diff options
Diffstat (limited to 'drivers/gpu/drm/xen/xen_drm_front_gem.c')
| -rw-r--r-- | drivers/gpu/drm/xen/xen_drm_front_gem.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c new file mode 100644 index 000000000000..c85bfe7571cb --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +/* + * Xen para-virtual DRM device + * + * Copyright (C) 2016-2018 EPAM Systems Inc. + * + * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> + */ + +#include "xen_drm_front_gem.h" + +#include <drm/drmP.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_gem.h> + +#include <linux/dma-buf.h> +#include <linux/scatterlist.h> +#include <linux/shmem_fs.h> + +#include <xen/balloon.h> + +#include "xen_drm_front.h" +#include "xen_drm_front_shbuf.h" + +struct xen_gem_object { + struct drm_gem_object base; + + size_t num_pages; + struct page **pages; + + /* set for buffers allocated by the backend */ + bool be_alloc; + + /* this is for imported PRIME buffer */ + struct sg_table *sgt_imported; +}; + +static inline struct xen_gem_object * +to_xen_gem_obj(struct drm_gem_object *gem_obj) +{ + return container_of(gem_obj, struct xen_gem_object, base); +} + +static int gem_alloc_pages_array(struct xen_gem_object *xen_obj, + size_t buf_size) +{ + xen_obj->num_pages = DIV_ROUND_UP(buf_size, PAGE_SIZE); + xen_obj->pages = kvmalloc_array(xen_obj->num_pages, + sizeof(struct page *), GFP_KERNEL); + return !xen_obj->pages ? -ENOMEM : 0; +} + +static void gem_free_pages_array(struct xen_gem_object *xen_obj) +{ + kvfree(xen_obj->pages); + xen_obj->pages = NULL; +} + +static struct xen_gem_object *gem_create_obj(struct drm_device *dev, + size_t size) +{ + struct xen_gem_object *xen_obj; + int ret; + + xen_obj = kzalloc(sizeof(*xen_obj), GFP_KERNEL); + if (!xen_obj) + return ERR_PTR(-ENOMEM); + + ret = drm_gem_object_init(dev, &xen_obj->base, size); + if (ret < 0) { + kfree(xen_obj); + return ERR_PTR(ret); + } + + return xen_obj; +} + +static struct xen_gem_object *gem_create(struct drm_device *dev, size_t size) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct xen_gem_object *xen_obj; + int ret; + + size = round_up(size, PAGE_SIZE); + xen_obj = gem_create_obj(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return xen_obj; + + if (drm_info->front_info->cfg.be_alloc) { + /* + * backend will allocate space for this buffer, so + * only allocate array of pointers to pages + */ + ret = gem_alloc_pages_array(xen_obj, size); + if (ret < 0) + goto fail; + + /* + * allocate ballooned pages which will be used to map + * grant references provided by the backend + */ + ret = alloc_xenballooned_pages(xen_obj->num_pages, + xen_obj->pages); + if (ret < 0) { + DRM_ERROR("Cannot allocate %zu ballooned pages: %d\n", + xen_obj->num_pages, ret); + gem_free_pages_array(xen_obj); + goto fail; + } + + xen_obj->be_alloc = true; + return xen_obj; + } + /* + * need to allocate backing pages now, so we can share those + * with the backend + */ + xen_obj->num_pages = DIV_ROUND_UP(size, PAGE_SIZE); + xen_obj->pages = drm_gem_get_pages(&xen_obj->base); + if (IS_ERR_OR_NULL(xen_obj->pages)) { + ret = PTR_ERR(xen_obj->pages); + xen_obj->pages = NULL; + goto fail; + } + + return xen_obj; + +fail: + DRM_ERROR("Failed to allocate buffer with size %zu\n", size); + return ERR_PTR(ret); +} + +struct drm_gem_object *xen_drm_front_gem_create(struct drm_device *dev, + size_t size) +{ + struct xen_gem_object *xen_obj; + + xen_obj = gem_create(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return ERR_CAST(xen_obj); + + return &xen_obj->base; +} + +void