2 * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation.
14 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/vmalloc.h>
20 #include <media/videobuf2-core.h>
21 #include <media/videobuf2-vmalloc.h>
22 #include <media/videobuf2-memops.h>
24 struct vb2_vmalloc_buf {
27 struct vm_area_struct *vma;
32 struct vb2_vmarea_handler handler;
35 static void vb2_vmalloc_put(void *buf_priv);
37 static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
39 struct vb2_vmalloc_buf *buf;
41 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
46 buf->vaddr = vmalloc_user(buf->size);
47 buf->handler.refcount = &buf->refcount;
48 buf->handler.put = vb2_vmalloc_put;
49 buf->handler.arg = buf;
52 pr_debug("vmalloc of size %ld failed\n", buf->size);
57 atomic_inc(&buf->refcount);
61 static void vb2_vmalloc_put(void *buf_priv)
63 struct vb2_vmalloc_buf *buf = buf_priv;
65 if (atomic_dec_and_test(&buf->refcount)) {
71 static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
72 unsigned long size, int write)
74 struct vb2_vmalloc_buf *buf;
75 unsigned long first, last;
77 struct vm_area_struct *vma;
80 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
85 offset = vaddr & ~PAGE_MASK;
89 vma = find_vma(current->mm, vaddr);
90 if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
91 if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
92 goto fail_pages_array_alloc;
94 buf->vaddr = ioremap_nocache(physp, size);
96 goto fail_pages_array_alloc;
98 first = vaddr >> PAGE_SHIFT;
99 last = (vaddr + size - 1) >> PAGE_SHIFT;
100 buf->n_pages = last - first + 1;
101 buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
104 goto fail_pages_array_alloc;
106 /* current->mm->mmap_sem is taken by videobuf2 core */
107 n_pages = get_user_pages(current, current->mm,
108 vaddr & PAGE_MASK, buf->n_pages,
109 write, 1, /* force */
111 if (n_pages != buf->n_pages)
112 goto fail_get_user_pages;
114 buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
117 goto fail_get_user_pages;
120 buf->vaddr += offset;
124 pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
126 while (--n_pages >= 0)
127 put_page(buf->pages[n_pages]);
130 fail_pages_array_alloc:
136 static void vb2_vmalloc_put_userptr(void *buf_priv)
138 struct vb2_vmalloc_buf *buf = buf_priv;
139 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
144 vm_unmap_ram((void *)vaddr, buf->n_pages);
145 for (i = 0; i < buf->n_pages; ++i) {
147 set_page_dirty_lock(buf->pages[i]);
148 put_page(buf->pages[i]);
153 vb2_put_vma(buf->vma);
159 static void *vb2_vmalloc_vaddr(void *buf_priv)
161 struct vb2_vmalloc_buf *buf = buf_priv;
164 pr_err("Address of an unallocated plane requested "
165 "or cannot map user pointer\n");
172 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
174 struct vb2_vmalloc_buf *buf = buf_priv;
175 return atomic_read(&buf->refcount);
178 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
180 struct vb2_vmalloc_buf *buf = buf_priv;
184 pr_err("No memory to map\n");
188 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
190 pr_err("Remapping vmalloc memory, error: %d\n", ret);
195 * Make sure that vm_areas for 2 buffers won't be merged together
197 vma->vm_flags |= VM_DONTEXPAND;
200 * Use common vm_area operations to track buffer refcount.
202 vma->vm_private_data = &buf->handler;
203 vma->vm_ops = &vb2_common_vm_ops;
205 vma->vm_ops->open(vma);
210 const struct vb2_mem_ops vb2_vmalloc_memops = {
211 .alloc = vb2_vmalloc_alloc,
212 .put = vb2_vmalloc_put,
213 .get_userptr = vb2_vmalloc_get_userptr,
214 .put_userptr = vb2_vmalloc_put_userptr,
215 .vaddr = vb2_vmalloc_vaddr,
216 .mmap = vb2_vmalloc_mmap,
217 .num_users = vb2_vmalloc_num_users,
219 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
221 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
222 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
223 MODULE_LICENSE("GPL");