[dragonfly.git] / sys / kern / kern_xio.c

/*
 * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
 * 
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.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.
 * 3. Neither the name of The DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 * 
 * $DragonFly: src/sys/kern/kern_xio.c,v 1.16 2008/05/09 07:24:45 dillon Exp $
 */
/*
 * Kernel XIO interface.  An initialized XIO is basically a collection of
 * appropriately held vm_page_t's.  XIO buffers are vmspace agnostic and
 * can represent userspace or kernelspace buffers, and can be passed to
 * foreign threads outside of the originating vmspace.  XIO buffers are
 * not mapped into KVM and thus can be manipulated and passed around with
 * very low overheads.
 *
 * The intent is for XIO to be used in the I/O path, VFS, CAPS, and other
 * places that need to pass (possibly userspace) data between threads.
 *
 * TODO: check for busy page when modifying, check writeable.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <sys/xio.h>

#include <cpu/lwbuf.h>

#include <vm/vm.h>
#include <vm/vm_param.h>
#include <sys/lock.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_extern.h>
#include <vm/vm_page2.h>

/*
 * Just do basic initialization of an empty XIO
 */
void
xio_init(xio_t xio)
{
    xio->xio_flags = 0;
    xio->xio_bytes = 0;
    xio->xio_error = 0;
    xio->xio_offset = 0;
    xio->xio_npages = 0;
    xio->xio_pages = xio->xio_internal_pages;
}

/*
 * Initialize an XIO given a userspace buffer.  0 is returned on success,
 * an error code on failure.  The actual number of bytes that could be
 * accomodated in the XIO will be stored in xio_bytes and the page offset
 * will be stored in xio_offset.
 */
int
xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int flags)
{
    vm_offset_t addr;
    vm_page_t m;
    vm_page_t m0;
    int error;
    int i;
    int n;
    int vmprot;

    addr = trunc_page((vm_offset_t)ubase);
    xio->xio_flags = flags;
    xio->xio_bytes = 0;
    xio->xio_error = 0;
    if (ubytes == 0) {
	xio->xio_offset = 0;
	xio->xio_npages = 0;
    } else {
	vmprot = (flags & XIOF_WRITE) ? VM_PROT_WRITE : VM_PROT_READ;
	xio->xio_offset = (vm_offset_t)ubase & PAGE_MASK;
	xio->xio_pages = xio->xio_internal_pages;
	if ((n = PAGE_SIZE - xio->xio_offset) > ubytes)
	    n = ubytes;
	m0 = NULL;
	for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
	    m = vm_fault_page_quick(addr, vmprot, &error);
	    if (m == NULL)
		break;
	    xio->xio_pages[i] = m;
	    ubytes -= n;
	    xio->xio_bytes += n;
	    if ((n = ubytes) > PAGE_SIZE)
		n = PAGE_SIZE;
	    addr += PAGE_SIZE;

	    /*
	     * Check linearity, used by syslink to memory map DMA buffers.
	     */
	    if (flags & XIOF_VMLINEAR) {
		if (i == 0) {
		    m0 = m;
		} else 
		if (m->object != m0->object || m->pindex != m0->pindex + i) {
		    error = EINVAL;
		    break;
		}
	    }
	}
	xio->xio_npages = i;

	/*
	 * If a failure occured clean out what we loaded and return EFAULT.
	 * Return 0 on success.  Do not dirty the pages.
	 */
	if (i < XIO_INTERNAL_PAGES && n) {
	    xio->xio_flags &= ~XIOF_WRITE;
	    xio_release(xio);
	    xio->xio_error = EFAULT;
	}
    }
    return(xio->xio_error);
}

