Hello, I'm really sorry for a late reply, but I was a bit busy with other stuff. On Tuesday, July 31, 2012 10:17 PM Federico Vaga wrote: > Signed-off-by: Federico Vaga <federico.vaga@xxxxxxxxx> > --- > drivers/media/video/Kconfig | 6 +- > drivers/media/video/Makefile | 1 + > drivers/media/video/videobuf2-dma-streaming.c | 187 ++++++++++++++++++++++++++ > include/media/videobuf2-dma-streaming.h | 24 ++++ > 4 file modificati, 217 inserzioni(+). 1 rimozione(-) > create mode 100644 drivers/media/video/videobuf2-dma-streaming.c > create mode 100644 include/media/videobuf2-dma-streaming.h > > diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig > index be6d718..6c60b59 100644 > --- a/drivers/media/video/Kconfig > +++ b/drivers/media/video/Kconfig > @@ -59,6 +59,10 @@ config VIDEOBUF2_DMA_NC > select VIDEOBUF2_CORE > select VIDEOBUF2_MEMOPS > tristate > +config VIDEOBUF2_DMA_STREAMING > + select VIDEOBUF2_CORE > + select VIDEOBUF2_MEMOPS > + tristate > > config VIDEOBUF2_VMALLOC > select VIDEOBUF2_CORE > @@ -844,7 +848,7 @@ config STA2X11_VIP > tristate "STA2X11 VIP Video For Linux" > depends on STA2X11 > select VIDEO_ADV7180 if VIDEO_HELPER_CHIPS_AUTO > - select VIDEOBUF_DMA_CONTIG > + select VIDEOBUF2_DMA_STREAMING This doesn't look like a part of this part. > depends on PCI && VIDEO_V4L2 && VIRT_TO_BUS > help > Say Y for support for STA2X11 VIP (Video Input Port) capture > diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile > index 30234af..c1a08b9e 100644 > --- a/drivers/media/video/Makefile > +++ b/drivers/media/video/Makefile > @@ -140,6 +140,7 @@ obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o > obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o > obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o > obj-$(CONFIG_VIDEOBUF2_DMA_NC) += videobuf2-dma-nc.o > +obj-$(CONFIG_VIDEOBUF2_DMA_STREAMING) += videobuf2-dma-streaming.o > > obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o > > diff --git a/drivers/media/video/videobuf2-dma-streaming.c b/drivers/media/video/videobuf2- > dma-streaming.c > new file mode 100644 > index 0000000..d96d3d9 > --- /dev/null > +++ b/drivers/media/video/videobuf2-dma-streaming.c > @@ -0,0 +1,187 @@ > +/* > + * videobuf2-dma-streaming.c - DMA streaming memory allocator for videobuf2 > + * > + * Copyright (C) 2012 Federico Vaga <federico.vaga@xxxxxxxxx> > + * * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include <linux/module.h> > +#include <linux/slab.h> > +#include <linux/pagemap.h> > +#include <linux/dma-mapping.h> > + > +#include <media/videobuf2-core.h> > +#include <media/videobuf2-dma-streaming.h> > +#include <media/videobuf2-memops.h> > + > +struct vb2_streaming_conf { > + struct device *dev; > +}; > +struct vb2_streaming_buf { > + struct vb2_streaming_conf *conf; > + void *vaddr; > + > + dma_addr_t dma_handle; > + > + unsigned long size; > + struct vm_area_struct *vma; > + > + atomic_t refcount; > + struct vb2_vmarea_handler handler; > +}; > + > +static void vb2_dma_streaming_put(void *buf_priv) > +{ > + struct vb2_streaming_buf *buf = buf_priv; > + > + if (atomic_dec_and_test(&buf->refcount)) { > + dma_unmap_single(buf->conf->dev, buf->dma_handle, buf->size, > + DMA_FROM_DEVICE); > + free_pages_exact(buf->vaddr, buf->size); > + kfree(buf); > + } > + > +} > + > +static void *vb2_dma_streaming_alloc(void *alloc_ctx, unsigned long size) > +{ > + struct vb2_streaming_conf *conf = alloc_ctx; > + struct vb2_streaming_buf *buf; > + int err; > + > + buf = kzalloc(sizeof *buf, GFP_KERNEL); > + if (!buf) > + return ERR_PTR(-ENOMEM); > + buf->vaddr = alloc_pages_exact(size, GFP_KERNEL | GFP_DMA); > + if (!buf->vaddr) { > + err = -ENOMEM; > + goto out; > + } > + buf->dma_handle = dma_map_single(conf->dev, buf->vaddr, size, > + DMA_FROM_DEVICE); > + err = dma_mapping_error(conf->dev, buf->dma_handle); > + if (err) { > + dev_err(conf->dev, "dma_map_single failed\n"); > + > + free_pages_exact(buf->vaddr, size); > + buf->vaddr = NULL; > + goto out_pages; > + } > + buf->conf = conf; > + buf->size = size; > + buf->handler.refcount = &buf->refcount; > + buf->handler.put = vb2_dma_streaming_put; > + buf->handler.arg = buf; > + > + atomic_inc(&buf->refcount); > + return buf; > + > +out_pages: > + free_pages_exact(buf->vaddr, buf->size); > +out: > + kfree(buf); > + return