[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 <sys/sfbuf.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;
    for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
	if ((paddr = pmap_kextract(addr)) == 0)
	    break;
	crit_enter();
	m = PHYS_TO_VM_PAGE(paddr);
	vm_page_hold(m);
	crit_exit();
	xio->xio_pages[i] = m;
	kbytes -= n;
	xio->xio_bytes += n;
	if ((n = kbytes) > PAGE_SIZE)
	    n = PAGE_SIZE;
	addr += PAGE_SIZE;
    }
    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 = 0;
    xio->xio_pages = xio->xio_internal_pages;
    xio->xio_npages = npages;
    xio->xio_error = 0;
    crit_enter();
    for (i = 0; i < npages; ++i) {
	vm_page_hold(mbase[i]);
	xio->xio_pages[i] = mbase[i];
    }
    crit_exit();
    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;

    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();
    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 sf_buf *sf;

    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];
	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	error = copyout((char *)sf_buf_kva(sf) + offset, uptr, n);
	sf_buf_free(sf);
	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 sf_buf *sf;

    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];
	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	bcopy((char *)sf_buf_kva(sf) + offset, kptr, n);
	sf_buf_free(sf);
	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 sf_buf *sf;

    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];
	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	error = copyin(uptr, (char *)sf_buf_kva(sf) + offset, n);
	sf_buf_free(sf);
	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 sf_buf *sf;

    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];
	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	bcopy(kptr, (char *)sf_buf_kva(sf) + offset, n);
	sf_buf_free(sf);
	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>
	57	#include <sys/sfbuf.h>
	58
	59	#include <vm/vm.h>
	60	#include <vm/vm_param.h>
	61	#include <sys/lock.h>
	62	#include <vm/vm_kern.h>
	63	#include <vm/pmap.h>
	64	#include <vm/vm_map.h>
	65	#include <vm/vm_object.h>
	66	#include <vm/vm_page.h>
	67	#include <vm/vm_pageout.h>
	68	#include <vm/vm_pager.h>
	69	#include <vm/vm_extern.h>
	70	#include <vm/vm_page2.h>
	71
	72	/*
d6a46bb7 MD	73	* Just do basic initialization of an empty XIO
	74	*/
	75	void
	76	xio_init(xio_t xio)
	77	{
	78	xio->xio_flags = 0;
	79	xio->xio_bytes = 0;
	80	xio->xio_error = 0;
	81	xio->xio_offset = 0;
	82	xio->xio_npages = 0;
	83	xio->xio_pages = xio->xio_internal_pages;
	84	}
	85
	86	/*
81ee925d MD	87	* Initialize an XIO given a userspace buffer. 0 is returned on success,
81ee925d MD	88	* an error code on failure. The actual number of bytes that could be
03aa69bd MD	89	* accomodated in the XIO will be stored in xio_bytes and the page offset
03aa69bd MD	90	* will be stored in xio_offset.
81ee925d MD	91	*/
	92	int
	93	xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int flags)
	94	{
	95	vm_offset_t addr;
81ee925d	96	vm_page_t m;
c4734fe7	97	vm_page_t m0;
06c5a8d6	98	int error;
81ee925d MD	99	int i;
	100	int n;
	101	int vmprot;
	102
	103	addr = trunc_page((vm_offset_t)ubase);
	104	xio->xio_flags = flags;
	105	xio->xio_bytes = 0;
	106	xio->xio_error = 0;
	107	if (ubytes == 0) {
	108	xio->xio_offset = 0;
	109	xio->xio_npages = 0;
	110	} else {
	111	vmprot = (flags & XIOF_WRITE) ? VM_PROT_WRITE : VM_PROT_READ;
	112	xio->xio_offset = (vm_offset_t)ubase & PAGE_MASK;
	113	xio->xio_pages = xio->xio_internal_pages;
	114	if ((n = PAGE_SIZE - xio->xio_offset) > ubytes)
	115	n = ubytes;
c4734fe7	116	m0 = NULL;
81ee925d	117	for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
06c5a8d6 MD	118	m = vm_fault_page_quick(addr, vmprot, &error);
06c5a8d6 MD	119	if (m == NULL)
81ee925d	120	break;
81ee925d MD	121	xio->xio_pages[i] = m;
	122	ubytes -= n;
	123	xio->xio_bytes += n;
	124	if ((n = ubytes) > PAGE_SIZE)
	125	n = PAGE_SIZE;
	126	addr += PAGE_SIZE;
c4734fe7 MD	127
	128	/*
	129	* Check linearity, used by syslink to memory map DMA buffers.
