Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757488AbbBEMCT (ORCPT ); Thu, 5 Feb 2015 07:02:19 -0500 Received: from cpsmtpb-ews10.kpnxchange.com ([213.75.39.15]:50811 "EHLO cpsmtpb-ews10.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757096AbbBEMCR (ORCPT ); Thu, 5 Feb 2015 07:02:17 -0500 Message-ID: <1423137734.27378.42.camel@x220> Subject: Re: [PATCH] modify the IO_TLB_SEGSIZE to io_tlb_segsize configurable as flexible requirement about SW-IOMMU. From: Paul Bolle To: xiaomin1 Cc: ralf@linux-mips.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, david.vrabel@citrix.com, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, akpm@linux-foundation.org, linux@horizon.com, lauraa@codeaurora.org, heiko.carstens@de.ibm.com, d.kasatkin@samsung.com, takahiro.akashi@linaro.org, chris@chris-wilson.co.uk, Chuansheng Liu , Zhang Dongxing Date: Thu, 05 Feb 2015 13:02:14 +0100 In-Reply-To: <1423177274-22118-1-git-send-email-xiaoming.wang@intel.com> References: <1423177274-22118-1-git-send-email-xiaoming.wang@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 05 Feb 2015 12:02:14.0903 (UTC) FILETIME=[94CC3070:01D0413B] X-RcptDomain: vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9461 Lines: 242 This needs From: Wang, Xiaoming at the top of the message to comply with real name policy for patches. On Fri, 2015-02-06 at 07:01 +0800, xiaomin1 wrote: > The maximum of SW-IOMMU is limited to 2^11*128 = 256K. > While in different platform and different requirements this seems improper. > So modify the IO_TLB_SEGSIZE to io_tlb_segsize as configurable is make sense. > > Signed-off-by: Chuansheng Liu > Signed-off-by: Zhang Dongxing > Signed-off-by: xiaomin1 And please edit that name here too. Or did you change your name after submitting your previous patches? > --- This is a v2. So the subject should contain something like '[PATCH v2]'. And it's nice to have a short list of changes here, below the --- marker, so people can see what changed since v1. Anyhow, I _think_ you took my comments on v1 into account. And by now there's little in this patch that I could say anything interesting about, so I don't really care that much. Thanks, Paul Bolle > arch/mips/cavium-octeon/dma-octeon.c | 2 +- > arch/mips/netlogic/common/nlm-dma.c | 2 +- > drivers/xen/swiotlb-xen.c | 6 +++--- > include/linux/swiotlb.h | 8 +------ > lib/swiotlb.c | 39 ++++++++++++++++++++++++---------- > 5 files changed, 34 insertions(+), 23 deletions(-) > > diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c > index 3778655..a521af6 100644 > --- a/arch/mips/cavium-octeon/dma-octeon.c > +++ b/arch/mips/cavium-octeon/dma-octeon.c > @@ -312,7 +312,7 @@ void __init plat_swiotlb_setup(void) > swiotlbsize = 64 * (1<<20); > #endif > swiotlb_nslabs = swiotlbsize >> IO_TLB_SHIFT; > - swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE); > + swiotlb_nslabs = ALIGN(swiotlb_nslabs, io_tlb_segsize); > swiotlbsize = swiotlb_nslabs << IO_TLB_SHIFT; > > octeon_swiotlb = alloc_bootmem_low_pages(swiotlbsize); > diff --git a/arch/mips/netlogic/common/nlm-dma.c b/arch/mips/netlogic/common/nlm-dma.c > index f3d4ae8..eeffa8f 100644 > --- a/arch/mips/netlogic/common/nlm-dma.c > +++ b/arch/mips/netlogic/common/nlm-dma.c > @@ -99,7 +99,7 @@ void __init plat_swiotlb_setup(void) > > swiotlbsize = 1 << 20; /* 1 MB for now */ > swiotlb_nslabs = swiotlbsize >> IO_TLB_SHIFT; > - swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE); > + swiotlb_nslabs = ALIGN(swiotlb_nslabs, io_tlb_segsize); > swiotlbsize = swiotlb_nslabs << IO_TLB_SHIFT; > > nlm_swiotlb = alloc_bootmem_low_pages(swiotlbsize); > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index 810ad41..3b3e9fe 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -164,11 +164,11 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) > dma_addr_t dma_handle; > phys_addr_t p = virt_to_phys(buf); > > - dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; > + dma_bits = get_order(io_tlb_segsize << IO_TLB_SHIFT) + PAGE_SHIFT; > > i = 0; > do { > - int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE); > + int slabs = min(nslabs - i, (unsigned long)io_tlb_segsize); > > do { > rc = xen_create_contiguous_region( > @@ -187,7 +187,7 @@ static unsigned long xen_set_nslabs(unsigned long nr_tbl) > { > if (!nr_tbl) { > xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT); > - xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE); > + xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, io_tlb_segsize); > } else > xen_io_tlb_nslabs = nr_tbl; > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index e7a018e..13506db 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -8,13 +8,7 @@ struct dma_attrs; > struct scatterlist; > > extern int swiotlb_force; > - > -/* > - * Maximum allowable number of contiguous slabs to map, > - * must be a power of 2. What is the appropriate