/* $OpenBSD: isadma_bounce.c,v 1.5 2002/06/25 21:33:21 miod Exp $ */ /* $NetBSD: isadma_bounce.c,v 1.3 2000/06/29 09:02:57 mrg Exp $ */ /*- * Copyright (c) 1996, 1997, 1998, 2000 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 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 _ALPHA_BUS_DMA_PRIVATE #include #include #include #include #include #include #include #include #include #include #include extern paddr_t avail_end; /* * ISA can only DMA to 0-16M. */ #define ISA_DMA_BOUNCE_THRESHOLD (16 * 1024 * 1024) /* * Cookie used by bouncing ISA DMA. A pointer to one of these is stashed * in the DMA map. */ struct isadma_bounce_cookie { int id_flags; /* flags; see below */ /* * Information about the original buffer used during * DMA map syncs. Note that origbuflen is only used * for ID_BUFTYPE_LINEAR. */ void *id_origbuf; /* pointer to orig buffer if bouncing */ bus_size_t id_origbuflen; /* ...and size */ int id_buftype; /* type of buffer */ void *id_bouncebuf; /* pointer to the bounce buffer */ bus_size_t id_bouncebuflen; /* ...and size */ int id_nbouncesegs; /* number of valid bounce segs */ bus_dma_segment_t id_bouncesegs[1]; /* array of bounce buffer physical memory segments */ }; /* id_flags */ #define ID_MIGHT_NEED_BOUNCE 0x01 /* map could need bounce buffers */ #define ID_HAS_BOUNCE 0x02 /* map currently has bounce buffers */ #define ID_IS_BOUNCING 0x04 /* map is bouncing current xfer */ /* id_buftype */ #define ID_BUFTYPE_INVALID 0 #define ID_BUFTYPE_LINEAR 1 #define ID_BUFTYPE_MBUF 2 #define ID_BUFTYPE_UIO 3 #define ID_BUFTYPE_RAW 4 int isadma_bounce_alloc_bouncebuf(bus_dma_tag_t, bus_dmamap_t, bus_size_t, int); void isadma_bounce_free_bouncebuf(bus_dma_tag_t, bus_dmamap_t); /* * Create an ISA DMA map. */ int isadma_bounce_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 isadma_bounce_cookie *cookie; bus_dmamap_t map; int error, cookieflags; void *cookiestore; size_t cookiesize; /* Call common function to create the basic map. */ error = _bus_dmamap_create(t, size, nsegments, maxsegsz, boundary, flags, dmamp); if (error) return (error); map = *dmamp; map->_dm_cookie = NULL; cookiesize = sizeof(*cookie); /* * ISA only has 24-bits of address space. This means * we can't DMA to pages over 16M. In order to DMA to * arbitrary buffers, we use "bounce buffers" - pages * in memory below the 16M boundary. On DMA reads, * DMA happens to the bounce buffers, and is copied into * the caller's buffer. On writes, data is copied into * but bounce buffer, and the DMA happens from those * pages. To software using the DMA mapping interface, * this looks simply like a data cache. * * If we have more than 16M of RAM in the system, we may * need bounce buffers. We check and remember that here. * * ...or, there is an opposite case. The most segments * a transfer will require is (maxxfer / PAGE_SIZE) + 1. If * the caller can't handle that many segments (e.g. the * ISA DMA controller), we may have to bounce it as well. */ cookieflags = 0; if (avail_end > (t->_wbase + t->_wsize) || ((map->_dm_size / PAGE_SIZE) + 1) > map->_dm_segcnt) { cookieflags |= ID_MIGHT_NEED_BOUNCE; cookiesize += (sizeof(bus_dma_segment_t) * (map->_dm_segcnt - 1)); } /* * Allocate our cookie. */ if ((cookiestore = malloc(cookiesize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL) { error = ENOMEM; goto out; } memset(cookiestore, 0, cookiesize); cookie = (struct isadma_bounce_cookie *)cookiestore; cookie->id_flags = cookieflags; map->_dm_cookie = cookie; if (cookieflags & ID_MIGHT_NEED_BOUNCE) { /* * Allocate the bounce pages now if the caller * wishes us to do so. */ if ((flags & BUS_DMA_ALLOCNOW) == 0) goto out; error = isadma_bounce_alloc_bouncebuf(t, map, size, flags); } out: if (error) { if (map->_dm_cookie != NULL) free(map->_dm_cookie, M_DEVBUF); _bus_dmamap_destroy(t, map); } return (error); } /* * Destroy an ISA DMA map. */ void isadma_bounce_dmamap_destroy(bus_dma_tag_t t, bus_dmamap_t map) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; /* * Free any bounce pages this map might hold. */ if (cookie->id_flags & ID_HAS_BOUNCE) isadma_bounce_free_bouncebuf(t, map); free(cookie, M_DEVBUF); _bus_dmamap_destroy(t, map); } /* * Load an ISA DMA map with a linear buffer. */ int isadma_bounce_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf, size_t buflen, struct proc *p, int flags) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; int error; /* * Make sure that on error condition we return "no valid mappings." */ map->dm_mapsize = 0; map->dm_nsegs = 0; /* * Try to load the map the normal way. If this errors out, * and we can bounce, we will. */ error = _bus_dmamap_load_direct(t, map, buf, buflen, p, flags); if (error == 0 || (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) return (error); /* * First attempt failed; bounce it. */ /* * Allocate bounce pages, if necessary. */ if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { error = isadma_bounce_alloc_bouncebuf(t, map, buflen, flags); if (error) return (error); } /* * Cache a pointer to the caller's buffer and load the DMA map * with the bounce buffer. */ cookie->id_origbuf = buf; cookie->id_origbuflen = buflen; cookie->id_buftype = ID_BUFTYPE_LINEAR; error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, buflen, p, flags); if (error) { /* * Free the bounce pages, unless our resources * are reserved for our exclusive use. */ if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) isadma_bounce_free_bouncebuf(t, map); return (error); } /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ cookie->id_flags |= ID_IS_BOUNCING; return (0); } /* * Like isadma_bounce_dmamap_load(), but for mbufs. */ int isadma_bounce_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0, int flags) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; int error; /* * Make sure 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("isadma_bounce_dmamap_load_mbuf: no packet header"); #endif if (m0->m_pkthdr.len > map->_dm_size) return (EINVAL); /* * Try to load the map the normal way. If this errors out, * and we can bounce, we will. */ error = _bus_dmamap_load_mbuf_direct(t, map, m0, flags); if (error == 0 || (error != 0 && (cookie->id_flags & ID_MIGHT_NEED_BOUNCE) == 0)) return (error); /* * First attempt failed; bounce it. */ /* * Allocate bounce pages, if necessary. */ if ((cookie->id_flags & ID_HAS_BOUNCE) == 0) { error = isadma_bounce_alloc_bouncebuf(t, map, m0->m_pkthdr.len, flags); if (error) return (error); } /* * Cache a pointer to the caller's buffer and load the DMA map * with the bounce buffer. */ cookie->id_origbuf = m0; cookie->id_origbuflen = m0->m_pkthdr.len; /* not really used */ cookie->id_buftype = ID_BUFTYPE_MBUF; error = _bus_dmamap_load_direct(t, map, cookie->id_bouncebuf, m0->m_pkthdr.len, NULL, flags); if (error) { /* * Free the bounce pages, unless our resources * are reserved for our exclusive use. */ if ((map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) isadma_bounce_free_bouncebuf(t, map); return (error); } /* ...so isadma_bounce_dmamap_sync() knows we're bouncing */ cookie->id_flags |= ID_IS_BOUNCING; return (0); } /* * Like isadma_bounce_dmamap_load(), but for uios. */ int isadma_bounce_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio, int flags) { panic("isadma_bounce_dmamap_load_uio: not implemented"); } /* * Like isadma_bounce_dmamap_load(), but for raw memory allocated with * bus_dmamem_alloc(). */ int isadma_bounce_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) { panic("isadma_bounce_dmamap_load_raw: not implemented"); } /* * Unload an ISA DMA map. */ void isadma_bounce_dmamap_unload(bus_dma_tag_t t, bus_dmamap_t map) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; /* * If we have bounce pages, free them, unless they're * reserved for our exclusive use. */ if ((cookie->id_flags & ID_HAS_BOUNCE) && (map->_dm_flags & BUS_DMA_ALLOCNOW) == 0) isadma_bounce_free_bouncebuf(t, map); cookie->id_flags &= ~ID_IS_BOUNCING; cookie->id_buftype = ID_BUFTYPE_INVALID; /* * Do the generic bits of the unload. */ _bus_dmamap_unload(t, map); } void isadma_bounce_dmamap_sync(bus_dma_tag_t t, bus_dmamap_t map, bus_addr_t offset, bus_size_t len, int