/*
 * Initialize an XIO given a kernelspace buffer.  0 is returned on success,
 * an error code on failure.  The actual number of bytes that could be
 * accomodated in the XIO will be stored in xio_bytes and the page offset
 * will be stored in xio_offset.
 */
int
xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes)
{
    vm_offset_t addr;
    vm_paddr_t paddr;
    vm_page_t m;
    int i;
    int n;

    addr = trunc_page((vm_offset_t)kbase);
    xio->xio_flags = 0;
    xio->xio_offset = (vm_offset_t)kbase & PAGE_MASK;
    xio->xio_bytes = 0;
    xio->xio_pages = xio->xio_internal_pages;
    xio->xio_error = 0;
    if ((n = PAGE_SIZE - xio->xio_offset) > kbytes)
	n = kbytes;
    lwkt_gettoken(&vm_token);
    crit_enter();
    for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
	if ((paddr = pmap_kextract(addr)) == 0)
	    break;
	m = PHYS_TO_VM_PAGE(paddr);
	vm_page_hold(m);
	xio->xio_pages[i] = m;
	kbytes -= n;
	xio->xio_bytes += n;
	if ((n = kbytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	addr += PAGE_SIZE;
    }
    crit_exit();
    lwkt_reltoken(&vm_token);
    xio->xio_npages = i;

    /*
     * If a failure occured clean out what we loaded and return EFAULT.
     * Return 0 on success.
     */
    if (i < XIO_INTERNAL_PAGES && n) {
	xio_release(xio);
	xio->xio_error = EFAULT;
    }
    return(xio->xio_error);
}

/*
 * Initialize an XIO given an array of vm_page pointers.  The caller is
 * responsible for any modified state changes for the pages.
 */
int
xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags)
{
    int i;

    KKASSERT(npages <= XIO_INTERNAL_PAGES);

    xio->xio_flags = xflags;
    xio->xio_offset = 0;
    xio->xio_bytes = npages * PAGE_SIZE;
    xio->xio_pages = xio->xio_internal_pages;
    xio->xio_npages = npages;
    xio->xio_error = 0;
    lwkt_gettoken(&vm_token);
    crit_enter();
    for (i = 0; i < npages; ++i) {
	vm_page_hold(mbase[i]);
	xio->xio_pages[i] = mbase[i];
    }
    crit_exit();
    lwkt_reltoken(&vm_token);
    return(0);
}

/*
 * Cleanup an XIO so it can be destroyed.  The pages associated with the
 * XIO are released.
 */
void
xio_release(xio_t xio)
{
    int i;
    vm_page_t m;

    lwkt_gettoken(&vm_token);
    crit_enter();
    for (i = 0; i < xio->xio_npages; ++i) {
	m = xio->xio_pages[i];
	if (xio->xio_flags & XIOF_WRITE)
		vm_page_dirty(m);
	vm_page_unhold(m);
    }
    crit_exit();
    lwkt_reltoken(&vm_token);
    xio->xio_offset = 0;
    xio->xio_npages = 0;
    xio->xio_bytes = 0;
    xio->xio_error = ENOBUFS;
}

/*
 * Copy data between an XIO and a UIO.  If the UIO represents userspace it
 * must be relative to the current context.
 *
 * uoffset is the abstracted starting offset in the XIO, not the actual
 * offset, and usually starts at 0.
 *
 * The XIO is not modified.  The UIO is updated to reflect the copy.
 *
 * UIO_READ	xio -> uio
 * UIO_WRITE	uio -> xio
 */
int
xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, size_t *sizep)
{
    size_t bytes;
    int error;

    bytes = xio->xio_bytes - uoffset;
    if (bytes > uio->uio_resid)
	bytes = uio->uio_resid;
    KKASSERT(bytes >= 0);
    error = uiomove_fromphys(xio->xio_pages, xio->xio_offset + uoffset, 
				bytes, uio);
    if (error == 0)
	*sizep = bytes;
    else
	*sizep = 0;
    return(error);
}

