1 files changed, 279 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 00000000000..313d9771b2b
--- /dev/null
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -0,0 +1,279 @@
+/*
+ * 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;
+	struct dma_buf			*dbuf;
+};
+
+static void vb2_vmalloc_put(void *buf_priv);
+
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
+{
+	struct vb2_vmalloc_buf *buf;
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags);
+	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;
+}
+
+/*********************************************/
+/*       callbacks for DMABUF buffers        */
+/*********************************************/
+
+static int vb2_vmalloc_map_dmabuf(void *mem_priv)
+{
+	struct vb2_vmalloc_buf *buf = mem_priv;
+
+	buf->vaddr = dma_buf_vmap(buf->dbuf);
+
+	return buf->vaddr ? 0 : -EFAULT;
+}
+
+static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
+{
+	struct vb2_vmalloc_buf *buf = mem_priv;
+
+	dma_buf_vunmap(buf->dbuf, buf->vaddr);
+	buf->vaddr = NULL;
+}
+
+static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
+{
+	struct vb2_vmalloc_buf *buf = mem_priv;
+
+	if (buf->vaddr)
+		dma_buf_vunmap(buf->dbuf, buf->vaddr);
+
+	kfree(buf);
+}
+
+static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
+	unsigned long size, int write)
+{
+	struct vb2_vmalloc_buf *buf;
+
+	if (dbuf->size < size)
+		return ERR_PTR(-EFAULT);
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->dbuf = dbuf;
+	buf->write = write;
+	buf->size = size;
+
+	return buf;
+}
+
+
+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,
+	.map_dmabuf	= vb2_vmalloc_map_dmabuf,
+	.unmap_dmabuf	= vb2_vmalloc_unmap_dmabuf,
+	.attach_dmabuf	= vb2_vmalloc_attach_dmabuf,
+	.detach_dmabuf	= vb2_vmalloc_detach_dmabuf,
+	.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");