Date: Sun, 10 Feb 2019 14:25:29 +0000 (UTC) From: Michal Meloun <mmel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r343962 - head/sys/arm/arm Message-ID: <201902101425.x1AEPTXB034242@repo.freebsd.org>
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Author: mmel Date: Sun Feb 10 14:25:29 2019 New Revision: 343962 URL: https://svnweb.freebsd.org/changeset/base/343962 Log: Properly handle alignment requests bigger that page size. - for now, alignments bigger that page size is allowed only for buffers allocated by bus_dmamem_alloc(), cover this fact by KASSERT. - never bounce buffers allocated by bus_dmamem_alloc(), these always comply with the required rules (alignment, boundary, address range). MFC after: 1 week Reviewed by: jah PR: 235542 Modified: head/sys/arm/arm/busdma_machdep-v6.c Modified: head/sys/arm/arm/busdma_machdep-v6.c ============================================================================== --- head/sys/arm/arm/busdma_machdep-v6.c Sun Feb 10 14:02:14 2019 (r343961) +++ head/sys/arm/arm/busdma_machdep-v6.c Sun Feb 10 14:25:29 2019 (r343962) @@ -339,16 +339,27 @@ cacheline_bounce(bus_dmamap_t map, bus_addr_t addr, bu * * Note that the addr argument might be either virtual or physical. It doesn't * matter because we only look at the low-order bits, which are the same in both - * address spaces. + * address spaces and maximum alignment of generic buffer is limited up to page + * size. + * Bouncing of buffers allocated by bus_dmamem_alloc()is not necessary, these + * always comply with the required rules (alignment, boundary, and address + * range). */ static __inline int might_bounce(bus_dma_tag_t dmat, bus_dmamap_t map, bus_addr_t addr, bus_size_t size) { - return ((dmat->flags & BUS_DMA_EXCL_BOUNCE) || + KASSERT(dmat->flags & DMAMAP_DMAMEM_ALLOC || + dmat->alignment <= PAGE_SIZE, + ("%s: unsupported alignment (0x%08lx) for buffer not " + "allocated by bus_dmamem_alloc()", + __func__, dmat->alignment)); + + return (!(dmat->flags & DMAMAP_DMAMEM_ALLOC) && + ((dmat->flags & BUS_DMA_EXCL_BOUNCE) || alignment_bounce(dmat, addr) || - cacheline_bounce(map, addr, size)); + cacheline_bounce(map, addr, size))); } /*
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