/* * arch/ppc/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 "ppc_asm.h" #include <asm/processor.h> #include <asm/page.h> #include <asm/mmu.h> #include <asm/thread_info.h> #include <linux/errno.h> #include <linux/sys.h> #include <linux/config.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 r0,THREAD+LAST_SYSCALL(r13) 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) cmp 0,r13,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) mr r6,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. */ #ifdef CONFIG_BINFMT_ELF32 andi. r11,r10,_TIF_32BIT beq- 15f ld r10,.SYS_CALL_TABLE32@toc(2) /* * Now mung the first 4 parameters into shape, by making certain that * the high bits (most significant 32 bits in 64 bit reg) are 0 * for the first 4 parameter regs(3-6). */ clrldi r3,r3,32 clrldi r4,r4,32 clrldi r5,r5,32 clrldi r6,r6,32 #if 0 /* XXX Why not ??? - Anton */ clrldi r7,r7,32 clrldi r8,r8,32 #endif b 17f 15: #endif 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) 20: std r3,RESULT(r1) /* Save result */ #ifdef SHOW_SYSCALLS #ifdef SHOW_SYSCALLS_TASK cmp 0,r13,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 cmpi 0,r3,ERESTARTNOHAND bne 22f li r3,EINTR 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. */ #ifdef CONFIG_BINFMT_ELF32 clrrdi r10,r1,THREAD_SHIFT ld r10,TI_FLAGS(r10) andi. r11,r10,_TIF_32BIT beq- 55f ld r10,.SYS_CALL_TABLE32@toc(2) /* * Now mung the first 4 parameters into shape, by making certain that * the high bits (most significant 32 bits in 64 bit reg) are 0 * for the first 4 parameter regs(3-6). */ clrldi r3,r3,32 clrldi r4,r4,32 clrldi r5,r5,32 clrldi r6,r6,32 #if 0 /* XXX Why not ??? - Anton */ clrldi r7,r7,32 clrldi r8,r8,32 #endif b 57f 55: #endif 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) 58: std r3,RESULT(r1) /* Save result */ std r3,GPR0(r1) /* temporary gross hack to make strace work */ li r10,-_LAST_ERRNO cmpl 0,r3,r10 blt 60f neg r3,r3 cmpi 0,r3,ERESTARTNOHAND bne 57f li r3,EINTR 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_sigreturn) bl .sys_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 20b 81: cmpi 0,r3,0 blt 58b 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 */ mfspr r5,SPRG3 /* Get paca */ addi r13,r4,-THREAD /* Convert THREAD to 'current' */ std r13,PACACURRENT(r5) /* 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) ld r7,_NIP(r1) /* Return to _switch caller in new task */ mtlr r7 addi r1,r1,SWITCH_FRAME_SIZE blr _GLOBAL(ret_from_fork) #if CONFIG_SMP || CONFIG_PREEMPT bl .schedule_tail #endif 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 */ 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|MSR_RI andc r10,r10,r4 /* clear MSR_EE and MSR_RI */ mtmsrd r10 /* 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 */ std r0,THREAD+KSP(r13) /* save kernel stack pointer */ mfspr r4,SPRG3 /* current task's PACA */ std r1,PACAKSAVE(r4) /* save exception stack pointer */ 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 ld r0,SOFTE(r1) stb r0,PACAPROCENABLED(r13) #endif ld r0,_MSR(r1) mtspr SRR1,r0 ld r2,_CCR(r1) mtcrf 0xFF,r2 ld r2,_NIP(r1) mtspr SRR0,r2 REST_GPR(13,r1) ld r0,GPR0(r1) ld r2,GPR2(r1) ld r3,GPR3(r1) ld r4,GPR4(r1) ld r1,GPR1(r1) rfid do_work: /* Enable interrupts */ ori r10,r10,MSR_EE|MSR_RI mtmsrd r10 andi. r0,r3,_TIF_NEED_RESCHED beq 1f bl .schedule b recheck 1: andi. r0,r3,_TIF_SIGPENDING beq 2f li r3,0 addi r4,r1,STACK_FRAME_OVERHEAD bl .do_signal b recheck 2: /* nobody uses the TIF_NOTIFY_RESUME bit yet */ 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 current */ 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) /* Unfortunatly, the stack pointer and the MSR are also clobbered, * so they are saved in the PACA (SPRG3) which allows us to restore * our original state after RTAS returns. */ mfspr r4,SPRG3 /* Get PACA */ std r1,PACAR1(r4) mfmsr r6 std r6,PACASAVEDMSR(r4) /* 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|MSR_RI andc r6,r0,r9 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 current */ REST_8GPRS(14, r1) /* Restore the non-volatiles */ REST_10GPRS(22, r1) /* ditto */ /* put back current in r13 */ mfspr r4,SPRG3 ld r13,PACACURRENT(r4) 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 current */ 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 current */ 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 current */ 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 */