/* $NetBSD: bus_dma.c,v 1.56 2023/12/15 09:43:59 rin 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 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. */ #define _POWERPC_BUS_DMA_PRIVATE #include __KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.56 2023/12/15 09:43:59 rin Exp $"); #ifdef _KERNEL_OPT #include "opt_ppcarch.h" #endif #include #include #include #include #include #include #include #include #include #include #include #if defined(PPC_BOOKE) #define EIEIO __asm volatile("mbar\t0" ::: "memory") #define SYNC __asm volatile("msync" ::: "memory") #elif defined(PPC_IBM4XX) && !defined(PPC_IBM440) /* eieio is implemented as sync */ #define EIEIO __asm volatile("eieio" ::: "memory") #define SYNC /* nothing */ #else #define EIEIO __asm volatile("eieio" ::: "memory") #define SYNC __asm volatile("sync" ::: "memory") #endif int _bus_dmamap_load_buffer (bus_dma_tag_t, bus_dmamap_t, void *, bus_size_t, struct vmspace *, int, paddr_t *, int *, int); static inline void dcbst(paddr_t pa, long len, int dcache_line_size) { paddr_t epa; for (epa = pa + len; pa < epa; pa += dcache_line_size) __asm volatile("dcbst 0,%0" :: "r"(pa) : "memory"); } static inline void dcbi(paddr_t pa, long len, int dcache_line_size) { paddr_t epa; for (epa = pa + len; pa < epa; pa += dcache_line_size) __asm volatile("dcbi 0,%0" :: "r"(pa) : "memory"); } static inline void dcbf(paddr_t pa, long len, int dcache_line_size) { paddr_t epa; for (epa = pa + len; pa < epa; pa += dcache_line_size) __asm volatile("dcbf 0,%0" :: "r"(pa) : "memory"); } /* * 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 powerpc_bus_dmamap *map; void *mapstore; size_t mapsize; /* * 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(*map) + sizeof(bus_dma_segment_t [nsegments - 1]); if ((mapstore = kmem_intr_alloc(mapsize, (flags & BUS_DMA_NOWAIT) ? KM_NOSLEEP : KM_SLEEP)) == NULL) return (ENOMEM); memset(mapstore, 0, mapsize); map = (struct powerpc_bus_dmamap *)mapstore; map->_dm_size = size; map->_dm_segcnt = nsegments; map->_dm_maxmaxsegsz = maxsegsz; map->_dm_boundary = boundary; map->_dm_bounce_thresh = t->_bounce_thresh; map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT); map->dm_maxsegsz = maxsegsz; map->dm_mapsize = 0; /* no valid mappings */ map->dm_nsegs = 0; *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 = sizeof(*map) + sizeof(bus_dma_segment_t [map->_dm_segcnt - 1]); kmem_intr_free(map, mapsize); } /* * 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 vmspace *vm, int flags, paddr_t *lastaddrp, int *segp, int first) { bus_size_t sgsize; bus_addr_t curaddr, lastaddr, baddr, bmask; vaddr_t vaddr = (vaddr_t)buf; int seg; // printf("%s(%p,%p,%p,%u,%p,%#x,%p,%p,%u)\n", __func__, // t, map, buf, buflen, vm, flags, lastaddrp, segp, first); lastaddr = *lastaddrp; bmask = ~(map->_dm_boundary - 1); for (seg = *segp; buflen > 0 ; ) { /* * Get the physical address for this segment. */ if (!VMSPACE_IS_KERNEL_P(vm)) (void) pmap_extract(vm_map_pmap(&vm->vm_map), vaddr, (void *)&curaddr); else curaddr = vtophys(vaddr); /* * If we're beyond the bounce threshold, notify * the caller. */ if (map->_dm_bounce_thresh != 0 && curaddr >= map->_dm_bounce_thresh) return (EINVAL); /* * Compute the segment size, and adjust counts. */ sgsize = PAGE_SIZE - ((u_long)vaddr & PGOFSET); if (buflen < sgsize) sgsize = buflen; sgsize = uimin(sgsize, map->dm_maxsegsz); /* * 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 * the previous segment if possible. */ if (first) { map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr); map->dm_segs[seg].ds_len = sgsize; 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) == (PHYS_TO_BUS_MEM(t, curaddr) & bmask))) map->dm_segs[seg].ds_len += sgsize; else { if (++seg >= map->_dm_segcnt) break; map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr); map->dm_segs[seg].ds_len = sgsize; } } lastaddr = curaddr + sgsize; vaddr += sgsize; buflen -= sgsize; } *segp = seg; *lastaddrp = lastaddr; /* * Did we fit? */ if (buflen != 0) return (EFBIG); /* XXX better return value here? */ return (0); } /* * 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) { paddr_t lastaddr = 0; int seg, error; struct vmspace *vm; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_mapsize = 0; map->dm_nsegs = 0; KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz); if (buflen > map->_dm_size) return (EINVAL); if (p != NULL) { vm = p->p_vmspace; } else { vm = vmspace_kernel(); } seg = 0; error = _bus_dmamap_load_buffer(t, map, buf, buflen, vm, flags, &lastaddr, &seg, 1); if (error == 0) { map->dm_mapsize = buflen; map->dm_nsegs = seg + 1; } 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, error, first; struct mbuf *m; /* * Make sure that on error condition we return "no valid mappings." */ map->dm_mapsize = 0; map->dm_nsegs = 0; KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz); #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; error = 0; for (m = m0; m != NULL && error == 0; m = m->m_next, first = 0) { if (m->m_len == 0) continue; #ifdef POOL_VTOPHYS /* XXX Could be better about coalescing. */ /* XXX Doesn't check boundaries. */ switch (m->m_flags & (M_EXT|M_EXT_CLUSTER)) { case M_EXT|M_EXT_CLUSTER: /* XXX KDASSERT */ KASSERT(m->m_ext.ext_paddr != M_PADDR_INVALID); lastaddr = m->m_ext.ext_paddr + (m->m_data - m->m_ext.ext_buf); have_addr: if (first == 0 && ++seg >= map->_dm_segcnt) { error = EFBIG; continue; } map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, lastaddr); map->dm_segs[seg].ds_len = m->m_len; lastaddr += m->m_len; continue; case 0: lastaddr = m->m_paddr + M_BUFOFFSET(m) + (m->m_data - M_BUFADDR(m)); goto have_addr; default: break; } #endif error = _bus_dmamap_load_buffer(t, map, m->m_data, m->m_len, vmspace_kernel(), flags, &lastaddr, &seg, first); } if (error == 0) { map->dm_mapsize = m0->m_pkthdr.len; map->dm_nsegs = seg + 1; } 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, i, error, first; bus_size_t minlen, resid; struct iovec *iov; void *addr; /* * Make sure that on error condition we return "no valid mappings." */ map->dm_mapsize = 0; map->dm_nsegs = 0; KASSERT(map->dm_maxsegsz <= map->_dm_maxmaxsegsz); resid = uio->uio_resid; iov = uio->uio_iov; first = 1; seg = 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 = (void *)iov[i].iov_base; error = _bus_dmamap_load_buffer(t, map, addr, minlen, uio->uio_vmspace, flags, &lastaddr, &seg, first); first = 0; resid -= minlen; } if (error == 0) { map->dm_mapsize = uio->uio_resid; map->dm_nsegs = seg + 1; } return (error); } /* * Like _bus_dmamap_load(), but for raw memory allocated with * bus_dmamem_alloc(). * * XXX This is too much copypasta of _bus_dmamap_load_buffer. */ 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_size_t sgsize, isgsize; bus_size_t busaddr, curaddr, lastaddr, baddr, bmask; int seg, iseg, first; if (size == 0) return 0; lastaddr = 0; bmask = ~(map->_dm_boundary - 1); first = 0; iseg = 0; busaddr = segs[iseg].ds_addr; isgsize = segs[iseg].ds_len; for (seg = 0; size > 0;) { /* * Get the physical address for this segment. */ curaddr = BUS_MEM_TO_PHYS(t, busaddr); /* * If we're beyond the bounce threshold, notify * the caller. */ if (map->_dm_bounce_thresh != 0 && curaddr >= map->_dm_bounce_thresh) return EINVAL; /* * Compute the segment size, and adjust counts. */ sgsize = PAGE_SIZE - ((u_long)curaddr & PGOFSET); sgsize = MIN(sgsize, isgsize); sgsize = MIN(sgsize, size); sgsize = MIN(sgsize, map->dm_maxsegsz); /* * 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 * the previous segment if possible. */ if (first) { map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr); map->dm_segs[seg].ds_len = sgsize; 