From f1600e549b948a32ad7672e069b2915314637ae3 Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Thu, 12 Mar 2015 20:02:36 -0400 Subject: sparc: Make sparc64 use scalable lib/iommu-common.c functions In iperf experiments running linux as the Tx side (TCP client) with 10 threads results in a severe performance drop when TSO is disabled, indicating a weakness in the software that can be avoided by using the scalable IOMMU arena DMA allocation. Baseline numbers before this patch: with default settings (TSO enabled) : 9-9.5 Gbps Disable TSO using ethtool- drops badly: 2-3 Gbps. After this patch, iperf client with 10 threads, can give a throughput of at least 8.5 Gbps, even when TSO is disabled. Signed-off-by: Sowmini Varadhan Signed-off-by: David S. Miller --- arch/sparc/kernel/pci_sun4v.c | 193 ++++++++++++++++++++---------------------- 1 file changed, 94 insertions(+), 99 deletions(-) (limited to 'arch/sparc/kernel/pci_sun4v.c') diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 47ddbd496a1e..9b76b9d639e1 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -15,6 +15,8 @@ #include #include #include +#include +#include #include #include @@ -28,6 +30,7 @@ #define DRIVER_NAME "pci_sun4v" #define PFX DRIVER_NAME ": " +static DEFINE_PER_CPU(unsigned int, iommu_pool_hash); static unsigned long vpci_major = 1; static unsigned long vpci_minor = 1; @@ -155,14 +158,13 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size, iommu = dev->archdata.iommu; - spin_lock_irqsave(&iommu->lock, flags); - entry = iommu_range_alloc(dev, iommu, npages, NULL); - spin_unlock_irqrestore(&iommu->lock, flags); + entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL, + __this_cpu_read(iommu_pool_hash)); if (unlikely(entry == DMA_ERROR_CODE)) goto range_alloc_fail; - *dma_addrp = (iommu->page_table_map_base + + *dma_addrp = (iommu->tbl.page_table_map_base + (entry << IO_PAGE_SHIFT)); ret = (void *) first_page; first_page = __pa(first_page); @@ -188,45 +190,46 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size, return ret; iommu_map_fail: - /* Interrupts are disabled. */ - spin_lock(&iommu->lock); - iommu_range_free(iommu, *dma_addrp, npages); - spin_unlock_irqrestore(&iommu->lock, flags); + iommu_tbl_range_free(&iommu->tbl, *dma_addrp, npages, false, NULL); range_alloc_fail: free_pages(first_page, order); return NULL; } +static void dma_4v_iommu_demap(void *demap_arg, unsigned long entry, + unsigned long npages) +{ + u32 devhandle = *(u32 *)demap_arg; + unsigned long num, flags; + + local_irq_save(flags); + do { + num = pci_sun4v_iommu_demap(devhandle, + HV_PCI_TSBID(0, entry), + npages); + + entry += num; + npages -= num; + } while (npages != 0); + local_irq_restore(flags); +} + static void dma_4v_free_coherent(struct device *dev, size_t size, void *cpu, dma_addr_t dvma, struct dma_attrs *attrs) { struct pci_pbm_info *pbm; struct iommu *iommu; - unsigned long flags, order, npages, entry; + unsigned long order, npages, entry; u32 devhandle; npages = IO_PAGE_ALIGN(size) >> IO_PAGE_SHIFT; iommu = dev->archdata.iommu; pbm = dev->archdata.host_controller; devhandle = pbm->devhandle; - entry = ((dvma - iommu->page_table_map_base) >> IO_PAGE_SHIFT); - - spin_lock_irqsave(&iommu->lock, flags); - - iommu_range_free(iommu, dvma, npages); - - do { - unsigned long num; - - num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry), - npages); - entry += num; - npages -= num; - } while (npages != 0); - - spin_unlock_irqrestore(&iommu->lock, flags); - + entry = ((dvma - iommu->tbl.page_table_map_base) >> IO_PAGE_SHIFT); + dma_4v_iommu_demap(&devhandle, entry, npages); + iommu_tbl_range_free(&iommu->tbl, dvma, npages, false, NULL); order = get_order(size); if (order < 10) free_pages((unsigned long)cpu, order); @@ -253,14 +256,13 @@ static dma_addr_t dma_4v_map_page(struct device *dev, struct page *page, npages = IO_PAGE_ALIGN(oaddr + sz) - (oaddr & IO_PAGE_MASK); npages >>= IO_PAGE_SHIFT; - spin_lock_irqsave(&iommu->lock, flags); - entry = iommu_range_alloc(dev, iommu, npages, NULL); - spin_unlock_irqrestore(&iommu->lock, flags); + entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL, + __this_cpu_read(iommu_pool_hash)); if (unlikely(entry == DMA_ERROR_CODE)) goto bad; - bus_addr = (iommu->page_table_map_base + + bus_addr = (iommu->tbl.page_table_map_base + (entry << IO_PAGE_SHIFT)); ret = bus_addr | (oaddr & ~IO_PAGE_MASK); base_paddr = __pa(oaddr & IO_PAGE_MASK); @@ -290,11 +292,7 @@ bad: return DMA_ERROR_CODE; iommu_map_fail: - /* Interrupts are disabled. */ - spin_lock(&iommu->lock); - iommu_range_free(iommu, bus_addr, npages); - spin_unlock_irqrestore(&iommu->lock, flags); - + iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, false, NULL); return DMA_ERROR_CODE; } @@ -304,7 +302,7 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr, { struct pci_pbm_info *pbm; struct iommu *iommu; - unsigned long flags, npages; + unsigned long npages; long entry; u32 devhandle; @@ -321,22 +319,9 @@ static void dma_4v_unmap_page(struct device *dev, dma_addr_t bus_addr, npages = IO_PAGE_ALIGN(bus_addr + sz) - (bus_addr & IO_PAGE_MASK); npages >>= IO_PAGE_SHIFT; bus_addr &= IO_PAGE_MASK; - - spin_lock_irqsave(&iommu->lock, flags); - - iommu_range_free(iommu, bus_addr, npages); - - entry = (bus_addr - iommu->page_table_map_base) >> IO_PAGE_SHIFT; - do { - unsigned long num; - - num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry), - npages); - entry += num; - npages -= num; - } while (npages != 0); - - spin_unlock_irqrestore(&iommu->lock, flags); + entry = (bus_addr - iommu->tbl.page_table_map_base) >> IO_PAGE_SHIFT; + dma_4v_iommu_demap(&devhandle, entry, npages); + iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, false, NULL); } static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, @@ -371,14 +356,14 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, /* Init first segment length for backout at failure */ outs->dma_length = 0; - spin_lock_irqsave(&iommu->lock, flags); + local_irq_save(flags); iommu_batch_start(dev, prot, ~0UL); max_seg_size = dma_get_max_seg_size(dev); seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, IO_PAGE_SIZE) >> IO_PAGE_SHIFT; - base_shift = iommu->page_table_map_base >> IO_PAGE_SHIFT; + base_shift = iommu->tbl.page_table_map_base >> IO_PAGE_SHIFT; for_each_sg(sglist, s, nelems, i) { unsigned long paddr, npages, entry, out_entry = 0, slen; @@ -391,7 +376,8 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, /* Allocate iommu entries for that segment */ paddr = (unsigned long) SG_ENT_PHYS_ADDRESS(s); npages = iommu_num_pages(paddr, slen, IO_PAGE_SIZE); - entry = iommu_range_alloc(dev, iommu, npages, &handle); + entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, &handle, + __this_cpu_read(iommu_pool_hash)); /* Handle failure */ if (unlikely(entry == DMA_ERROR_CODE)) { @@ -404,7 +390,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, iommu_batch_new_entry(entry); /* Convert entry to a dma_addr_t */ - dma_addr = iommu->page_table_map_base + + dma_addr = iommu->tbl.page_table_map_base + (entry << IO_PAGE_SHIFT); dma_addr |= (s->offset & ~IO_PAGE_MASK); @@ -451,7 +437,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, if (unlikely(err < 0L)) goto iommu_map_failed; - spin_unlock_irqrestore(&iommu->lock, flags); + local_irq_restore(flags); if (outcount < incount) { outs = sg_next(outs); @@ -469,7 +455,8 @@ iommu_map_failed: vaddr = s->dma_address & IO_PAGE_MASK; npages = iommu_num_pages(s->dma_address, s->dma_length, IO_PAGE_SIZE); - iommu_range_free(iommu, vaddr, npages); + iommu_tbl_range_free(&iommu->tbl, vaddr, npages, + false, NULL); /* XXX demap? XXX */ s->dma_address = DMA_ERROR_CODE; s->dma_length = 0; @@ -477,7 +464,7 @@ iommu_map_failed: if (s == outs) break; } - spin_unlock_irqrestore(&iommu->lock, flags); + local_irq_restore(flags); return 0; } @@ -489,7 +476,7 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist, struct pci_pbm_info *pbm; struct scatterlist *sg; struct iommu *iommu; - unsigned long flags; + unsigned long