(obj->dev, bo->pages, bo->base.size >> PAGE_SHIFT);
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}
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static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
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struct dma_buf *dma_buf)
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{
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struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
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return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
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}
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static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
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struct dma_buf_attachment *attach, struct sg_table *sg)
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{
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struct drm_vgem_gem_object *obj;
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int npages;
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obj = __vgem_gem_create(dev, attach->dmabuf->size);
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if (IS_ERR(obj))
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return ERR_CAST(obj);
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npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
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obj->table = sg;
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obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
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if (!obj->pages) {
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__vgem_gem_destroy(obj);
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return ERR_PTR(-ENOMEM);
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}
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obj->pages_pin_count++; /* perma-pinned */
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drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
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return &obj->base;
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}
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static int vgem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
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{
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struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
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long n_pages = obj->size >> PAGE_SHIFT;
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struct page **pages;
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void *vaddr;
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pages = vgem_pin_pages(bo);
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if (IS_ERR(pages))
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return PTR_ERR(pages);
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vaddr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
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if (!vaddr)
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return -ENOMEM;
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dma_buf_map_set_vaddr(map, vaddr);
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return 0;
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}
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static void vgem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
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{
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struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
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vunmap(map->vaddr);
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vgem_unpin_pages(bo);
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}
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static int vgem_prime_mmap(struct drm_gem_object *obj,
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struct vm_area_struct *vma)
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{
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int ret;
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if (obj->size < vma->vm_end - vma->vm_start)
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return -EINVAL;
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if (!obj->filp)
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return -ENODEV;
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ret = call_mmap(obj->filp, vma);
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if (ret)
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return ret;
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vma_set_file(vma, obj->filp);
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vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
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vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
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return 0;
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}
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static const struct drm_gem_object_funcs vgem_gem_object_funcs = {
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.free = vgem_gem_free_object,
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.pin = vgem_prime_pin,
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.unpin = vgem_prime_unpin,
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.get_sg_table = vgem_prime_get_sg_table,
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.vmap = vgem_prime_vmap,
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.vunmap = vgem_prime_vunmap,
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.vm_ops = &vgem_gem_vm_ops,
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};
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static const struct drm_driver vgem_driver = {
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.driver_features = DRIVER_GEM | DRIVER_RENDER,
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.open = vgem_open,
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@ -427,13 +116,8 @@ static const struct drm_driver vgem_driver = {
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.num_ioctls = ARRAY_SIZE(vgem_ioctls),
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.fops = &vgem_driver_fops,
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.dumb_create = vgem_gem_dumb_create,
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.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
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.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
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.gem_prime_import = vgem_prime_import,
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.gem_prime_import_sg_table = vgem_prime_import_sg_table,
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.gem_prime_mmap = vgem_prime_mmap,
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DRM_GEM_SHMEM_DRIVER_OPS,
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.gem_create_object = vgem_gem_create_object,
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.name = DRIVER_NAME,
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.desc = DRIVER_DESC,
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