[media] v4l: videobuf2: add vmalloc allocator (3c18ff06) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/media/video/Kconfig

+5 −0

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		@@ -50,6 +50,11 @@ config VIDEOBUF2_CORE
		config VIDEOBUF2_MEMOPS
		tristate

		config VIDEOBUF2_VMALLOC
		select VIDEOBUF2_CORE
		select VIDEOBUF2_MEMOPS
		tristate

		#
		# Multimedia Video device configuration
		#

drivers/media/video/Makefile

+1 −0

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		@@ -113,6 +113,7 @@ obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o

		obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
		obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
		obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o

		obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

drivers/media/video/videobuf2-vmalloc.c

0 → 100644

+132 −0

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		/*
		* videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
		*
		* Copyright (C) 2010 Samsung Electronics
		*
		* Author: Pawel Osciak <p.osciak@samsung.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/module.h>
		#include <linux/mm.h>
		#include <linux/slab.h>
		#include <linux/vmalloc.h>

		#include <media/videobuf2-core.h>
		#include <media/videobuf2-memops.h>

		struct vb2_vmalloc_buf {
		void *vaddr;
		unsigned long size;
		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) {
		printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
		kfree(buf);
		return NULL;
		}

		atomic_inc(&buf->refcount);
		printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
		buf->size, buf->vaddr);

		return buf;
		}

		static void vb2_vmalloc_put(void *buf_priv)
		{
		struct vb2_vmalloc_buf *buf = buf_priv;

		if (atomic_dec_and_test(&buf->refcount)) {
		printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n",
		__func__, buf->vaddr);
		vfree(buf->vaddr);
		kfree(buf);
		}
		}

		static void vb2_vmalloc_vaddr(void buf_priv)
		{
		struct vb2_vmalloc_buf *buf = buf_priv;

		BUG_ON(!buf);

		if (!buf->vaddr) {
		printk(KERN_ERR "Address of an unallocated plane requested\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) {
		printk(KERN_ERR "No memory to map\n");
		return -EINVAL;
		}

		ret = remap_vmalloc_range(vma, buf->vaddr, 0);
		if (ret) {
		printk(KERN_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,
		.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");
		MODULE_LICENSE("GPL");

include/media/videobuf2-vmalloc.h

0 → 100644

+20 −0

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		/*
		* videobuf2-vmalloc.h - vmalloc memory allocator for videobuf2
		*
		* Copyright (C) 2010 Samsung Electronics
		*
		* Author: Pawel Osciak <p.osciak@samsung.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.
		*/

		#ifndef _MEDIA_VIDEOBUF2_VMALLOC_H
		#define _MEDIA_VIDEOBUF2_VMALLOC_H

		#include <media/videobuf2-core.h>

		extern const struct vb2_mem_ops vb2_vmalloc_memops;

		#endif