	130	*/
	131	if (flags & XIOF_VMLINEAR) {
	132	if (i == 0) {
	133	m0 = m;
	134	} else
	135	if (m->object != m0->object \|\| m->pindex != m0->pindex + i) {
	136	error = EINVAL;
	137	break;
	138	}
	139	}
81ee925d MD	140	}
	141	xio->xio_npages = i;
	142
	143	/*
	144	* If a failure occured clean out what we loaded and return EFAULT.
17cde63e	145	* Return 0 on success. Do not dirty the pages.
81ee925d MD	146	*/
81ee925d MD	147	if (i < XIO_INTERNAL_PAGES && n) {
17cde63e	148	xio->xio_flags &= ~XIOF_WRITE;
81ee925d MD	149	xio_release(xio);
	150	xio->xio_error = EFAULT;
	151	}
	152	}
	153	return(xio->xio_error);
	154	}
	155
	156	/*
	157	* Initialize an XIO given a kernelspace buffer. 0 is returned on success,
	158	* an error code on failure. The actual number of bytes that could be
03aa69bd MD	159	* accomodated in the XIO will be stored in xio_bytes and the page offset
03aa69bd MD	160	* will be stored in xio_offset.
81ee925d MD	161	*/
	162	int
	163	xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes)
	164	{
	165	vm_offset_t addr;
	166	vm_paddr_t paddr;
	167	vm_page_t m;
	168	int i;
	169	int n;
	170
	171	addr = trunc_page((vm_offset_t)kbase);
	172	xio->xio_flags = 0;
	173	xio->xio_offset = (vm_offset_t)kbase & PAGE_MASK;
	174	xio->xio_bytes = 0;
	175	xio->xio_pages = xio->xio_internal_pages;
	176	xio->xio_error = 0;
	177	if ((n = PAGE_SIZE - xio->xio_offset) > kbytes)
	178	n = kbytes;
	179	for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) {
	180	if ((paddr = pmap_kextract(addr)) == 0)
	181	break;
e43a034f	182	crit_enter();
81ee925d MD	183	m = PHYS_TO_VM_PAGE(paddr);
81ee925d MD	184	vm_page_hold(m);
e43a034f	185	crit_exit();
81ee925d MD	186	xio->xio_pages[i] = m;
	187	kbytes -= n;
	188	xio->xio_bytes += n;
	189	if ((n = kbytes) > PAGE_SIZE)
	190	n = PAGE_SIZE;
	191	addr += PAGE_SIZE;
	192	}
	193	xio->xio_npages = i;
	194
	195	/*
	196	* If a failure occured clean out what we loaded and return EFAULT.
	197	* Return 0 on success.
	198	*/
	199	if (i < XIO_INTERNAL_PAGES && n) {
	200	xio_release(xio);
	201	xio->xio_error = EFAULT;
	202	}
	203	return(xio->xio_error);
	204	}
	205
06ecca5a	206	/*
17cde63e MD	207	* Initialize an XIO given an array of vm_page pointers. The caller is
17cde63e MD	208	* responsible for any modified state changes for the pages.
83269e7d MD	209	*/
	210	int
	211	xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags)
	212	{
	213	int i;
	214
	215	KKASSERT(npages <= XIO_INTERNAL_PAGES);
	216
	217	xio->xio_flags = xflags;
	218	xio->xio_offset = 0;
	219	xio->xio_bytes = 0;
	220	xio->xio_pages = xio->xio_internal_pages;
	221	xio->xio_npages = npages;
	222	xio->xio_error = 0;
	223	crit_enter();
	224	for (i = 0; i < npages; ++i) {
	225	vm_page_hold(mbase[i]);
	226	xio->xio_pages[i] = mbase[i];
	227	}
	228	crit_exit();
	229	return(0);
	230	}
	231
	232	/*
06ecca5a	233	* Cleanup an XIO so it can be destroyed. The pages associated with the
03aa69bd	234	* XIO are released.
