/*
* arch/ppc64/kernel/entry.S
*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
* MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
*
* This file contains the system call entry code, context switch
* code, and exception/interrupt return code for PowerPC.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/config.h>
#include <linux/errno.h>
#include <asm/unistd.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/offsets.h>
#ifdef CONFIG_PPC_ISERIES
#define DO_SOFT_DISABLE
#endif
#undef SHOW_SYSCALLS
#undef SHOW_SYSCALLS_TASK
#ifdef SHOW_SYSCALLS_TASK
.data
show_syscalls_task:
.long -1
#endif
.section ".toc","aw"
.SYS_CALL_TABLE:
.tc .sys_call_table[TC],.sys_call_table
.SYS_CALL_TABLE32:
.tc .sys_call_table32[TC],.sys_call_table32
.section ".text"
.align 3
/*
* Handle a system call.
*/
_GLOBAL(DoSyscall)
std r3,ORIG_GPR3(r1)
ld r11,_CCR(r1) /* Clear SO bit in CR */
lis r10,0x1000
andc r11,r11,r10
std r11,_CCR(r1)
#ifdef SHOW_SYSCALLS
#ifdef SHOW_SYSCALLS_TASK
LOADBASE(r31,show_syscalls_task)
ld r31,show_syscalls_task@l(r31)
ld r10,PACACURRENT(r13)
cmp 0,r10,r31
bne 1f
#endif
LOADADDR(r3,7f)
ld r4,GPR0(r1)
ld r5,GPR3(r1)
ld r6,GPR4(r1)
ld r7,GPR5(r1)
ld r8,GPR6(r1)
ld r9,GPR7(r1)
bl .printk
LOADADDR(r3,77f)
ld r4,GPR8(r1)
ld r5,GPR9(r1)
ld r6, PACACURRENT(r13)
bl .printk
ld r0,GPR0(r1)
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r5,GPR5(r1)
ld r6,GPR6(r1)
ld r7,GPR7(r1)
ld r8,GPR8(r1)
1:
#endif /* SHOW_SYSCALLS */
clrrdi r10,r1,THREAD_SHIFT
ld r10,TI_FLAGS(r10)
andi. r11,r10,_TIF_SYSCALL_TRACE
bne- 50f
cmpli 0,r0,NR_syscalls
bge- 66f
/*
* Need to vector to 32 Bit or default sys_call_table here,
* based on caller's run-mode / personality.
*/
andi. r11,r10,_TIF_32BIT
beq- 15f
ld r10,.SYS_CALL_TABLE32@toc(2)
/*
* We now zero extend all six arguments (r3 - r8), the compatibility
* layer assumes this.
*/
clrldi r3,r3,32
clrldi r4,r4,32
clrldi r5,r5,32
clrldi r6,r6,32
clrldi r7,r7,32
clrldi r8,r8,32
b 17f
15:
ld r10,.SYS_CALL_TABLE@toc(2)
17: slwi r0,r0,3
ldx r10,r10,r0 /* Fetch system call handler [ptr] */
mtlr r10
addi r9,r1,STACK_FRAME_OVERHEAD
blrl /* Call handler */
_GLOBAL(ret_from_syscall_1)
std r3,RESULT(r1) /* Save result */
#ifdef SHOW_SYSCALLS
#ifdef SHOW_SYSCALLS_TASK
ld r10, PACACURRENT(13)
cmp 0,r10,r31
bne 91f
#endif
mr r4,r3
LOADADDR(r3,79f)
bl .printk
ld r3,RESULT(r1)
91:
#endif
li r10,-_LAST_ERRNO
cmpl 0,r3,r10
blt 30f
neg r3,r3
22: ld r10,_CCR(r1) /* Set SO bit in CR */
oris r10,r10,0x1000
std r10,_CCR(r1)
30: std r3,GPR3(r1) /* Update return value */
b .ret_from_except
66: li r3,ENOSYS
b 22b
/* Traced system call support */
50: bl .do_syscall_trace
ld r0,GPR0(r1) /* Restore original registers */
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r5,GPR5(r1)
ld r6,GPR6(r1)
ld r7,GPR7(r1)
ld r8,GPR8(r1)
/* XXX check this - Anton */
ld r9,GPR9(r1)
cmpli 0,r0,NR_syscalls
bge- 66f
/*
* Need to vector to 32 Bit or default sys_call_table here,
* based on caller's run-mode / personality.
*/
clrrdi r10,r1,THREAD_SHIFT
ld r10,TI_FLAGS(r10)
andi. r11,r10,_TIF_32BIT
beq- 55f
ld r10,.SYS_CALL_TABLE32@toc(2)
/*
* We now zero extend all six arguments (r3 - r8), the compatibility
* layer assumes this.