xen_drm_front_gem_free_object_unlocked(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (xen_obj->base.import_attach) { + drm_prime_gem_destroy(&xen_obj->base, xen_obj->sgt_imported); + gem_free_pages_array(xen_obj); + } else { + if (xen_obj->pages) { + if (xen_obj->be_alloc) { + free_xenballooned_pages(xen_obj->num_pages, + xen_obj->pages); + gem_free_pages_array(xen_obj); + } else { + drm_gem_put_pages(&xen_obj->base, + xen_obj->pages, true, false); + } + } + } + drm_gem_object_release(gem_obj); + kfree(xen_obj); +} + +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + return xen_obj->pages; +} + +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (!xen_obj->pages) + return NULL; + + return drm_prime_pages_to_sg(xen_obj->pages, xen_obj->num_pages); +} + +struct drm_gem_object * +xen_drm_front_gem_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, + struct sg_table *sgt) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct xen_gem_object *xen_obj; + size_t size; + int ret; + + size = attach->dmabuf->size; + xen_obj = gem_create_obj(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return ERR_CAST(xen_obj); + + ret = gem_alloc_pages_array(xen_obj, size); + if (ret < 0) + return ERR_PTR(ret); + + xen_obj->sgt_imported = sgt; + + ret = drm_prime_sg_to_page_addr_arrays(sgt, xen_obj->pages, + NULL, xen_obj->num_pages); + if (ret < 0) + return ERR_PTR(ret); + + ret = xen_drm_front_dbuf_create(drm_info->front_info, + xen_drm_front_dbuf_to_cookie(&xen_obj->base), + 0, 0, 0, size, xen_obj->pages); + if (ret < 0) + return ERR_PTR(ret); + + DRM_DEBUG("Imported buffer of size %zu with nents %u\n", + size, sgt->nents); + + return &xen_obj->base; +} + +static int gem_mmap_obj(struct xen_gem_object *xen_obj, + struct vm_area_struct *vma) +{ + unsigned long addr = vma->vm_start; + int i; + + /* + * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map + * the whole buffer. + */ + vma->vm_flags &= ~VM_PFNMAP; + vma->vm_flags |= VM_MIXEDMAP; + vma->vm_pgoff = 0; + vma->vm_page_prot = + pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + + /* + * vm_operations_struct.fault handler will be called if CPU access + * to VM is here. For GPUs this isn't the case, because CPU + * doesn't touch the memory. Insert pages now, so both CPU and GPU are + * happy. + * FIXME: as we insert all the pages now then no .fault handler must + * be called, so don't provide one + */ + for (i = 0; i < xen_obj->num_pages; i++) { + int ret; + + ret = vm_insert_page(vma, addr, xen_obj->pages[i]); + if (ret < 0) { + DRM_ERROR("Failed to insert pages into vma: %d\n", ret); + return ret; + } + + addr += PAGE_SIZE; + } + return 0; +} + +int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct xen_gem_object *xen_obj; + struct drm_gem_object *gem_obj; + int ret; + + ret = drm_gem_mmap(filp, vma); + if (ret < 0) + return ret; + + gem_obj = vma->vm_private_data; + xen_obj = to_xen_gem_obj(gem_obj); + return gem_mmap_obj(xen_obj, vma); +} + +void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (!xen_obj->pages) + return NULL; + + return vmap(xen_obj->pages, xen_obj->num_pages, + VM_MAP, pgprot_writecombine(PAGE_KERNEL)); +} + +void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, + void *vaddr) +{ + vunmap(vaddr); +} + +int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj, + struct vm_area_struct *vma) +{ + struct xen_gem_object *xen_obj; + int ret; + + ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma); + if (ret < 0) + return ret; + + xen_obj = to_xen_gem_obj(gem_obj); + return gem_mmap_obj(xen_obj, vma); +} |