06ecca5a	235	*/
81ee925d MD	236	void
	237	xio_release(xio_t xio)
	238	{
	239	int i;
	240	vm_page_t m;
	241
e43a034f	242	crit_enter();
81ee925d MD	243	for (i = 0; i < xio->xio_npages; ++i) {
81ee925d MD	244	m = xio->xio_pages[i];
17cde63e MD	245	if (xio->xio_flags & XIOF_WRITE)
17cde63e MD	246	vm_page_dirty(m);
81ee925d MD	247	vm_page_unhold(m);
81ee925d MD	248	}
e43a034f	249	crit_exit();
81ee925d MD	250	xio->xio_offset = 0;
	251	xio->xio_npages = 0;
	252	xio->xio_bytes = 0;
	253	xio->xio_error = ENOBUFS;
	254	}
	255
	256	/*
	257	* Copy data between an XIO and a UIO. If the UIO represents userspace it
03aa69bd MD	258	* must be relative to the current context.
	259	*
	260	* uoffset is the abstracted starting offset in the XIO, not the actual
	261	* offset, and usually starts at 0.
	262	*
	263	* The XIO is not modified. The UIO is updated to reflect the copy.
81ee925d MD	264	*
	265	* UIO_READ xio -> uio
	266	* UIO_WRITE uio -> xio
	267	*/
	268	int
e54488bb	269	xio_uio_copy(xio_t xio, int uoffset, struct uio uio, size_t sizep)
81ee925d	270	{
e54488bb	271	size_t bytes;
81ee925d	272	int error;
81ee925d	273
03aa69bd MD	274	bytes = xio->xio_bytes - uoffset;
03aa69bd MD	275	if (bytes > uio->uio_resid)
81ee925d	276	bytes = uio->uio_resid;
03aa69bd MD	277	KKASSERT(bytes >= 0);
	278	error = uiomove_fromphys(xio->xio_pages, xio->xio_offset + uoffset,
	279	bytes, uio);
	280	if (error == 0)
81ee925d	281	*sizep = bytes;
03aa69bd	282	else
81ee925d	283	*sizep = 0;
81ee925d MD	284	return(error);
	285	}
	286
	287	/*
	288	* Copy the specified number of bytes from the xio to a userland
03aa69bd	289	* buffer. Return an error code or 0 on success.
81ee925d	290	*
03aa69bd MD	291	* uoffset is the abstracted starting offset in the XIO, not the actual
	292	* offset, and usually starts at 0.
	293	*
	294	* The XIO is not modified.
81ee925d MD	295	*/
81ee925d MD	296	int
03aa69bd	297	xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes)
81ee925d MD	298	{
	299	int i;
	300	int n;
	301	int error;
	302	int offset;
	303	vm_page_t m;
	304	struct sf_buf *sf;
	305
0a7648b9	306	if (uoffset + bytes > xio->xio_bytes)
81ee925d MD	307	return(EFAULT);
81ee925d MD	308
03aa69bd	309	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
82f4c82a	310	if ((n = PAGE_SIZE - offset) > bytes)
81ee925d MD	311	n = bytes;
	312
	313	error = 0;
03aa69bd MD	314	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	315	i < xio->xio_npages;
	316	++i
	317	) {
81ee925d	318	m = xio->xio_pages[i];
4f1640d6	319	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
81ee925d	320	error = copyout((char *)sf_buf_kva(sf) + offset, uptr, n);
5ed411ff	321	sf_buf_free(sf);
81ee925d MD	322	if (error)
	323	break;
	324	bytes -= n;
81ee925d MD	325	uptr = (char *)uptr + n;
	326	if (bytes == 0)
	327	break;
	328	if ((n = bytes) > PAGE_SIZE)
	329	n = PAGE_SIZE;
	330	offset = 0;
	331	}
	332	return(error);
	333	}
	334
	335	/*
	336	* Copy the specified number of bytes from the xio to a kernel
	337	* buffer. Return an error code or 0 on success.
