--- zzzz-none-000/linux-3.10.107/drivers/media/v4l2-core/videobuf2-memops.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/media/v4l2-core/videobuf2-memops.c 2021-02-04 17:41:59.000000000 +0000 @@ -19,122 +19,66 @@ #include #include -#include +#include #include /** - * 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 & PAGE_MASK, nr, write, true, 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