Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756248AbXLGO5e (ORCPT ); Fri, 7 Dec 2007 09:57:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753262AbXLGO5B (ORCPT ); Fri, 7 Dec 2007 09:57:01 -0500 Received: from mo11.iij4u.or.jp ([210.138.174.79]:53596 "EHLO mo11.iij4u.or.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751850AbXLGO45 (ORCPT ); Fri, 7 Dec 2007 09:56:57 -0500 Date: Fri, 7 Dec 2007 23:56:41 +0900 To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org Cc: akpm@linux-foundation.org, benh@kernel.crashing.org, paulus@samba.org, olof@lixom.net, anton@samba.org Cc: fujita.tomonori@lab.ntt.co.jp Subject: [PATCH -mm 3/6] powerpc: remove DMA 4GB boundary protection From: FUJITA Tomonori In-Reply-To: <21710c4b9cd6848e70e29949dfb54894e9aabbe6.tomof@acm.org> References: <21710c4b9cd6848e70e29949dfb54894e9aabbe6.tomof@acm.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: <20071207235712O.tomof@acm.org> X-Dispatcher: imput version 20040704(IM147) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2308 Lines: 62 Previously, during initialization of the IOMMU tables, the last entry at each 4GB boundary is marked as used since there are many adapters which cannot handle DMAing across any 4GB boundary. The IOMMU doesn't allocate a memory area spanning LLD's segment boundary anymore. The segment boundary of devices are set to 4GB by default. So we can remove 4GB boundary protection now. Signed-off-by: FUJITA Tomonori --- arch/powerpc/kernel/iommu.c | 21 +-------------------- 1 files changed, 1 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 6abf4c3..bdb194c 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -448,9 +448,6 @@ void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist, struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid) { unsigned long sz; - unsigned long start_index, end_index; - unsigned long entries_per_4g; - unsigned long index; static int welcomed = 0; struct page *page; @@ -472,6 +469,7 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid) #ifdef CONFIG_CRASH_DUMP if (ppc_md.tce_get) { + unsigned long index; unsigned long tceval; unsigned long tcecount = 0; @@ -502,23 +500,6 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid) ppc_md.tce_free(tbl, tbl->it_offset, tbl->it_size); #endif - /* - * DMA cannot cross 4 GB boundary. Mark last entry of each 4 - * GB chunk as reserved. - */ - if (protect4gb) { - entries_per_4g = 0x100000000l >> IOMMU_PAGE_SHIFT; - - /* Mark the last bit before a 4GB boundary as used */ - start_index = tbl->it_offset | (entries_per_4g - 1); - start_index -= tbl->it_offset; - - end_index = tbl->it_size; - - for (index = start_index; index < end_index - 1; index += entries_per_4g) - __set_bit(index, tbl->it_map); - } - if (!welcomed) { printk(KERN_INFO "IOMMU table initialized, virtual merging %s\n", novmerge ? "disabled" : "enabled"); -- 1.5.3.4 -- 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/