Dear Wilk: > -----Original Message----- > From: Konrad Rzeszutek Wilk [mailto:konrad.wilk@xxxxxxxxxx] > Sent: Saturday, February 7, 2015 2:12 AM > To: Wang, Xiaoming > Cc: ralf@xxxxxxxxxxxxxx; boris.ostrovsky@xxxxxxxxxx; > david.vrabel@xxxxxxxxxx; linux-mips@xxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx; akpm@linux- > foundation.org; linux@xxxxxxxxxxx; lauraa@xxxxxxxxxxxxxx; > heiko.carstens@xxxxxxxxxx; d.kasatkin@xxxxxxxxxxx; > takahiro.akashi@xxxxxxxxxx; chris@xxxxxxxxxxxxxxxxxx; pebolle@xxxxxxxxxx; Liu, > Chuansheng; Zhang, Dongxing > Subject: Re: [PATCH] modify the IO_TLB_SEGSIZE to io_tlb_segsize > configurable as flexible requirement about SW-IOMMU. > > On Fri, Feb 06, 2015 at 12:10:15AM +0000, Wang, Xiaoming wrote: > > > > > > > -----Original Message----- > > > From: Konrad Rzeszutek Wilk [mailto:konrad.wilk@xxxxxxxxxx] > > > Sent: Friday, February 6, 2015 3:33 AM > > > To: Wang, Xiaoming > > > Cc: ralf@xxxxxxxxxxxxxx; boris.ostrovsky@xxxxxxxxxx; > > > david.vrabel@xxxxxxxxxx; linux-mips@xxxxxxxxxxxxxx; linux- > > > kernel@xxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxxx; akpm@linux- > > > foundation.org; linux@xxxxxxxxxxx; lauraa@xxxxxxxxxxxxxx; > > > heiko.carstens@xxxxxxxxxx; d.kasatkin@xxxxxxxxxxx; > > > takahiro.akashi@xxxxxxxxxx; chris@xxxxxxxxxxxxxxxxxx; > > > pebolle@xxxxxxxxxx; Liu, Chuansheng; Zhang, Dongxing > > > Subject: Re: [PATCH] modify the IO_TLB_SEGSIZE to io_tlb_segsize > > > configurable as flexible requirement about SW-IOMMU. > > > > > > On Fri, Feb 06, 2015 at 07:01:14AM +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. > > > > > > More details please. What is the issue you are hitting? > > > > > Example: > > If 1M bytes are requied. There has an error like. > > Ok, but even with 1MB size - you only have 64 'slots' (if you allocate an 64MB > buffer). And the other 'slots' can be fragmented so you might still not have > enough 1MB chunks available. > > Do you have some thoughts on how that would be addressed? > Yes, If IO_TLB_SEGSIZE is 128 the slabs is 32K/128 = 256 While IO_TLB_SEGSIZE is 512 the slabs is 32K/512 =64 (for 1M). So it is dilemma between slabs and segsize. I have a thought how about modifying the IO_TLB_DEFAULT_SIZE to io_tlb_default_size configurable too? Because of the multivariate requirement. > > [ 31.474769] dwc3_otg 0000:00:16.0: > dwc3_intel_byt_notify_charger_type(): dwc3_intel_byt_notify_charger_type: > invalid SDP current! > > [ 31.554077] android_work: sent uevent USB_STATE=CONNECTED > > [ 31.564244] android_usb gadget: high-speed config #1: android > > [ 31.571468] android_work: sent uevent USB_STATE=CONFIGURED > > [ 31.942738] DMA: Out of SW-IOMMU space for 1048576 bytes at device > gadget > > [ 31.950345] Kernel panic - not syncing: DMA: Random memory could be > DMA written > > [ 31.950345] > > [ 31.960170] CPU: 1 PID: 172 Comm: droidboot Tainted: G W > 3.10.20-x86_64_byt-g1077f87 #2 > > [ 31.970086] Hardware name: Intel Corp. VALLEYVIEW C0 > PLATFORM/BYT-T FFD8, BIOS BLADE_21.X64.0004.R14.1412311144 > FFD8_X64_R_2014_12_31_1151 12/31/2014 > > [ 31.985053] 0000000000100000 ffff880136c2fc98 ffffffff82967d45 > ffff880136c2fd10 > > [ 31.993327] ffffffff82961761 0000000000000008 ffff880136c2fd20 > ffff880136c2fcc0 > > [ 32.001590] ffffffff829618fb 0000000000000002 ffffffff820aeff9 > 0000000000008d8c > > [ 32.009871] Call Trace: > > [ 32.012610] [<ffffffff82967d45>] dump_stack+0x19/0x1b > > [ 32.018353] [<ffffffff82961761>] panic+0xc8/0x1d6 > > [ 32.023707] [<ffffffff829618fb>] ? printk+0x55/0x57 > > [ 32.029258] [<ffffffff820aeff9>] ? console_unlock+0x1f9/0x460 > > [ 32.035772] [<ffffffff82347cbe>] swiotlb_map_page+0x12e/0x140 > > [ 32.042283] [<ffffffff82599d4d>] > usb_gadget_map_request+0x16d/0x220 > > [ 32.049387] [<ffffffff8255ce89>] dwc3_gadget_ep_queue+0x229/0x460 > > [ 32.056297] [<ffffffff825b4624>] ffs_epfile_io.isra.96+0x3e4/0x520 > > [ 32.063296] [<ffffffff820e438d>] ? get_parent_ip+0xd/0x50 > > [ 32.069427] [<ffffffff82975a61>] ? sub_preempt_count+0x71/0x100 > > [ 32.076142] [<ffffffff825b47b8>] ffs_epfile_read+0x28/0x30 > > [ 32.082370] [<ffffffff821b6b8c>] vfs_read+0x9c/0x170 > > [ 32.088014] [<ffffffff821b765d>] SyS_read+0x4d/0xa0 > > [ 32.093562] [<ffffffff8297b179>] ia32_do_call+0x13/0x13 > > > > > > > > Signed-off-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx> > > > > Signed-off-by: Zhang Dongxing <dongxing.zhang@xxxxxxxxx> > > > > Signed-off-by: xiaomin1 <xiaoming.wang@xxxxxxxxx> > > > > --- > > > > 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); > > > > -- > > > > 1.7.9.5 > > > >
