69 lines
1.5 KiB
C
69 lines
1.5 KiB
C
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#include "syslib.h"
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#include <stdlib.h>
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#include <errno.h>
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#include <sys/mman.h>
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#include <minix/sysutil.h>
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int sys_umap_data_fb(endpoint_t ep, vir_bytes buf, vir_bytes len, phys_bytes *phys)
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{
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int r;
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if((r=sys_umap(ep, VM_D, buf, len, phys)) != OK) {
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if(r != EINVAL)
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return r;
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r = sys_umap(ep, D, buf, len, phys);
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}
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return r;
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}
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void *alloc_contig(size_t len, int flags, phys_bytes *phys)
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{
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int r;
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vir_bytes buf;
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int mmapflags = MAP_PREALLOC|MAP_CONTIG|MAP_ANON;
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if(flags & AC_LOWER16M)
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mmapflags |= MAP_LOWER16M;
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/* First try to get memory with mmap. This is gauranteed
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* to be page-aligned, and we can tell VM it has to be
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* pre-allocated and contiguous.
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*/
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errno = 0;
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buf = (vir_bytes) mmap(0, len, PROT_READ|PROT_WRITE, mmapflags, -1, 0);
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/* If that failed, maybe we're not running in paged mode.
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* If that's the case, ENXIO will be returned.
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* Memory returned with malloc() will be preallocated and
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* contiguous, so fallback on that, and ask for a little extra
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* so we can page align it ourselves.
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*/
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if(buf == (vir_bytes) MAP_FAILED) {
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if(errno != (_SIGN ENXIO)) {
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return NULL;
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}
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#define ALIGN 4096
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if(flags & AC_ALIGN4K) {
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if(len + ALIGN < len)
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return NULL;
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len += ALIGN;
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}
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if(!(buf = (vir_bytes) malloc(len))) {
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return NULL;
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}
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if(flags & AC_ALIGN4K)
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buf += ALIGN - (buf % ALIGN);
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}
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/* Get physical address. */
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if(sys_umap_data_fb(SELF, buf, len, phys) != OK)
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panic("alloc_contig.c", "sys_umap_data_fb failed", NO_NUM);
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return (void *) buf;
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}
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