Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754017Ab2FMLvT (ORCPT ); Wed, 13 Jun 2012 07:51:19 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:53370 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753957Ab2FMLvB (ORCPT ); Wed, 13 Jun 2012 07:51:01 -0400 X-AuditID: cbfee61b-b7fcc6d000003a7a-fa-4fd87ea42ba5 From: Marek Szyprowski To: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Marek Szyprowski , Kyungmin Park , Arnd Bergmann , Russell King - ARM Linux , Chunsang Jeong , Krishna Reddy , Benjamin Herrenschmidt , Konrad Rzeszutek Wilk , Hiroshi Doyu , Subash Patel , Sumit Semwal , Abhinav Kochhar , Tomasz Stanislawski Subject: [PATCHv2 2/6] ARM: dma-mapping: add support for DMA_ATTR_NO_KERNEL_MAPPING attribute Date: Wed, 13 Jun 2012 13:50:14 +0200 Message-id: <1339588218-24398-3-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.7.10 In-reply-to: <1339588218-24398-1-git-send-email-m.szyprowski@samsung.com> References: <1339588218-24398-1-git-send-email-m.szyprowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrKJMWRmVeSWpSXmKPExsVy+t9jAd0ldTf8Db5MFLHo2PWVxeLyrjls DkwenzfJBTBGcdmkpOZklqUW6dslcGUcvTubseCWaMWJK5+YGxgnC3UxcnBICJhIXD/m3sXI CWSKSVy4t56ti5GLQ0hgEaNE8702dpCEkEAXk8TXDk8Qm03AUKLrbRcbiC0iMINRYldfGkgD s8A+FonOzScYQRLCAvESp9a8YwFZwCKgKnFjIQtImFfAQ6Jz3ndGiGXyEk/v94HN4RTwlPj9 bB8TxC4Pid/TDjNPYORdwMiwilE0tSC5oDgpPddIrzgxt7g0L10vOT93EyPY88+kdzCuarA4 xCjAwajEw5sBDAgh1sSy4srcQ4wSHMxKIrzPsoFCvCmJlVWpRfnxRaU5qcWHGKU5WJTEeZus L/gLCaQnlqRmp6YWpBbBZJk4OKUaGA12Hntz+n7UPDutl/LbD1bH5n0/bbvTS87q1w7v7Gk5 GwzunHf9uKjXZa2ZnIvH92DpmT+me7Y+rnXIfF/+LvOmWe7dC1I24ZxW03n/dz++sOjW1bfL BXolAooXNU28t0qCL3Mz5yQ+0Ujr52HtJe/bjYrC453P2fuyyx1oy7OONHD/wtutpcRSnJFo qMVcVJwIABLWu974AQAA X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2946 Lines: 82 This patch adds support for DMA_ATTR_NO_KERNEL_MAPPING attribute for IOMMU allocations, what let drivers to save precious kernel virtual address space for large buffers that are intended to be accessed only from userspace. This patch is heavily based on initial work kindly provided by Abhinav Kochhar . Signed-off-by: Marek Szyprowski Reviewed-by: Kyungmin Park --- arch/arm/mm/dma-mapping.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index b3ffcf9..5d8b8b2 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1071,10 +1071,13 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si return 0; } -static struct page **__iommu_get_pages(void *cpu_addr) +static struct page **__iommu_get_pages(void *cpu_addr, struct dma_attrs *attrs) { struct vm_struct *area; + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return cpu_addr; + area = find_vm_area(cpu_addr); if (area && (area->flags & VM_DMA)) return area->pages; @@ -1099,6 +1102,9 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, if (*handle == DMA_ERROR_CODE) goto err_buffer; + if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) + return pages; + addr = __iommu_alloc_remap(pages, size, gfp, prot, __builtin_return_address(0)); if (!addr) @@ -1119,7 +1125,7 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, { unsigned long uaddr = vma->vm_start; unsigned long usize = vma->vm_end - vma->vm_start; - struct page **pages = __iommu_get_pages(cpu_addr); + struct page **pages = __iommu_get_pages(cpu_addr, attrs); vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); @@ -1146,7 +1152,7 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs) { - struct page **pages = __iommu_get_pages(cpu_addr); + struct page **pages = __iommu_get_pages(cpu_addr, attrs); size = PAGE_ALIGN(size); if (!pages) { @@ -1156,8 +1162,10 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, return; } - unmap_kernel_range((unsigned long)cpu_addr, size); - vunmap(cpu_addr); + if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) { + unmap_kernel_range((unsigned long)cpu_addr, size); + vunmap(cpu_addr); + } __iommu_remove_mapping(dev, handle, size); __iommu_free_buffer(dev, pages, size); -- 1.7.1.569.g6f426 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/