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Rearrange the exit path so that we don't do a idcache_wbinv_all *twice*

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when a process exits.
This commit is contained in:
thorpej 2002-08-06 19:20:29 +00:00
parent 62d83d05b1
commit 0886c8cc0f
1 changed files with 41 additions and 15 deletions
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56
sys/arch/arm/arm32/cpuswitch.S
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@ -1,4 +1,4 @@
/* $NetBSD: cpuswitch.S,v 1.8 2002/08/06 17:44:35 thorpej Exp $ */ /* $NetBSD: cpuswitch.S,v 1.9 2002/08/06 19:20:29 thorpej Exp $ */
/* /*
* Copyright (c) 1994-1998 Mark Brinicombe. * Copyright (c) 1994-1998 Mark Brinicombe.
@ -467,26 +467,26 @@ Lidle_ret:
teq r1, r6 teq r1, r6
beq switch_return beq switch_return
/* Remember the old process in r0 */
mov r0, r1
/* /*
* If the curproc on entry to cpu_switch was zero then the * If the curproc on entry to cpu_switch was zero then the
* process that called it was exiting. This means that we do * process that called it was exiting. This means that we do
* not need to save the current context. Instead we can jump * not need to save the current context. Instead we can jump
* straight to restoring the context for the new process. * straight to restoring the context for the new process.
*/ */
teq r1, #0x00000000 teq r0, #0x00000000
beq switch_exited beq switch_exited
/* rem: r1 = old proc */ /* rem: r0 = old proc */
/* rem: r6 = new process */ /* rem: r6 = new process */
/* rem: interrupts are enabled */ /* rem: interrupts are enabled */
/* Stage two : Save old context */ /* Stage two : Save old context */
/* Remember the old process in r0 */
mov r0, r1
/* Get the user structure for the old process. */ /* Get the user structure for the old process. */
ldr r1, [r1, #(P_ADDR)] ldr r1, [r0, #(P_ADDR)]
/* Save all the registers in the old process's pcb */ /* Save all the registers in the old process's pcb */
add r7, r1, #(PCB_R8) add r7, r1, #(PCB_R8)
@ -512,27 +512,36 @@ Lidle_ret:
/* What else needs to be saved Only FPA stuff when that is supported */ /* What else needs to be saved Only FPA stuff when that is supported */
/* r1 now free! */
/* Third phase : restore saved context */ /* Third phase : restore saved context */
switch_exited: /* rem: r0 = old proc */
/* Don't allow user space access beween the purge and the switch */ /* rem: r6 = new process */
/* rem: interrupts are enabled */
/*
* Don't allow user space access between the purge and the switch.
*/
ldr r3, Lblock_userspace_access ldr r3, Lblock_userspace_access
ldr r2, [r3] mov r1, #0x00000001
orr r0, r2, #1 mov r2, #0x00000000
str r0, [r3] str r1, [r3]
stmfd sp!, {r0-r3} stmfd sp!, {r0-r3}
ldr r0, Lcpufuncs ldr r1, Lcpufuncs
add lr, pc, #Lcs_cache_purged - . - 8 add lr, pc, #Lcs_cache_purged - . - 8
ldr pc, [r0, #CF_IDCACHE_WBINV_ALL] ldr pc, [r1, #CF_IDCACHE_WBINV_ALL]
Lcs_cache_purged: Lcs_cache_purged:
ldmfd sp!, {r0-r3} ldmfd sp!, {r0-r3}
Lcs_cache_purge_skipped:
/* At this point we need to kill IRQ's again. */ /* At this point we need to kill IRQ's again. */
IRQdisable IRQdisable
/* Interrupts are disabled so we can allow user space accesses again /*
* Interrupts are disabled so we can allow user space accesses again
* as none will occur until interrupts are re-enabled after the * as none will occur until interrupts are re-enabled after the
* switch. * switch.
*/ */
@ -591,6 +600,16 @@ switch_return:
*/ */
ldmfd sp!, {r4-r7, pc} ldmfd sp!, {r4-r7, pc}
switch_exited:
/*
* We skip the cache purge because switch_exit() already did
* it. Load up registers the way Lcs_cache_purge_skipped
* expects. Userspace access already blocked in switch_exit().
*/
ldr r3, Lblock_userspace_access
mov r2, #0x00000000
b Lcs_cache_purge_skipped
Lproc0: Lproc0:
.word _C_LABEL(proc0) .word _C_LABEL(proc0)
@ -620,6 +639,13 @@ ENTRY(switch_exit)
/* ldr r0, Lcurpcb /* ldr r0, Lcurpcb
str r2, [r0]*/ str r2, [r0]*/
/*
* Don't allow user space access between the purge and the switch.
*/
ldr r0, Lblock_userspace_access
mov r2, #0x00000001
str r2, [r0]
/* Switch to proc0 context */ /* Switch to proc0 context */
stmfd sp!, {r0-r3} stmfd sp!, {r0-r3}