flags, entry; u32 devhandle; BUG_ON(direction == DMA_NONE); @@ -498,33 +485,27 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist, pbm = dev->archdata.host_controller; devhandle = pbm->devhandle; - spin_lock_irqsave(&iommu->lock, flags); + local_irq_save(flags); sg = sglist; while (nelems--) { dma_addr_t dma_handle = sg->dma_address; unsigned int len = sg->dma_length; - unsigned long npages, entry; + unsigned long npages; + struct iommu_table *tbl = &iommu->tbl; + unsigned long shift = IO_PAGE_SHIFT; if (!len) break; npages = iommu_num_pages(dma_handle, len, IO_PAGE_SIZE); - iommu_range_free(iommu, dma_handle, npages); - - entry = ((dma_handle - iommu->page_table_map_base) >> IO_PAGE_SHIFT); - while (npages) { - unsigned long num; - - num = pci_sun4v_iommu_demap(devhandle, HV_PCI_TSBID(0, entry), - npages); - entry += num; - npages -= num; - } - + entry = ((dma_handle - tbl->page_table_map_base) >> shift); + dma_4v_iommu_demap(&devhandle, entry, npages); + iommu_tbl_range_free(&iommu->tbl, dma_handle, npages, + false, NULL); sg = sg_next(sg); } - spin_unlock_irqrestore(&iommu->lock, flags); + local_irq_restore(flags); } static struct dma_map_ops sun4v_dma_ops = { @@ -536,6 +517,8 @@ static struct dma_map_ops sun4v_dma_ops = { .unmap_sg = dma_4v_unmap_sg, }; +static struct iommu_tbl_ops dma_4v_iommu_ops; + static void pci_sun4v_scan_bus(struct pci_pbm_info *pbm, struct device *parent) { struct property *prop; @@ -550,30 +533,33 @@ static void pci_sun4v_scan_bus(struct pci_pbm_info *pbm, struct device *parent) } static unsigned long probe_existing_entries(struct pci_pbm_info *pbm, - struct iommu *iommu) + struct iommu_table *iommu) { - struct iommu_arena *arena = &iommu->arena; - unsigned long i, cnt = 0; + struct iommu_pool *pool; + unsigned long i, pool_nr, cnt = 0; u32 devhandle; devhandle = pbm->devhandle; - for (i = 0; i < arena->limit; i++) { - unsigned long ret, io_attrs, ra; - - ret = pci_sun4v_iommu_getmap(devhandle, - HV_PCI_TSBID(0, i), - &io_attrs, &ra); - if (ret == HV_EOK) { - if (page_in_phys_avail(ra)) { - pci_sun4v_iommu_demap(devhandle, - HV_PCI_TSBID(0, i), 1); - } else { - cnt++; - __set_bit(i, arena->map); + for (pool_nr = 0; pool_nr < iommu->nr_pools; pool_nr++) { + pool = &(iommu->arena_pool[pool_nr]); + for (i = pool->start; i <= pool->end; i++) { + unsigned long ret, io_attrs, ra; + + ret = pci_sun4v_iommu_getmap(devhandle, + HV_PCI_TSBID(0, i), + &io_attrs, &ra); + if (ret == HV_EOK) { + if (page_in_phys_avail(ra)) { + pci_sun4v_iommu_demap(devhandle, + HV_PCI_TSBID(0, + i), 1); + } else { + cnt++; + __set_bit(i, iommu->map); + } } } } - return cnt; } @@ -601,22 +587,22 @@ static int pci_sun4v_iommu_init(struct pci_pbm_info *pbm) dma_offset = vdma[0]; /* Setup initial software IOMMU state. */ - spin_lock_init(&iommu->lock); iommu->ctx_lowest_free = 1; - iommu->page_table_map_base = dma_offset; + iommu->tbl.page_table_map_base = dma_offset; iommu->dma_addr_mask = dma_mask; /* Allocate and initialize the free area map. */ sz = (num_tsb_entries + 7) / 8; sz = (sz + 7UL) & ~7UL; - iommu->arena.map = kzalloc(sz, GFP_KERNEL); - if (!iommu->arena.map) { + iommu->tbl.map = kzalloc(sz, GFP_KERNEL); + if (!iommu->tbl.map) { printk(KERN_ERR PFX "Error, kmalloc(arena.map) failed.\n"); return -ENOMEM; } - iommu->arena.limit = num_tsb_entries; - - sz = probe_existing_entries(pbm, iommu); + iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT, + &dma_4v_iommu_ops, false /* no large_pool */, + 0 /* default npools */); + sz = probe_existing_entries(pbm, &iommu->tbl); if (sz) printk("%s: Imported %lu TSB entries from OBP\n", pbm->name, sz); @@ -1015,8 +1001,17 @@ static struct platform_driver pci_sun4v_driver = { .probe = pci_sun4v_probe, }; +static void setup_iommu_pool_hash(void) +{ + unsigned int i; + + for_each_possible_cpu(i) + per_cpu(iommu_pool_hash, i) = hash_32(i, IOMMU_POOL_HASHBITS); +} + static int __init pci_sun4v_init(void) { + setup_iommu_pool_hash(); return platform_driver_register(&pci_sun4v_driver); } -- cgit