Date: Fri, 9 Aug 2019 10:28:21 +0000 (UTC) From: Michal Meloun <mmel@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r350819 - stable/12/sys/arm/arm Message-ID: <201908091028.x79ASLAV081616@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: mmel Date: Fri Aug 9 10:28:20 2019 New Revision: 350819 URL: https://svnweb.freebsd.org/changeset/base/350819 Log: MFC r343962,r343965: r343962: 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). r343965: Fix bug introduced by r343962. DMAMAP_DMAMEM_ALLOC is property of dmamap, not dmatag. Modified: stable/12/sys/arm/arm/busdma_machdep-v6.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/arm/arm/busdma_machdep-v6.c ============================================================================== --- stable/12/sys/arm/arm/busdma_machdep-v6.c Fri Aug 9 10:00:11 2019 (r350818) +++ stable/12/sys/arm/arm/busdma_machdep-v6.c Fri Aug 9 10:28:20 2019 (r350819) @@ -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(map->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 (!(map->flags & DMAMAP_DMAMEM_ALLOC) && + ((dmat->flags & BUS_DMA_EXCL_BOUNCE) || alignment_bounce(dmat, addr) || - cacheline_bounce(map, addr, size)); + cacheline_bounce(map, addr, size))); } /*
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201908091028.x79ASLAV081616>