/*
 * Copy the specified number of bytes from the xio to a userland
 * buffer.  Return an error code or 0 on success.  
 *
 * uoffset is the abstracted starting offset in the XIO, not the actual
 * offset, and usually starts at 0.
 *
 * The XIO is not modified.
 */
int
xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes)
{
    int i;
    int n;
    int error;
    int offset;
    vm_page_t m;
    struct lwbuf *lwb;
    struct lwbuf lwb_cache;

    if (uoffset + bytes > xio->xio_bytes)
	return(EFAULT);

    offset = (xio->xio_offset + uoffset) & PAGE_MASK;
    if ((n = PAGE_SIZE - offset) > bytes)
	n = bytes;

    error = 0;
    for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 
	 i < xio->xio_npages; 
	 ++i
    ) {
	m = xio->xio_pages[i];
	lwb = lwbuf_alloc(m, &lwb_cache);
	error = copyout((char *)lwbuf_kva(lwb) + offset, uptr, n);
	lwbuf_free(lwb);
	if (error)
	    break;
	bytes -= n;
	uptr = (char *)uptr + n;
	if (bytes == 0)
	    break;
	if ((n = bytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	offset = 0;
    }
    return(error);
}

/*
 * Copy the specified number of bytes from the xio to a kernel
 * buffer.  Return an error code or 0 on success.
 *
 * uoffset is the abstracted starting offset in the XIO, not the actual
 * offset, and usually starts at 0.
 *
 * The XIO is not modified.
 */
int
xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes)
{
    int i;
    int n;
    int error;
    int offset;
    vm_page_t m;
    struct lwbuf *lwb;
    struct lwbuf lwb_cache;

    if (bytes + uoffset > xio->xio_bytes)
	return(EFAULT);

    offset = (xio->xio_offset + uoffset) & PAGE_MASK;
    if ((n = PAGE_SIZE - offset) > bytes)
	n = bytes;

    error = 0;
    for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 
	 i < xio->xio_npages; 
	 ++i
    ) {
	m = xio->xio_pages[i];
	lwb = lwbuf_alloc(m, &lwb_cache);
	bcopy((char *)lwbuf_kva(lwb) + offset, kptr, n);
	lwbuf_free(lwb);
	bytes -= n;
	kptr = (char *)kptr + n;
	if (bytes == 0)
	    break;
	if ((n = bytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	offset = 0;
    }
    return(error);
}

/*
 * Copy the specified number of bytes from userland to the xio.
 * Return an error code or 0 on success.  
 *
 * uoffset is the abstracted starting offset in the XIO, not the actual
 * offset, and usually starts at 0.
 *
 * Data in pages backing the XIO will be modified.
 */
int
xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes)
{
    int i;
    int n;
    int error;
    int offset;
    vm_page_t m;
    struct lwbuf *lwb;
    struct lwbuf lwb_cache;

    if (uoffset + bytes > xio->xio_bytes)
	return(EFAULT);

    offset = (xio->xio_offset + uoffset) & PAGE_MASK;
    if ((n = PAGE_SIZE - offset) > bytes)
	n = bytes;

    error = 0;
    for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 
	 i < xio->xio_npages; 
	 ++i
    ) {
	m = xio->xio_pages[i];
	lwb = lwbuf_alloc(m, &lwb_cache);
	error = copyin(uptr, (char *)lwbuf_kva(lwb) + offset, n);
	lwbuf_free(lwb);
	if (error)
	    break;
	bytes -= n;
	uptr = (const char *)uptr + n;
	if (bytes == 0)
	    break;
	if ((n = bytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	offset = 0;
    }
    return(error);
}

