diff options
author | Abdiel Janulgue <abdiel.janulgue@linux.intel.com> | 2019-12-31 20:03:56 +0000 |
---|---|---|
committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-12-31 20:41:50 +0000 |
commit | 1764b992be0f1c4295d2d9572ec46d568bd3fc14 (patch) | |
tree | 788f80935ebd15df9676dc6a66339062f71e382d /drivers/gpu/drm | |
parent | cc39da0e4c5d084b96d44c56aba3d712a83f7567 (diff) | |
download | linux-1764b992be0f1c4295d2d9572ec46d568bd3fc14.tar.bz2 |
drm/i915: Introduce remap_io_sg() to prefault discontiguous objects
Provide a way to set the PTE within apply_page_range for discontiguous
objects in addition to the existing method of just incrementing the pfn
for a page range.
Fixes: cc662126b413 ("drm/i915: Introduce DRM_I915_GEM_MMAP_OFFSET")
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191231200356.409475-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r-- | drivers/gpu/drm/i915/gem/i915_gem_mman.c | 32 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/i915_drv.h | 3 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/i915_mm.c | 59 |
3 files changed, 74 insertions, 20 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index 879fff8adc48..905527ce2999 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -236,42 +236,34 @@ static vm_fault_t vm_fault_cpu(struct vm_fault *vmf) struct vm_area_struct *area = vmf->vma; struct i915_mmap_offset *mmo = area->vm_private_data; struct drm_i915_gem_object *obj = mmo->obj; - unsigned long i, size = area->vm_end - area->vm_start; - bool write = area->vm_flags & VM_WRITE; - vm_fault_t ret = VM_FAULT_SIGBUS; int err; - if (!i915_gem_object_has_struct_page(obj)) - return ret; + if (unlikely(!i915_gem_object_has_struct_page(obj))) + return VM_FAULT_SIGBUS; /* Sanity check that we allow writing into this object */ - if (i915_gem_object_is_readonly(obj) && write) - return ret; + if (unlikely(i915_gem_object_is_readonly(obj) && + area->vm_flags & VM_WRITE)) + return VM_FAULT_SIGBUS; err = i915_gem_object_pin_pages(obj); if (err) - return i915_error_to_vmf_fault(err); + goto out; /* PTEs are revoked in obj->ops->put_pages() */ - for (i = 0; i < size >> PAGE_SHIFT; i++) { - struct page *page = i915_gem_object_get_page(obj, i); - - ret = vmf_insert_pfn(area, - (unsigned long)area->vm_start + i * PAGE_SIZE, - page_to_pfn(page)); - if (ret != VM_FAULT_NOPAGE) - break; - } + err = remap_io_sg_page(area, + area->vm_start, area->vm_end - area->vm_start, + obj->mm.pages->sgl); - if (write) { + if (area->vm_flags & VM_WRITE) { GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj)); - obj->cache_dirty = true; /* XXX flush after PAT update? */ obj->mm.dirty = true; } i915_gem_object_unpin_pages(obj); - return ret; +out: + return i915_error_to_vmf_fault(err); } static vm_fault_t vm_fault_gtt(struct vm_fault *vmf) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index b7f122dccdca..c2348272e211 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2015,6 +2015,9 @@ int i915_reg_read_ioctl(struct drm_device *dev, void *data, int remap_io_mapping(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, unsigned long size, struct io_mapping *iomap); +int remap_io_sg_page(struct vm_area_struct *vma, + unsigned long addr, unsigned long size, + struct scatterlist *sgl); static inline int intel_hws_csb_write_index(struct drm_i915_private *i915) { diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c index 318562ce64c0..2998689e6d42 100644 --- a/drivers/gpu/drm/i915/i915_mm.c +++ b/drivers/gpu/drm/i915/i915_mm.c @@ -33,6 +33,8 @@ struct remap_pfn { struct mm_struct *mm; unsigned long pfn; pgprot_t prot; + + struct sgt_iter sgt; }; static int remap_pfn(pte_t *pte, unsigned long addr, void *data) @@ -46,6 +48,30 @@ static int remap_pfn(pte_t *pte, unsigned long addr, void *data) return 0; } +static inline unsigned long sgt_pfn(const struct sgt_iter *sgt) +{ + return sgt->pfn + (sgt->curr >> PAGE_SHIFT); +} + +static int remap_sg_page(pte_t *pte, unsigned long addr, void *data) +{ + struct remap_pfn *r = data; + + if (GEM_WARN_ON(!r->sgt.pfn)) + return -EINVAL; + + /* Special PTE are not associated with any struct page */ + set_pte_at(r->mm, addr, pte, + pte_mkspecial(pfn_pte(sgt_pfn(&r->sgt), r->prot))); + r->pfn++; /* track insertions in case we need to unwind later */ + + r->sgt.curr += PAGE_SIZE; + if (r->sgt.curr >= r->sgt.max) + r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), false); + + return 0; +} + /** * remap_io_mapping - remap an IO mapping to userspace * @vma: user vma to map to @@ -80,3 +106,36 @@ int remap_io_mapping(struct vm_area_struct *vma, return 0; } + +/** + * remap_io_sg_page - remap an IO mapping to userspace + * @vma: user vma to map to + * @addr: target user address to start at + * @size: size of map area + * @sgl: Start sg entry + * + * Note: this is only safe if the mm semaphore is held when called. + */ +int remap_io_sg_page(struct vm_area_struct *vma, + unsigned long addr, unsigned long size, + struct scatterlist *sgl) +{ + struct remap_pfn r = { + .mm = vma->vm_mm, + .prot = vma->vm_page_prot, + .sgt = __sgt_iter(sgl, false), + }; + int err; + + /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ + GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS); + + flush_cache_range(vma, addr, size); + err = apply_to_page_range(r.mm, addr, size, remap_sg_page, &r); + if (unlikely(err)) { + zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT); + return err; + } + + return 0; +} |