*/
clrldi r3,r3,32
clrldi r4,r4,32
clrldi r5,r5,32
clrldi r6,r6,32
clrldi r7,r7,32
clrldi r8,r8,32
b 57f
55:
ld r10,.SYS_CALL_TABLE@toc(2)
57:
slwi r0,r0,3
ldx r10,r10,r0 /* Fetch system call handler [ptr] */
mtlr r10
addi r9,r1,STACK_FRAME_OVERHEAD
blrl /* Call handler */
_GLOBAL(ret_from_syscall_2)
std r3,RESULT(r1) /* Save result */
li r10,-_LAST_ERRNO
cmpl 0,r3,r10
blt 60f
neg r3,r3
57: ld r10,_CCR(r1) /* Set SO bit in CR */
oris r10,r10,0x1000
std r10,_CCR(r1)
60: std r3,GPR3(r1) /* Update return value */
bl .do_syscall_trace
b .ret_from_except
66: li r3,ENOSYS
b 57b
#ifdef SHOW_SYSCALLS
7: .string "syscall %d(%x, %x, %x, %x, %x, "
77: .string "%x, %x), current=%p\n"
79: .string " -> %x\n"
.align 2,0
#endif
_GLOBAL(ppc32_sigreturn)
bl .sys32_sigreturn
b 80f
_GLOBAL(ppc32_rt_sigreturn)
bl .sys32_rt_sigreturn
b 80f
_GLOBAL(ppc64_rt_sigreturn)
bl .sys_rt_sigreturn
80: clrrdi r4,r1,THREAD_SHIFT
ld r4,TI_FLAGS(r4)
andi. r4,r4,_TIF_SYSCALL_TRACE
bne- 81f
cmpi 0,r3,0
bge .ret_from_except
b .ret_from_syscall_1
81: cmpi 0,r3,0
blt .ret_from_syscall_2
bl .do_syscall_trace
b .ret_from_except
/*
* This routine switches between two different tasks. The process
* state of one is saved on its kernel stack. Then the state
* of the other is restored from its kernel stack. The memory
* management hardware is updated to the second process's state.
* Finally, we can return to the second process, via ret_from_except.
* On entry, r3 points to the THREAD for the current task, r4
* points to the THREAD for the new task.
*
* Note: there are two ways to get to the "going out" portion
* of this code; either by coming in via the entry (_switch)
* or via "fork" which must set up an environment equivalent
* to the "_switch" path. If you change this you'll have to change
* the fork code also.
*
* The code which creates the new task context is in 'copy_thread'
* in arch/ppc64/kernel/process.c
*/
_GLOBAL(_switch)
mflr r0
std r0,16(r1)
stdu r1,-SWITCH_FRAME_SIZE(r1)
/* r3-r13 are caller saved -- Cort */
SAVE_8GPRS(14, r1)
SAVE_10GPRS(22, r1)
mflr r20 /* Return to switch caller */
mfmsr r22
andi. r21, r22, MSR_FP
beq+ 1f
li r6,MSR_FP /* Disable floating-point */
andc r22,r22,r6
mtmsrd r22
isync
1: std r20,_NIP(r1)
mfcr r23
std r23,_CCR(r1)
std r1,KSP(r3) /* Set old stack pointer */
addi r6,r4,-THREAD /* Convert THREAD to 'current' */
std r6,PACACURRENT(r13) /* Set new 'current' */
#ifdef CONFIG_PPC_ISERIES
#error fixme
ld r7,TI_FLAGS(r4) /* Get run light flag */
mfspr r9,CTRLF
srdi r7,r7,1 /* Align to run light bit in CTRL reg */
insrdi r9,r7,1,63 /* Insert run light into CTRL */
mtspr CTRLT,r9
#endif
ld r1,KSP(r4) /* Load new stack pointer */
ld r6,_CCR(r1)
mtcrf 0xFF,r6
/* r3-r13 are destroyed -- Cort */
REST_8GPRS(14, r1)
REST_10GPRS(22, r1)
/* convert old thread to its task_struct for return value */
addi r3,r3,-THREAD
ld r7,_NIP(r1) /* Return to _switch caller in new task */
mtlr r7
addi r1,r1,SWITCH_FRAME_SIZE
blr
_GLOBAL(ret_from_fork)
bl .schedule_tail
clrrdi r4,r1,THREAD_SHIFT
ld r4,TI_FLAGS(r4)
andi. r4,r4,_TIF_SYSCALL_TRACE
beq+ .ret_from_except
bl .do_syscall_trace
b .ret_from_except
_GLOBAL(ret_from_except)
#ifdef CONFIG_PPC_ISERIES
ld r5,SOFTE(r1)
cmpdi 0,r5,0
beq 4f
irq_recheck:
/* Check for pending interrupts (iSeries) */
CHECKANYINT(r3,r4)
beq+ 4f /* skip do_IRQ if no interrupts */
#warning FIX ISERIES
mfspr r5,SPRG3
li r3,0
stb r3,PACAPROCENABLED(r5) /* ensure we are disabled */
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_IRQ
b irq_recheck /* loop back and handle more */
4:
#endif
/*
* Disable interrupts so that current_thread_info()->flags
* can't change between when we test it and when we return
* from the interrupt.