/*
 * Copy the specified number of bytes from the kernel to the xio.
 * Return an error code or 0 on success.  
 *
 * uoffset is the abstracted starting offset in the XIO, not the actual
 * offset, and usually starts at 0.
 *
 * Data in pages backing the XIO will be modified.
 */
int
xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes)
{
    int i;
    int n;
    int error;
    int offset;
    vm_page_t m;
    struct lwbuf *lwb;
    struct lwbuf lwb_cache;

    if (uoffset + bytes > xio->xio_bytes)
	return(EFAULT);

    offset = (xio->xio_offset + uoffset) & PAGE_MASK;
    if ((n = PAGE_SIZE - offset) > bytes)
	n = bytes;

    error = 0;
    for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 
	 i < xio->xio_npages; 
	 ++i
    ) {
	m = xio->xio_pages[i];
	lwb = lwbuf_alloc(m, &lwb_cache);
	bcopy(kptr, (char *)lwbuf_kva(lwb) + offset, n);
	lwbuf_free(lwb);
	bytes -= n;
	kptr = (const char *)kptr + n;
	if (bytes == 0)
	    break;
	if ((n = bytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	offset = 0;
    }
    return(error);
}
Commit	Line	Data
81ee925d	1	/*
8c10bfcf MD	2	* Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
	3	*
	4	* This code is derived from software contributed to The DragonFly Project
	5	* by Matthew Dillon <dillon@backplane.com>
	6	*
81ee925d MD	7	* Redistribution and use in source and binary forms, with or without
	8	* modification, are permitted provided that the following conditions
	9	* are met:
8c10bfcf	10	*
81ee925d MD	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
8c10bfcf MD	14	* notice, this list of conditions and the following disclaimer in
	15	* the documentation and/or other materials provided with the
	16	* distribution.
	17	* 3. Neither the name of The DragonFly Project nor the names of its
	18	* contributors may be used to endorse or promote products derived
	19	* from this software without specific, prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	22	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	23	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	24	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	25	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	26	* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
	27	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	28	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
	29	* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
	30	* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
	31	* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
81ee925d	32	* SUCH DAMAGE.
8c10bfcf	33	*
17cde63e	34	* $DragonFly: src/sys/kern/kern_xio.c,v 1.16 2008/05/09 07:24:45 dillon Exp $
81ee925d MD	35	*/
	36	/*
	37	* Kernel XIO interface. An initialized XIO is basically a collection of
	38	* appropriately held vm_page_t's. XIO buffers are vmspace agnostic and
	39	* can represent userspace or kernelspace buffers, and can be passed to
	40	* foreign threads outside of the originating vmspace. XIO buffers are
	41	* not mapped into KVM and thus can be manipulated and passed around with
	42	* very low overheads.
	43	*
	44	* The intent is for XIO to be used in the I/O path, VFS, CAPS, and other
