From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [LINUX] dma: Use swiotlb mask for coherent mappings too Date: Wed, 20 Dec 2006 11:50:35 +0000 Message-ID: <4589319B.76E4.0078.0@novell.com> References: <20061220051443.GA25598@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20061220051443.GA25598@gondor.apana.org.au> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Herbert Xu , Keir Fraser Cc: Xen Development Mailing List , Calvin Webster List-Id: xen-devel@lists.xenproject.org As we're going to have a swiotlb_{alloc,free}_coherent implementation after the sync with lib/swiotlb.c anyway, wouldn't it make sense to have dma_{alloc,free}_coherent call the former rather than setting up things by itself? If course, this will increase pressure on the swiotlb memory, but otoh it could reduce the likelihood of the contiguous region setup failing (especially if those are of non-zero order). Jan >>> Herbert Xu 20.12.06 06:14 >>> Hi Keir: [LINUX] dma: Use swiotlb mask for coherent mappings too The recent change to use a default DMA bit width of 30 bits (required by chips like the b44) only converted the streaming DMA primitives. The coherent mappings are still hard-coded to 31 bits. This means that b44 still doesn't work under Xen. This patch makes the io_tlb_dma_bits variable global and uses it for coherent memory mappings. Thanks to Calvin Webster for providing a machine with a b44 and 2G of memory I've been able to verify that this finally makes the b44 work under Xen. Signed-off-by: Herbert Xu Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff -r 057f7c4dbed1 linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c --- a/linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c Tue Dec 19 12:00:11 2006 +0000 +++ b/linux-2.6-xen-sparse/arch/i386/kernel/pci-dma-xen.c Wed Dec 20 16:07:24 2006 +1100 @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -183,8 +184,8 @@ void *dma_alloc_coherent(struct device * ret = (void *)vstart; if (ret != NULL) { - /* NB. Hardcode 31 address bits for now: aacraid limitation. */ - if (xen_create_contiguous_region(vstart, order, 31) != 0) { + if (xen_create_contiguous_region(vstart, order, + io_tlb_dma_bits) != 0) { free_pages(vstart, order); return NULL; } diff -r 057f7c4dbed1 linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c --- a/linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c Tue Dec 19 12:00:11 2006 +0000 +++ b/linux-2.6-xen-sparse/arch/i386/kernel/swiotlb.c Wed Dec 20 16:07:24 2006 +1100 @@ -98,7 +98,7 @@ static struct phys_addr { */ static DEFINE_SPINLOCK(io_tlb_lock); -static unsigned int io_tlb_dma_bits = DEFAULT_IO_TLB_DMA_BITS; +unsigned int io_tlb_dma_bits = DEFAULT_IO_TLB_DMA_BITS; static int __init setup_io_tlb_bits(char *str) { diff -r 057f7c4dbed1 linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h --- a/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h Tue Dec 19 12:00:11 2006 +0000 +++ b/linux-2.6-xen-sparse/include/asm-i386/mach-xen/asm/swiotlb.h Wed Dec 20 16:07:24 2006 +1100 @@ -34,6 +34,8 @@ extern int swiotlb_dma_supported(struct extern int swiotlb_dma_supported(struct device *hwdev, u64 mask); extern void swiotlb_init(void); +extern int io_tlb_dma_bits; + #ifdef CONFIG_SWIOTLB extern int swiotlb; #else _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel