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Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 842 |
1 files changed, 842 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S new file mode 100644 index 000000000000..2d22bf03484e --- /dev/null +++ b/arch/powerpc/kernel/entry_64.S @@ -0,0 +1,842 @@ +/* + * 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/asm-offsets.h> +#include <asm/cputable.h> + +#ifdef CONFIG_PPC_ISERIES +#define DO_SOFT_DISABLE +#endif + +/* + * System calls. + */ + .section ".toc","aw" +.SYS_CALL_TABLE: + .tc .sys_call_table[TC],.sys_call_table + +/* This value is used to mark exception frames on the stack. */ +exception_marker: + .tc ID_72656773_68657265[TC],0x7265677368657265 + + .section ".text" + .align 7 + +#undef SHOW_SYSCALLS + + .globl system_call_common +system_call_common: + andi. r10,r12,MSR_PR + mr r10,r1 + addi r1,r1,-INT_FRAME_SIZE + beq- 1f + ld r1,PACAKSAVE(r13) +1: std r10,0(r1) + std r11,_NIP(r1) + std r12,_MSR(r1) + std r0,GPR0(r1) + std r10,GPR1(r1) + std r2,GPR2(r1) + std r3,GPR3(r1) + std r4,GPR4(r1) + std r5,GPR5(r1) + std r6,GPR6(r1) + std r7,GPR7(r1) + std r8,GPR8(r1) + li r11,0 + std r11,GPR9(r1) + std r11,GPR10(r1) + std r11,GPR11(r1) + std r11,GPR12(r1) + std r9,GPR13(r1) + crclr so + mfcr r9 + mflr r10 + li r11,0xc01 + std r9,_CCR(r1) + std r10,_LINK(r1) + std r11,_TRAP(r1) + mfxer r9 + mfctr r10 + std r9,_XER(r1) + std r10,_CTR(r1) + std r3,ORIG_GPR3(r1) + ld r2,PACATOC(r13) + addi r9,r1,STACK_FRAME_OVERHEAD + ld r11,exception_marker@toc(r2) + std r11,-16(r9) /* "regshere" marker */ +#ifdef CONFIG_PPC_ISERIES + /* Hack for handling interrupts when soft-enabling on iSeries */ + cmpdi cr1,r0,0x5555 /* syscall 0x5555 */ + andi. r10,r12,MSR_PR /* from kernel */ + crand 4*cr0+eq,4*cr1+eq,4*cr0+eq + beq hardware_interrupt_entry + lbz r10,PACAPROCENABLED(r13) + std r10,SOFTE(r1) +#endif + mfmsr r11 + ori r11,r11,MSR_EE + mtmsrd r11,1 + +#ifdef SHOW_SYSCALLS + bl .do_show_syscall + REST_GPR(0,r1) + REST_4GPRS(3,r1) + REST_2GPRS(7,r1) + addi r9,r1,STACK_FRAME_OVERHEAD +#endif + clrrdi r11,r1,THREAD_SHIFT + li r12,0 + ld r10,TI_FLAGS(r11) + stb r12,TI_SC_NOERR(r11) + andi. r11,r10,_TIF_SYSCALL_T_OR_A + bne- syscall_dotrace +syscall_dotrace_cont: + cmpldi 0,r0,NR_syscalls + bge- syscall_enosys + +system_call: /* label this so stack traces look sane */ +/* + * Need to vector to 32 Bit or default sys_call_table here, + * based on caller's run-mode / personality. + */ + ld r11,.SYS_CALL_TABLE@toc(2) + andi. r10,r10,_TIF_32BIT + beq 15f + addi r11,r11,8 /* use 32-bit syscall entries */ + clrldi r3,r3,32 + clrldi r4,r4,32 + clrldi r5,r5,32 + clrldi r6,r6,32 + clrldi r7,r7,32 + clrldi r8,r8,32 +15: + slwi r0,r0,4 + ldx r10,r11,r0 /* Fetch system call handler [ptr] */ + mtctr r10 + bctrl /* Call handler */ + +syscall_exit: +#ifdef SHOW_SYSCALLS + std r3,GPR3(r1) + bl .do_show_syscall_exit + ld r3,GPR3(r1) +#endif + std r3,RESULT(r1) + ld r5,_CCR(r1) + li r10,-_LAST_ERRNO + cmpld r3,r10 + clrrdi r12,r1,THREAD_SHIFT + bge- syscall_error +syscall_error_cont: + + /* check for syscall tracing or audit */ + ld r9,TI_FLAGS(r12) + andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) + bne- syscall_exit_trace +syscall_exit_trace_cont: + + /* disable interrupts so current_thread_info()->flags can't change, + and so that we don't get interrupted after loading SRR0/1. */ + ld r8,_MSR(r1) + andi. r10,r8,MSR_RI + beq- unrecov_restore + mfmsr r10 + rldicl r10,r10,48,1 + rotldi r10,r10,16 + mtmsrd r10,1 + ld r9,TI_FLAGS(r12) + andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED) + bne- syscall_exit_work + ld r7,_NIP(r1) + stdcx. r0,0,r1 /* to clear the reservation */ + andi. r6,r8,MSR_PR + ld r4,_LINK(r1) + beq- 1f /* only restore r13 if */ + ld r13,GPR13(r1) /* returning to usermode */ +1: ld r2,GPR2(r1) + li r12,MSR_RI + andc r10,r10,r12 + mtmsrd r10,1 /* clear MSR.RI */ + ld r1,GPR1(r1) + mtlr r4 + mtcr r5 + mtspr SPRN_SRR0,r7 + mtspr SPRN_SRR1,r8 + rfid + b . /* prevent speculative execution */ + +syscall_enosys: + li r3,-ENOSYS + std r3,RESULT(r1) + clrrdi r12,r1,THREAD_SHIFT + ld r5,_CCR(r1) + +syscall_error: + lbz r11,TI_SC_NOERR(r12) + cmpwi 0,r11,0 + bne- syscall_error_cont + neg r3,r3 + oris r5,r5,0x1000 /* Set SO bit in CR */ + std r5,_CCR(r1) + b syscall_error_cont + +/* Traced system call support */ +syscall_dotrace: + bl .save_nvgprs + addi r3,r1,STACK_FRAME_OVERHEAD + bl .do_syscall_trace_enter + 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) + addi r9,r1,STACK_FRAME_OVERHEAD + clrrdi r10,r1,THREAD_SHIFT + ld r10,TI_FLAGS(r10) + b syscall_dotrace_cont + +syscall_exit_trace: + std r3,GPR3(r1) + bl .save_nvgprs + addi r3,r1,STACK_FRAME_OVERHEAD + bl .do_syscall_trace_leave + REST_NVGPRS(r1) + ld r3,GPR3(r1) + ld r5,_CCR(r1) + clrrdi r12,r1,THREAD_SHIFT + b syscall_exit_trace_cont + +/* Stuff to do on exit from a system call. */ +syscall_exit_work: + std r3,GPR3(r1) + std r5,_CCR(r1) + b .ret_from_except_lite + +/* Save non-volatile GPRs, if not already saved. */ +_GLOBAL(save_nvgprs) + ld r11,_TRAP(r1) + andi. r0,r11,1 + beqlr- + SAVE_NVGPRS(r1) + clrrdi r0,r11,1 + std r0,_TRAP(r1) + blr + +/* + * The sigsuspend and rt_sigsuspend system calls can call do_signal + * and thus put the process into the stopped state where we might + * want to examine its user state with ptrace. Therefore we need + * to save all the nonvolatile registers (r14 - r31) before calling + * the C code. Similarly, fork, vfork and clone need the full + * register state on the stack so that it can be copied to the child. + */ +_GLOBAL(ppc32_sigsuspend) + bl .save_nvgprs + bl .compat_sys_sigsuspend + b 70f + +_GLOBAL(ppc64_rt_sigsuspend) + bl .save_nvgprs + bl .sys_rt_sigsuspend + b 70f + +_GLOBAL(ppc32_rt_sigsuspend) + bl .save_nvgprs + bl .compat_sys_rt_sigsuspend +70: cmpdi 0,r3,0 + /* If it returned an error, we need to return via syscall_exit to set + the SO bit in cr0 and potentially stop for ptrace. */ + bne syscall_exit + /* If sigsuspend() returns zero, we are going into a signal handler. We + may need to call audit_syscall_exit() to mark the