From 3c18ff06d811f743d380e6436fac0143ffcf1266 Mon Sep 17 00:00:00 2001 From: Pawel Osciak Date: Mon, 11 Oct 2010 10:58:53 -0300 Subject: [PATCH] [media] v4l: videobuf2: add vmalloc allocator Add an implementation of contiguous virtual memory allocator and handling routines for videobuf2, implemented on top of vmalloc()/vfree() calls. Signed-off-by: Pawel Osciak Signed-off-by: Kyungmin Park Signed-off-by: Marek Szyprowski CC: Pawel Osciak Reviewed-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/Kconfig | 5 ++ drivers/media/video/Makefile | 1 + drivers/media/video/videobuf2-vmalloc.c | 132 ++++++++++++++++++++++++++++++++ include/media/videobuf2-vmalloc.h | 20 +++++ 4 files changed, 158 insertions(+) create mode 100644 drivers/media/video/videobuf2-vmalloc.c create mode 100644 include/media/videobuf2-vmalloc.h diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig index aae5005cf86d..b8c21a729b86 100644 --- a/drivers/media/video/Kconfig +++ b/drivers/media/video/Kconfig @@ -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 # diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile index fca0444b66b1..e31c88e9ca76 100644 --- a/drivers/media/video/Makefile +++ b/drivers/media/video/Makefile @@ -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 diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c new file mode 100644 index 000000000000..b5e6936fb628 --- /dev/null +++ b/drivers/media/video/videobuf2-vmalloc.c @@ -0,0 +1,132 @@ +/* + * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak + * + * 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 +#include +#include +#include + +#include +#include + +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"); diff --git a/include/media/videobuf2-vmalloc.h b/include/media/videobuf2-vmalloc.h new file mode 100644 index 000000000000..a76b8afaa31e --- /dev/null +++ b/include/media/videobuf2-vmalloc.h @@ -0,0 +1,20 @@ +/* + * videobuf2-vmalloc.h - vmalloc memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak + * + * 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 + +extern const struct vb2_mem_ops vb2_vmalloc_memops; + +#endif -- 2.11.0