	45	* places that need to pass (possibly userspace) data between threads.
	46	*
	47	* TODO: check for busy page when modifying, check writeable.
	48	*/
	49
	50	#include <sys/param.h>
	51	#include <sys/systm.h>
	52	#include <sys/malloc.h>
	53	#include <sys/proc.h>
	54	#include <sys/vmmeter.h>
	55	#include <sys/vnode.h>
	56	#include <sys/xio.h>
5c5185ae SG	57
5c5185ae SG	58	#include <cpu/lwbuf.h>
81ee925d MD	59
	60	#include <vm/vm.h>
	61	#include <vm/vm_param.h>
	62	#include <sys/lock.h>
	63	#include <vm/vm_kern.h>
	64	#include <vm/pmap.h>
	65	#include <vm/vm_map.h>
	66	#include <vm/vm_object.h>
	67	#include <vm/vm_page.h>
	68	#include <vm/vm_pageout.h>
	69	#include <vm/vm_pager.h>
	70	#include <vm/vm_extern.h>
	71	#include <vm/vm_page2.h>
	72
d6a46bb7 MD	73	/*
	74	* Just do basic initialization of an empty XIO
	75	*/
	76	void
	77	xio_init(xio_t xio)
	78	{
	79	xio->xio_flags = 0;
	80	xio->xio_bytes = 0;
	81	xio->xio_error = 0;
	82	xio->xio_offset = 0;
	83	xio->xio_npages = 0;
	84	xio->xio_pages = xio->xio_internal_pages;
	85	}
	86
81ee925d MD	87	/*
	88	* Initialize an XIO given a userspace buffer. 0 is returned on success,
	89	* an error code on failure. The actual number of bytes that could be
03aa69bd MD	90	* accomodated in the XIO will be stored in xio_bytes and the page offset
03aa69bd MD	91	* will be stored in xio_offset.
81ee925d MD	92	*/
	93	int
	94	xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int flags)
	95	{
	96	vm_offset_t addr;
81ee925d	97	vm_page_t m;
c4734fe7	98	vm_page_t m0;
06c5a8d6	99	int error;
81ee925d MD	100	int i;
	101	int n;
	102	int vmprot;
	103
	104	addr = trunc_page((vm_offset_t)ubase);
	105	xio->xio_flags = flags;
	106	xio->xio_bytes = 0;
	107	xio->xio_error = 0;
	108	if (ubytes == 0) {
	109	xio->xio_offset = 0;
	110	xio->xio_npages = 0;
	111	} else {
	112	vmprot = (flags & XIOF_WRITE) ? VM_PROT_WRITE : VM_PROT_READ;
	113	xio->xio_offset = (vm_offset_t)ubase & PAGE_MASK;
	114	xio->xio_pages = xio->xio_internal_pages;
	115	if ((n = PAGE_SIZE - xio->xio_offset) > ubytes)
	116	n = ubytes;
c4734fe7	117	m0 = NULL;
81ee925d	118	for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
06c5a8d6 MD	119	m = vm_fault_page_quick(addr, vmprot, &error);
06c5a8d6 MD	120	if (m == NULL)
81ee925d	121	break;
81ee925d MD	122	xio->xio_pages[i] = m;
	123	ubytes -= n;
	124	xio->xio_bytes += n;
	125	if ((n = ubytes) > PAGE_SIZE)
	126	n = PAGE_SIZE;
	127	addr += PAGE_SIZE;
c4734fe7 MD	128
	129	/*
	130	* Check linearity, used by syslink to memory map DMA buffers.
	131	*/
	132	if (flags & XIOF_VMLINEAR) {
	133	if (i == 0) {
	134	m0 = m;
	135	} else
	136	if (m->object != m0->object \|\| m->pindex != m0->pindex + i) {
	137	error = EINVAL;
	138	break;
	139	}
	140	}
81ee925d MD	141	}
	142	xio->xio_npages = i;
	143
	144	/*
	145	* If a failure occured clean out what we loaded and return EFAULT.
17cde63e	146	* Return 0 on success. Do not dirty the pages.
81ee925d MD	147	*/
81ee925d MD	148	if (i < XIO_INTERNAL_PAGES && n) {
17cde63e	149	xio->xio_flags &= ~XIOF_WRITE;
81ee925d MD	150	xio_release(xio);
	151	xio->xio_error = EFAULT;
	152	}
	153	}
	154	return(xio->xio_error);
