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Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
-rw-r--r-- | arch/powerpc/kernel/entry_64.S | 1354 |
1 files changed, 0 insertions, 1354 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S deleted file mode 100644 index 3fd3ef352e3f..000000000000 --- a/arch/powerpc/kernel/entry_64.S +++ /dev/null @@ -1,1354 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * 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. - */ - -#include <linux/errno.h> -#include <linux/err.h> -#include <asm/unistd.h> -#include <asm/processor.h> -#include <asm/page.h> -#include <asm/mmu.h> -#include <asm/thread_info.h> -#include <asm/code-patching-asm.h> -#include <asm/ppc_asm.h> -#include <asm/asm-offsets.h> -#include <asm/cputable.h> -#include <asm/firmware.h> -#include <asm/bug.h> -#include <asm/ptrace.h> -#include <asm/irqflags.h> -#include <asm/hw_irq.h> -#include <asm/context_tracking.h> -#include <asm/tm.h> -#include <asm/ppc-opcode.h> -#include <asm/barrier.h> -#include <asm/export.h> -#include <asm/asm-compat.h> -#ifdef CONFIG_PPC_BOOK3S -#include <asm/exception-64s.h> -#else -#include <asm/exception-64e.h> -#endif -#include <asm/feature-fixups.h> -#include <asm/kup.h> - -/* - * System calls. - */ - .section ".toc","aw" -SYS_CALL_TABLE: - .tc sys_call_table[TC],sys_call_table - -COMPAT_SYS_CALL_TABLE: - .tc compat_sys_call_table[TC],compat_sys_call_table - -/* This value is used to mark exception frames on the stack. */ -exception_marker: - .tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER - - .section ".text" - .align 7 - - .globl system_call_common -system_call_common: -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM -BEGIN_FTR_SECTION - extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */ - bne .Ltabort_syscall -END_FTR_SECTION_IFSET(CPU_FTR_TM) -#endif - mr r10,r1 - ld r1,PACAKSAVE(r13) - std r10,0(r1) - std r11,_NIP(r1) - std r12,_MSR(r1) - std r0,GPR0(r1) - std r10,GPR1(r1) -#ifdef CONFIG_PPC_FSL_BOOK3E -START_BTB_FLUSH_SECTION - BTB_FLUSH(r10) -END_BTB_FLUSH_SECTION -#endif - ACCOUNT_CPU_USER_ENTRY(r13, r10, r11) - std r2,GPR2(r1) - std r3,GPR3(r1) - mfcr r2 - 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 r11,_XER(r1) - std r11,_CTR(r1) - std r9,GPR13(r1) - mflr r10 - /* - * This clears CR0.SO (bit 28), which is the error indication on - * return from this system call. - */ - rldimi r2,r11,28,(63-28) - li r11,0xc01 - std r10,_LINK(r1) - std r11,_TRAP(r1) - std r3,ORIG_GPR3(r1) - std r2,_CCR(r1) - ld r2,PACATOC(r13) - addi r9,r1,STACK_FRAME_OVERHEAD - ld r11,exception_marker@toc(r2) - std r11,-16(r9) /* "regshere" marker */ - - kuap_check_amr r10, r11 - -#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC_SPLPAR) -BEGIN_FW_FTR_SECTION - /* see if there are any DTL entries to process */ - ld r10,PACALPPACAPTR(r13) /* get ptr to VPA */ - ld r11,PACA_DTL_RIDX(r13) /* get log read index */ - addi r10,r10,LPPACA_DTLIDX - LDX_BE r10,0,r10 /* get log write index */ - cmpd r11,r10 - beq+ 33f - bl accumulate_stolen_time - REST_GPR(0,r1) - REST_4GPRS(3,r1) - REST_2GPRS(7,r1) - addi r9,r1,STACK_FRAME_OVERHEAD -33: -END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) -#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE && CONFIG_PPC_SPLPAR */ - - /* - * A syscall should always be called with interrupts enabled - * so we just unconditionally hard-enable here. When some kind - * of irq tracing is used, we additionally check that condition - * is correct - */ -#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG) - lbz r10,PACAIRQSOFTMASK(r13) -1: tdnei r10,IRQS_ENABLED - EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - li r11,MSR_RI - ori r11,r11,MSR_EE - mtmsrd r11,1 -#endif /* CONFIG_PPC_BOOK3E */ - -system_call: /* label this so stack traces look sane */ - /* We do need to set SOFTE in the stack frame or the return - * from interrupt will be painful - */ - li r10,IRQS_ENABLED - std r10,SOFTE(r1) - - ld r11, PACA_THREAD_INFO(r13) - ld r10,TI_FLAGS(r11) - andi. r11,r10,_TIF_SYSCALL_DOTRACE - bne .Lsyscall_dotrace /* does not return */ - cmpldi 0,r0,NR_syscalls - bge- .Lsyscall_enosys - -.Lsyscall: -/* - * 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) - andis. r10,r10,_TIF_32BIT@h - beq 15f - ld r11,COMPAT_SYS_CALL_TABLE@toc(2) - 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,r0,3 - - barrier_nospec_asm - /* - * Prevent the load of the handler below (based on the user-passed - * system call number) being speculatively executed until the test - * against NR_syscalls and branch to .Lsyscall_enosys above has - * committed. - */ - - ldx r12,r11,r0 /* Fetch system call handler [ptr] */ - mtctr r12 - bctrl /* Call handler */ - - /* syscall_exit can exit to kernel mode, via ret_from_kernel_thread */ -.Lsyscall_exit: - std r3,RESULT(r1) - -#ifdef CONFIG_DEBUG_RSEQ - /* Check whether the syscall is issued inside a restartable sequence */ - addi r3,r1,STACK_FRAME_OVERHEAD - bl rseq_syscall - ld r3,RESULT(r1) -#endif - - ld r12, PACA_THREAD_INFO(r13) - - ld r8,_MSR(r1) - -/* - * This is a few instructions into the actual syscall exit path (which actually - * starts at .Lsyscall_exit) to cater to kprobe blacklisting and to reduce the - * number of visible symbols for profiling purposes. - * - * We can probe from system_call until this point as MSR_RI is set. But once it - * is cleared below, we won't be able to take a trap. - * - * This is blacklisted from kprobes further below with _ASM_NOKPROBE_SYMBOL(). - */ -system_call_exit: - /* - * Disable interrupts so current_thread_info()->flags can't change, - * and so that we don't get interrupted after loading SRR0/1. - * - * Leave MSR_RI enabled for now, because with THREAD_INFO_IN_TASK we - * could fault on the load of the TI_FLAGS below. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r11,MSR_RI - mtmsrd r11,1 -#endif /* CONFIG_PPC_BOOK3E */ - - ld r9,TI_FLAGS(r12) - li r11,-MAX_ERRNO - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) - bne- .Lsyscall_exit_work - - andi. r0,r8,MSR_FP - beq 2f -#ifdef CONFIG_ALTIVEC - andis. r0,r8,MSR_VEC@h - bne 3f -#endif -2: addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_math - ld r8,_MSR(r1) - ld r3,RESULT(r1) - li r11,-MAX_ERRNO - -3: cmpld r3,r11 - ld r5,_CCR(r1) - bge- .Lsyscall_error -.Lsyscall_error_cont: - ld r7,_NIP(r1) -BEGIN_FTR_SECTION - stdcx. r0,0,r1 /* to clear the reservation */ -END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) - andi. r6,r8,MSR_PR - ld r4,_LINK(r1) - - kuap_check_amr r10, r11 - -#ifdef CONFIG_PPC_BOOK3S - /* - * Clear MSR_RI, MSR_EE is already and remains disabled. We could do - * this later, but testing shows that doing it here causes less slow - * down than doing it closer to the rfid. - */ - li r11,0 - mtmsrd r11,1 -#endif - - beq- 1f - ACCOUNT_CPU_USER_EXIT(r13, r11, r12) - -BEGIN_FTR_SECTION - HMT_MEDIUM_LOW -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - std r8, PACATMSCRATCH(r13) -#endif - - /* - * We don't need to restore AMR on the way back to userspace for KUAP. - * The value of AMR only matters while we're in the kernel. - */ - ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ - ld r2,GPR2(r1) - ld r1,GPR1(r1) - mtlr r4 - mtcr r5 - mtspr SPRN_SRR0,r7 - mtspr SPRN_SRR1,r8 - RFI_TO_USER - b . /* prevent speculative execution */ - -1: /* exit to kernel */ - kuap_restore_amr r2 - - ld r2,GPR2(r1) - ld r1,GPR1(r1) - mtlr r4 - mtcr r5 - mtspr SPRN_SRR0,r7 - mtspr SPRN_SRR1,r8 - RFI_TO_KERNEL - b . /* prevent speculative execution */ - -.Lsyscall_error: - oris r5,r5,0x1000 /* Set SO bit in CR */ - neg r3,r3 - std r5,_CCR(r1) - b .Lsyscall_error_cont - -/* Traced system call support */ -.Lsyscall_dotrace: - bl save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_enter - - /* - * We use the return value of do_syscall_trace_enter() as the syscall - * number. If the syscall was rejected for any reason do_syscall_trace_enter() - * returns an invalid syscall number and the test below against - * NR_syscalls will fail. - */ - mr r0,r3 - - /* Restore argument registers just clobbered and/or possibly changed. */ - ld r3,GPR3(r1) - ld r4,GPR4(r1) - ld r5,GPR5(r1) - ld r6,GPR6(r1) - ld r7,GPR7(r1) - ld r8,GPR8(r1) - - /* Repopulate r9 and r10 for the syscall path */ - addi r9,r1,STACK_FRAME_OVERHEAD - ld r10, PACA_THREAD_INFO(r13) - ld r10,TI_FLAGS(r10) - - cmpldi r0,NR_syscalls - blt+ .Lsyscall - - /* Return code is already in r3 thanks to do_syscall_trace_enter() */ - b .Lsyscall_exit - - -.Lsyscall_enosys: - li r3,-ENOSYS - b .Lsyscall_exit - -.Lsyscall_exit_work: - /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. - If TIF_NOERROR is set, just save r3 as it is. */ - - andi. r0,r9,_TIF_RESTOREALL - beq+ 0f - REST_NVGPRS(r1) - b 2f -0: cmpld r3,r11 /* r11 is -MAX_ERRNO */ - blt+ 1f - andi. r0,r9,_TIF_NOERROR - bne- 1f - ld r5,_CCR(r1) - neg r3,r3 - oris r5,r5,0x1000 /* Set SO bit in CR */ - std r5,_CCR(r1) -1: std r3,GPR3(r1) -2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) - beq 4f - - /* Clear per-syscall TIF flags if any are set. */ - - li r11,_TIF_PERSYSCALL_MASK - addi r12,r12,TI_FLAGS -3: ldarx r10,0,r12 - andc r10,r10,r11 - stdcx. r10,0,r12 - bne- 3b - subi r12,r12,TI_FLAGS - -4: /* Anything else left to do? */ -BEGIN_FTR_SECTION - lis r3,DEFAULT_PPR@highest /* Set default PPR */ - sldi r3,r3,32 /* bits 11-13 are used for ppr */ - std r3,_PPR(r1) -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - - andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP) - beq ret_from_except_lite - - /* Re-enable interrupts */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 1 -#else - li r10,MSR_RI - ori r10,r10,MSR_EE - mtmsrd r10,1 -#endif /* CONFIG_PPC_BOOK3E */ - - bl save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_syscall_trace_leave - b ret_from_except - -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM -.Ltabort_syscall: - /* Firstly we need to enable TM in the kernel */ - mfmsr r10 - li r9, 1 - rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG - mtmsrd r10, 0 - - /* tabort, this dooms the transaction, nothing else */ - li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT) - TABORT(R9) - - /* - * Return directly to userspace. We have corrupted user register state, - * but userspace will never see that register state. Execution will - * resume after the tbegin of the aborted transaction with the - * checkpointed register state. - */ - li r9, MSR_RI - andc r10, r10, r9 - mtmsrd r10, 1 - mtspr SPRN_SRR0, r11 - mtspr SPRN_SRR1, r12 - RFI_TO_USER - b . /* prevent speculative execution */ -#endif -_ASM_NOKPROBE_SYMBOL(system_call_common); -_ASM_NOKPROBE_SYMBOL(system_call_exit); - -/* 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 -_ASM_NOKPROBE_SYMBOL(save_nvgprs); - - -/* - * 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(ppc_fork) - bl save_nvgprs - bl sys_fork - b .Lsyscall_exit - -_GLOBAL(ppc_vfork) - bl save_nvgprs - bl sys_vfork - b .Lsyscall_exit - -_GLOBAL(ppc_clone) - bl save_nvgprs - bl sys_clone - b .Lsyscall_exit - -_GLOBAL(ppc_clone3) - bl save_nvgprs - bl sys_clone3 - b .Lsyscall_exit - -_GLOBAL(ppc32_swapcontext) - bl save_nvgprs - bl compat_sys_swapcontext - b .Lsyscall_exit - -_GLOBAL(ppc64_swapcontext) - bl save_nvgprs - bl sys_swapcontext - b .Lsyscall_exit - -_GLOBAL(ppc_switch_endian) - bl save_nvgprs - bl sys_switch_endian - b .Lsyscall_exit - -_GLOBAL(ret_from_fork) - bl schedule_tail - REST_NVGPRS(r1) - li r3,0 - b .Lsyscall_exit - -_GLOBAL(ret_from_kernel_thread) - bl schedule_tail - REST_NVGPRS(r1) - mtlr r14 - mr r3,r15 -#ifdef PPC64_ELF_ABI_v2 - mr r12,r14 -#endif - blrl - li r3,0 - b .Lsyscall_exit - -#ifdef CONFIG_PPC_BOOK3S_64 - -#define FLUSH_COUNT_CACHE \ -1: nop; \ - patch_site 1b, patch__call_flush_count_cache - - -#define BCCTR_FLUSH .long 0x4c400420 - -.macro nops number - .rept \number - nop - .endr -.endm - -.balign 32 -.global flush_count_cache -flush_count_cache: - /* Save LR into r9 */ - mflr r9 - - // Flush the link stack - .rept 64 - bl .+4 - .endr - b 1f - nops 6 - - .balign 32 - /* Restore LR */ -1: mtlr r9 - - // If we're just flushing the link stack, return here -3: nop - patch_site 3b patch__flush_link_stack_return - - li r9,0x7fff - mtctr r9 - - BCCTR_FLUSH - -2: nop - patch_site 2b patch__flush_count_cache_return - - nops 3 - - .rept 278 - .balign 32 - BCCTR_FLUSH - nops 7 - .endr - - blr -#else -#define FLUSH_COUNT_CACHE -#endif /* CONFIG_PPC_BOOK3S_64 */ - -/* - * 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/powerpc/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) - std r0,_NIP(r1) /* Return to switch caller */ - mfcr r23 - std r23,_CCR(r1) - std r1,KSP(r3) /* Set old stack pointer */ - - kuap_check_amr r9, r10 - - FLUSH_COUNT_CACHE - - /* - * On SMP kernels, care must be taken because a task may be - * scheduled off CPUx and on to CPUy. Memory ordering must be - * considered. - * - * Cacheable stores on CPUx will be visible when the task is - * scheduled on CPUy by virtue of the core scheduler barriers - * (see "Notes on Program-Order guarantees on SMP systems." in - * kernel/sched/core.c). - * - * Uncacheable stores in the case of involuntary preemption must - * be taken care of. The smp_mb__before_spin_lock() in __schedule() - * is implemented as hwsync on powerpc, which orders MMIO too. So - * long as there is an hwsync in the context switch path, it will - * be executed on the source CPU after the task has performed - * all MMIO ops on that CPU, and on the destination CPU before the - * task performs any MMIO ops there. - */ - - /* - * The kernel context switch path must contain a spin_lock, - * which contains larx/stcx, which will clear any reservation - * of the task being switched. - */ -#ifdef CONFIG_PPC_BOOK3S -/* Cancel all explict user streams as they will have no use after context - * switch and will stop the HW from creating streams itself - */ - DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r6) -#endif - - addi r6,r4,-THREAD /* Convert THREAD