[media] v4l: videobuf2: add DMA coherent allocator (1a758d4e) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/media/video/Kconfig

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Original line number	Diff line number	Diff line
		@@ -50,6 +50,11 @@ config VIDEOBUF2_CORE
		config VIDEOBUF2_MEMOPS
		tristate

		config VIDEOBUF2_DMA_CONTIG
		select VIDEOBUF2_CORE
		select VIDEOBUF2_MEMOPS
		tristate

		config VIDEOBUF2_VMALLOC
		select VIDEOBUF2_CORE
		select VIDEOBUF2_MEMOPS

drivers/media/video/Makefile

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		@@ -114,6 +114,7 @@ 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_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o

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

drivers/media/video/videobuf2-dma-contig.c

0 → 100644

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		/*
		* videobuf2-dma-contig.c - DMA contig 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/slab.h>
		#include <linux/dma-mapping.h>

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

		struct vb2_dc_conf {
		struct device *dev;
		};

		struct vb2_dc_buf {
		struct vb2_dc_conf *conf;
		void *vaddr;
		dma_addr_t paddr;
		unsigned long size;
		struct vm_area_struct *vma;
		atomic_t refcount;
		struct vb2_vmarea_handler handler;
		};

		static void vb2_dma_contig_put(void *buf_priv);

		static void vb2_dma_contig_alloc(void alloc_ctx, unsigned long size)
		{
		struct vb2_dc_conf *conf = alloc_ctx;
		struct vb2_dc_buf *buf;

		buf = kzalloc(sizeof *buf, GFP_KERNEL);
		if (!buf)
		return ERR_PTR(-ENOMEM);

		buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->paddr,
		GFP_KERNEL);
		if (!buf->vaddr) {
		dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n",
		buf->size);
		kfree(buf);
		return ERR_PTR(-ENOMEM);
		}

		buf->conf = conf;
		buf->size = size;

		buf->handler.refcount = &buf->refcount;
		buf->handler.put = vb2_dma_contig_put;
		buf->handler.arg = buf;

		atomic_inc(&buf->refcount);

		return buf;
		}

		static void vb2_dma_contig_put(void *buf_priv)
		{
		struct vb2_dc_buf *buf = buf_priv;

		if (atomic_dec_and_test(&buf->refcount)) {
		dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr,
		buf->paddr);
		kfree(buf);
		}
		}

		static void vb2_dma_contig_cookie(void buf_priv)
		{
		struct vb2_dc_buf *buf = buf_priv;

		return (void *)buf->paddr;
		}

		static void vb2_dma_contig_vaddr(void buf_priv)
		{
		struct vb2_dc_buf *buf = buf_priv;
		if (!buf)
		return 0;

		return buf->vaddr;
		}

		static unsigned int vb2_dma_contig_num_users(void *buf_priv)
		{
		struct vb2_dc_buf *buf = buf_priv;

		return atomic_read(&buf->refcount);
		}

		static int vb2_dma_contig_mmap(void buf_priv, struct vm_area_struct vma)
		{
		struct vb2_dc_buf *buf = buf_priv;

		if (!buf) {
		printk(KERN_ERR "No buffer to map\n");
		return -EINVAL;
		}

		return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
		&vb2_common_vm_ops, &buf->handler);
		}

		static void vb2_dma_contig_get_userptr(void alloc_ctx, unsigned long vaddr,
		unsigned long size, int write)
		{
		struct vb2_dc_buf *buf;
		struct vm_area_struct *vma;
		dma_addr_t paddr = 0;
		int ret;

		buf = kzalloc(sizeof *buf, GFP_KERNEL);
		if (!buf)
		return ERR_PTR(-ENOMEM);

		ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr);
		if (ret) {
		printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
		vaddr);
		kfree(buf);
		return ERR_PTR(ret);
		}

		buf->size = size;
		buf->paddr = paddr;
		buf->vma = vma;

		return buf;
		}

		static void vb2_dma_contig_put_userptr(void *mem_priv)
		{
		struct vb2_dc_buf *buf = mem_priv;

		if (!buf)
		return;

		vb2_put_vma(buf->vma);
		kfree(buf);
		}

		const struct vb2_mem_ops vb2_dma_contig_memops = {
		.alloc = vb2_dma_contig_alloc,
		.put = vb2_dma_contig_put,
		.cookie = vb2_dma_contig_cookie,
		.vaddr = vb2_dma_contig_vaddr,
		.mmap = vb2_dma_contig_mmap,
		.get_userptr = vb2_dma_contig_get_userptr,
		.put_userptr = vb2_dma_contig_put_userptr,
		.num_users = vb2_dma_contig_num_users,
		};
		EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);

		void vb2_dma_contig_init_ctx(struct device dev)
		{
		struct vb2_dc_conf *conf;

		conf = kzalloc(sizeof *conf, GFP_KERNEL);
		if (!conf)
		return ERR_PTR(-ENOMEM);

		conf->dev = dev;

		return conf;
		}
		EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);

		void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
		{
		kfree(alloc_ctx);
		}
		EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);

		MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
		MODULE_AUTHOR("Pawel Osciak");
		MODULE_LICENSE("GPL");

include/media/videobuf2-dma-contig.h

0 → 100644

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		/*
		* videobuf2-dma-coherent.h - DMA coherent 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_DMA_COHERENT_H
		#define _MEDIA_VIDEOBUF2_DMA_COHERENT_H

		#include <media/videobuf2-core.h>

		static inline unsigned long vb2_dma_contig_plane_paddr(
		struct vb2_buffer *vb, unsigned int plane_no)
		{
		return (unsigned long)vb2_plane_cookie(vb, plane_no);
		}

		void vb2_dma_contig_init_ctx(struct device dev);
		void vb2_dma_contig_cleanup_ctx(void *alloc_ctx);

		extern const struct vb2_mem_ops vb2_dma_contig_memops;

		#endif