value ? > - * The complexity of {map,unmap}_single is linearly dependent on this value. > - */ > -#define IO_TLB_SEGSIZE 128 > +extern int io_tlb_segsize; > > /* > * log of the size of each IO TLB slab. The number of slabs is command line > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index 4abda07..50c415a 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -56,6 +56,15 @@ > int swiotlb_force; > > /* > + * Maximum allowable number of contiguous slabs to map, > + * must be a power of 2. What is the appropriate value ? > + * define io_tlb_segsize as a parameter > + * which can be changed dynamically in config file for special usage. > + * The complexity of {map,unmap}_single is linearly dependent on this value. > + */ > +int io_tlb_segsize = 128; > + > +/* > * Used to do a quick range check in swiotlb_tbl_unmap_single and > * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this > * API. > @@ -97,12 +106,20 @@ static DEFINE_SPINLOCK(io_tlb_lock); > static int late_alloc; > > static int __init > +setup_io_tlb_segsize(char *str) > +{ > + get_option(&str, &io_tlb_segsize); > + return 0; > +} > +__setup("io_tlb_segsize=", setup_io_tlb_segsize); > + > +static int __init > setup_io_tlb_npages(char *str) > { > if (isdigit(*str)) { > io_tlb_nslabs = simple_strtoul(str, &str, 0); > - /* avoid tail segment of size < IO_TLB_SEGSIZE */ > - io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > + /* avoid tail segment of size < io_tlb_segsize */ > + io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize); > } > if (*str == ',') > ++str; > @@ -183,7 +200,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) > > /* > * Allocate and initialize the free list array. This array is used > - * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE > + * to find contiguous free memory regions of size up to io_tlb_segsize > * between io_tlb_start and io_tlb_end. > */ > io_tlb_list = memblock_virt_alloc( > @@ -193,7 +210,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) > PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)), > PAGE_SIZE); > for (i = 0; i < io_tlb_nslabs; i++) { > - io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); > + io_tlb_list[i] = io_tlb_segsize - OFFSET(i, io_tlb_segsize); > io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; > } > io_tlb_index = 0; > @@ -217,7 +234,7 @@ swiotlb_init(int verbose) > > if (!io_tlb_nslabs) { > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > - io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > + io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize); > } > > bytes = io_tlb_nslabs << IO_TLB_SHIFT; > @@ -249,7 +266,7 @@ swiotlb_late_init_with_default_size(size_t default_size) > > if (!io_tlb_nslabs) { > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > - io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > + io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize); > } > > /* > @@ -308,7 +325,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) > > /* > * Allocate and initialize the free list array. This array is used > - * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE > + * to find contiguous free memory regions of size up to io_tlb_segsize > * between io_tlb_start and io_tlb_end. > */ > io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL, > @@ -324,7 +341,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) > goto cleanup4; > > for (i = 0; i < io_tlb_nslabs; i++) { > - io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); > + io_tlb_list[i] = io_tlb_segsize - OFFSET(i, io_tlb_segsize); > io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; > } > io_tlb_index = 0; > @@ -493,7 +510,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, > > for (i = index; i < (int) (index + nslots); i++) > io_tlb_list[i] = 0; > - for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--) > + for (i = index - 1; (OFFSET(i, io_tlb_segsize) != io_tlb_segsize - 1) && io_tlb_list[i]; i--) > io_tlb_list[i] = ++count; > tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT); > > @@ -571,7 +588,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, > */ > spin_lock_irqsave(&io_tlb_lock, flags); > { > - count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ? > + count = ((index + nslots) < ALIGN(index + 1, io_tlb_segsize) ? > io_tlb_list[index + nslots] : 0); > /* > * Step 1: return the slots to the free list, merging the > @@ -585,7 +602,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, > * Step 2: merge the returned slots with the preceding slots, > * if available (non zero) > */ > - for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--) > + for (i = index - 1; (OFFSET(i, io_tlb_segsize) != io_tlb_segsize -1) && io_tlb_list[i]; i--) > io_tlb_list[i] = ++count; > } > spin_unlock_irqrestore(&io_tlb_lock, flags); -- 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/