to 'current' */ - std r6,PACACURRENT(r13) /* Set new 'current' */ -#if defined(CONFIG_STACKPROTECTOR) - ld r6, TASK_CANARY(r6) - std r6, PACA_CANARY(r13) -#endif - - ld r8,KSP(r4) /* new stack pointer */ -#ifdef CONFIG_PPC_BOOK3S_64 -BEGIN_MMU_FTR_SECTION - b 2f -END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) -BEGIN_FTR_SECTION - clrrdi r6,r8,28 /* get its ESID */ - clrrdi r9,r1,28 /* get current sp ESID */ -FTR_SECTION_ELSE - clrrdi r6,r8,40 /* get its 1T ESID */ - clrrdi r9,r1,40 /* get current sp 1T ESID */ -ALT_MMU_FTR_SECTION_END_IFCLR(MMU_FTR_1T_SEGMENT) - 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 -BEGIN_FTR_SECTION - li r9,MMU_SEGSIZE_1T /* insert B field */ - oris r6,r6,(MMU_SEGSIZE_1T << SLBIE_SSIZE_SHIFT)@h - rldimi r7,r9,SLB_VSID_SSIZE_SHIFT,0 -END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT) - - /* Update the last bolted SLB. No write barriers are needed - * here, provided we only update the current CPU's SLB shadow - * buffer. - */ - ld r9,PACA_SLBSHADOWPTR(r13) - li r12,0 - std r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */ - li r12,SLBSHADOW_STACKVSID - STDX_BE r7,r12,r9 /* Save VSID */ - li r12,SLBSHADOW_STACKESID - STDX_BE r0,r12,r9 /* Save ESID */ - - /* No need to check for MMU_FTR_NO_SLBIE_B here, since when - * we have 1TB segments, the only CPUs known to have the errata - * only support less than 1TB of system memory and we'll never - * actually hit this code path. - */ - - isync - slbie r6 -BEGIN_FTR_SECTION - slbie r6 /* Workaround POWER5 < DD2.1 issue */ -END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) - slbmte r7,r0 - isync -2: -#endif /* CONFIG_PPC_BOOK3S_64 */ - - 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 - - /* - * PMU interrupts in radix may come in here. They will use r1, not - * PACAKSAVE, so this stack switch will not cause a problem. They - * will store to the process stack, which may then be migrated to - * another CPU. However the rq lock release on this CPU paired with - * the rq lock acquire on the new CPU before the stack becomes - * active on the new CPU, will order those stores. - */ - mr r1,r8 /* start using new stack pointer */ - std r7,PACAKSAVE(r13) - - 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 - - .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. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r10,MSR_RI - mtmsrd r10,1 /* Update machine state */ -#endif /* CONFIG_PPC_BOOK3E */ - - ld r9, PACA_THREAD_INFO(r13) - ld r3,_MSR(r1) -#ifdef CONFIG_PPC_BOOK3E - ld r10,PACACURRENT(r13) -#endif /* CONFIG_PPC_BOOK3E */ - ld r4,TI_FLAGS(r9) - andi. r3,r3,MSR_PR - beq resume_kernel -#ifdef CONFIG_PPC_BOOK3E - lwz r3,(THREAD+THREAD_DBCR0)(r10) -#endif /* CONFIG_PPC_BOOK3E */ - - /* Check current_thread_info()->flags */ - andi. r0,r4,_TIF_USER_WORK_MASK - bne 1f -#ifdef CONFIG_PPC_BOOK3E - /* - * Check to see if the dbcr0 register is set up to debug. - * Use the internal debug mode bit to do this. - */ - andis. r0,r3,DBCR0_IDM@h - beq restore - mfmsr r0 - rlwinm r0,r0,0,~MSR_DE /* Clear MSR.DE */ - mtmsr r0 - mtspr SPRN_DBCR0,r3 - li r10, -1 - mtspr SPRN_DBSR,r10 - b restore -#else - addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_math - b restore -#endif -1: andi. r0,r4,_TIF_NEED_RESCHED - beq 2f - bl restore_interrupts - SCHEDULE_USER - b ret_from_except_lite -2: -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - andi. r0,r4,_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM - bne 3f /* only restore