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-memops.h>
23 struct vb2_vmalloc_buf {
26 struct vm_area_struct *vma;
31 struct vb2_vmarea_handler handler;
34 static void vb2_vmalloc_put(void *buf_priv);
36 static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
38 struct vb2_vmalloc_buf *buf;
40 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
45 buf->vaddr = vmalloc_user(buf->size);
46 buf->handler.refcount = &buf->refcount;
47 buf->handler.put = vb2_vmalloc_put;
48 buf->handler.arg = buf;
51 pr_debug("vmalloc of size %ld failed\n", buf->size);
56 atomic_inc(&buf->refcount);
60 static void vb2_vmalloc_put(void *buf_priv)
62 struct vb2_vmalloc_buf *buf = buf_priv;
64 if (atomic_dec_and_test(&buf->refcount)) {
70 static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
71 unsigned long size, int write)
73 struct vb2_vmalloc_buf *buf;
74 unsigned long first, last;
76 struct vm_area_struct *vma;
79 buf = kzalloc(sizeof(*buf), GFP_KERNEL);
84 offset = vaddr & ~PAGE_MASK;
88 vma = find_vma(current->mm, vaddr);
89 if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
90 if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
91 goto fail_pages_array_alloc;
93 buf->vaddr = ioremap_nocache(physp, size);
95 goto fail_pages_array_alloc;
97 first = vaddr >> PAGE_SHIFT;
98 last = (vaddr + size - 1) >> PAGE_SHIFT;
99 buf->n_pages = last - first + 1;
100 buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
103 goto fail_pages_array_alloc;
105 /* current->mm->mmap_sem is taken by videobuf2 core */
106 n_pages = get_user_pages(current, current->mm,
107 vaddr & PAGE_MASK, buf->n_pages,
108 write, 1, /* force */
110 if (n_pages != buf->n_pages)
111 goto fail_get_user_pages;
113 buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
116 goto fail_get_user_pages;
119 buf->vaddr += offset;
123 pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
125 while (--n_pages >= 0)
126 put_page(buf->pages[n_pages]);
129 fail_pages_array_alloc:
135 static void vb2_vmalloc_put_userptr(void *buf_priv)
137 struct vb2_vmalloc_buf *buf = buf_priv;
138 unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
143 vm_unmap_ram((void *)vaddr, buf->n_pages);
144 for (i = 0; i < buf->n_pages; ++i) {
146 set_page_dirty_lock(buf->pages[i]);
147 put_page(buf->pages[i]);
152 vb2_put_vma(buf->vma);
158 static void *vb2_vmalloc_vaddr(void *buf_priv)
160 struct vb2_vmalloc_buf *buf = buf_priv;
163 pr_err("Address of an unallocated plane requested "
164 "or cannot map user pointer\n");
171 static unsigned int vb2_vmalloc_num_users(void *buf_priv)
173 struct vb2_vmalloc_buf *buf = buf_priv;
174 return atomic_read(&buf->refcount);
177 static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
179 struct vb2_vmalloc_buf *buf = buf_priv;
183 pr_err("No memory to map\n");
187 ret = remap_vmalloc_range(vma, buf->vaddr, 0);
189 pr_err("Remapping vmalloc memory, error: %d\n", ret);
194 * Make sure that vm_areas for 2 buffers won't be merged together
196 vma->vm_flags |= VM_DONTEXPAND;
199 * Use common vm_area operations to track buffer refcount.
201 vma->vm_private_data = &buf->handler;
202 vma->vm_ops = &vb2_common_vm_ops;
204 vma->vm_ops->open(vma);
209 const struct vb2_mem_ops vb2_vmalloc_memops = {
210 .alloc = vb2_vmalloc_alloc,
211 .put = vb2_vmalloc_put,
212 .get_userptr = vb2_vmalloc_get_userptr,
213 .put_userptr = vb2_vmalloc_put_userptr,
214 .vaddr = vb2_vmalloc_vaddr,
215 .mmap = vb2_vmalloc_mmap,
216 .num_users = vb2_vmalloc_num_users,
218 EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
220 MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
221 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
222 MODULE_LICENSE("GPL");