	338	*
03aa69bd MD	339	* uoffset is the abstracted starting offset in the XIO, not the actual
	340	* offset, and usually starts at 0.
	341	*
	342	* The XIO is not modified.
81ee925d MD	343	*/
81ee925d MD	344	int
03aa69bd	345	xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes)
81ee925d MD	346	{
	347	int i;
	348	int n;
	349	int error;
	350	int offset;
	351	vm_page_t m;
	352	struct sf_buf *sf;
	353
03aa69bd	354	if (bytes + uoffset > xio->xio_bytes)
81ee925d MD	355	return(EFAULT);
81ee925d MD	356
03aa69bd	357	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
82f4c82a	358	if ((n = PAGE_SIZE - offset) > bytes)
81ee925d MD	359	n = bytes;
	360
	361	error = 0;
03aa69bd MD	362	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	363	i < xio->xio_npages;
	364	++i
	365	) {
81ee925d	366	m = xio->xio_pages[i];
4f1640d6	367	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
81ee925d	368	bcopy((char *)sf_buf_kva(sf) + offset, kptr, n);
5ed411ff	369	sf_buf_free(sf);
81ee925d	370	bytes -= n;
81ee925d MD	371	kptr = (char *)kptr + n;
	372	if (bytes == 0)
	373	break;
	374	if ((n = bytes) > PAGE_SIZE)
	375	n = PAGE_SIZE;
	376	offset = 0;
	377	}
	378	return(error);
	379	}
	380
0a7648b9 MD	381	/*
	382	* Copy the specified number of bytes from userland to the xio.
	383	* Return an error code or 0 on success.
	384	*
	385	* uoffset is the abstracted starting offset in the XIO, not the actual
	386	* offset, and usually starts at 0.
	387	*
	388	* Data in pages backing the XIO will be modified.
	389	*/
	390	int
	391	xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes)
	392	{
	393	int i;
	394	int n;
	395	int error;
	396	int offset;
	397	vm_page_t m;
	398	struct sf_buf *sf;
	399
	400	if (uoffset + bytes > xio->xio_bytes)
	401	return(EFAULT);
	402
	403	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
	404	if ((n = PAGE_SIZE - offset) > bytes)
	405	n = bytes;
	406
	407	error = 0;
	408	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
	409	i < xio->xio_npages;
	410	++i
	411	) {
	412	m = xio->xio_pages[i];
	413	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
	414	error = copyin(uptr, (char *)sf_buf_kva(sf) + offset, n);
	415	sf_buf_free(sf);
	416	if (error)
	417	break;
	418	bytes -= n;
	419	uptr = (const char *)uptr + n;
	420	if (bytes == 0)
	421	break;
	422	if ((n = bytes) > PAGE_SIZE)
	423	n = PAGE_SIZE;
	424	offset = 0;
	425	}
	426	return(error);
	427	}
	428
	429	/*
	430	* Copy the specified number of bytes from the kernel to the xio.
	431	* Return an error code or 0 on success.
	432	*
	433	* uoffset is the abstracted starting offset in the XIO, not the actual
	434	* offset, and usually starts at 0.
	435	*
	436	* Data in pages backing the XIO will be modified.
	437	*/
	438	int
	439	xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes)
	440	{
	441	int i;
	442	int n;
	443	int error;
	444	int offset;
445	vm_page_t m;
446	struct sf_buf *sf;
447
448	if (uoffset + bytes > xio->xio_bytes)
449	return(EFAULT);
450
451	offset = (xio->xio_offset + uoffset) & PAGE_MASK;
452	if ((n = PAGE_SIZE - offset) > bytes)
453	n = bytes;
454
455	error = 0;
456	for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT;
457	i < xio->xio_npages;
458	++i
459	) {
460	m = xio->xio_pages[i];
461	sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
462	bcopy(kptr, (char *)sf_buf_kva(sf) + offset, n);
463	sf_buf_free(sf);
464	bytes -= n;
465	kptr = (const char *)kptr + n;
466	if (bytes == 0)
467	break;
468	if ((n = bytes) > PAGE_SIZE)
469	n = PAGE_SIZE;
470	offset = 0;
471	}
472	return(error);
473	}