/* $OpenBSD: bus_dma.c,v 1.7 2022/12/29 11:35:01 kettenis Exp $ */ /* * Copyright (c) 2003-2004 Opsycon AB (www.opsycon.se / www.opsycon.com) * * 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 AUTHOR ``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 AUTHOR 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. * */ /*- * 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. */ #include #include #include #include #include #include #include #include #include /* * Common function for DMA map creation. May be called by bus-specific * DMA map creation functions. */ int _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 machine_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(struct machine_bus_dmamap) + (sizeof(bus_dma_segment_t) * (nsegments - 1)); if ((mapstore = malloc(mapsize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? (M_NOWAIT | M_ZERO) : (M_WAITOK | M_ZERO))) == NULL) return (ENOMEM); map = (struct machine_bus_dmamap *)mapstore; map->_dm_size = size; map->_dm_segcnt = nsegments; map->_dm_maxsegsz = maxsegsz; map->_dm_boundary = boundary; *dmamp = map; return (0); } /* * Common function for DMA map destruction. May be called by bus-specific * DMA map destruction functions. */ void _dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) { size_t mapsize; mapsize = sizeof(struct machine_bus_dmamap) + (sizeof(bus_dma_segment_t) * (map->_dm_segcnt - 1)); 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 _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; int seg, error; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_nsegs = 0; map->dm_mapsize = 0; if (buflen > map->_dm_size) return (EINVAL); seg = 0; error = (*t->_dmamap_load_buffer)(t, map, buf, buflen, p, flags, &lastaddr, &seg, 1); if (error == 0) { map->dm_nsegs = seg + 1; map->dm_mapsize = buflen; } return (error); } /* * Like _bus_dmamap_load(), but for mbufs. */ int _dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0, int flags) { paddr_t lastaddr; int seg, error, first; struct mbuf *m; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_nsegs = 0; map->dm_mapsize = 0; #ifdef DIAGNOSTIC if ((m0->m_flags & M_PKTHDR) == 0) panic("_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) { if (m->m_len == 0) continue; error = (*t->_dmamap_load_buffer)(t, map, m->m_data, m->m_len, NULL, flags, &lastaddr, &seg, first); first = 0; } if (error == 0) { map->dm_nsegs = seg + 1; map->dm_mapsize = m0->m_pkthdr.len; } return (error); } /* * Like _dmamap_load(), but for uios. */ int _dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio, int flags) { paddr_t lastaddr; int seg, i, error, first; bus_size_t minlen, resid; struct proc *p = NULL; struct iovec *iov; void *addr; /* * Make sure that on error condition we return "no valid mappings". */ map->dm_nsegs = 0; map->dm_mapsize = 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("_dmamap_load_uio: USERSPACE but no proc"); #endif } 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 = (*t->_dmamap_load_buffer)(t, map, addr, minlen, p, flags, &lastaddr, &seg, first); first = 0; resid -= minlen; } if (error == 0) { map->dm_nsegs = seg + 1; map->dm_mapsize = uio->uio_resid; } return (error); } /* * Like _dmamap_load(), but for raw memory allocated with * bus_dmamem_alloc(). */ int _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; vaddr_t vaddr; 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); /* * Assume the mapping is coherent until we run into a segment * that isn't. */ map->_dm_flags = BUS_DMA_COHERENT; for (i = 0; i < nsegs && size > 0; i++) { paddr = segs[i].ds_addr; vaddr = segs[i]._ds_vaddr; plen = MIN(segs[i].ds_len, size); if (!segs[i]._ds_coherent) map->_dm_flags &= ~BUS_DMA_COHERENT; while (plen > 0) { /* * Compute the segment size, and adjust counts. */ sgsize = PAGE_SIZE - ((u_long)paddr & PGOFSET); if (plen < sgsize) sgsize = plen; /* * 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; map->dm_segs[seg]._ds_paddr = paddr; map->dm_segs[seg]._ds_vaddr = vaddr; 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)) && (t->_flags & BUS_DMA_COHERENT || (map->dm_segs[seg]._ds_vaddr + map->dm_segs[seg].ds_len == vaddr))) 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; map->dm_segs[seg]._ds_paddr = paddr; map->dm_segs[seg]._ds_vaddr = vaddr; } } paddr += sgsize; vaddr += 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 _dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map) { /* * No resources to free; just mark the mappings as * invalid. */ map->dm_nsegs = 0; map->dm_mapsize = 0; } static void _dmamap_sync_segment(paddr_t pa, psize_t len, int ops) { switch (ops) { case BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE: case BUS_DMASYNC_PREREAD: cpu_dcache_wbinv_range(pa, len); break; case BUS_DMASYNC_PREWRITE: cpu_dcache_wb_range(pa, len); break; /* * RISC-V CPUs can do speculative loads so we need to clean the cache * after a DMA read to deal with any speculatively loaded cache lines. * Since these can't be dirty, we can just invalidate them and don't * have