exit from sigsuspend() */ +#ifdef CONFIG_AUDITSYSCALL + ld r3,PACACURRENT(r13) + ld r4,AUDITCONTEXT(r3) + cmpdi 0,r4,0 + beq .ret_from_except /* No audit_context: Leave immediately. */ + li r4, 2 /* AUDITSC_FAILURE */ + li r5,-4 /* It's always -EINTR */ + bl .audit_syscall_exit +#endif + b .ret_from_except + +_GLOBAL(ppc_fork) + bl .save_nvgprs + bl .sys_fork + b syscall_exit + +_GLOBAL(ppc_vfork) + bl .save_nvgprs + bl .sys_vfork + b syscall_exit + +_GLOBAL(ppc_clone) + bl .save_nvgprs + bl .sys_clone + b syscall_exit + +_GLOBAL(ppc32_swapcontext) + bl .save_nvgprs + bl .compat_sys_swapcontext + b 80f + +_GLOBAL(ppc64_swapcontext) + bl .save_nvgprs + bl .sys_swapcontext + b 80f + +_GLOBAL(ppc32_sigreturn) + bl .compat_sys_sigreturn + b 80f + +_GLOBAL(ppc32_rt_sigreturn) + bl .compat_sys_rt_sigreturn + b 80f + +_GLOBAL(ppc64_rt_sigreturn) + bl .sys_rt_sigreturn + +80: cmpdi 0,r3,0 + blt syscall_exit + clrrdi r4,r1,THREAD_SHIFT + ld r4,TI_FLAGS(r4) + andi. r4,r4,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) + beq+ 81f + addi r3,r1,STACK_FRAME_OVERHEAD + bl .do_syscall_trace_leave +81: b .ret_from_except + +_GLOBAL(ret_from_fork) + bl .schedule_tail + REST_NVGPRS(r1) + li r3,0 + b syscall_exit + +/* + * 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 + */ + .align 7 +_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 + li r0, MSR_FP +#ifdef CONFIG_ALTIVEC +BEGIN_FTR_SECTION + oris r0,r0,MSR_VEC@h /* Disable altivec */ + mfspr r24,SPRN_VRSAVE /* save vrsave register value */ + std r24,THREAD_VRSAVE(r3) +END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) +#endif /* CONFIG_ALTIVEC */ + and. r0,r0,r22 + beq+ 1f + andc r22,r22,r0 + mtmsrd r22 + isync +1: std r20,_NIP(r1) + mfcr r23 + std r23,_CCR(r1) + std r1,KSP(r3) /* Set old stack pointer */ + +#ifdef CONFIG_SMP + /* We need a sync somewhere here to make sure that if the + * previous task gets rescheduled on another CPU, it sees all + * stores it has performed on this one. + */ + sync +#endif /* CONFIG_SMP */ + + addi r6,r4,-THREAD /* Convert THREAD to 'current' */ + std r6,PACACURRENT(r13) /* Set new 'current' */ + + ld r8,KSP(r4) /* new stack pointer */ +BEGIN_FTR_SECTION + clrrdi r6,r8,28 /* get its ESID */ + clrrdi r9,r1,28 /* get current sp ESID */ + clrldi. r0,r6,2 /* is new ESID c00000000? */ + cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */ + cror eq,4*cr1+eq,eq + beq 2f /* if yes, don't slbie it */ + + /* Bolt in the new stack SLB entry */ + ld r7,KSP_VSID(r4) /* Get new stack's VSID */ + oris r0,r6,(SLB_ESID_V)@h + ori r0,r0,(SLB_NUM_BOLTED-1)@l + slbie r6 + slbie r6 /* Workaround POWER5 < DD2.1 issue */ + slbmte r7,r0 + isync + +2: +END_FTR_SECTION_IFSET(CPU_FTR_SLB) + clrrdi r7,r8,THREAD_SHIFT /* base of new stack */ + /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE + because we don't need to leave the 288-byte ABI gap at the + top of the kernel stack. */ + addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE + + mr r1,r8 /* start using new stack pointer */ + std r7,PACAKSAVE(r13) + + ld