Date: Sat, 26 Jul 2014 18:19:44 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r269136 - head/sys/arm/arm Message-ID: <201407261819.s6QIJiiS053133@svn.freebsd.org>
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Author: ian Date: Sat Jul 26 18:19:43 2014 New Revision: 269136 URL: http://svnweb.freebsd.org/changeset/base/269136 Log: Pull in the armv4 "fast out" code for checking whether busdma can bounce due to an excluded region of physical memory. 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 Sat Jul 26 18:14:16 2014 (r269135) +++ head/sys/arm/arm/busdma_machdep-v6.c Sat Jul 26 18:19:43 2014 (r269136) @@ -229,10 +229,26 @@ busdma_init(void *dummy) */ SYSINIT(busdma, SI_SUB_KMEM, SI_ORDER_FOURTH, busdma_init, NULL); +/* + * This routine checks the exclusion zone constraints from a tag against the + * physical RAM available on the machine. If a tag specifies an exclusion zone + * but there's no RAM in that zone, then we avoid allocating resources to bounce + * a request, and we can use any memory allocator (as opposed to needing + * kmem_alloc_contig() just because it can allocate pages in an address range). + * + * Most tags have BUS_SPACE_MAXADDR or BUS_SPACE_MAXADDR_32BIT (they are the + * same value on 32-bit architectures) as their lowaddr constraint, and we can't + * possibly have RAM at an address higher than the highest address we can + * express, so we take a fast out. + */ static __inline int _bus_dma_can_bounce(vm_offset_t lowaddr, vm_offset_t highaddr) { int i; + + if (lowaddr >= BUS_SPACE_MAXADDR) + return (0); + for (i = 0; phys_avail[i] && phys_avail[i + 1]; i += 2) { if ((lowaddr >= phys_avail[i] && lowaddr <= phys_avail[i + 1]) || (lowaddr < phys_avail[i] &&
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