/* $OpenBSD: bus_dma.c,v 1.59 2024/10/08 19:40:00 kettenis Exp $ */ /* $NetBSD: bus_dma.c,v 1.3 2003/05/07 21:33:58 fvdl Exp $ */ /*- * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace * Simulation Facility, NASA Ames Research Center. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * The following is included because _bus_dma_uiomove is derived from * uiomove() in kern_subr.c. */ /* * Copyright (c) 1982, 1986, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include /* #define FORCE_BOUNCE_BUFFER 1 */ #ifndef FORCE_BOUNCE_BUFFER #define FORCE_BOUNCE_BUFFER 0 #endif int _bus_dmamap_load_buffer(bus_dma_tag_t, bus_dmamap_t, void *, bus_size_t, struct proc *, int, paddr_t *, int *, int *, int); /* * Common function for DMA map creation. May be called by bus-specific * DMA map creation functions. */ int _bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int nsegments, bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp) { struct bus_dmamap *map; struct pglist mlist; struct vm_page **pg, *pgnext; size_t mapsize, sz, ssize; vaddr_t va, sva; void *mapstore; int npages, error; const struct kmem_dyn_mode *kd; /* allocate and use bounce buffers when running as SEV guest */ int use_bounce_buffer = cpu_sev_guestmode || FORCE_BOUNCE_BUFFER; /* * Allocate and initialize the DMA map. The end of the map * is a variable-sized array of segments, so we allocate enough * room for them in one shot. * * Note we don't preserve the WAITOK or NOWAIT flags. Preservation * of ALLOCNOW notifies others that we've reserved these resources, * and they are not to be freed. * * The bus_dmamap_t includes one bus_dma_segment_t, hence * the (nsegments - 1). */ mapsize = sizeof(struct bus_dmamap) + (sizeof(bus_dma_segment_t) * (nsegments - 1)); if (use_bounce_buffer) { /* this many pages plus one in case we get split */ npages = round_page(size) / PAGE_SIZE + 1; if (npages < nsegments) npages = nsegments; mapsize += sizeof(struct vm_page *) * npages; } mapstore = malloc(mapsize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? (M_NOWAIT|M_ZERO) : (M_WAITOK|M_ZERO)); if (mapstore == NULL) return (ENOMEM); map = (struct bus_dmamap *)mapstore; map->_dm_size = size; map->_dm_segcnt = nsegments; map->_dm_maxsegsz = maxsegsz; map->_dm_boundary = boundary; if (use_bounce_buffer) { map->_dm_pages = (void *)&map->dm_segs[nsegments]; map->_dm_npages = npages; } map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT); if (!use_bounce_buffer) { *dmamp = map; return (0); } sz = npages << PGSHIFT; kd = flags & BUS_DMA_NOWAIT ? &kd_trylock : &kd_waitok; va = (vaddr_t)km_alloc(sz, &kv_any, &kp_none, kd); if (va == 0) { map->_dm_npages = 0; free(map, M_DEVBUF, mapsize); return (ENOMEM); } TAILQ_INIT(&mlist); error = uvm_pglistalloc(sz, 0, -1, PAGE_SIZE, 0, &mlist, nsegments, (flags & BUS_DMA_NOWAIT) ? UVM_PLA_NOWAIT : UVM_PLA_WAITOK); if (error) { map->_dm_npages = 0; km_free((void *)va, sz, &kv_any, &kp_none); free(map, M_DEVBUF, mapsize); return (ENOMEM); } sva = va; ssize = sz; pgnext = TAILQ_FIRST(&mlist); for (pg = map->_dm_pages; npages--; va += PAGE_SIZE, pg++) { *pg = pgnext; error = pmap_enter(pmap_kernel(), va, VM_PAGE_TO_PHYS(*pg), PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE | PMAP_WIRED | PMAP_CANFAIL | PMAP_NOCRYPT); if (error) { pmap_update(pmap_kernel()); map->_dm_npages = 0; km_free((void *)sva, ssize, &kv_any, &kp_none); free(map, M_DEVBUF, mapsize); uvm_pglistfree(&mlist); return (ENOMEM); } pgnext = TAILQ_NEXT(*pg, pageq); bzero((void *)va, PAGE_SIZE); } pmap_update(pmap_kernel()); map->_dm_pgva = sva; *dmamp = map; return (0); } /* * Common function for DMA map destruction. May be called by bus-specific * DMA map destruction functions. */ void _bus_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) { size_t mapsize; struct vm_page **pg; struct pglist mlist; int use_bounce_buffer = cpu_sev_guestmode || FORCE_BOUNCE_BUFFER; if (map->_dm_pgva) { km_free((void *)map->_dm_pgva, map->_dm_npages << PGSHIFT, &kv_any, &kp_none); } mapsize = sizeof(struct bus_dmamap) + (sizeof(bus_dma_segment_t) * (map->_dm_segcnt - 1)); if (use_bounce_buffer) mapsize += sizeof(struct vm_page *) * map->_dm_npages; if (map->_dm_pages) { TAILQ_INIT(&mlist); for (pg = map->_dm_pages; map->_dm_npages--; pg++) { TAILQ_INSERT_TAIL(&mlist, *pg, pageq); } uvm_pglistfree(&mlist); } free(map, M_DEVBUF, mapsize); } /* * Common function for loading a DMA map with a linear buffer. May * be called by bus-specific DMA map load functions. */ int _bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf, bus_size_t buflen, struct proc *p, int flags) { bus_addr_t lastaddr = 0; int seg, used, error; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_mapsize = 0; map->dm_nsegs = 0; if (buflen > map->_dm_size) return (EINVAL); seg = 0; used = 0; error = _bus_dmamap_load_buffer(t, map, buf, buflen, p, flags, &lastaddr, &seg, &used, 1); if (error == 0) { map->dm_mapsize = buflen; map->dm_nsegs = seg + 1; map->_dm_nused = used; } return (error); } /* * Like _bus_dmamap_load(), but for mbufs. */ int _bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0, int flags) { paddr_t lastaddr = 0; int seg, used, error, first; struct mbuf *m; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_mapsize = 0; map->dm_nsegs = 0; #ifdef DIAGNOSTIC if ((m0->m_flags & M_PKTHDR) == 0) panic("_bus_dmamap_load_mbuf: no packet header"); #endif if (m0->m_pkthdr.len > map->_dm_size) return (EINVAL); first = 1; seg = 0; used = 0; error = 0; for (m = m0; m != NULL && error == 0; m = m->m_next) { if (m->m_len == 0) continue; error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len, NULL, flags, &lastaddr, &seg, &used, first); first = 0; } if (error == 0) { map->dm_mapsize = m0->m_pkthdr.len; map->dm_nsegs = seg + 1; map->_dm_nused = used; } return (error); } /* * Like _bus_dmamap_load(), but for uios. */ int _bus_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio, int flags) { paddr_t lastaddr = 0; int seg, used, i, error, first; bus_size_t minlen, resid; struct proc *p = NULL; struct iovec *iov; caddr_t addr; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_mapsize = 0; map->dm_nsegs = 0; resid = uio->uio_resid; iov = uio->uio_iov; if (uio->uio_segflg == UIO_USERSPACE) { p = uio->uio_procp; #ifdef DIAGNOSTIC if (p == NULL) panic("_bus_dmamap_load_uio: USERSPACE but no proc"); #endif } first = 1; seg = 0; used = 0; error = 0; for (i = 0; i < uio->uio_iovcnt && resid != 0 && error == 0; i++) { /* * Now at the first iovec to load. Load each iovec * until we have exhausted the residual count. */ minlen = resid < iov[i].iov_len ? resid : iov[i].iov_len; addr = (caddr_t)iov[i].iov_base; error = _bus_dmamap_load_buffer(t, map, addr, minlen, p, flags, &lastaddr, &seg, &used, first); first = 0; resid -= minlen; } if (error == 0) { map->dm_mapsize = uio->uio_resid; map->dm_nsegs = seg + 1; map->_dm_nused = used; } return (error); } /* * Like _bus_dmamap_load(), but for raw memory allocated with * bus_dmamem_alloc(). */ int _bus_dmamap_load_raw(bus_dma_tag_t t, bus_dmamap_t map, bus_dma_segment_t *segs, int