/* $OpenBSD: dma_alloc.c,v 1.12 2014/07/08 17:19:25 deraadt Exp $ */ /* * Copyright (c) 2010 Theo de Raadt <deraadt@openbsd.org> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/pool.h> #include <uvm/uvm_extern.h> static __inline int dma_alloc_index(size_t size); /* Create dma pools from objects sized 2^4 to 2^16 */ #define DMA_PAGE_SHIFT 16 #define DMA_BUCKET_OFFSET 4 static char dmanames[DMA_PAGE_SHIFT - DMA_BUCKET_OFFSET + 1][10]; struct pool dmapools[DMA_PAGE_SHIFT - DMA_BUCKET_OFFSET + 1]; void dma_alloc_init(void) { int i; for (i = 0; i < nitems(dmapools); i++) { snprintf(dmanames[i], sizeof(dmanames[0]), "dma%d", 1 << (i + DMA_BUCKET_OFFSET)); pool_init(&dmapools[i], 1 << (i + DMA_BUCKET_OFFSET), 0, 0, 0, dmanames[i], NULL); pool_set_constraints(&dmapools[i], &kp_dma_contig); pool_setipl(&dmapools[i], IPL_VM); /* XXX need pool_setlowat(&dmapools[i], dmalowat); */ } } static __inline int dma_alloc_index(size_t sz) { int b; for (b = 0; b < nitems(dmapools); b++) if (sz <= (1 << (b + DMA_BUCKET_OFFSET))) return (b); #ifdef DEBUG printf("dma_alloc/free: object %zd too large\n", sz); #endif return (-1); } void * dma_alloc(size_t size, int prflags) { int pi = dma_alloc_index(size); if (pi == -1) return (NULL); return pool_get(&dmapools[pi], prflags); } void dma_free(void *m, size_t size) { int pi = dma_alloc_index(size); if (pi == -1) return; pool_put(&dmapools[pi], m); }