#include <linux/sched.h>
#include <linux/file.h>
-#include <media/videobuf2-core.h>
+#include <media/videobuf2-v4l2.h>
#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 contigous, 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
Code Review / kvmfornfv.git / blobdiff