nsegs, bus_size_t size, int flags) { bus_addr_t paddr, baddr, bmask, lastaddr = 0; bus_size_t plen, sgsize, mapsize; int first = 1; int i, seg = 0; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_mapsize = 0; map->dm_nsegs = 0; if (nsegs > map->_dm_segcnt || size > map->_dm_size) return (EINVAL); mapsize = size; bmask = ~(map->_dm_boundary - 1); for (i = 0; i < nsegs && size > 0; i++) { paddr = segs[i].ds_addr; plen = MIN(segs[i].ds_len, size); while (plen > 0) { /* * Compute the segment size, and adjust counts. */ sgsize = PAGE_SIZE - ((u_long)paddr & PGOFSET); if (plen < sgsize) sgsize = plen; if (paddr > dma_constraint.ucr_high && (map->_dm_flags & BUS_DMA_64BIT) == 0) panic("Non dma-reachable buffer at " "paddr %#lx(raw)", paddr); /* * Make sure we don't cross any boundaries. */ if (map->_dm_boundary > 0) { baddr = (paddr + map->_dm_boundary) & bmask; if (sgsize > (baddr - paddr)) sgsize = (baddr - paddr); } /* * Insert chunk into a segment, coalescing with * previous segment if possible. */ if (first) { map->dm_segs[seg].ds_addr = paddr; map->dm_segs[seg].ds_len = sgsize; first = 0; } else { if (paddr == lastaddr && (map->dm_segs[seg].ds_len + sgsize) <= map->_dm_maxsegsz && (map->_dm_boundary == 0 || (map->dm_segs[seg].ds_addr & bmask) == (paddr & bmask))) map->dm_segs[seg].ds_len += sgsize; else { if (++seg >= map->_dm_segcnt) return (EINVAL); map->dm_segs[seg].ds_addr = paddr; map->dm_segs[seg].ds_len = sgsize; } } paddr += sgsize; plen -= sgsize; size -= sgsize; lastaddr = paddr; } } map->dm_mapsize = mapsize; map->dm_nsegs = seg + 1; return (0); } /* * Common function for unloading a DMA map. May be called by * bus-specific DMA map unload functions. */ void _bus_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map) { /* * No resources to free; just mark the mappings as * invalid. */ map->dm_mapsize = 0; map->dm_nsegs = 0; map->_dm_nused = 0; } /* * Common function for DMA map synchronization. May be called * by bus-specific DMA map synchronization functions. */ void _bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t addr, bus_size_t size, int op) { bus_dma_segment_t *sg; int i, off = addr; bus_size_t l; int use_bounce_buffer = cpu_sev_guestmode || FORCE_BOUNCE_BUFFER; if (!use_bounce_buffer) return; for (i = map->_dm_segcnt, sg = map->dm_segs; size && i; i--, sg++) { if (off >= sg->ds_len) { off -= sg->ds_len; continue; } l = sg->ds_len - off; if (l > size) l = size; size -= l; /* PREREAD and POSTWRITE are no-ops. */ /* READ: device -> memory */ if (op & BUS_DMASYNC_POSTREAD) { bcopy((void *)(sg->_ds_bounce_va + off), (void *)(sg->_ds_va + off), l); } /* WRITE: memory -> device */ if (op & BUS_DMASYNC_PREWRITE) { bcopy((void *)(sg->_ds_va + off), (void *)(sg->_ds_bounce_va + off), l); } off = 0; } } /* * Common function for DMA-safe memory allocation. May be called * by bus-specific DMA memory allocation functions. */ int _bus_dmamem_alloc(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs, int flags) { paddr_t low, high; if (flags & BUS_DMA_64BIT) { low = no_constraint.ucr_low; high = no_constraint.ucr_high; } else { low = dma_constraint.ucr_low; high = dma_constraint.ucr_high; } return _bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs, flags, low, high); } /* * Common function for freeing DMA-safe memory. May be called by * bus-specific DMA memory free functions. */ void _bus_dmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs) { struct vm_page *m; bus_addr_t addr; struct pglist mlist; int curseg; /* * Build a list of pages to free back