Merge remote-tracking branch 'torvalds/master' into perf/core

[linux-2.6-microblaze.git] / drivers / gpu / drm / i915 / i915_mm.c

diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
index 9a777b0..666808c 100644 (file)
--- a/drivers/gpu/drm/i915/i915_mm.c
+++ b/drivers/gpu/drm/i915/i915_mm.c
@@ -37,6 +37,17 @@ struct remap_pfn {
        resource_size_t iobase;
 };
 
+static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
+{
+       struct remap_pfn *r = data;
+
+       /* Special PTE are not associated with any struct page */
+       set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
+       r->pfn++;
+
+       return 0;
+}
+
 #define use_dma(io) ((io) != -1)
 
 static inline unsigned long sgt_pfn(const struct remap_pfn *r)
@@ -66,7 +77,40 @@ static int remap_sg(pte_t *pte, unsigned long addr, void *data)
        return 0;
 }
 
+/**
+ * remap_io_mapping - remap an IO mapping to userspace
+ * @vma: user vma to map to
+ * @addr: target user address to start at
+ * @pfn: physical address of kernel memory
+ * @size: size of map area
+ * @iomap: the source io_mapping
+ *
+ *  Note: this is only safe if the mm semaphore is held when called.
+ */
+int remap_io_mapping(struct vm_area_struct *vma,
+                    unsigned long addr, unsigned long pfn, unsigned long size,
+                    struct io_mapping *iomap)
+{
+       struct remap_pfn r;
+       int err;
+
 #define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
+       GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
+
+       /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
+       r.mm = vma->vm_mm;
+       r.pfn = pfn;
+       r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
+                         (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
+
+       err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
+       if (unlikely(err)) {
+               zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
+               return err;
+       }
+
+       return 0;
+}
 
 /**
  * remap_io_sg - remap an IO mapping to userspace