From: Songmao Tian Subject: Re: ALSA on MIPS platform Date: Fri, 03 Aug 2007 21:50:36 +0800 Message-ID: <46B332AC.8020403@lemote.com> References: <46B03CC0.3090000@lemote.com> <20070802.235606.122255120.anemo@mba.ocn.ne.jp> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from lemote.com (unknown [222.92.8.141]) by alsa0.perex.cz (Postfix) with SMTP id EFAF810382D for ; Fri, 3 Aug 2007 15:50:45 +0200 (CEST) In-Reply-To: <20070802.235606.122255120.anemo@mba.ocn.ne.jp> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Atsushi Nemoto Cc: linux-mips@linux-mips.org, alsa-devel@alsa-project.org, Dajie Tan , greg@kroah.com List-Id: alsa-devel@alsa-project.org Atsushi Nemoto wrote: > On Wed, 01 Aug 2007 15:56:48 +0800, Songmao Tian wrote: > >> The problem is clear: >> 1. dma_alloc_noncoherent() return a non-cached address, and >> virt_to_page() need a cached logical addr (Have I named it right?) >> 2. mmaped dam buffer should be non-cached. >> >> We have a ugly patch, but we want to solve the problem cleanly, so can >> anyone show me the way? >> > > virt_to_page() is used in many place in mm so making it robust might > affect performance. IMHO virt_to_page() seems too low-level as DMA > API. > > If something like dma_virt_to_page(dev, cpu_addr) which can take a cpu > address returned by dma_xxx APIs was defined, MIPS can implement it > appropriately. > > And then pgprot_noncached issues still exist... > > --- > Atsushi Nemoto > > > > I agree, and I am investigating to implement a dma_map_coherent, but It seems dma_map_coherent doesn't solve all the problem and will change a lot of code:( dma_virt_to_page can be something like this. diff --git a/include/asm-mips/page.h b/include/asm-mips/page.h index b92dd8c..d2ead8a 100644 --- a/include/asm-mips/page.h +++ b/include/asm-mips/page.h @@ -181,6 +181,8 @@ typedef struct { unsigned long pgprot; } pgprot_t; #define virt_to_page(kaddr) pfn_to_page(PFN_DOWN(virt_to_phys(kaddr))) #define virt_addr_valid(kaddr) pfn_valid(PFN_DOWN(virt_to_phys(kaddr))) +#define dma_virt_to_page(dma_addr) pfn_to_page(PFN_DOWN(virt_to_phys(CAC_ADDR(kaddr)))) + #define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \ VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) diff --git a/include/linux/mm.h b/include/linux/mm.h index 655094d..5e694dd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -39,6 +39,10 @@ extern int sysctl_legacy_va_layout; #include #include +#ifndef dma_virt_to_page +#define dma_virt_to_page virt_to_page +#endif + #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n)) /* diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c index cefd228..8b29bfd 100644 --- a/sound/core/sgbuf.c +++ b/sound/core/sgbuf.c @@ -91,7 +91,7 @@ void *snd_malloc_sgbuf_pages(struct device *device, } sgbuf->table[i].buf = tmpb.area; sgbuf->table[i].addr = tmpb.addr; - sgbuf->page_table[i] = virt_to_page(tmpb.area); + sgbuf->page_table[i] = dma_virt_to_page(tmpb.area); sgbuf->pages++; }