From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756800AbaEEVoI (ORCPT ); Mon, 5 May 2014 17:44:08 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:44289 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756251AbaEEVoF (ORCPT ); Mon, 5 May 2014 17:44:05 -0400 Message-ID: <536805FC.8090406@ti.com> Date: Mon, 5 May 2014 17:43:24 -0400 From: Santosh Shilimkar User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Russell King - ARM Linux CC: , , , Grygorii Strashko , Greg Kroah-Hartman , Arnd Bergmann , Olof Johansson , Grant Likely , Rob Herring , Catalin Marinas , Linus Walleij Subject: Re: [PATCH v3 5/7] ARM: dma: Use dma_pfn_offset for dma address translation References: <1398353407-2345-1-git-send-email-santosh.shilimkar@ti.com> <1398353407-2345-6-git-send-email-santosh.shilimkar@ti.com> <20140502145852.GC3693@n2100.arm.linux.org.uk> <5363B42C.4010404@ti.com> <20140505195040.GE3693@n2100.arm.linux.org.uk> In-Reply-To: <20140505195040.GE3693@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 05 May 2014 03:50 PM, Russell King - ARM Linux wrote: > On Fri, May 02, 2014 at 11:05:16AM -0400, Santosh Shilimkar wrote: >> On Friday 02 May 2014 10:58 AM, Russell King - ARM Linux wrote: >>> On Thu, Apr 24, 2014 at 11:30:05AM -0400, Santosh Shilimkar wrote: >>>> static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) >>>> { >>>> - return (void *)__bus_to_virt((unsigned long)addr); >>>> + if (!dev) >>>> + return (void *)__bus_to_virt((unsigned long)addr); >>>> + else >>>> + return (void *)__bus_to_virt(__pfn_to_bus(dma_to_pfn(dev, addr))); >>> >>> This is quite horrendous. There's easier ways to do this... I assume >>> you haven't looked at the assembler resulting from this at all with >>> stuff like the p2v patching enabled? >>> >> I haven't. Will check. > > if (dev) { > unsigned long pfn = dma_to_pfn(dev, addr); > > return phys_to_virt(__pfn_to_phys(pfn)); > } > > return (void *)__bus_to_virt((unsigned long)addr); > Thanks a lot Russell. Updated patch below for archive records. >>From 97a6f063270265d03ffcb010b9dc156b274631e7 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Thu, 24 Apr 2014 11:30:05 -0400 Subject: [PATCH v3 5/7] ARM: dma: Use dma_pfn_offset for dma address translation In most of cases DMA addresses can be performed using offset value of Bus address space relatively to physical address space as following: PFN->DMA: __pfn_to_phys(pfn + [-]dma_pfn_offset) DMA->PFN: __phys_to_pfn(dma_addr) + [-]dma_pfn_offset Thanks to Russell King for suggesting the optimised macro's for conversion. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- arch/arm/include/asm/dma-mapping.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e701a4d..b0c79fd 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -58,21 +58,37 @@ static inline int dma_set_mask(struct device *dev, u64 mask) #ifndef __arch_pfn_to_dma static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) { + if (dev) + pfn -= dev->dma_pfn_offset; return (dma_addr_t)__pfn_to_bus(pfn); } static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) { - return __bus_to_pfn(addr); + unsigned long pfn = __bus_to_pfn(addr); + + if (dev) + pfn += dev->dma_pfn_offset; + + return pfn; } static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) { + if (dev) { + unsigned long pfn = dma_to_pfn(dev, addr); + + return phys_to_virt(__pfn_to_phys(pfn)); + } + return (void *)__bus_to_virt((unsigned long)addr); } static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) { + if (dev) + return pfn_to_dma(dev, virt_to_pfn(addr)); + return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); } -- 1.7.9.5