From 2b45fde3791641ae80ffecab4309e1d41c219d8c Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Thu, 12 May 2016 12:13:28 +0000 Subject: [PATCH] Restrict the memory barriers in bus_dmamap_sync to just the operations where it's needed. Obtained from: ABT Systems Ltd Sponsored by: The FreeBSD Foundation --- sys/arm64/arm64/busdma_bounce.c | 97 +++++++++++++++++---------------- 1 file changed, 49 insertions(+), 48 deletions(-) diff --git a/sys/arm64/arm64/busdma_bounce.c b/sys/arm64/arm64/busdma_bounce.c index 22a8f0f1fb7b..bad74ed2f14c 100644 --- a/sys/arm64/arm64/busdma_bounce.c +++ b/sys/arm64/arm64/busdma_bounce.c @@ -799,12 +799,6 @@ bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, struct bounce_page *bpage; vm_offset_t datavaddr, tempvaddr; - if ((bpage = STAILQ_FIRST(&map->bpages)) == NULL) { - /* Wait for any memory access to complete */ - dsb(sy); - return; - } - /* * XXX ARM64TODO: * This bus_dma implementation requires IO-Coherent architecutre. @@ -812,56 +806,63 @@ bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map, * added to this function. */ - CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " - "performing bounce", __func__, dmat, dmat->common.flags, op); - - if ((op & BUS_DMASYNC_PREWRITE) != 0) { - while (bpage != NULL) { - tempvaddr = 0; - datavaddr = bpage->datavaddr; - if (datavaddr == 0) { - tempvaddr = - pmap_quick_enter_page(bpage->datapage); - datavaddr = tempvaddr | bpage->dataoffs; - } - - bcopy((void *)datavaddr, - (void *)bpage->vaddr, bpage->datacount); - if (tempvaddr != 0) - pmap_quick_remove_page(tempvaddr); - bpage = STAILQ_NEXT(bpage, links); - } - dmat->bounce_zone->total_bounced++; - - /* - * Wait for the bcopy to complete before any DMA operations. - */ - dsb(sy); - } - if ((op & BUS_DMASYNC_POSTREAD) != 0) { /* * Wait for any DMA operations to complete before the bcopy. */ dsb(sy); + } - while (bpage != NULL) { - tempvaddr = 0; - datavaddr = bpage->datavaddr; - if (datavaddr == 0) { - tempvaddr = - pmap_quick_enter_page(bpage->datapage); - datavaddr = tempvaddr | bpage->dataoffs; + if ((bpage = STAILQ_FIRST(&map->bpages)) != NULL) { + CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x op 0x%x " + "performing bounce", __func__, dmat, dmat->common.flags, + op); + + if ((op & BUS_DMASYNC_PREWRITE) != 0) { + while (bpage != NULL) { + tempvaddr = 0; + datavaddr = bpage->datavaddr; + if (datavaddr == 0) { + tempvaddr = pmap_quick_enter_page( + bpage->datapage); + datavaddr = tempvaddr | bpage->dataoffs; + } + + bcopy((void *)datavaddr, + (void *)bpage->vaddr, bpage->datacount); + if (tempvaddr != 0) + pmap_quick_remove_page(tempvaddr); + bpage = STAILQ_NEXT(bpage, links); } - - bcopy((void *)bpage->vaddr, - (void *)datavaddr, bpage->datacount); - - if (tempvaddr != 0) - pmap_quick_remove_page(tempvaddr); - bpage = STAILQ_NEXT(bpage, links); + dmat->bounce_zone->total_bounced++; } - dmat->bounce_zone->total_bounced++; + + if ((op & BUS_DMASYNC_POSTREAD) != 0) { + while (bpage != NULL) { + tempvaddr = 0; + datavaddr = bpage->datavaddr; + if (datavaddr == 0) { + tempvaddr = pmap_quick_enter_page( + bpage->datapage); + datavaddr = tempvaddr | bpage->dataoffs; + } + + bcopy((void *)bpage->vaddr, + (void *)datavaddr, bpage->datacount); + + if (tempvaddr != 0) + pmap_quick_remove_page(tempvaddr); + bpage = STAILQ_NEXT(bpage, links); + } + dmat->bounce_zone->total_bounced++; + } + } + + if ((op & BUS_DMASYNC_PREWRITE) != 0) { + /* + * Wait for the bcopy to complete before any DMA operations. + */ + dsb(sy); } }