From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:63177 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752636Ab0IIRe3 (ORCPT ); Thu, 9 Sep 2010 13:34:29 -0400 Message-ID: <4C891AAD.7000902@redhat.com> Date: Thu, 09 Sep 2010 14:34:37 -0300 From: Mauro Carvalho Chehab MIME-Version: 1.0 To: Pawel Osciak CC: linux-media@vger.kernel.org, kyungmin.park@samsung.com, m.szyprowski@samsung.com, t.fujak@samsung.com Subject: Re: [PATCH v1 2/7] v4l: videobuf2: add generic memory handling routines References: <1284023988-23351-1-git-send-email-p.osciak@samsung.com> <1284023988-23351-3-git-send-email-p.osciak@samsung.com> In-Reply-To: <1284023988-23351-3-git-send-email-p.osciak@samsung.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-ID: Sender: Mauro Carvalho Chehab Em 09-09-2010 06:19, Pawel Osciak escreveu: > Add generic memory handling routines for userspace pointer handling, > contiguous memory verification and mapping. > > Signed-off-by: Pawel Osciak > Signed-off-by: Kyungmin Park > --- > drivers/media/video/Kconfig | 3 + > drivers/media/video/Makefile | 2 + > drivers/media/video/videobuf2-memops.c | 181 ++++++++++++++++++++++++++++++++ > include/media/videobuf2-memops.h | 27 +++++ > 4 files changed, 213 insertions(+), 0 deletions(-) > create mode 100644 drivers/media/video/videobuf2-memops.c > create mode 100644 include/media/videobuf2-memops.h > > diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig > index 5764443..e4ac3e2 100644 > --- a/drivers/media/video/Kconfig > +++ b/drivers/media/video/Kconfig > @@ -51,6 +51,9 @@ config V4L2_MEM2MEM_DEV > config VIDEOBUF2_CORE > tristate > > +config VIDEOBUF2_MEMOPS > + tristate > + > > # > # Multimedia Video device configuration > diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile > index e66f53b..ab5b521 100644 > --- a/drivers/media/video/Makefile > +++ b/drivers/media/video/Makefile > @@ -118,6 +118,8 @@ obj-$(CONFIG_VIDEOBUF_DVB) += videobuf-dvb.o > obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o > > obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o > +obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o > + > > obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o > > diff --git a/drivers/media/video/videobuf2-memops.c b/drivers/media/video/videobuf2-memops.c > new file mode 100644 > index 0000000..fa76983 > --- /dev/null > +++ b/drivers/media/video/videobuf2-memops.c > @@ -0,0 +1,181 @@ > +/* > + * videobuf2-memops.c - generic memory handling routines 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. Hmm... it should be saying GPL version 2 (or v2+). Please fix on all files for your next set of RFC patches. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +/** > + * vb2_contig_verify_userptr() - verify contiguity of a userspace-mapped memory > + * @vma: virtual memory region which maps the physical memory > + * to be verified > + * @vaddr: starting virtual address of the area to be verified > + * @size: size of the area to be verified > + * @paddr: will return physical address for the given vaddr > + * > + * This function will go through memory area of size size mapped at vaddr and > + * verify that the underlying physical pages are contiguous. > + * > + * Returns 0 on success and a physical address to the memory pointed > + * to by vaddr in paddr. > + */ > +int vb2_contig_verify_userptr(struct vm_area_struct *vma, > + unsigned long vaddr, unsigned long size, > + unsigned long *paddr) > +{ > + struct mm_struct *mm = current->mm; > + unsigned long offset; > + unsigned long vma_size; > + unsigned long curr_pfn, prev_pfn; > + unsigned long num_pages; > + int ret = -EINVAL; > + unsigned int i; > + > + offset = vaddr & ~PAGE_MASK; > + > + down_read(&mm->mmap_sem); > + > + vma = find_vma(mm, vaddr); > + if (!vma) { > + printk(KERN_ERR "Invalid userspace address\n"); > + goto done; > + } > + > + vma_size = vma->vm_end - vma->vm_start; > + > + if (size > vma_size - offset) { > + printk(KERN_ERR "Region too small\n"); > + goto done; > + } > + num_pages = (size + offset) >> PAGE_SHIFT; > + > + ret = follow_pfn(vma, vaddr, &curr_pfn); > + if (ret) { > + printk(KERN_ERR "Invalid userspace address\n"); > + goto done; > + } > + > + *paddr = (curr_pfn << PAGE_SHIFT) + offset; > + > + for (i = 1; i < num_pages; ++i) { > + prev_pfn = curr_pfn; > + vaddr += PAGE_SIZE; > + > + ret = follow_pfn(vma, vaddr, &curr_pfn); > + if (ret || curr_pfn != prev_pfn + 1) { > + printk(KERN_ERR "Invalid userspace address\n"); > + ret = -EINVAL; > + break; > + } > + } > + > +done: > + up_read(&mm->mmap_sem); > + return ret; > +} > + > +/** > + * vb2_mmap_pfn_range() - map physical pages to userspace > + * @vma: virtual memory region for the mapping > + * @paddr: starting physical address of the memory to be mapped > + * @size: size of the memory to be mapped > + * @vm_ops: vm operations to be assigned to the created area > + * @priv: private data to be associated with the area > + * > + * Returns 0 on success. > + */ > +int vb2_mmap_pfn_range(struct vm_area_struct *vma, unsigned long paddr, > + unsigned long size, > + const struct vm_operations_struct *vm_ops, > + void *priv) > +{ > + int ret; > + > + size = min_t(unsigned long, vma->vm_end - vma->vm_start, size); > + > + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > + ret = remap_pfn_range(vma, vma->vm_start, paddr >> PAGE_SHIFT, > + size, vma->vm_page_prot); > + if (ret) { > + printk(KERN_ERR "Remapping memory failed, error: %d\n", ret); > + return ret; > + } > + > + vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED; > + vma->vm_private_data = priv; > + vma->vm_ops = vm_ops; > + > + vm_ops->open(vma); > + > + printk(KERN_DEBUG "%s: mapped paddr 0x%08lx at 0x%08lx, size %ld\n", > + __func__, paddr, vma->vm_start, size); > + > + return 0; > +} > + > +/** > + * vb2_get_userptr() - acquire an area pointed to by userspace addres vaddr > + * @vaddr: virtual userspace address to the given area > + * > + * This function attempts to acquire an area mapped in the userspace for > + * the duration of a hardware operation. > + * > + * Returns a virtual memory region associated with the given vaddr on success > + * or NULL. > + */ > +struct vm_area_struct *vb2_get_userptr(unsigned long vaddr) > +{ > + struct mm_struct *mm = current->mm; > + struct vm_area_struct *vma; > + > + down_read(&mm->mmap_sem); > + > + vma = find_vma(mm, vaddr); > + if (!vma) > + goto done; > + > + if (vma->vm_ops && vma->vm_ops->open) > + vma->vm_ops->open(vma); > + > + if (vma->vm_file) > + get_file(vma->vm_file); > + > +done: > + up_read(&mm->mmap_sem); > + return vma; > +} > + > +/** > + * vb2_put_userptr() - release a userspace memory area > + * @vma: virtual memory region associated with the area to be released > + * > + * This function releases the previously acquired memory area after a hardware > + * operation. > + */ > +void vb2_put_userptr(struct vm_area_struct *vma) > +{ > + if (!vma) > + return; > + > + if (vma->vm_file) > + fput(vma->vm_file); > + > + if (vma->vm_ops && vma->vm_ops->close) > + vma->vm_ops->close(vma); > +} > diff --git a/include/media/videobuf2-memops.h b/include/media/videobuf2-memops.h > new file mode 100644 > index 0000000..23db249 > --- /dev/null > +++ b/include/media/videobuf2-memops.h > @@ -0,0 +1,27 @@ > +/* > + * videobuf2-memops.h - generic memory handling routines 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 > + > +int vb2_contig_verify_userptr(struct vm_area_struct *vma, > + unsigned long vaddr, unsigned long size, > + unsigned long *paddr); > + > +int vb2_mmap_pfn_range(struct vm_area_struct *vma, unsigned long paddr, > + unsigned long size, > + const struct vm_operations_struct *vm_ops, > + void *priv); > + > +struct vm_area_struct *vb2_get_userptr(unsigned long vaddr); > + > +void vb2_put_userptr(struct vm_area_struct *vma); > +