	155	}
	156
	157	/*
	158	* Initialize an XIO given a kernelspace buffer. 0 is returned on success,
	159	* an error code on failure. The actual number of bytes that could be
03aa69bd MD	160	* accomodated in the XIO will be stored in xio_bytes and the page offset
03aa69bd MD	161	* will be stored in xio_offset.
81ee925d MD	162	*/
	163	int
	164	xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes)
	165	{
	166	vm_offset_t addr;
	167	vm_paddr_t paddr;
	168	vm_page_t m;
	169	int i;
	170	int n;
	171
	172	addr = trunc_page((vm_offset_t)kbase);
	173	xio->xio_flags = 0;
	174	xio->xio_offset = (vm_offset_t)kbase & PAGE_MASK;
	175	xio->xio_bytes = 0;
	176	xio->xio_pages = xio->xio_internal_pages;
	177	xio->xio_error = 0;
	178	if ((n = PAGE_SIZE - xio->xio_offset) > kbytes)
	179	n = kbytes;
573fb415 MD	180	lwkt_gettoken(&vm_token);
573fb415 MD	181	crit_enter();
81ee925d MD	182	for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
	183	if ((paddr = pmap_kextract(addr)) == 0)
	184	break;
	185	m = PHYS_TO_VM_PAGE(paddr);
	186	vm_page_hold(m);
	187	xio->xio_pages[i] = m;
	188	kbytes -= n;
	189	xio->xio_bytes += n;
	190	if ((n = kbytes) > PAGE_SIZE)
	191	n = PAGE_SIZE;
	192	addr += PAGE_SIZE;
	193	}
573fb415 MD	194	crit_exit();
573fb415 MD	195	lwkt_reltoken(&vm_token);
81ee925d MD	196	xio->xio_npages = i;
	197
	198	/*
	199	* If a failure occured clean out what we loaded and return EFAULT.
	200	* Return 0 on success.
	201	*/
	202	if (i < XIO_INTERNAL_PAGES && n) {
	203	xio_release(xio);
	204	xio->xio_error = EFAULT;
	205	}
	206	return(xio->xio_error);
	207	}
	208
83269e7d	209	/*
17cde63e MD	210	* Initialize an XIO given an array of vm_page pointers. The caller is
17cde63e MD	211	* responsible for any modified state changes for the pages.
83269e7d MD	212	*/
	213	int
	214	xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags)
	215	{
	216	int i;
	217
	218	KKASSERT(npages <= XIO_INTERNAL_PAGES);
	219
	220	xio->xio_flags = xflags;
	221	xio->xio_offset = 0;
255b6068	222	xio->xio_bytes = npages * PAGE_SIZE;
83269e7d MD	223	xio->xio_pages = xio->xio_internal_pages;
	224	xio->xio_npages = npages;
	225	xio->xio_error = 0;
573fb415	226	lwkt_gettoken(&vm_token);
83269e7d MD	227	crit_enter();
	228	for (i = 0; i < npages; ++i) {
	229	vm_page_hold(mbase[i]);
	230	xio->xio_pages[i] = mbase[i];
	231	}
	232	crit_exit();
573fb415	233	lwkt_reltoken(&vm_token);
83269e7d MD	234	return(0);
	235	}
	236
06ecca5a MD	237	/*
06ecca5a MD	238	* Cleanup an XIO so it can be destroyed. The pages associated with the
03aa69bd	239	* XIO are released.
06ecca5a	240	*/
81ee925d MD	241	void
	242	xio_release(xio_t xio)
	243	{
	244	int i;
	245	vm_page_t m;
	246
573fb415	247	lwkt_gettoken(&vm_token);
e43a034f	248	crit_enter();
81ee925d MD	249	for (i = 0; i < xio->xio_npages; ++i) {
81ee925d MD	250	m = xio->xio_pages[i];
17cde63e MD	251	if (xio->xio_flags & XIOF_WRITE)
17cde63e MD	252	vm_page_dirty(m);
81ee925d MD	253	vm_page_unhold(m);
81ee925d MD	254	}
e43a034f	255	crit_exit();
573fb415	256	lwkt_reltoken(&vm_token);
81ee925d MD	257	xio->xio_offset = 0;
	258	xio->xio_npages = 0;
	259	xio->xio_bytes = 0;
	260	xio->xio_error = ENOBUFS;
	261	}
