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/include/asm/iommu_64.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/sparc/include') diff --git a/arch/sparc/include/asm/iommu_64.h b/arch/sparc/include/asm/iommu_64.h index 2b9321ab064d..e3cd4493d81d 100644 --- a/arch/sparc/include/asm/iommu_64.h +++ b/arch/sparc/include/asm/iommu_64.h @@ -16,6 +16,7 @@ #define IOPTE_WRITE 0x0000000000000002UL #define IOMMU_NUM_CTXS 4096 +#include struct iommu_arena { unsigned long *map; @@ -24,11 +25,10 @@ struct iommu_arena { }; struct iommu { + struct iommu_table tbl; spinlock_t lock; - struct iommu_arena arena; - void (*flush_all)(struct iommu *); + u32 dma_addr_mask; iopte_t *page_table; - u32 page_table_map_base; unsigned long iommu_control; unsigned long iommu_tsbbase; unsigned long iommu_flush; @@ -40,7 +40,6 @@ struct iommu { unsigned long dummy_page_pa; unsigned long ctx_lowest_free; DECLARE_BITMAP(ctx_bitmap, IOMMU_NUM_CTXS); - u32 dma_addr_mask; }; struct strbuf { -- cgit v1.2.3