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#

# Copyright (c) 2001-2004 Jakub Jermar

# All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

#

# - Redistributions of source code must retain the above copyright

#   notice, this list of conditions and the following disclaimer.

# - 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.

# - The name of the author may not be used to endorse or promote products

#   derived from this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.

#

## very low and hardware-level functions

# Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int has no error word

# and 1 means interrupt with error word

#define ERROR_WORD_INTERRUPT_LIST 0x00027D00

.text

.global xen_callback

.global xen_failsafe_callback

.global enable_l_apic_in_msr

.global memcpy

.global memcpy_from_uspace

.global memcpy_from_uspace_failover_address

.global memcpy_to_uspace

.global memcpy_to_uspace_failover_address

xen_callback:

	iret

xen_failsafe_callback:

	iret

#define MEMCPY_DST	4

#define MEMCPY_SRC	8

#define MEMCPY_SIZE	12

/** Copy memory to/from userspace.

 *

 * This is almost conventional memcpy().

 * The difference is that there is a failover part

 * to where control is returned from a page fault

 * if the page fault occurs during copy_from_uspace()

 * or copy_to_uspace().

 *

 * @param MEMCPY_DST(%esp)	Destination address.

 * @param MEMCPY_SRC(%esp)	Source address.

 * @param MEMCPY_SIZE(%esp)	Size.

 *

 * @return MEMCPY_SRC(%esp) on success and 0 on failure.

 */

memcpy:

memcpy_from_uspace:

memcpy_to_uspace:

	movl %edi, %edx				/* save %edi */

	movl %esi, %eax				/* save %esi */

	movl MEMCPY_SIZE(%esp), %ecx

	shrl $2, %ecx				/* size / 4 */

	movl MEMCPY_DST(%esp), %edi

	movl MEMCPY_SRC(%esp), %esi

	rep movsl				/* copy as much as possible word by word */

	movl MEMCPY_SIZE(%esp), %ecx

	andl $3, %ecx				/* size % 4 */

	jz 0f

	rep movsb				/* copy the rest byte by byte */

0:

	movl %edx, %edi

	movl %eax, %esi

	movl MEMCPY_SRC(%esp), %eax		/* MEMCPY_SRC(%esp), success */

	ret

/*

 * We got here from as_page_fault() after the memory operations

 * above had caused a page fault.

 */

memcpy_from_uspace_failover_address:

memcpy_to_uspace_failover_address:

	movl %edx, %edi

	movl %eax, %esi

	xorl %eax, %eax				/* return 0, failure */

	ret

## Enable local APIC

#

# Enable local APIC in MSR.

#

enable_l_apic_in_msr:

	push %eax

	movl $0x1b, %ecx

	rdmsr

	orl $(1<<11),%eax

	orl $(0xfee00000),%eax

	wrmsr

	pop %eax

	ret