ERR_PTR(err); > +} > + > +static void *vb2_dma_streaming_cookie(void *buf_priv) > +{ > + struct vb2_streaming_buf *buf = buf_priv; > + > + return (void *)buf->dma_handle; > +} > + > +static void *vb2_dma_streaming_vaddr(void *buf_priv) > +{ > + struct vb2_streaming_buf *buf = buf_priv; > + > + if (!buf) > + return NULL; > + return buf->vaddr; > +} > + > +static unsigned int vb2_dma_streaming_num_users(void *buf_priv) > +{ > + struct vb2_streaming_buf *buf = buf_priv; > + > + return atomic_read(&buf->refcount); > +} > + > +static int vb2_dma_streaming_mmap(void *buf_priv, struct vm_area_struct *vma) > +{ > + struct vb2_streaming_buf *buf = buf_priv; > + unsigned long pos, start = vma->vm_start; > + unsigned long size; > + struct page *page; > + int err; > + > + /* Try to remap memory */ > + size = vma->vm_end - vma->vm_start; > + size = (size < buf->size) ? size : buf->size; > + pos = (unsigned long)buf->vaddr; > + > + while (size > 0) { > + page = virt_to_page((void *)pos); > + if (!page) { > + dev_err(buf->conf->dev, "mmap: virt_to_page failed\n"); > + return -ENOMEM; > + } > + err = vm_insert_page(vma, start, page); > + if (err) { > + dev_err(buf->conf->dev, "mmap: insert failed %d\n", err); > + return -ENOMEM; > + } > + start += PAGE_SIZE; > + pos += PAGE_SIZE; > + > + if (size > PAGE_SIZE) > + size -= PAGE_SIZE; > + else > + size = 0; > + } > + > + > + vma->vm_ops = &vb2_common_vm_ops; > + vma->vm_flags |= VM_DONTEXPAND; > + vma->vm_private_data = &buf->handler; > + > + vma->vm_ops->open(vma); > + > + return 0; > +} > + > +const struct vb2_mem_ops vb2_dma_streaming_memops = { > + .alloc = vb2_dma_streaming_alloc, > + .put = vb2_dma_streaming_put, > + .cookie = vb2_dma_streaming_cookie, > + .vaddr = vb2_dma_streaming_vaddr, > + .mmap = vb2_dma_streaming_mmap, > + .num_users = vb2_dma_streaming_num_users, > +}; > +EXPORT_SYMBOL_GPL(vb2_dma_streaming_memops); > + > +void *vb2_dma_streaming_init_ctx(struct device *dev) > +{ > + struct vb2_streaming_conf *conf; > + > + conf = kmalloc(sizeof *conf, GFP_KERNEL); > + if (!conf) > + return ERR_PTR(-ENOMEM); > + > + conf->dev = dev; > + > + return conf; > +} > +EXPORT_SYMBOL_GPL(vb2_dma_streaming_init_ctx); > + > +void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx) > +{ > + kfree(alloc_ctx); > +} > +EXPORT_SYMBOL_GPL(vb2_dma_streaming_cleanup_ctx); > + > +MODULE_DESCRIPTION("DMA-streaming memory allocator for videobuf2"); > +MODULE_AUTHOR("Federico Vaga <federico.vaga@xxxxxxxxx>"); > +MODULE_LICENSE("GPL v2"); > diff --git a/include/media/videobuf2-dma-streaming.h b/include/media/videobuf2-dma-streaming.h > new file mode 100644 > index 0000000..89cbd06 > --- /dev/null > +++ b/include/media/videobuf2-dma-streaming.h > @@ -0,0 +1,24 @@ > +/* > + * videobuf2-dma-streaming.h - DMA steaming memory allocator for videobuf2 > + * > + * Copyright (C) 2012 Federico Vaga > + * > + * Author: Federico Vaga <federico.vaga@xxxxxxxxx> > + * > + * 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_STREAMING_H > +#define _MEDIA_VIDEOBUF2_DMA_STREAMING_H > + > +#include <media/videobuf2-core.h> > +#include <linux/dma-mapping.h> > + > +void *vb2_dma_streaming_init_ctx(struct device *dev); > +void vb2_dma_streaming_cleanup_ctx(void *alloc_ctx); > + > +extern const struct vb2_mem_ops vb2_dma_streaming_memops; > + > +#endif > -- > 1.7.11.2 I'm aware of the fact that some system might require such method of memory allocation. I don't want to delay merging it. I hope that one day it will be finally possible to use dma_alloc_attrs() from dma-mapping subsystem for this purpose and extended videobuf2-dma-contig will handle it. Getting back to your patch - in your approach cpu cache handling is missing. I suspect that it worked fine only because it has been tested on some simple platform without any cpu caches (or with very small ones). Please check the following thread: http://www.spinics.net/lists/linux-media/msg51768.html where Tomasz has posted his ongoing effort on updating and extending videobuf2 and dma-contig allocator. Especially the patch http://www.spinics.net/lists/linux-media/msg51776.html will be interesting for you, because cpu cache synchronization (dma_sync_single_for_device / dma_sync_single_for_cpu) should be called from prepare/finish callbacks. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html