#
# Copyright (C) 2005 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.
#

#include <arch/arch.h>
#include <arch/stack.h>
#include <arch/regdef.h>
#include <arch/mm/mmu.h>

.text

.register       %g2, #scratch
.register       %g3, #scratch

/*
 * This is the assembly language version of our _memcpy() generated by gcc.
 */
.global memcpy
memcpy:
	add	%o1, 7, %g1
	and	%g1, -8, %g1
	cmp	%o1, %g1
	be,pn	%xcc, 3f
	add	%o0, 7, %g1
	mov	0, %g3
0:
	brz,pn	%o2, 2f
	mov	0, %g2
1:
	ldub	[%g3 + %o1], %g1
	add	%g2, 1, %g2
	cmp	%o2, %g2
	stb	%g1, [%g3 + %o0]
	bne,pt	%xcc, 1b
	mov	%g2, %g3
2:
	jmp	%o7 + 8			! exit point
	mov	%o1, %o0
3:
	and	%g1, -8, %g1
	cmp	%o0, %g1
	bne,pt	%xcc, 0b
	mov	0, %g3
	srlx	%o2, 3, %g4
	brz,pn	%g4, 5f
	mov	0, %g5
4:
	sllx	%g3, 3, %g2
	add	%g5, 1, %g3
	ldx	[%o1 + %g2], %g1
	mov	%g3, %g5
	cmp	%g4, %g3
	bne,pt	%xcc, 4b
	stx	%g1, [%o0 + %g2]
5:
	and	%o2, 7, %o2
	brz,pn	%o2, 2b
	sllx	%g4, 3, %g1
	mov	0, %g2
	add	%g1, %o0, %o0
	add	%g1, %o1, %g4
	mov	0, %g3
6:
	ldub	[%g2 + %g4], %g1
	stb	%g1, [%g2 + %o0]
	add	%g3, 1, %g2
	cmp	%o2, %g2
	bne,pt	%xcc, 6b
	mov	%g2, %g3

	jmp	%o7 + 8			! exit point
	mov	%o1, %o0

/*
 * Almost the same as memcpy() except the loads are from userspace.
 */
.global memcpy_from_uspace
memcpy_from_uspace:
	add	%o1, 7, %g1
	and	%g1, -8, %g1
	cmp	%o1, %g1
	be,pn	%xcc, 3f
	add	%o0, 7, %g1
	mov	0, %g3
0:
	brz,pn	%o2, 2f
	mov	0, %g2
1:
	lduba	[%g3 + %o1] ASI_AIUS, %g1
	add	%g2, 1, %g2
	cmp	%o2, %g2
	stb	%g1, [%g3 + %o0]
	bne,pt	%xcc, 1b
	mov	%g2, %g3
2:
	jmp	%o7 + 8			! exit point
	mov	%o1, %o0
3:
	and	%g1, -8, %g1
	cmp	%o0, %g1
	bne,pt	%xcc, 0b
	mov	0, %g3
	srlx	%o2, 3, %g4
	brz,pn	%g4, 5f
	mov	0, %g5
4:
	sllx	%g3, 3, %g2
	add	%g5, 1, %g3
	ldxa	[%o1 + %g2] ASI_AIUS, %g1
	mov	%g3, %g5
	cmp	%g4, %g3
	bne,pt	%xcc, 4b
	stx	%g1, [%o0 + %g2]
5:
	and	%o2, 7, %o2
	brz,pn	%o2, 2b
	sllx	%g4, 3, %g1
	mov	0, %g2
	add	%g1, %o0, %o0
	add	%g1, %o1, %g4
	mov	0, %g3
6:
	lduba	[%g2 + %g4] ASI_AIUS, %g1
	stb	%g1, [%g2 + %o0]
	add	%g3, 1, %g2
	cmp	%o2, %g2
	bne,pt	%xcc, 6b
	mov	%g2, %g3