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) == (PHYS_TO_BUS_MEM(t, curaddr) & bmask))) map->dm_segs[seg].ds_len += sgsize; else { if (++seg >= map->_dm_segcnt) break; map->dm_segs[seg].ds_addr = PHYS_TO_BUS_MEM(t, curaddr); map->dm_segs[seg].ds_len = sgsize; } } lastaddr = curaddr + sgsize; size -= sgsize; if ((isgsize -= sgsize) == 0) { iseg++; KASSERT(iseg < nsegs); busaddr = segs[iseg].ds_addr; isgsize = segs[iseg].ds_len; } } if (size > 0) return EFBIG; return 0; } /* * Common function for unloading a DMA map. May be called by * chipset-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_maxsegsz = map->_dm_maxmaxsegsz; map->dm_mapsize = 0; map->dm_nsegs = 0; } /* * Common function for DMA map synchronization. May be called * by chipset-specific DMA map synchronization functions. */ void _bus_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset, bus_size_t len, int ops) { const int dcache_line_size = curcpu()->ci_ci.dcache_line_size; const bus_dma_segment_t *ds = map->dm_segs; // printf("%s(%p,%p,%#x,%u,%#x) from %p\n", __func__, // t, map, offset, len, ops, __builtin_return_address(0)); if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 && (ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0) panic("_bus_dmamap_sync: invalid ops %#x", ops); #ifdef DIAGNOSTIC if (offset + len > map->dm_mapsize) panic("%s: ops %#x mapsize %u: bad offset (%u) and/or length (%u)", __func__, ops, map->dm_mapsize, offset, len); #endif /* * Skip leading amount */ while (offset >= ds->ds_len) { offset -= ds->ds_len; ds++; } EIEIO; for (; len > 0; ds++, offset = 0) { bus_size_t seglen = ds->ds_len - offset; bus_addr_t addr = BUS_MEM_TO_PHYS(t, ds->ds_addr) + offset; if (seglen > len) seglen = len; len -= seglen; KASSERT(ds < &map->dm_segs[map->dm_nsegs]); /* * Readjust things to start on cacheline boundarys */ offset = (addr & (dcache_line_size-1)); seglen += offset; addr -= offset; /* * Now do the appropriate thing. */ switch (ops) { case BUS_DMASYNC_PREWRITE: /* * Make sure cache contents are in memory for the DMA. */ dcbst(addr, seglen, dcache_line_size); break; case BUS_DMASYNC_PREREAD: /* * If the region to be invalidated doesn't fall on * cacheline boundary, flush that cacheline so we * preserve the leading content. */ if (offset) { dcbf(addr, 1, 1); /* * If we are doing <= one cache line, stop now. */ if (seglen <= dcache_line_size) break; /* * Advance one cache line since we've flushed * this one. */ addr += dcache_line_size; seglen -= dcache_line_size; } /* * If the byte after the region to be invalidated * doesn't fall on cacheline boundary, flush that * cacheline so we preserve the trailing content. */ if (seglen & (dcache_line_size-1)) { dcbf(addr + seglen, 1, 1); if (seglen <= dcache_line_size) break; /* * Truncate the length to a multiple of a * dcache line size. No reason to flush * the last entry again. */ seglen &= ~(dcache_line_size - 1); } SYNC; /* is this needed? */ EIEIO; /* is this needed? */ /* FALLTHROUGH */ case BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE: case BUS_DMASYNC_POSTREAD: /* * The contents will have changed, make sure to remove * them from the cache. Note: some implementation * implement dcbi identically to dcbf. Thus if the * cacheline has data, it will be written to memory. * If the DMA is updating the same cacheline at the * time, bad things can happen. */ dcbi(addr, seglen, dcache_line_size); break; case BUS_DMASYNC_POSTWRITE: /* * Do nothing. */ break; case BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE: /* * Force it to memory and remove from cache. */ dcbf(addr, seglen, dcache_line_size); break; } } __asm volatile("sync"); } /* * 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 start = 0xffffffff, end = 0; uvm_physseg_t bank; for (bank = uvm_physseg_get_first(); uvm_physseg_valid_p(bank); bank = uvm_physseg_get_next(bank)) { if (start > ptoa(uvm_physseg_get_avail_start(bank))) start = ptoa(uvm_physseg_get_avail_start(bank)); if (end < ptoa(uvm_physseg_get_avail_end(bank))) end = ptoa(uvm_physseg_get_avail_end(bank)); } return _bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs, flags, start, end - PAGE_SIZE); } /* * 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 = BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr); addr < (BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr) + segs[curseg].ds_len); addr += PAGE_SIZE) { m = PHYS_TO_VM_PAGE(addr); TAILQ_INSERT_TAIL(&mlist, m, pageq.queue); } } 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, void **kvap, int flags) { vaddr_t va; bus_addr_t addr; int curseg; const uvm_flag_t kmflags = (flags & BUS_DMA_NOWAIT) != 0 ? UVM_KMF_NOWAIT : 0; size = round_page(size); #ifdef PMAP_MAP_POOLPAGE /* * If we are mapping a cacheable physically contiguous segment, treat * it as if we are mapping a poolpage and avoid consuming any KVAs. */ if (nsegs == 1 && (flags & BUS_DMA_DONTCACHE) == 0) { KASSERT(size == segs->ds_len); addr = BUS_MEM_TO_PHYS(t, segs->ds_addr); if (__predict_true(addr + size < PMAP_DIRECT_MAPPED_LEN)) { *kvap = (void *)PMAP_MAP_POOLPAGE(addr); return 0; } } #endif va = uvm_km_alloc(kernel_map, size, 0, UVM_KMF_VAONLY | kmflags); if (va == 0) return (ENOMEM); *kvap = (void *)va; for (curseg = 0; curseg < nsegs; curseg++) { for (addr = BUS_MEM_TO_PHYS(t, segs[curseg].ds_addr); addr < (BUS_MEM_TO_PHYS(t, 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"); /* * If we are mapping nocache, flush the page from * cache before we map it. */ if (flags & BUS_DMA_DONTCACHE) dcbf(addr, PAGE_SIZE, curcpu()->ci_ci.dcache_line_size); pmap_kenter_pa(va, addr, VM_PROT_READ | VM_PROT_WRITE, PMAP_WIRED | ((flags & BUS_DMA_DONTCACHE) ? PMAP_NOCACHE : 0)); } } 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, void *kva, size_t size) { vaddr_t va = (vaddr_t) kva; #ifdef DIAGNOSTIC if (va & PGOFSET) panic("_bus_dmamem_unmap"); #endif if (va >= VM_MIN_KERNEL_ADDRESS && va < VM_MAX_KERNEL_ADDRESS) { size = round_page(size); pmap_kremove(va, size); uvm_km_free(kernel_map, va, size, UVM_KMF_VAONLY); } } /* * 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; for (i = 0; i < nsegs; i++) { #ifdef DIAGNOSTIC if (off & PGOFSET) panic("_bus_dmamem_mmap: offset unaligned"); if (BUS_MEM_TO_PHYS(t, 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 (BUS_MEM_TO_PHYS(t, segs[i].ds_addr) + off); } /* Page not found. */ return (-1); } /* * 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, paddr_t low, paddr_t high) { paddr_t curaddr, lastaddr; struct vm_page *m; struct pglist mlist; int curseg, error; /* Always round the size. */ size = round_page(size); /* * Allocate pages from the VM system. */ error = uvm_pglistalloc(size, low, high, alignment, boundary, &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0); if (error) return (error); /* * Compute the location, size, and number of segments actually * returned by the VM code. */ m = mlist.tqh_first; curseg = 0; lastaddr = VM_PAGE_TO_PHYS(m); segs[curseg].ds_addr = PHYS_TO_BUS_MEM(t, lastaddr); segs[curseg].ds_len = PAGE_SIZE; m = m->pageq.queue.tqe_next; for (; m != NULL; m = m->pageq.queue.tqe_next) { curaddr = VM_PAGE_TO_PHYS(m); #ifdef DIAGNOSTIC if (curaddr < low || curaddr >= high) { printf("vm_page_alloc_memory 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 = PHYS_TO_BUS_MEM(t, curaddr); segs[curseg].ds_len = PAGE_SIZE; } lastaddr = curaddr; } *rsegs = curseg + 1; return (0); } /* * Generic form of PHYS_TO_BUS_MEM(). */ bus_addr_t _bus_dma_phys_to_bus_mem_generic(bus_dma_tag_t t, bus_addr_t addr) { return (addr); } /* * Generic form of BUS_MEM_TO_PHYS(). */ bus_addr_t _bus_dma_bus_mem_to_phys_generic(bus_dma_tag_t t, bus_addr_t addr) { return (addr); }