to worry about having to write back their contents. */ case BUS_DMASYNC_POSTREAD: case BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE: membar_sync(); cpu_dcache_inv_range(pa, len); break; } } /* * Common function for DMA map synchronization. May be called * by bus-specific DMA map synchronization functions. */ void _dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t addr, bus_size_t size, int op) { int nsegs; int curseg; /* * If our tag tells us that the device we are doing DMA * with is coherent, make sure the write buffer is synced * and return. */ if (t->_flags & BUS_DMA_COHERENT || map->_dm_flags & BUS_DMA_COHERENT) { __asm volatile ("fence iorw,iorw" ::: "memory"); return; } nsegs = map->dm_nsegs; curseg = 0; while (size && nsegs) { paddr_t paddr; bus_size_t ssize; ssize = map->dm_segs[curseg].ds_len; paddr = map->dm_segs[curseg]._ds_paddr; if (addr != 0) { if (addr >= ssize) { addr -= ssize; ssize = 0; } else { paddr += addr; ssize -= addr; addr = 0; } } if (ssize > size) ssize = size; if (ssize != 0) { _dmamap_sync_segment(paddr, ssize, op); size -= ssize; } curseg++; nsegs--; } if (size != 0) { panic("_dmamap_sync: ran off map!"); } } /* * Common function for DMA-safe memory allocation. May be called * by bus-specific DMA memory allocation functions. */ int _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) { return _dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs, flags, dma_constraint.ucr_low, dma_constraint.ucr_high); } /* * Common function for freeing DMA-safe memory. May be called by * bus-specific DMA memory free functions. */ void _dmamem_free(bus_dma_tag_t t, bus_dma_segment_t *segs, int nsegs) { vm_page_t 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 _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, pmap_flags, cache; const struct kmem_dyn_mode *kd; 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; pmap_flags = PMAP_WIRED | PMAP_CANFAIL; cache = PMAP_CACHE_WB; if (((t->_flags & BUS_DMA_COHERENT) == 0 && (flags & BUS_DMA_COHERENT)) || (flags & BUS_DMA_NOCACHE)) cache = PMAP_CACHE_CI; for (curseg = 0; curseg < nsegs; curseg++) { segs[curseg]._ds_vaddr = va; segs[curseg]._ds_coherent = !!(flags & BUS_DMA_COHERENT); for (addr = segs[curseg].ds_addr; addr < (segs[curseg].ds_addr + segs[curseg].ds_len); addr += NBPG, va += NBPG, size -= NBPG) { if (size == 0) panic("_dmamem_map: size botch"); pmap_kenter_cache(va, addr, PROT_READ | PROT_WRITE | pmap_flags, cache); } pmap_update(pmap_kernel()); } return (0); } /* * Common function for unmapping DMA-safe memory. May be called by * bus-specific DMA memory unmapping functions. */ void _dmamem_unmap(bus_dma_tag_t t, caddr_t kva, size_t size) { 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 _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("_dmamem_mmap: offset unaligned"); if (segs[i].ds_addr & PGOFSET) panic("_dmamem_mmap: segment unaligned"); if (segs[i].ds_len & PGOFSET) panic("_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 _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 first) { bus_size_t sgsize; bus_addr_t lastaddr, baddr, bmask; paddr_t curaddr; vaddr_t vaddr = (vaddr_t)buf; int seg; pmap_t pmap; if (p != NULL) pmap = p->p_vmspace->vm_map.pmap; else pmap = pmap_kernel(); lastaddr = *lastaddrp; bmask = ~(map->_dm_boundary - 1); if (t->_dma_mask != 0) bmask &= t->_dma_mask; for (seg = *segp; buflen > 0; ) { /* * Get the physical address for this segment. */ if (pmap_extract(pmap, vaddr, &curaddr) == FALSE) panic("_dmapmap_load_buffer: pmap_extract(%p, %lx) failed!", pmap, vaddr); /* * Compute the segment size, and adjust counts. */ sgsize = NBPG - ((u_long)vaddr & PGOFSET); if (buflen < sgsize) sgsize = buflen; /* * Make sure we don't cross any boundaries. */ if (map->_dm_boundary > 0) { baddr = ((bus_addr_t)curaddr + map->_dm_boundary) & bmask; if (sgsize > (baddr - (bus_addr_t)curaddr)) sgsize = (baddr - (bus_addr_t)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_paddr = curaddr; map->dm_segs[seg]._ds_vaddr = vaddr; first = 0; } else { if ((bus_addr_t)curaddr == lastaddr && (map->dm_segs[seg].ds_len + sgsize) <= map->_dm_maxsegsz && (map->_dm_boundary == 0 || (map->dm_segs[seg].ds_addr & bmask) == ((bus_addr_t)curaddr & bmask)) && (t->_flags & BUS_DMA_COHERENT || (map->dm_segs[seg]._ds_vaddr + 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_paddr = curaddr; map->dm_segs[seg]._ds_vaddr = vaddr; } } lastaddr = (bus_addr_t)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); } /* * Allocate physical memory from the given physical address range. * Called by DMA-safe memory allocation methods. */ int _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; vm_page_t m; struct pglist mlist; int curseg, error, plaflag; /* Always round the size. */ size = round_page(size); /* * 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; m = TAILQ_NEXT(m, pageq); for (; m != NULL; m = TAILQ_NEXT(m, pageq)) { 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("_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); }