	jmp	%o7 + 8			! exit point
	mov	%o1, %o0

/*
 * Almost the same as memcpy() except the stores are to userspace.
 */
.global memcpy_to_uspace
memcpy_to_uspace:
	add	%o1, 7, %g1
	and	%g1, -8, %g1
	cmp	%o1, %g1
	be,pn	%xcc, 3f
	add	%o0, 7, %g1
	mov	0, %g3
0:
	brz,pn	%o2, 2f
	mov	0, %g2
1:
	ldub	[%g3 + %o1], %g1
	add	%g2, 1, %g2
	cmp	%o2, %g2
	stba	%g1, [%g3 + %o0] ASI_AIUS
	bne,pt	%xcc, 1b
	mov	%g2, %g3
2:
	jmp	%o7 + 8			! exit point
	mov	%o1, %o0
3:
	and	%g1, -8, %g1
	cmp	%o0, %g1
	bne,pt	%xcc, 0b
	mov	0, %g3
	srlx	%o2, 3, %g4
	brz,pn	%g4, 5f
	mov	0, %g5
4:
	sllx	%g3, 3, %g2
	add	%g5, 1, %g3
	ldx	[%o1 + %g2], %g1
	mov	%g3, %g5
	cmp	%g4, %g3
	bne,pt	%xcc, 4b
	stxa	%g1, [%o0 + %g2] ASI_AIUS
5:
	and	%o2, 7, %o2
	brz,pn	%o2, 2b
	sllx	%g4, 3, %g1
	mov	0, %g2
	add	%g1, %o0, %o0
	add	%g1, %o1, %g4
	mov	0, %g3
6:
	ldub	[%g2 + %g4], %g1
	stba	%g1, [%g2 + %o0] ASI_AIUS
	add	%g3, 1, %g2
	cmp	%o2, %g2
	bne,pt	%xcc, 6b
	mov	%g2, %g3

	jmp	%o7 + 8			! exit point
	mov	%o1, %o0

.global memcpy_from_uspace_failover_address
.global memcpy_to_uspace_failover_address
memcpy_from_uspace_failover_address:
memcpy_to_uspace_failover_address:
	jmp	%o7 + 8			! exit point
	mov	%g0, %o0		! return 0 on failure

.global memsetb
memsetb:
	b _memsetb
	nop


.macro WRITE_ALTERNATE_REGISTER reg, bit
	save %sp, -STACK_WINDOW_SAVE_AREA_SIZE, %sp
	rdpr %pstate, %l0
	wrpr %l0, \bit, %pstate
	mov %i0, \reg
	wrpr %l0, 0, %pstate
	ret
	restore
.endm

.macro READ_ALTERNATE_REGISTER reg, bit
	save %sp, -STACK_WINDOW_SAVE_AREA_SIZE, %sp
	rdpr %pstate, %l0
	wrpr %l0, \bit, %pstate
	mov \reg, %i0
	wrpr %l0, 0, %pstate
	ret
	restore
.endm

.global write_to_ag_g6
write_to_ag_g6:
	WRITE_ALTERNATE_REGISTER %g6, PSTATE_AG_BIT

.global write_to_ag_g7
write_to_ag_g7:
	WRITE_ALTERNATE_REGISTER %g7, PSTATE_AG_BIT

.global write_to_ig_g6
write_to_ig_g6:
	WRITE_ALTERNATE_REGISTER %g6, PSTATE_IG_BIT

.global read_from_ag_g7
read_from_ag_g7:
	READ_ALTERNATE_REGISTER %g7, PSTATE_AG_BIT


/** Switch to userspace.
 *
 * %o0	Userspace entry address.
 * %o1	Userspace stack pointer address.
 * %o2  Userspace address of uarg structure.
 */
.global switch_to_userspace
switch_to_userspace:
	save %o1, -STACK_WINDOW_SAVE_AREA_SIZE, %sp
	flushw
	wrpr %g0, 0, %cleanwin		! avoid information leak

	mov %i3, %o0			! uarg

	clr %i2
	clr %i3
	clr %i4
	clr %i5
	clr %i6

	wrpr %g0, 1, %tl		! enforce mapping via nucleus

	rdpr %cwp, %g1
	wrpr %g1, TSTATE_IE_BIT, %tstate
	wrpr %i0, 0, %tnpc
	
	/*
	 * Set primary context according to secondary context.
	 * Secondary context has been already installed by
	 * higher-level functions.
	 */
	wr %g0, ASI_DMMU, %asi
	ldxa [VA_SECONDARY_CONTEXT_REG] %asi, %g1
	stxa %g1, [VA_PRIMARY_CONTEXT_REG] %asi
	flush %i7

	/*
	 * Spills and fills will be handled by the userspace handlers.
	 */
	wrpr %g0, WSTATE_OTHER(0) | WSTATE_NORMAL(1), %wstate
	
	done				! jump to userspace