	262
	263	/*
	264	* Copy data between an XIO and a UIO. If the UIO represents userspace it
03aa69bd MD	265	* must be relative to the current context.
	266	*
	267	* uoffset is the abstracted starting offset in the XIO, not the actual
	268	* offset, and usually starts at 0.
	269	*
	270	* The XIO is not modified. The UIO is updated to reflect the copy.
81ee925d MD	271	*
	272	* UIO_READ xio -> uio
	273	* UIO_WRITE uio -> xio
	274	*/
	275	int
e54488bb	276	xio_uio_copy(xio_t xio, int uoffset, struct uio uio, size_t sizep)
81ee925d	277	{
e54488bb	278	size_t bytes;
81ee925d	279	int error;
81ee925d	280
03aa69bd MD	281	bytes = xio->xio_bytes - uoffset;
03aa69bd MD	282	if (bytes > uio->uio_resid)
81ee925d	283	bytes = uio->uio_resid;
03aa69bd MD	284	KKASSERT(bytes >= 0);
	285	error = uiomove_fromphys(xio->xio_pages, xio->xio_offset + uoffset,
	286	bytes, uio);
	287	if (error == 0)
81ee925d	288	*sizep = bytes;
03aa69bd	289	else
81ee925d	290	*sizep = 0;
81ee925d MD	291	return(error);
	292	}
	293
	294	/*
	295	* Copy the specified number of bytes from the xio to a userland
03aa69bd	296	* buffer. Return an error code or 0 on success.
81ee925d	297	*
03aa69bd MD	298	* uoffset is the abstracted starting offset in the XIO, not the actual
	299	* offset, and usually starts at 0.
	300	*
	301	* The XIO is not modified.
81ee925d MD	302	*/
81ee925d MD	303	int
03aa69bd	304	xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes)
81ee925d MD	305	{
	306	int i;
	307	int n;
	308	int error;
	309	int offset;
	310	vm_page_t m;
5c5185ae	311	struct lwbuf *lwb;
7a683a24	312	struct lwbuf lwb_cache;
81ee925d	313
0a7648b9	314	if (uoffset + bytes > xio->xio_bytes)
81ee925d MD	315	return(EFAULT);
81ee925d MD	316
03aa69bd	317	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
82f4c82a	318	if ((n = PAGE_SIZE - offset) > bytes)
81ee925d MD	319	n = bytes;
	320
	321	error = 0;
03aa69bd MD	322	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	323	i < xio->xio_npages;
	324	++i
	325	) {
81ee925d	326	m = xio->xio_pages[i];
7a683a24	327	lwb = lwbuf_alloc(m, &lwb_cache);
5c5185ae SG	328	error = copyout((char *)lwbuf_kva(lwb) + offset, uptr, n);
5c5185ae SG	329	lwbuf_free(lwb);
81ee925d MD	330	if (error)
	331	break;
	332	bytes -= n;
81ee925d MD	333	uptr = (char *)uptr + n;
	334	if (bytes == 0)
	335	break;
	336	if ((n = bytes) > PAGE_SIZE)
	337	n = PAGE_SIZE;
	338	offset = 0;
	339	}
	340	return(error);
	341	}
	342
	343	/*
	344	* Copy the specified number of bytes from the xio to a kernel
	345	* buffer. Return an error code or 0 on success.
	346	*
03aa69bd MD	347	* uoffset is the abstracted starting offset in the XIO, not the actual
	348	* offset, and usually starts at 0.
	349	*
	350	* The XIO is not modified.
81ee925d MD	351	*/
81ee925d MD	352	int
03aa69bd	353	xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes)
81ee925d MD	354	{
	355	int i;
	356	int n;
	357	int error;
	358	int offset;
	359	vm_page_t m;
5c5185ae	360	struct lwbuf *lwb;
7a683a24	361	struct lwbuf lwb_cache;
81ee925d	362
03aa69bd	363	if (bytes + uoffset > xio->xio_bytes)
81ee925d MD	364	return(EFAULT);
81ee925d MD	365
03aa69bd	366	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
