From patchwork Fri Nov 19 15:55:39 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 339871 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id oAJFv5vG026197 for ; Fri, 19 Nov 2010 15:57:06 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755303Ab0KSP4B (ORCPT ); Fri, 19 Nov 2010 10:56:01 -0500 Received: from mailout1.w1.samsung.com ([210.118.77.11]:25011 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755289Ab0KSPz7 (ORCPT ); Fri, 19 Nov 2010 10:55:59 -0500 Received: from eu_spt1 (mailout1.w1.samsung.com [210.118.77.11]) by mailout1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTP id <0LC5005Z62X8QQ@mailout1.w1.samsung.com> for linux-media@vger.kernel.org; Fri, 19 Nov 2010 15:55:56 +0000 (GMT) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LC5001VI2X714@spt1.w1.samsung.com> for linux-media@vger.kernel.org; Fri, 19 Nov 2010 15:55:56 +0000 (GMT) Received: from mcdsrvbld02.digital.local (unknown [106.116.37.23]) by linux.samsung.com (Postfix) with ESMTP id 809C72700EB; Fri, 19 Nov 2010 16:55:55 +0100 (CET) Date: Fri, 19 Nov 2010 16:55:39 +0100 From: Marek Szyprowski Subject: [PATCH 2/7] v4l: videobuf2: add generic memory handling routines In-reply-to: <1290182144-10878-1-git-send-email-m.szyprowski@samsung.com> To: linux-media@vger.kernel.org Cc: m.szyprowski@samsung.com, pawel@osciak.com, kyungmin.park@samsung.com Message-id: <1290182144-10878-3-git-send-email-m.szyprowski@samsung.com> MIME-version: 1.0 X-Mailer: git-send-email 1.7.1 Content-type: TEXT/PLAIN Content-transfer-encoding: 7BIT References: <1290182144-10878-1-git-send-email-m.szyprowski@samsung.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter1.kernel.org [140.211.167.41]); Fri, 19 Nov 2010 15:57:06 +0000 (UTC) diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig index fef6a14..83ce858 100644 --- a/drivers/media/video/Kconfig +++ b/drivers/media/video/Kconfig @@ -52,6 +52,9 @@ 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 77c4f85..a97a2a0 100644 --- a/drivers/media/video/Makefile +++ b/drivers/media/video/Makefile @@ -115,6 +115,7 @@ 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..67ebdff --- /dev/null +++ b/drivers/media/video/videobuf2-memops.c @@ -0,0 +1,199 @@ +/* + * videobuf2-memops.c - generic memory handling routines for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak + * Marek Szyprowski + * + * 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 +#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; + struct vm_area_struct *vma_copy; + + vma_copy = kmalloc(sizeof(struct vm_area_struct), GFP_KERNEL); + if (vma_copy == NULL) + return NULL; + + 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); + + memcpy(vma_copy, vma, sizeof(*vma)); +done: + up_read(&mm->mmap_sem); + + vma_copy->vm_mm = NULL; + vma_copy->vm_next = NULL; + vma_copy->vm_prev = NULL; + + return vma_copy; +} + +/** + * 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); + + kfree(vma); +} + +MODULE_DESCRIPTION("common memory handling routines for videobuf2"); +MODULE_AUTHOR("Pawel Osciak"); +MODULE_LICENSE("GPL"); diff --git a/include/media/videobuf2-memops.h b/include/media/videobuf2-memops.h new file mode 100644 index 0000000..3257411 --- /dev/null +++ b/include/media/videobuf2-memops.h @@ -0,0 +1,31 @@ +/* + * 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. + */ + +#ifndef _MEDIA_VIDEOBUF2_MEMOPS_H +#define _MEDIA_VIDEOBUF2_MEMOPS_H + +#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); + +#endif