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/*	$OpenBSD: dma.c,v 1.25 2007/05/27 15:46:02 drahn Exp $	*/
/*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/

/*-
 * Copyright (c) 1996, 1997 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.
 */

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/extent.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>

#include <uvm/uvm.h>
#include <uvm/uvm_page.h>

#include <machine/bus.h>
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, vaddr_t low, vaddr_t high);
int _dmamap_load_buffer(bus_dma_tag_t, bus_dmamap_t, void *, bus_size_t,
    struct proc *, int, bus_addr_t *, int *, int);
/*
 * 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 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(struct powerpc_bus_dmamap) +
	    (sizeof(bus_dma_segment_t) * (nsegments - 1));
	if ((mapstore = malloc(mapsize, M_DEVBUF,
	    (flags & BUS_DMA_NOWAIT) ? M_NOWAIT : M_WAITOK)) == NULL)
		return (ENOMEM);

	bzero(mapstore, mapsize);
	map = (struct powerpc_bus_dmamap *)mapstore;
	map->_dm_size = size;
	map->_dm_segcnt = nsegments;
	map->_dm_maxsegsz = maxsegsz;
	map->_dm_boundary = boundary;
	map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
	map->dm_nsegs = 0;		/* no valid mappings */
	map->dm_mapsize = 0;

	*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)
{

	free(map, M_DEVBUF);
}


int
_dmamap_load_buffer(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
    bus_size_t buflen, struct proc *p, int flags, bus_addr_t *lastaddrp,
    int *segp, int first)
{
	bus_size_t sgsize;
	bus_addr_t curaddr, lastaddr, baddr, bmask;
	vaddr_t vaddr = (vaddr_t)buf;
	pmap_t pmap;
	int seg;

	lastaddr = *lastaddrp;
	bmask = ~(map->_dm_boundary - 1);

	if (p != NULL)
		pmap = p->p_vmspace->vm_map.pmap;
	else
		pmap = pmap_kernel();

	for (seg = *segp; buflen > 0; ) {
		/*
		 * Get the physical address for this segment.
		 */
		if (pmap_extract(pmap, vaddr, (paddr_t *)&curaddr) != TRUE) {
			panic("dmamap_load_buffer pmap %p vaddr %lx "
				"pmap_extract failed", pmap, vaddr);
		}

		/*
		 * 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 the
		 * previous segment if possible.
		 */
		if (first) {
			map->dm_segs[seg].ds_addr = 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) ==
			     (curaddr & bmask)))
				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;
			}
		}

		lastaddr = curaddr + sgsize;
		vaddr += sgsize;
		buflen -= sgsize;
	}

	*segp = seg;
	*lastaddrp = lastaddr;

	/*
	 * Did we fit?
	 */
	if (buflen != 0)
		return (EFBIG);		/* XX 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
_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;
	int seg, 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;
	error = _dmamap_load_buffer(t, map, buf, buflen, p, 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
_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
    int flags)
{
	bus_addr_t lastaddr;
	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;

#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) {
		if (m->m_len == 0)
			continue;
		error = _dmamap_load_buffer(t, map, m->m_data, m->m_len,
		    NULL, flags, &lastaddr, &seg, first);
		first = 0;
	}
	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
_dmamap_load_uio(bus_dma_tag_t t, bus_dmamap_t map, struct uio *uio, int flags)
{
	bus_addr_t lastaddr;
	int seg, 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 (resid > map->_dm_size)
		return (EINVAL);

	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;
	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 = _dmamap_load_buffer(t, map, addr, minlen,
		    p, 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().
 */
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)
{
	if (nsegs > map->_dm_segcnt || size > map->_dm_size)
		return (EINVAL);

	/*
	 * Make sure we don't cross any boundaries.
	 */
	if (map->_dm_boundary) {
		bus_addr_t bmask = ~(map->_dm_boundary - 1);
		int i;

		for (i = 0; i < nsegs; i++) {
			if (segs[i].ds_len > map->_dm_maxsegsz)
				return (EINVAL);
			if ((segs[i].ds_addr & bmask) !=
			    ((segs[i].ds_addr + segs[i].ds_len - 1) & bmask))
				return (EINVAL);
		}
	}

	bcopy(segs, map->dm_segs, nsegs * sizeof(*segs));
	map->dm_nsegs = nsegs;
	map->dm_mapsize = size;
	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;
}

/*
 * 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 offset,
bus_size_t len, int op)
{
	int i;
	bus_size_t minlen, wlen;
	bus_addr_t pa, addr;
	struct vm_page *pg;

	for (i = 0; i < map->dm_nsegs && len != 0; i++) {
		/* Find the beginning segment. */
		if (offset >= map->dm_segs[i].ds_len) {
			offset -= map->dm_segs[i].ds_len;
			continue;
		}

		minlen = len < map->dm_segs[i].ds_len - offset ?
		    len : map->dm_segs[i].ds_len - offset;

		addr = map->dm_segs[i].ds_addr + offset;

		switch (op) {
		case BUS_DMASYNC_POSTWRITE:
			for (pa = trunc_page(addr), wlen = 0;
			    pa < round_page(addr + minlen);
			    pa += PAGE_SIZE) {
				pg = PHYS_TO_VM_PAGE(pa);
				if (pg != NULL)
					atomic_clearbits_int(&pg->pg_flags,
					    PG_PMAP_EXE);
			}
		}
		
	}
}

/*
 * 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, 0, 0xf0000000));
}

/*
 * 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)
{
	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
_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;
	bus_addr_t addr;
	int curseg;

	size = round_page(size);
	va = uvm_km_valloc(kernel_map, size);
	if (va == 0)
		return (ENOMEM);

	*kvap = (caddr_t)va;

	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");
			pmap_enter(pmap_kernel(), va, addr,
			    VM_PROT_READ | VM_PROT_WRITE,
			    VM_PROT_READ | VM_PROT_WRITE | PMAP_WIRED);
		}
	}
	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)
{

#ifdef DIAGNOSTIC
	if ((u_long)kva & PGOFSET)
		panic("_bus_dmamem_unmap");
#endif

	size = round_page(size);
	uvm_km_free(kernel_map, (vaddr_t)kva, size);
}

/*
 * Common functin 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;

	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 (atop(segs[i].ds_addr + off));
	}

	/* Page not found. */
	return (-1);
}

/**********************************************************************
 * DMA utility functions
 **********************************************************************/

/*
 * 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, vaddr_t low, vaddr_t high)
{
	vaddr_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.
	 */
	TAILQ_INIT(&mlist);
	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 = 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);
}