Merge tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media updates from Mauro Carvalho Chehab:
 "A series of patches that move part of the code used to allocate memory
  from the media subsystem to the mm subsystem"

[ The mm parts have been acked by VM people, and the series was
  apparently in -mm for a while   - Linus ]

* tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames()
  [media] media: vb2: Remove unused functions
  [media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector
  [media] media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector
  [media] media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector
  [media] vb2: Provide helpers for mapping virtual addresses
  [media] media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns()
  [media] mm: Provide new get_vaddr_frames() helper
  [media] vb2: Push mmap_sem down to memops

1 files changed, 46 insertions, 102 deletions

diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c
index 0d49b7951f84..48c6a49c4928 100644
--- a/drivers/media/v4l2-core/videobuf2-memops.c
+++ b/drivers/media/v4l2-core/videobuf2-memops.c
@@ -23,118 +23,62 @@
 #include <media/videobuf2-memops.h>
 
 /**
- * vb2_get_vma() - acquire and lock the virtual memory area
- * @vma:        given virtual memory area
+ * vb2_create_framevec() - map virtual addresses to pfns
+ * @start:      Virtual user address where we start mapping
+ * @length:     Length of a range to map
+ * @write:      Should we map for writing into the area
  *
- * This function attempts to acquire an area mapped in the userspace for
- * the duration of a hardware operation. The area is "locked" by performing
- * the same set of operation that are done when process calls fork() and
- * memory areas are duplicated.
- *
- * Returns a copy of a virtual memory region on success or NULL.
- */
-struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma)
-{
-        struct vm_area_struct *vma_copy;
-
-        vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
-        if (vma_copy == NULL)
-                return NULL;
-
-        if (vma->vm_ops && vma->vm_ops->open)
-                vma->vm_ops->open(vma);
-
-        if (vma->vm_file)
-                get_file(vma->vm_file);
-
-        memcpy(vma_copy, vma, sizeof(*vma));
-
-        vma_copy->vm_mm = NULL;
-        vma_copy->vm_next = NULL;
-        vma_copy->vm_prev = NULL;
-
-        return vma_copy;
-}
-EXPORT_SYMBOL_GPL(vb2_get_vma);
-
-/**
- * vb2_put_userptr() - release a userspace virtual memory area
- * @vma:        virtual memory region associated with the area to be released
- *
- * This function releases the previously acquired memory area after a hardware
- * operation.
+ * This function allocates and fills in a vector with pfns corresponding to
+ * virtual address range passed in arguments. If pfns have corresponding pages,
+ * page references are also grabbed to pin pages in memory. The function
+ * returns pointer to the vector on success and error pointer in case of
+ * failure. Returned vector needs to be freed via vb2_destroy_pfnvec().
  */
-void vb2_put_vma(struct vm_area_struct *vma)
+struct frame_vector *vb2_create_framevec(unsigned long start,
+                                         unsigned long length,
+                                         bool write)
 {
-        if (!vma)
-                return;
-
-        if (vma->vm_ops && vma->vm_ops->close)
-                vma->vm_ops->close(vma);
-
-        if (vma->vm_file)
-                fput(vma->vm_file);
-
-        kfree(vma);
+        int ret;
+        unsigned long first, last;
+        unsigned long nr;
+        struct frame_vector *vec;
+
+        first = start >> PAGE_SHIFT;
+        last = (start + length - 1) >> PAGE_SHIFT;
+        nr = last - first + 1;
+        vec = frame_vector_create(nr);
+        if (!vec)
+                return ERR_PTR(-ENOMEM);
+        ret = get_vaddr_frames(start, nr, write, 1, vec);
+        if (ret < 0)
+                goto out_destroy;
+        /* We accept only complete set of PFNs */
+        if (ret != nr) {
+                ret = -EFAULT;
+                goto out_release;
+        }
+        return vec;
+out_release:
+        put_vaddr_frames(vec);
+out_destroy:
+        frame_vector_destroy(vec);
+        return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(vb2_put_vma);
+EXPORT_SYMBOL(vb2_create_framevec);
 
 /**
- * vb2_get_contig_userptr() - lock physically contiguous userspace mapped memory
- * @vaddr:      starting virtual address of the area to be verified
- * @size:       size of the area
- * @res_paddr:  will return physical address for the given vaddr
- * @res_vma:    will return locked copy of struct vm_area for the given area
- *
- * This function will go through memory area of size @size mapped at @vaddr and
- * verify that the underlying physical pages are contiguous. If they are
- * contiguous the virtual memory area is locked and a @res_vma is filled with
- * the copy and @res_pa set to the physical address of the buffer.
+ * vb2_destroy_framevec() - release vector of mapped pfns
+ * @vec:        vector of pfns / pages to release
  *
- * Returns 0 on success.
+ * This releases references to all pages in the vector @vec (if corresponding
+ * pfns are backed by pages) and frees the passed vector.
  */
-int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
-                           struct vm_area_struct **res_vma, dma_addr_t *res_pa)
+void vb2_destroy_framevec(struct frame_vector *vec)
 {
-        struct mm_struct *mm = current->mm;
-        struct vm_area_struct *vma;
-        unsigned long offset, start, end;
-        unsigned long this_pfn, prev_pfn;
-        dma_addr_t pa = 0;
-
-        start = vaddr;
-        offset = start & ~PAGE_MASK;
-        end = start + size;
-
-        vma = find_vma(mm, start);
-
-        if (vma == NULL || vma->vm_end < end)
-                return -EFAULT;
-
-        for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
-                int ret = follow_pfn(vma, start, &this_pfn);
-                if (ret)
-                        return ret;
-
-                if (prev_pfn == 0)
-                        pa = this_pfn << PAGE_SHIFT;
-                else if (this_pfn != prev_pfn + 1)
-                        return -EFAULT;
-
-                prev_pfn = this_pfn;
-        }
-
-        /*
-         * Memory is contiguous, lock vma and return to the caller
-         */
-        *res_vma = vb2_get_vma(vma);
-        if (*res_vma == NULL)
-                return -ENOMEM;
-
-        *res_pa = pa + offset;
-        return 0;
+        put_vaddr_frames(vec);
+        frame_vector_destroy(vec);
 }
-EXPORT_SYMBOL_GPL(vb2_get_contig_userptr);
+EXPORT_SYMBOL(vb2_destroy_framevec);
 
 /**
  * vb2_common_vm_open() - increase refcount of the vma