 @@ -1,798 +1,884 @@
-/*	$NetBSD: bus_dma.c,v 1.52 2020/07/06 10:31:24 rin Exp $	*/
+/*	$NetBSD: bus_dma.c,v 1.53 2022/02/16 23:30:52 riastradh 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 <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.52 2020/07/06 10:31:24 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: bus_dma.c,v 1.53 2022/02/16 23:30:52 riastradh Exp $");
 #ifdef _KERNEL_OPT
 #include "opt_ppcarch.h"
 #endif
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>
 #include <sys/device.h>
 #include <sys/kmem.h>
 #include <sys/proc.h>
 #include <sys/mbuf.h>
 #include <sys/bus.h>
 #include <sys/intr.h>
 #include <uvm/uvm.h>
 #include <uvm/uvm_physseg.h>
 #if defined(PPC_BOOKE)
 #define	EIEIO	__asm volatile("mbar\t0")
 #define	SYNC	__asm volatile("msync")
 #elif defined(PPC_IBM4XX) && !defined(PPC_IBM440)
 /* eieio is implemented as sync */
 #define	EIEIO	__asm volatile("eieio")
 #define	SYNC	/* nothing */
 #else
 #define	EIEIO	__asm volatile("eieio")
 #define	SYNC	__asm volatile("sync")
 #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));
+}
 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));
+}
 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));
+}
 /*
  * 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_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;
-	panic("_bus_dmamap_load_raw: not implemented");
+	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);
 		*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 functin 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);
+}