82f4c82a	367	if ((n = PAGE_SIZE - offset) > bytes)
81ee925d MD	368	n = bytes;
	369
	370	error = 0;
03aa69bd MD	371	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	372	i < xio->xio_npages;
	373	++i
	374	) {
81ee925d	375	m = xio->xio_pages[i];
7a683a24	376	lwb = lwbuf_alloc(m, &lwb_cache);
5c5185ae SG	377	bcopy((char *)lwbuf_kva(lwb) + offset, kptr, n);
5c5185ae SG	378	lwbuf_free(lwb);
81ee925d	379	bytes -= n;
81ee925d MD	380	kptr = (char *)kptr + n;
	381	if (bytes == 0)
	382	break;
	383	if ((n = bytes) > PAGE_SIZE)
	384	n = PAGE_SIZE;
	385	offset = 0;
	386	}
	387	return(error);
	388	}
	389
0a7648b9 MD	390	/*
	391	* Copy the specified number of bytes from userland to the xio.
	392	* Return an error code or 0 on success.
	393	*
	394	* uoffset is the abstracted starting offset in the XIO, not the actual
	395	* offset, and usually starts at 0.
	396	*
	397	* Data in pages backing the XIO will be modified.
	398	*/
	399	int
	400	xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes)
	401	{
	402	int i;
	403	int n;
	404	int error;
	405	int offset;
	406	vm_page_t m;
5c5185ae	407	struct lwbuf *lwb;
7a683a24	408	struct lwbuf lwb_cache;
0a7648b9 MD	409
	410	if (uoffset + bytes > xio->xio_bytes)
	411	return(EFAULT);
	412
	413	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
	414	if ((n = PAGE_SIZE - offset) > bytes)
	415	n = bytes;
	416
	417	error = 0;
	418	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	419	i < xio->xio_npages;
	420	++i
	421	) {
	422	m = xio->xio_pages[i];
7a683a24	423	lwb = lwbuf_alloc(m, &lwb_cache);
5c5185ae SG	424	error = copyin(uptr, (char *)lwbuf_kva(lwb) + offset, n);
5c5185ae SG	425	lwbuf_free(lwb);
0a7648b9 MD	426	if (error)
	427	break;
	428	bytes -= n;
	429	uptr = (const char *)uptr + n;
	430	if (bytes == 0)
	431	break;
	432	if ((n = bytes) > PAGE_SIZE)
	433	n = PAGE_SIZE;
	434	offset = 0;
	435	}
	436	return(error);
	437	}
	438
	439	/*
	440	* Copy the specified number of bytes from the kernel to the xio.
	441	* Return an error code or 0 on success.
	442	*
	443	* uoffset is the abstracted starting offset in the XIO, not the actual
	444	* offset, and usually starts at 0.
	445	*
	446	* Data in pages backing the XIO will be modified.
	447	*/
	448	int
	449	xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes)
	450	{
	451	int i;
	452	int n;
	453	int error;
	454	int offset;
	455	vm_page_t m;
5c5185ae	456	struct lwbuf *lwb;
7a683a24	457	struct lwbuf lwb_cache;
0a7648b9 MD	458
	459	if (uoffset + bytes > xio->xio_bytes)
	460	return(EFAULT);
	461
	462	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
	463	if ((n = PAGE_SIZE - offset) > bytes)
	464	n = bytes;
	465
	466	error = 0;
	467	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	468	i < xio->xio_npages;
	469	++i
	470	) {
	471	m = xio->xio_pages[i];
7a683a24	472	lwb = lwbuf_alloc(m, &lwb_cache);
5c5185ae SG	473	bcopy(kptr, (char *)lwbuf_kva(lwb) + offset, n);
5c5185ae SG	474	lwbuf_free(lwb);
0a7648b9 MD	475	bytes -= n;
	476	kptr = (const char *)kptr + n;
	477	if (bytes == 0)
	478	break;
	479	if ((n = bytes) > PAGE_SIZE)
	480	n = PAGE_SIZE;
	481	offset = 0;
	482	}
	483	return(error);
	484	}