From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762658AbYDBVUO (ORCPT ); Wed, 2 Apr 2008 17:20:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762530AbYDBVT6 (ORCPT ); Wed, 2 Apr 2008 17:19:58 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:44836 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762521AbYDBVT4 (ORCPT ); Wed, 2 Apr 2008 17:19:56 -0400 Date: Wed, 2 Apr 2008 14:19:23 -0700 From: Andrew Morton To: FUJITA Tomonori Cc: linux-kernel@vger.kernel.org, tomof@acm.org, fujita.tomonori@lab.ntt.co.jp, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, tony.luck@intel.com Subject: Re: [PATCH -mm] SWIOTLB: use iommu_is_span_boundary helper function Message-Id: <20080402141923.2122a8ed.akpm@linux-foundation.org> In-Reply-To: <1207170155-8065-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> References: <1207170155-8065-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 3 Apr 2008 06:02:35 +0900 FUJITA Tomonori wrote: > iommu_is_span_boundary in lib/iommu-helper.c was exported for PARISC > IOMMUs (commit 3715863aa142c4f4c5208f5f3e5e9bac06006d2f). SWIOTLB can > use it instead of the homegrown function. > > Signed-off-by: FUJITA Tomonori > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: H. Peter Anvin > Cc: Tony Luck > Cc: Andrew Morton > --- > arch/ia64/Kconfig | 5 ++++- > arch/x86/Kconfig | 5 ++--- > lib/swiotlb.c | 14 +++----------- > 3 files changed, 9 insertions(+), 15 deletions(-) > > diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig > index 53b8410..6840a13 100644 > --- a/arch/ia64/Kconfig > +++ b/arch/ia64/Kconfig > @@ -47,6 +47,9 @@ config MMU > config SWIOTLB > bool > > +config IOMMU_HELPER > + bool > + > config GENERIC_LOCKBREAK > bool > default y > @@ -624,7 +627,7 @@ config IRQ_PER_CPU > default y > > config IOMMU_HELPER > - def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC) > + def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC || SWIOTLB) > > source "arch/ia64/hp/sim/Kconfig" > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 1f44517..e6c01c2 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -502,9 +502,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT > Calgary anyway, pass 'iommu=calgary' on the kernel command line. > If unsure, say Y. > > -config IOMMU_HELPER > - def_bool (CALGARY_IOMMU || GART_IOMMU) > - > # need this always selected by IOMMU for the VIA workaround > config SWIOTLB > bool > @@ -515,6 +512,8 @@ config SWIOTLB > access 32-bits of memory can be used on systems with more than > 3 GB of memory. If unsure, say Y. > > +config IOMMU_HELPER > + def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB) > > config NR_CPUS > int "Maximum number of CPUs (2-255)" > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 62c9a18..b50c7e0 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -31,6 +31,7 @@ > > #include > #include > +#include > > #define OFFSET(val,align) ((unsigned long) \ > ( (val) & ( (align) - 1))) > @@ -282,15 +283,6 @@ address_needs_mapping(struct device *hwdev, dma_addr_t addr) > return (addr & ~mask) != 0; > } > > -static inline unsigned int is_span_boundary(unsigned int index, > - unsigned int nslots, > - unsigned long offset_slots, > - unsigned long max_slots) > -{ > - unsigned long offset = (offset_slots + index) & (max_slots - 1); > - return offset + nslots > max_slots; > -} > - > /* > * Allocates bounce buffer and returns its kernel virtual address. > */ > @@ -338,8 +330,8 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir) > wrap = index; > > do { > - while (is_span_boundary(index, nslots, offset_slots, > - max_slots)) { > + while (iommu_is_span_boundary(index, nslots, offset_slots, > + max_slots)) { > index += stride; > if (index >= io_tlb_nslabs) > index = 0; Fair enough. It's confusing that iommu_is_span_boundary() uses index, nr, shift and boundary_size whereas is_span_boundary() used index, nslots, offset_slots, and max_slots. Which one was most accurate, clearer, etc?