TM if nothing else to do */ - addi r3,r1,STACK_FRAME_OVERHEAD - bl restore_tm_state - b restore -3: -#endif - bl save_nvgprs - /* - * Use a non volatile GPR to save and restore our thread_info flags - * across the call to restore_interrupts. - */ - mr r30,r4 - bl restore_interrupts - mr r4,r30 - addi r3,r1,STACK_FRAME_OVERHEAD - bl do_notify_resume - b ret_from_except - -resume_kernel: - /* check current_thread_info, _TIF_EMULATE_STACK_STORE */ - andis. r8,r4,_TIF_EMULATE_STACK_STORE@h - beq+ 1f - - addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */ - - ld r3,GPR1(r1) - subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */ - mr r4,r1 /* src: current exception frame */ - mr r1,r3 /* Reroute the trampoline frame to r1 */ - - /* Copy from the original to the trampoline. */ - li r5,INT_FRAME_SIZE/8 /* size: INT_FRAME_SIZE */ - li r6,0 /* start offset: 0 */ - mtctr r5 -2: ldx r0,r6,r4 - stdx r0,r6,r3 - addi r6,r6,8 - bdnz 2b - - /* Do real store operation to complete stdu */ - ld r5,GPR1(r1) - std r8,0(r5) - - /* Clear _TIF_EMULATE_STACK_STORE flag */ - lis r11,_TIF_EMULATE_STACK_STORE@h - addi r5,r9,TI_FLAGS -0: ldarx r4,0,r5 - andc r4,r4,r11 - stdcx. r4,0,r5 - bne- 0b -1: - -#ifdef CONFIG_PREEMPT - /* Check if we need to preempt */ - andi. r0,r4,_TIF_NEED_RESCHED - beq+ restore - /* Check that preempt_count() == 0 and interrupts are enabled */ - lwz r8,TI_PREEMPT(r9) - cmpwi cr0,r8,0 - bne restore - ld r0,SOFTE(r1) - andi. r0,r0,IRQS_DISABLED - bne restore - - /* - * Here we are preempting the current task. We want to make - * sure we are soft-disabled first and reconcile irq state. - */ - RECONCILE_IRQ_STATE(r3,r4) - bl preempt_schedule_irq - - /* - * arch_local_irq_restore() from preempt_schedule_irq above may - * enable hard interrupt but we really should disable interrupts - * when we return from the interrupt, and so that we don't get - * interrupted after loading SRR0/1. - */ -#ifdef CONFIG_PPC_BOOK3E - wrteei 0 -#else - li r10,MSR_RI - mtmsrd r10,1 /* Update machine state */ -#endif /* CONFIG_PPC_BOOK3E */ -#endif /* CONFIG_PREEMPT */ - - .globl fast_exc_return_irq -fast_exc_return_irq: -restore: - /* - * This is the main kernel exit path. First we check if we - * are about to re-enable interrupts - */ - ld r5,SOFTE(r1) - lbz r6,PACAIRQSOFTMASK(r13) - andi. r5,r5,IRQS_DISABLED - bne .Lrestore_irq_off - - /* We are enabling, were we already enabled ? Yes, just return */ - andi. r6,r6,IRQS_DISABLED - beq cr0,.Ldo_restore - - /* - * We are about to soft-enable interrupts (we are hard disabled - * at this point). We check if there's anything that needs to - * be replayed first. - */ - lbz r0,PACAIRQHAPPENED(r13) - cmpwi cr0,r0,0 - bne- .Lrestore_check_irq_replay - - /* - * Get here when nothing happened while soft-disabled, just - * soft-enable and move-on. We will hard-enable as a side - * effect of rfi - */ -.Lrestore_no_replay: - TRACE_ENABLE_INTS - li r0,IRQS_ENABLED - stb r0,PACAIRQSOFTMASK(r13); - - /* - * Final return path. BookE is handled in a different file - */ -.Ldo_restore: -#ifdef CONFIG_PPC_BOOK3E - b exception_return_book3e -#else - /* - * Clear the reservation. If we know the CPU tracks the address of - * the reservation then we can potentially save some cycles and use - * a larx. On POWER6 and POWER7 this is significantly faster. - */ -BEGIN_FTR_SECTION - stdcx. r0,0,r1 /* to clear the reservation */ -FTR_SECTION_ELSE - ldarx r4,0,r1 -ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS) - - /* - * Some