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linux-hardened/arch/arm/kernel/iwmmxt.S
Lennert Buytenhek ae95bfbb2b [ARM] 3707/1: iwmmxt: use the generic thread notifier infrastructure 
Patch from Lennert Buytenhek

This patch makes the iWMMXt context switch hook use the generic
thread notifier infrastructure that was recently merged in commit
d6551e884c.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-07-01 19:56:48 +01:00

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/*
* linux/arch/arm/kernel/iwmmxt.S
*
* XScale iWMMXt (Concan) context switching and handling
*
* Initial code:
* Copyright (c) 2003, Intel Corporation
*
* Full lazy switching support, optimizations and more, by Nicolas Pitre
* Copyright (c) 2003-2004, MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <asm/ptrace.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#define MMX_WR0 (0x00)
#define MMX_WR1 (0x08)
#define MMX_WR2 (0x10)
#define MMX_WR3 (0x18)
#define MMX_WR4 (0x20)
#define MMX_WR5 (0x28)
#define MMX_WR6 (0x30)
#define MMX_WR7 (0x38)
#define MMX_WR8 (0x40)
#define MMX_WR9 (0x48)
#define MMX_WR10 (0x50)
#define MMX_WR11 (0x58)
#define MMX_WR12 (0x60)
#define MMX_WR13 (0x68)
#define MMX_WR14 (0x70)
#define MMX_WR15 (0x78)
#define MMX_WCSSF (0x80)
#define MMX_WCASF (0x84)
#define MMX_WCGR0 (0x88)
#define MMX_WCGR1 (0x8C)
#define MMX_WCGR2 (0x90)
#define MMX_WCGR3 (0x94)
#define MMX_SIZE (0x98)
.text
/*
* Lazy switching of Concan coprocessor context
*
* r10 = struct thread_info pointer
* r9 = ret_from_exception
* lr = undefined instr exit
*
* called from prefetch exception handler with interrupts disabled
*/
ENTRY(iwmmxt_task_enable)
mrc p15, 0, r2, c15, c1, 0
tst r2, #0x3 @ CP0 and CP1 accessible?
movne pc, lr @ if so no business here
orr r2, r2, #0x3 @ enable access to CP0 and CP1
mcr p15, 0, r2, c15, c1, 0
ldr r3, =concan_owner
add r0, r10, #TI_IWMMXT_STATE @ get task Concan save area
ldr r2, [sp, #60] @ current task pc value
ldr r1, [r3] @ get current Concan owner
str r0, [r3] @ this task now owns Concan regs
sub r2, r2, #4 @ adjust pc back
str r2, [sp, #60]
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
teq r1, #0 @ test for last ownership
mov lr, r9 @ normal exit from exception
beq concan_load @ no owner, skip save
concan_save:
tmrc r2, wCon
@ CUP? wCx
tst r2, #0x1
beq 1f
concan_dump:
wstrw wCSSF, [r1, #MMX_WCSSF]
wstrw wCASF, [r1, #MMX_WCASF]
wstrw wCGR0, [r1, #MMX_WCGR0]
wstrw wCGR1, [r1, #MMX_WCGR1]
wstrw wCGR2, [r1, #MMX_WCGR2]
wstrw wCGR3, [r1, #MMX_WCGR3]
1: @ MUP? wRn
tst r2, #0x2
beq 2f
wstrd wR0, [r1, #MMX_WR0]
wstrd wR1, [r1, #MMX_WR1]
wstrd wR2, [r1, #MMX_WR2]
wstrd wR3, [r1, #MMX_WR3]
wstrd wR4, [r1, #MMX_WR4]
wstrd wR5, [r1, #MMX_WR5]
wstrd wR6, [r1, #MMX_WR6]
wstrd wR7, [r1, #MMX_WR7]
wstrd wR8, [r1, #MMX_WR8]
wstrd wR9, [r1, #MMX_WR9]
wstrd wR10, [r1, #MMX_WR10]
wstrd wR11, [r1, #MMX_WR11]
wstrd wR12, [r1, #MMX_WR12]
wstrd wR13, [r1, #MMX_WR13]
wstrd wR14, [r1, #MMX_WR14]
wstrd wR15, [r1, #MMX_WR15]
2: teq r0, #0 @ anything to load?
moveq pc, lr
concan_load:
@ Load wRn
wldrd wR0, [r0, #MMX_WR0]
wldrd wR1, [r0, #MMX_WR1]
wldrd wR2, [r0, #MMX_WR2]
wldrd wR3, [r0, #MMX_WR3]
wldrd wR4, [r0, #MMX_WR4]
wldrd wR5, [r0, #MMX_WR5]
wldrd wR6, [r0, #MMX_WR6]
wldrd wR7, [r0, #MMX_WR7]
wldrd wR8, [r0, #MMX_WR8]
wldrd wR9, [r0, #MMX_WR9]
wldrd wR10, [r0, #MMX_WR10]
wldrd wR11, [r0, #MMX_WR11]
wldrd wR12, [r0, #MMX_WR12]
wldrd wR13, [r0, #MMX_WR13]
wldrd wR14, [r0, #MMX_WR14]
wldrd wR15, [r0, #MMX_WR15]
@ Load wCx
wldrw wCSSF, [r0, #MMX_WCSSF]
wldrw wCASF, [r0, #MMX_WCASF]
wldrw wCGR0, [r0, #MMX_WCGR0]
wldrw wCGR1, [r0, #MMX_WCGR1]
wldrw wCGR2, [r0, #MMX_WCGR2]
wldrw wCGR3, [r0, #MMX_WCGR3]
@ clear CUP/MUP (only if r1 != 0)
teq r1, #0
mov r2, #0
moveq pc, lr
tmcr wCon, r2
mov pc, lr
/*
* Back up Concan regs to save area and disable access to them
* (mainly for gdb or sleep mode usage)
*
* r0 = struct thread_info pointer of target task or NULL for any
*/
ENTRY(iwmmxt_task_disable)
stmfd sp!, {r4, lr}
mrs ip, cpsr
orr r2, ip, #PSR_I_BIT @ disable interrupts
msr cpsr_c, r2
ldr r3, =concan_owner
add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
ldr r1, [r3] @ get current Concan owner
teq r1, #0 @ any current owner?