ops) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; /* * Mixing PRE and POST operations is not allowed. */ if ((ops & (BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE)) != 0 && (ops & (BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE)) != 0) panic("isadma_bounce_dmamap_sync: mix PRE and POST"); #ifdef DIAGNOSTIC if ((ops & (BUS_DMASYNC_PREWRITE|BUS_DMASYNC_POSTREAD)) != 0) { if (offset >= map->dm_mapsize) panic("isadma_bounce_dmamap_sync: bad offset"); if (len == 0 || (offset + len) > map->dm_mapsize) panic("isadma_bounce_dmamap_sync: bad length"); } #endif /* * If we're not bouncing, just drain the write buffer * and return. */ if ((cookie->id_flags & ID_IS_BOUNCING) == 0) { alpha_mb(); return; } switch (cookie->id_buftype) { case ID_BUFTYPE_LINEAR: /* * Nothing to do for pre-read. */ if (ops & BUS_DMASYNC_PREWRITE) { /* * Copy the caller's buffer to the bounce buffer. */ memcpy((char *)cookie->id_bouncebuf + offset, (char *)cookie->id_origbuf + offset, len); } if (ops & BUS_DMASYNC_POSTREAD) { /* * Copy the bounce buffer to the caller's buffer. */ memcpy((char *)cookie->id_origbuf + offset, (char *)cookie->id_bouncebuf + offset, len); } /* * Nothing to do for post-write. */ break; case ID_BUFTYPE_MBUF: { struct mbuf *m, *m0 = cookie->id_origbuf; bus_size_t minlen, moff; /* * Nothing to do for pre-read. */ if (ops & BUS_DMASYNC_PREWRITE) { /* * Copy the caller's buffer to the bounce buffer. */ m_copydata(m0, offset, len, (char *)cookie->id_bouncebuf + offset); } if (ops & BUS_DMASYNC_POSTREAD) { /* * Copy the bounce buffer to the caller's buffer. */ for (moff = offset, m = m0; m != NULL && len != 0; m = m->m_next) { /* Find the beginning mbuf. */ if (moff >= m->m_len) { moff -= m->m_len; continue; } /* * Now at the first mbuf to sync; nail * each one until we have exhausted the * length. */ minlen = len < m->m_len - moff ? len : m->m_len - moff; memcpy(mtod(m, caddr_t) + moff, (char *)cookie->id_bouncebuf + offset, minlen); moff = 0; len -= minlen; offset += minlen; } } /* * Nothing to do for post-write. */ break; } case ID_BUFTYPE_UIO: panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_UIO"); break; case ID_BUFTYPE_RAW: panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_RAW"); break; case ID_BUFTYPE_INVALID: panic("isadma_bounce_dmamap_sync: ID_BUFTYPE_INVALID"); break; default: panic("isadma_bounce_dmamap_sync: unknown buffer type %d", cookie->id_buftype); } /* Drain the write buffer. */ alpha_mb(); } /* * Allocate memory safe for ISA DMA. */ int isadma_bounce_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 high; if (avail_end > ISA_DMA_BOUNCE_THRESHOLD) high = trunc_page(ISA_DMA_BOUNCE_THRESHOLD); else high = trunc_page(avail_end); return (_bus_dmamem_alloc_range(t, size, alignment, boundary, segs, nsegs, rsegs, flags, 0, high)); } /********************************************************************** * ISA DMA utility functions **********************************************************************/ int isadma_bounce_alloc_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map, bus_size_t size, int flags) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; int error = 0; cookie->id_bouncebuflen = round_page(size); error = isadma_bounce_dmamem_alloc(t, cookie->id_bouncebuflen, PAGE_SIZE, map->_dm_boundary, cookie->id_bouncesegs, map->_dm_segcnt, &cookie->id_nbouncesegs, flags); if (error) goto out; error = _bus_dmamem_map(t, cookie->id_bouncesegs, cookie->id_nbouncesegs, cookie->id_bouncebuflen, (caddr_t *)&cookie->id_bouncebuf, flags); out: if (error) { _bus_dmamem_free(t, cookie->id_bouncesegs, cookie->id_nbouncesegs); cookie->id_bouncebuflen = 0; cookie->id_nbouncesegs = 0; } else cookie->id_flags |= ID_HAS_BOUNCE; return (error); } void isadma_bounce_free_bouncebuf(bus_dma_tag_t t, bus_dmamap_t map) { struct isadma_bounce_cookie *cookie = map->_dm_cookie; _bus_dmamem_unmap(t, cookie->id_bouncebuf, cookie->id_bouncebuflen); _bus_dmamem_free(t, cookie->id_bouncesegs, cookie->id_nbouncesegs); cookie->id_bouncebuflen = 0; cookie->id_nbouncesegs = 0; cookie->id_flags &= ~ID_HAS_BOUNCE; }