*/
recheck:
mfmsr r10 /* Get current interrupt state */
li r4,0
ori r4,r4,MSR_EE
andc r10,r10,r4 /* clear MSR_EE */
mtmsrd r10,1 /* Update machine state */
#ifdef CONFIG_PPC_ISERIES
#error fix iSeries soft disable
#endif
ld r3,_MSR(r1) /* Returning to user mode? */
andi. r3,r3,MSR_PR
beq restore /* if not, just restore regs and return */
/* Check current_thread_info()->flags */
clrrdi r3,r1,THREAD_SHIFT
ld r3,TI_FLAGS(r3)
andi. r0,r3,_TIF_USER_WORK_MASK
bne do_work
addi r0,r1,INT_FRAME_SIZE /* size of frame */
ld r4,PACACURRENT(r13)
std r0,THREAD+KSP(r4) /* save kernel stack pointer */
std r1,PACAKSAVE(r13) /* save exception stack pointer */
/*
* r13 is our per cpu area, only restore it if we are returning to
* userspace
*/
REST_GPR(13,r1)
restore:
ld r3,_CTR(r1)
ld r0,_LINK(r1)
mtctr r3
mtlr r0
ld r3,_XER(r1)
mtspr XER,r3
REST_8GPRS(5, r1)
REST_10GPRS(14, r1)
REST_8GPRS(24, r1)
stdcx. r0,0,r1 /* to clear the reservation */
#ifdef DO_SOFT_DISABLE
/* XXX do this in do_work, r13 isnt valid here */
ld r0,SOFTE(r1)
stb r0,PACAPROCENABLED(r13)
#endif
mfmsr r0
li r2, MSR_RI
andc r0,r0,r2
mtmsrd r0,1
ld r0,_MSR(r1)
mtspr SRR1,r0
ld r2,_CCR(r1)
mtcrf 0xFF,r2
ld r2,_NIP(r1)
mtspr SRR0,r2
ld r0,GPR0(r1)
ld r2,GPR2(r1)
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r1,GPR1(r1)
rfid
/* Note: this must change if we start using the TIF_NOTIFY_RESUME bit */
do_work:
/* Enable interrupts */
ori r10,r10,MSR_EE
mtmsrd r10,1
andi. r0,r3,_TIF_NEED_RESCHED
beq 1f
bl .schedule
b recheck
1: andi. r0,r3,_TIF_SIGPENDING
beq recheck
li r3,0
addi r4,r1,STACK_FRAME_OVERHEAD
bl .do_signal
b recheck
/*
* On CHRP, the Run-Time Abstraction Services (RTAS) have to be
* called with the MMU off.
*
* In addition, we need to be in 32b mode, at least for now.
*
* Note: r3 is an input parameter to rtas, so don't trash it...
*/
_GLOBAL(enter_rtas)
mflr r0
std r0,16(r1)
stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */
/* Because RTAS is running in 32b mode, it clobbers the high order half
* of all registers that it saves. We therefore save those registers
* RTAS might touch to the stack. (r0, r3-r13 are caller saved)
*/
SAVE_GPR(2, r1) /* Save the TOC */
SAVE_GPR(13, r1) /* Save paca */
SAVE_8GPRS(14, r1) /* Save the non-volatiles */
SAVE_10GPRS(22, r1) /* ditto */
mfcr r4
std r4,_CCR(r1)
mfctr r5
std r5,_CTR(r1)
mfspr r6,XER
std r6,_XER(r1)
mfdar r7
std r7,_DAR(r1)
mfdsisr r8
std r8,_DSISR(r1)
mfsrr0 r9
std r9,_SRR0(r1)
mfsrr1 r10
std r10,_SRR1(r1)
/* Unfortunately, the stack pointer and the MSR are also clobbered,
* so they are saved in the PACA which allows us to restore
* our original state after RTAS returns.