to the VM system. */ TAILQ_INIT(&mlist); for (curseg = 0; curseg < nsegs; curseg++) { for (addr = segs[curseg].ds_addr; addr < (segs[curseg].ds_addr + segs[curseg].ds_len); addr += PAGE_SIZE) { m = PHYS_TO_VM_PAGE(addr); TAILQ_INSERT_TAIL(&mlist, m, pageq); } } uvm_pglistfree(&mlist); } /* * Common function for mapping DMA-safe memory. May be called by * bus-specific DMA memory map functions. */ int _bus_dmamem_map(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs, size_t size, caddr_t *kvap, int flags) { vaddr_t va, sva; size_t ssize; bus_addr_t addr; int curseg, pmapflags = 0, error; const struct kmem_dyn_mode *kd; if (nsegs == 1 && (flags & BUS_DMA_NOCACHE) == 0) { *kvap = (caddr_t)PMAP_DIRECT_MAP(segs[0].ds_addr); return (0); } if (flags & BUS_DMA_NOCACHE) pmapflags |= PMAP_NOCACHE; size = round_page(size); kd = flags & BUS_DMA_NOWAIT ? &kd_trylock : &kd_waitok; va = (vaddr_t)km_alloc(size, &kv_any, &kp_none, kd); if (va == 0) return (ENOMEM); *kvap = (caddr_t)va; sva = va; ssize = size; for (curseg = 0; curseg < nsegs; curseg++) { for (addr = segs[curseg].ds_addr; addr < (segs[curseg].ds_addr + segs[curseg].ds_len); addr += PAGE_SIZE, va += PAGE_SIZE, size -= PAGE_SIZE) { if (size == 0) panic("_bus_dmamem_map: size botch"); error = pmap_enter(pmap_kernel(), va, addr | pmapflags, PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE | PMAP_WIRED | PMAP_CANFAIL); if (error) { pmap_update(pmap_kernel()); km_free((void *)sva, ssize, &kv_any, &kp_none); return (error); } } } pmap_update(pmap_kernel()); return (0); } /* * Common function for unmapping DMA-safe memory. May be called by * bus-specific DMA memory unmapping functions. */ void _bus_dmamem_unmap(bus_dma_tag_t t, caddr_t kva, size_t size) { #ifdef DIAGNOSTIC if ((u_long)kva & PGOFSET) panic("_bus_dmamem_unmap"); #endif if (kva >= (caddr_t)PMAP_DIRECT_BASE && kva <= (caddr_t)PMAP_DIRECT_END) return; km_free(kva, round_page(size), &kv_any, &kp_none); } /* * Common function for mmap(2)'ing DMA-safe memory. May be called by * bus-specific DMA mmap(2)'ing functions. */ paddr_t _bus_dmamem_mmap(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs, off_t off, int prot, int flags) { int i, pmapflags = 0; if (flags & BUS_DMA_NOCACHE) pmapflags |= PMAP_NOCACHE; for (i = 0; i < nsegs; i++) { #ifdef DIAGNOSTIC if (off & PGOFSET) panic("_bus_dmamem_mmap: offset unaligned"); if (segs[i].ds_addr & PGOFSET) panic("_bus_dmamem_mmap: segment unaligned"); if (segs[i].ds_len & PGOFSET) panic("_bus_dmamem_mmap: segment size not multiple" " of page size"); #endif if (off >= segs[i].ds_len) { off -= segs[i].ds_len; continue; } return ((segs[i].ds_addr + off) | pmapflags); } /* Page not found. */ return (-1); } /********************************************************************** * DMA utility functions **********************************************************************/ /* * Utility function to load a linear buffer. lastaddrp holds state * between invocations (for multiple-buffer loads). segp contains * the starting segment on entrance, and the ending segment on exit. * first indicates if this is the first invocation of this function. */ int _bus_dmamap_load_buffer(bus_dma_tag_t t, bus_dmamap_t map, void *buf, bus_size_t buflen, struct proc *p, int flags, paddr_t *lastaddrp, int *segp, int *usedp, int first) { bus_size_t sgsize; bus_addr_t curaddr, lastaddr, baddr, bmask; vaddr_t pgva = -1, vaddr = (vaddr_t)buf; int seg, page, off; pmap_t pmap; struct vm_page *pg; int use_bounce_buffer = cpu_sev_guestmode || FORCE_BOUNCE_BUFFER; if (p != NULL) pmap = p->p_vmspace->vm_map.pmap; else pmap = pmap_kernel(); page = *usedp; lastaddr = *lastaddrp; bmask = ~(map->_dm_boundary - 1); for (seg = *segp; buflen > 0 ; ) { /* * Get the physical address for this segment. */ pmap_extract(pmap, vaddr, (paddr_t *)&curaddr); if (curaddr > dma_constraint.ucr_high && (map->_dm_flags & BUS_DMA_64BIT) == 0) panic("Non dma-reachable buffer at curaddr %#lx(raw)", curaddr); if (use_bounce_buffer) { if (page >= map->_dm_npages) return (EFBIG); off = vaddr & PAGE_MASK; pg = map->_dm_pages[page]; curaddr = VM_PAGE_TO_PHYS(pg) + off; pgva = map->_dm_pgva + (page << PGSHIFT) + off; page++; } /* * Compute the segment size, and adjust counts. */ sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET); if (buflen < sgsize) sgsize = buflen; /* * Make sure we don't cross any boundaries. */ if (map->_dm_boundary > 0) { baddr = (curaddr + map->_dm_boundary) & bmask; if (sgsize > (baddr - curaddr)) sgsize = (baddr - curaddr); } /* * Insert chunk into a segment, coalescing with * previous segment if possible. */ if (first) { map->dm_segs[seg].ds_addr = curaddr; map->dm_segs[seg].ds_len = sgsize; map->dm_segs[seg]._ds_va = vaddr; map->dm_segs[seg]._ds_bounce_va = pgva; first = 0; } else { if (curaddr == lastaddr && (map->dm_segs[seg].ds_len + sgsize) <= map->_dm_maxsegsz && (map->_dm_boundary == 0 || (map->dm_segs[seg].ds_addr & bmask) == (curaddr & bmask)) && (!use_bounce_buffer || (map->dm_segs[seg]._ds_va + map->dm_segs[seg].ds_len) == vaddr)) { map->dm_segs[seg].ds_len += sgsize; } else { if (++seg >= map->_dm_segcnt) break; map->dm_segs[seg].ds_addr = curaddr; map->dm_segs[seg].ds_len = sgsize; map->dm_segs[seg]._ds_va = vaddr; map->dm_segs[seg]._ds_bounce_va = pgva; } } lastaddr = curaddr + sgsize; vaddr += sgsize; buflen -= sgsize; } *segp = seg; *usedp = page; *lastaddrp = lastaddr; /* * Did we fit? */ if (buflen != 0) return (EFBIG); /* XXX better return value here? */ return (0); } /* * Allocate physical memory from the given physical address range. * Called by DMA-safe memory allocation methods. */ int _bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, int nsegs, int *rsegs, int flags, bus_addr_t low, bus_addr_t high) { paddr_t curaddr, lastaddr; struct vm_page *m; struct pglist mlist; int curseg, error, plaflag; /* Always round the size. */ size = round_page(size); segs[0]._ds_boundary = boundary; segs[0]._ds_align = alignment; /* * Allocate pages from the VM system. */ plaflag = flags & BUS_DMA_NOWAIT ? UVM_PLA_NOWAIT : UVM_PLA_WAITOK; if (flags & BUS_DMA_ZERO) plaflag |= UVM_PLA_ZERO; TAILQ_INIT(&mlist); error = uvm_pglistalloc(size, low, high, alignment, boundary, &mlist, nsegs, plaflag); if (error) return (error); /* * Compute the location, size, and number of segments actually * returned by the VM code. */ m = TAILQ_FIRST(&mlist); curseg = 0; lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m); segs[curseg].ds_len = PAGE_SIZE; for (m = TAILQ_NEXT(m, pageq); m != NULL; m = TAILQ_NEXT(m, pageq)) { curaddr = VM_PAGE_TO_PHYS(m); #ifdef DIAGNOSTIC if (curseg == nsegs) { printf("uvm_pglistalloc returned too many\n"); panic("_bus_dmamem_alloc_range"); } if (curaddr < low || curaddr >= high) { printf("uvm_pglistalloc returned non-sensical" " address 0x%lx\n", curaddr); panic("_bus_dmamem_alloc_range"); } #endif if (curaddr == (lastaddr + PAGE_SIZE)) segs[curseg].ds_len += PAGE_SIZE; else { curseg++; segs[curseg].ds_addr = curaddr; segs[curseg].ds_len = PAGE_SIZE; } lastaddr = curaddr; } *rsegs = curseg + 1; return (0); }