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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-06-14 16:35:52 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-08-13 23:02:38 -0300
commit5bc3cb743bbab408792c1b4ef31adf6268aa4b7e (patch)
tree94faf3260c80a9626b450a6472780828cdf03b26 /drivers/media/v4l2-core/videobuf2-vmalloc.c
parent2ea4b442589b30210a166b9630c2547ebbe2cb82 (diff)
[media] v4l: move v4l2 core into a separate directory
Currently, the v4l2 core is mixed together with other non-core drivers. Move them into a separate directory. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-vmalloc.c')
-rw-r--r--drivers/media/v4l2-core/videobuf2-vmalloc.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
new file mode 100644
index 000000000000..94efa04d8d55
--- /dev/null
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -0,0 +1,223 @@
+/*
+ * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <pawel@osciak.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-vmalloc.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_vmalloc_buf {
+ void *vaddr;
+ struct page **pages;
+ struct vm_area_struct *vma;
+ int write;
+ unsigned long size;
+ unsigned int n_pages;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_vmalloc_put(void *buf_priv);
+
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_vmalloc_buf *buf;
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->size = size;
+ buf->vaddr = vmalloc_user(buf->size);
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_vmalloc_put;
+ buf->handler.arg = buf;
+
+ if (!buf->vaddr) {
+ pr_debug("vmalloc of size %ld failed\n", buf->size);
+ kfree(buf);
+ return NULL;
+ }
+
+ atomic_inc(&buf->refcount);
+ return buf;
+}
+
+static void vb2_vmalloc_put(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ vfree(buf->vaddr);
+ kfree(buf);
+ }
+}
+
+static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write)
+{
+ struct vb2_vmalloc_buf *buf;
+ unsigned long first, last;
+ int n_pages, offset;
+ struct vm_area_struct *vma;
+ dma_addr_t physp;
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->write = write;
+ offset = vaddr & ~PAGE_MASK;
+ buf->size = size;
+
+
+ vma = find_vma(current->mm, vaddr);
+ if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) {
+ if (vb2_get_contig_userptr(vaddr, size, &vma, &physp))
+ goto fail_pages_array_alloc;
+ buf->vma = vma;
+ buf->vaddr = ioremap_nocache(physp, size);
+ if (!buf->vaddr)
+ goto fail_pages_array_alloc;
+ } else {
+ first = vaddr >> PAGE_SHIFT;
+ last = (vaddr + size - 1) >> PAGE_SHIFT;
+ buf->n_pages = last - first + 1;
+ buf->pages = kzalloc(buf->n_pages * sizeof(struct page *),
+ GFP_KERNEL);
+ if (!buf->pages)
+ goto fail_pages_array_alloc;
+
+ /* current->mm->mmap_sem is taken by videobuf2 core */
+ n_pages = get_user_pages(current, current->mm,
+ vaddr & PAGE_MASK, buf->n_pages,
+ write, 1, /* force */
+ buf->pages, NULL);
+ if (n_pages != buf->n_pages)
+ goto fail_get_user_pages;
+
+ buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1,
+ PAGE_KERNEL);
+ if (!buf->vaddr)
+ goto fail_get_user_pages;
+ }
+
+ buf->vaddr += offset;
+ return buf;
+
+fail_get_user_pages:
+ pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages,
+ buf->n_pages);
+ while (--n_pages >= 0)
+ put_page(buf->pages[n_pages]);
+ kfree(buf->pages);
+
+fail_pages_array_alloc:
+ kfree(buf);
+
+ return NULL;
+}
+
+static void vb2_vmalloc_put_userptr(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK;
+ unsigned int i;
+
+ if (buf->pages) {
+ if (vaddr)
+ vm_unmap_ram((void *)vaddr, buf->n_pages);
+ for (i = 0; i < buf->n_pages; ++i) {
+ if (buf->write)
+ set_page_dirty_lock(buf->pages[i]);
+ put_page(buf->pages[i]);
+ }
+ kfree(buf->pages);
+ } else {
+ if (buf->vma)
+ vb2_put_vma(buf->vma);
+ iounmap(buf->vaddr);
+ }
+ kfree(buf);
+}
+
+static void *vb2_vmalloc_vaddr(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ if (!buf->vaddr) {
+ pr_err("Address of an unallocated plane requested "
+ "or cannot map user pointer\n");
+ return NULL;
+ }
+
+ return buf->vaddr;
+}
+
+static unsigned int vb2_vmalloc_num_users(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ int ret;
+
+ if (!buf) {
+ pr_err("No memory to map\n");
+ return -EINVAL;
+ }
+
+ ret = remap_vmalloc_range(vma, buf->vaddr, 0);
+ if (ret) {
+ pr_err("Remapping vmalloc memory, error: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * Make sure that vm_areas for 2 buffers won't be merged together
+ */
+ vma->vm_flags |= VM_DONTEXPAND;
+
+ /*
+ * Use common vm_area operations to track buffer refcount.
+ */
+ vma->vm_private_data = &buf->handler;
+ vma->vm_ops = &vb2_common_vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ return 0;
+}
+
+const struct vb2_mem_ops vb2_vmalloc_memops = {
+ .alloc = vb2_vmalloc_alloc,
+ .put = vb2_vmalloc_put,
+ .get_userptr = vb2_vmalloc_get_userptr,
+ .put_userptr = vb2_vmalloc_put_userptr,
+ .vaddr = vb2_vmalloc_vaddr,
+ .mmap = vb2_vmalloc_mmap,
+ .num_users = vb2_vmalloc_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
+
+MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
+MODULE_LICENSE("GPL");

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