r6,_CCR(r1) + mtcrf 0xFF,r6 + +#ifdef CONFIG_ALTIVEC +BEGIN_FTR_SECTION + ld r0,THREAD_VRSAVE(r4) + mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ +END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) +#endif /* CONFIG_ALTIVEC */ + + /* 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 + + .align 7 +_GLOBAL(ret_from_except) + ld r11,_TRAP(r1) + andi. r0,r11,1 + bne .ret_from_except_lite + REST_NVGPRS(r1) + +_GLOBAL(ret_from_except_lite) + /* + * Disable interrupts so that current_thread_info()->flags + * can't change between when we test it and when we return + * from the interrupt. + */ + mfmsr r10 /* Get current interrupt state */ + rldicl r9,r10,48,1 /* clear MSR_EE */ + rotldi r9,r9,16 + mtmsrd r9,1 /* Update machine state */ + +#ifdef CONFIG_PREEMPT + clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */ + li r0,_TIF_NEED_RESCHED /* bits to check */ + ld r3,_MSR(r1) + ld r4,TI_FLAGS(r9) + /* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */ + rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING + and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */ + bne do_work + +#else /* !CONFIG_PREEMPT */ + 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 r9,r1,THREAD_SHIFT + ld r4,TI_FLAGS(r9) + andi. r0,r4,_TIF_USER_WORK_MASK + bne do_work +#endif + +restore: +#ifdef CONFIG_PPC_ISERIES + ld r5,SOFTE(r1) + cmpdi 0,r5,0 + beq 4f + /* Check for pending interrupts (iSeries) */ + ld r3,PACALPPACA+LPPACAANYINT(r13) + cmpdi r3,0 + beq+ 4f /* skip do_IRQ if no interrupts */ + + li r3,0 + stb r3,PACAPROCENABLED(r13) /* ensure we are soft-disabled */ + ori r10,r10,MSR_EE + mtmsrd r10 /* hard-enable again */ + addi r3,r1,STACK_FRAME_OVERHEAD + bl .do_IRQ + b .ret_from_except_lite /* loop back and handle more */ + +4: stb r5,PACAPROCENABLED(r13) +#endif + + ld r3,_MSR(r1) + andi. r0,r3,MSR_RI + beq- unrecov_restore + + andi. r0,r3,MSR_PR + + /* + * r13 is our per cpu area, only restore it if we are returning to + * userspace + */ + beq 1f + REST_GPR(13, r1) +1: + ld r3,_CTR(r1) + ld r0,_LINK(r1) + mtctr r3 + mtlr r0 + ld r3,_XER(r1) + mtspr SPRN_XER,r3 + + REST_8GPRS(5, r1) + + stdcx. r0,0,r1 /* to clear the reservation */ + + mfmsr r0 + li r2, MSR_RI + andc r0,r0,r2 + mtmsrd r0,1 + + ld r0,_MSR(r1) + mtspr SPRN_SRR1,r0 + + ld r2,_CCR(r1) + mtcrf 0xFF,r2 + ld r2,_NIP(r1) + mtspr SPRN_SRR0,r2 + + ld r0,GPR0(r1) + ld r2,GPR2(r1) + ld r3,GPR3(r1) + ld r4,GPR4(r1) + ld r1,GPR1(r1) + + rfid + b . /* prevent speculative execution */ + +/* Note: this must change if we start using the TIF_NOTIFY_RESUME bit */ +do_work: +#ifdef CONFIG_PREEMPT + andi. r0,r3,MSR_PR /* Returning to user mode? */ + bne user_work + /* Check that preempt_count() == 0 and interrupts are enabled */ + lwz r8,TI_PREEMPT(r9) + cmpwi cr1,r8,0 +#ifdef CONFIG_PPC_ISERIES + ld r0,SOFTE(r1) + cmpdi r0,0 +#else + andi. r0,r3,MSR_EE +#endif + crandc eq,cr1*4+eq,eq + bne restore + /* here we are preempting the current task */ +1: +#ifdef CONFIG_PPC_ISERIES + li r0,1 + stb r0,PACAPROCENABLED(r13) +#endif + ori r10,r10,MSR_EE + mtmsrd r10,1 /* reenable interrupts */ + bl .preempt_schedule + mfmsr r10 + clrrdi r9,r1,THREAD_SHIFT + rldicl r10,r10,48,1 /* disable interrupts again */ + rotldi r10,r10,16 + mtmsrd r10,1 + ld r4,TI_FLAGS(r9) + andi. r0,r4,_TIF_NEED_RESCHED + bne 1b + b restore + +user_work: +#endif + /* Enable interrupts */ + ori r10,r10,MSR_EE + mtmsrd r10,1 + + andi. r0,r4,_TIF_NEED_RESCHED + beq 1f + bl .schedule + b .ret_from_except_lite + +1: bl .save_nvgprs + li r3,0 + addi r4,r1,STACK_FRAME_OVERHEAD + bl .do_signal + b .ret_from_except + +unrecov_restore: + addi r3,r1,STACK_FRAME_OVERHEAD + bl .unrecoverable_exception + b unrecov_restore + +#ifdef CONFIG_PPC_RTAS +/* + * 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,SPRN_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) + + /* There is no way it is acceptable to get here with interrupts enabled, + * check it with the asm equivalent of WARN_ON + */ + mfmsr r6 + andi. r0,r6,MSR_EE +1: tdnei r0,0 +.section __bug_table,"a" + .llong 1b,__LINE__ + 0x1000000, 1f, 2f +.previous +.section .rodata,"a" +1: .asciz __FILE__ +2: .asciz "enter_rtas" +.previous + + /* 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) + 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 SPRN_SRR0,r5 + mtspr SPRN_SRR1,r6 + rfid + b . /* prevent speculative execution */ + +_STATIC(rtas_return_loc) + /* relocation is off at this point */ + mfspr r4,SPRN_SPRG3 /* Get PACA */ + SET_REG_TO_CONST(r5, KERNELBASE) + sub r4,r4,r5 /* RELOC the PACA base pointer */ + + mfmsr r6 + li r0,MSR_RI + andc r6,r6,r0 + sync + mtmsrd r6 + + ld r1,PACAR1(r4) /* Restore our SP */ + LOADADDR(r3,.rtas_restore_regs) + ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ + + mtspr SPRN_SRR0,r3 + mtspr SPRN_SRR1,r4 + rfid + b . /* prevent speculative execution */ + +_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,SPRN_SPRG3 + + ld r4,_CCR(r1) + mtcr r4 + ld r5,_CTR(r1) + mtctr r5 + ld r6,_XER(r1) + mtspr SPRN_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 */ + +#endif /* CONFIG_PPC_RTAS */ + +#ifdef CONFIG_PPC_MULTIPLATFORM + +_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_GPR(13, r1) + SAVE_8GPRS(14, r1) + SAVE_10GPRS(22, r1) + mfcr r4 + std r4,_CCR(r1) + mfctr r5 + std r5,_CTR(r1) + mfspr r6,SPRN_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) + + /* Get the PROM entrypoint */ + ld r0,GPR4(r1) + mtlr r0 + + /* Switch MSR to 32 bits mode + */ + mfmsr r11 + 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 + + /* Restore arguments & enter PROM here... */ + ld r3,GPR3(r1) + blrl + + /* Just make sure that r1 top 32 bits didn't get + * corrupt by OF + */ + rldicl r1,r1,0,32 + + /* Restore the MSR (back to 64 bits) */ + ld r0,_MSR(r1) + mtmsrd r0 + isync + + /* Restore other registers */ + REST_GPR(2, r1) + REST_GPR(13, r1) + REST_8GPRS(14, r1) + REST_10GPRS(22, r1) + ld r4,_CCR(r1) + mtcr r4 + ld r5,_CTR(r1) + mtctr r5 + ld r6,_XER(r1) + mtspr SPRN_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) + mtlr r0 + blr + +#endif /* CONFIG_PPC_MULTIPLATFORM */ |