powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S
The system call table has been consolidated into systbl.S. We have
separate 32-bit and 64-bit versions of entry.S and misc.S since the
code is mostly sufficiently different to be not worth merging.
There are some common bits that will be extracted in future.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
new file mode 100644
index 0000000..22796e2
--- /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 .sys32_sigsuspend
+ b 70f
+
+_GLOBAL(ppc64_rt_sigsuspend)
+ bl .save_nvgprs
+ bl .sys_rt_sigsuspend
+ b 70f
+
+_GLOBAL(ppc32_rt_sigsuspend)
+ bl .save_nvgprs
+ bl .sys32_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_AUDIT
+ 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 .sys32_swapcontext
+ b 80f
+
+_GLOBAL(ppc64_swapcontext)
+ bl .save_nvgprs
+ bl .sys_swapcontext
+ b 80f
+
+_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: 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 */