*/
std r1,PACAR1(r13)
mfmsr r6
std r6,PACASAVEDMSR(r13)
/* Setup our real return addr */
SET_REG_TO_LABEL(r4,.rtas_return_loc)
SET_REG_TO_CONST(r9,KERNELBASE)
sub r4,r4,r9
mtlr r4
li r0,0
ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
andc r0,r6,r0
li r9,1
rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP
andc r6,r0,r9
ori r6,r6,MSR_RI
sync /* disable interrupts so SRR0/1 */
mtmsrd r0 /* don't get trashed */
SET_REG_TO_LABEL(r4,rtas)
ld r5,RTASENTRY(r4) /* get the rtas->entry value */
ld r4,RTASBASE(r4) /* get the rtas->base value */
mtspr SRR0,r5
mtspr SRR1,r6
rfid
_STATIC(rtas_return_loc)
/* relocation is off at this point */
mfspr r4,SPRG3 /* Get PACA */
SET_REG_TO_CONST(r5, KERNELBASE)
sub r4,r4,r5 /* RELOC the PACA base pointer */
ld r1,PACAR1(r4) /* Restore our SP */
LOADADDR(r3,.rtas_restore_regs)
ld r4,PACASAVEDMSR(r4) /* Restore our MSR */
mtspr SRR0,r3
mtspr SRR1,r4
rfid
_STATIC(rtas_restore_regs)
/* relocation is on at this point */
REST_GPR(2, r1) /* Restore the TOC */
REST_GPR(13, r1) /* Restore paca */
REST_8GPRS(14, r1) /* Restore the non-volatiles */
REST_10GPRS(22, r1) /* ditto */
mfspr r13,SPRG3
ld r4,_CCR(r1)
mtcr r4
ld r5,_CTR(r1)
mtctr r5
ld r6,_XER(r1)
mtspr XER,r6
ld r7,_DAR(r1)
mtdar r7
ld r8,_DSISR(r1)
mtdsisr r8
ld r9,_SRR0(r1)
mtsrr0 r9
ld r10,_SRR1(r1)
mtsrr1 r10
addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */
ld r0,16(r1) /* get return address */
mtlr r0
blr /* return to caller */
_GLOBAL(enter_prom)
mflr r0
std r0,16(r1)
stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
/* Because PROM is running in 32b mode, it clobbers the high order half
* of all registers that it saves. We therefore save those registers
* PROM might touch to the stack. (r0, r3-r13 are caller saved)
*/
SAVE_8GPRS(2, r1) /* Save the TOC & incoming param(s) */
SAVE_GPR(13, r1) /* Save paca */
SAVE_8GPRS(14, r1) /* Save the non-volatiles */
SAVE_10GPRS(22, r1) /* ditto */
mfcr r4
std r4,_CCR(r1)
mfctr r5
std r5,_CTR(r1)
mfspr r6,XER
std r6,_XER(r1)
mfdar r7
std r7,_DAR(r1)
mfdsisr r8
std r8,_DSISR(r1)
mfsrr0 r9
std r9,_SRR0(r1)
mfsrr1 r10
std r10,_SRR1(r1)
mfmsr r11
std r11,_MSR(r1)
/* Unfortunatly, the stack pointer is also clobbered, so it is saved
* in the SPRG2 which allows us to restore our original state after
* PROM returns.
*/
mtspr SPRG2,r1
/* put a relocation offset into r3 */
bl .reloc_offset
LOADADDR(r12,prom)
sub r12,r12,r3
ld r12,PROMENTRY(r12) /* get the prom->entry value */
mtlr r12
mfmsr r11 /* grab the current MSR */
li r12,1
rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
andc r11,r11,r12
li r12,1
rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
andc r11,r11,r12
mtmsrd r11
isync
REST_8GPRS(2, r1) /* Restore the TOC & param(s) */
REST_GPR(13, r1) /* Restore paca */
REST_8GPRS(14, r1) /* Restore the non-volatiles */
REST_10GPRS(22, r1) /* ditto */
blrl /* Entering PROM here... */
mfspr r1,SPRG2 /* Restore the stack pointer */
ld r6,_MSR(r1) /* Restore the MSR */
mtmsrd r6
isync
REST_GPR(2, r1) /* Restore the TOC */
REST_GPR(13, r1) /* Restore paca */
REST_8GPRS(14, r1) /* Restore the non-volatiles */
REST_10GPRS(22, r1) /* ditto */
ld r4,_CCR(r1)
mtcr r4
ld r5,_CTR(r1)
mtctr r5
ld r6,_XER(r1)
mtspr XER,r6
ld r7,_DAR(r1)
mtdar r7
ld r8,_DSISR(r1)
mtdsisr r8
ld r9,_SRR0(r1)
mtsrr0 r9
ld r10,_SRR1(r1)
mtsrr1 r10
addi r1,r1,PROM_FRAME_SIZE
ld r0,16(r1) /* get return address */
mtlr r0
blr /* return to caller */
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