beq 1f @ no: quit
teq r0, #0 @ any owner?
teqne r1, r2 @ or specified one?
bne 1f @ no: quit
mrc p15, 0, r4, c15, c1, 0
orr r4, r4, #0x3 @ enable access to CP0 and CP1
mcr p15, 0, r4, c15, c1, 0
mov r0, #0 @ nothing to load
str r0, [r3] @ no more current owner
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
bl concan_save
bic r4, r4, #0x3 @ disable access to CP0 and CP1
mcr p15, 0, r4, c15, c1, 0
mrc p15, 0, r2, c2, c0, 0
mov r2, r2 @ cpwait
1: msr cpsr_c, ip @ restore interrupt mode
ldmfd sp!, {r4, pc}
/*
* Copy Concan state to given memory address
*
* r0 = struct thread_info pointer of target task
* r1 = memory address where to store Concan state
*
* this is called mainly in the creation of signal stack frames
*/
ENTRY(iwmmxt_task_copy)
mrs ip, cpsr
orr r2, ip, #PSR_I_BIT @ disable interrupts
msr cpsr_c, r2
ldr r3, =concan_owner
add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
ldr r3, [r3] @ get current Concan owner
teq r2, r3 @ does this task own it...
beq 1f
@ current Concan values are in the task save area
msr cpsr_c, ip @ restore interrupt mode
mov r0, r1
mov r1, r2
mov r2, #MMX_SIZE
b memcpy
1: @ this task owns Concan regs -- grab a copy from there
mov r0, #0 @ nothing to load
mov r2, #3 @ save all regs
mov r3, lr @ preserve return address
bl concan_dump
msr cpsr_c, ip @ restore interrupt mode
mov pc, r3
/*
* Restore Concan state from given memory address
*
* r0 = struct thread_info pointer of target task
* r1 = memory address where to get Concan state from
*
* this is used to restore Concan state when unwinding a signal stack frame
*/
ENTRY(iwmmxt_task_restore)
mrs ip, cpsr
orr r2, ip, #PSR_I_BIT @ disable interrupts
msr cpsr_c, r2
ldr r3, =concan_owner
add r2, r0, #TI_IWMMXT_STATE @ get task Concan save area
ldr r3, [r3] @ get current Concan owner
bic r2, r2, #0x7 @ 64-bit alignment
teq r2, r3 @ does this task own it...
beq 1f
@ this task doesn't own Concan regs -- use its save area
msr cpsr_c, ip @ restore interrupt mode
mov r0, r2
mov r2, #MMX_SIZE
b memcpy
1: @ this task owns Concan regs -- load them directly
mov r0, r1
mov r1, #0 @ don't clear CUP/MUP
mov r3, lr @ preserve return address
bl concan_load
msr cpsr_c, ip @ restore interrupt mode
mov pc, r3
/*
* Concan handling on task switch
*
* r0 = next thread_info pointer
*
* Called only from the iwmmxt notifier with task preemption disabled.
*/
ENTRY(iwmmxt_task_switch)
mrc p15, 0, r1, c15, c1, 0
tst r1, #0x3 @ CP0 and CP1 accessible?
bne 1f @ yes: block them for next task
ldr r2, =concan_owner
add r3, r0, #TI_IWMMXT_STATE @ get next task Concan save area
ldr r2, [r2] @ get current Concan owner
teq r2, r3 @ next task owns it?
movne pc, lr @ no: leave Concan disabled
1: eor r1, r1, #3 @ flip Concan access
mcr p15, 0, r1, c15, c1, 0
mrc p15, 0, r1, c2, c0, 0
sub pc, lr, r1, lsr #32 @ cpwait and return
/*
* Remove Concan ownership of given task
*
* r0 = struct thread_info pointer
*/
ENTRY(iwmmxt_task_release)
mrs r2, cpsr
orr ip, r2, #PSR_I_BIT @ disable interrupts
msr cpsr_c, ip
ldr r3, =concan_owner
add r0, r0, #TI_IWMMXT_STATE @ get task Concan save area
ldr r1, [r3] @ get current Concan owner
eors r0, r0, r1 @ if equal...
streq r0, [r3] @ then clear ownership
msr cpsr_c, r2 @ restore interrupts
mov pc, lr
.data
concan_owner:
.word 0
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