code path such as load_up_fpu or altivec return directly - * here. They run entirely hard disabled and do not alter the - * interrupt state. They also don't use lwarx/stwcx. and thus - * are known not to leave dangling reservations. - */ - .globl fast_exception_return -fast_exception_return: - ld r3,_MSR(r1) - ld r4,_CTR(r1) - ld r0,_LINK(r1) - mtctr r4 - mtlr r0 - ld r4,_XER(r1) - mtspr SPRN_XER,r4 - - kuap_check_amr r5, r6 - - REST_8GPRS(5, r1) - - andi. r0,r3,MSR_RI - beq- .Lunrecov_restore - - /* - * Clear RI before restoring r13. If we are returning to - * userspace and we take an exception after restoring r13, - * we end up corrupting the userspace r13 value. - */ - li r4,0 - mtmsrd r4,1 - -#ifdef CONFIG_PPC_TRANSACTIONAL_MEM - /* TM debug */ - std r3, PACATMSCRATCH(r13) /* Stash returned-to MSR */ -#endif - /* - * r13 is our per cpu area, only restore it if we are returning to - * userspace the value stored in the stack frame may belong to - * another CPU. - */ - andi. r0,r3,MSR_PR - beq 1f -BEGIN_FTR_SECTION - /* Restore PPR */ - ld r2,_PPR(r1) - mtspr SPRN_PPR,r2 -END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) - ACCOUNT_CPU_USER_EXIT(r13, r2, r4) - REST_GPR(13, r1) - - /* - * We don't need to restore AMR on the way back to userspace for KUAP. - * The value of AMR only matters while we're in the kernel. - */ - mtspr SPRN_SRR1,r3 - - 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) - RFI_TO_USER - b . /* prevent speculative execution */ - -1: mtspr SPRN_SRR1,r3 - - ld r2,_CCR(r1) - mtcrf 0xFF,r2 - ld r2,_NIP(r1) - mtspr SPRN_SRR0,r2 - - /* - * Leaving a stale exception_marker on the stack can confuse - * the reliable stack unwinder later on. Clear it. - */ - li r2,0 - std r2,STACK_FRAME_OVERHEAD-16(r1) - - ld r0,GPR0(r1) - ld r2,GPR2(r1) - ld r3,GPR3(r1) - - kuap_restore_amr r4 - - ld r4,GPR4(r1) - ld r1,GPR1(r1) - RFI_TO_KERNEL - b . /* prevent speculative execution */ - -#endif /* CONFIG_PPC_BOOK3E */ - - /* - * We are returning to a context with interrupts soft disabled. - * - * However, we may also about to hard enable, so we need to - * make sure that in this case, we also clear PACA_IRQ_HARD_DIS - * or that bit can get out of sync and bad things will happen - */ -.Lrestore_irq_off: - ld r3,_MSR(r1) - lbz r7,PACAIRQHAPPENED(r13) - andi. r0,r3,MSR_EE - beq 1f - rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS - stb r7,PACAIRQHAPPENED(r13) -1: -#if defined(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG) && defined(CONFIG_BUG) - /* The interrupt should not have soft enabled. */ - lbz r7,PACAIRQSOFTMASK(r13) -1: tdeqi r7,IRQS_ENABLED - EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - b .Ldo_restore - - /* - * Something did happen, check if a re-emit is needed - * (this also clears paca->irq_happened) - */ -.Lrestore_check_irq_replay: - /* XXX: We could implement a fast path here where we check - * for irq_happened being just 0x01, in which case we can - * clear it and return. That means that we would potentially - * miss a decrementer having wrapped all the way around. - * - * Still, this might be useful for things like hash_page - */ - bl __check_irq_replay - cmpwi cr0,r3,0 - beq .Lrestore_no_replay - - /* - * We need to re-emit an interrupt. We do so by re-using our - * existing exception frame. We first change the trap value, - * but we need to ensure we preserve the low nibble of it - */ - ld r4,_TRAP(r1) - clrldi r4,r4,60 - or r4,r4,r3 - std r4,_TRAP(r1) - - /* - * PACA_IRQ_HARD_DIS won't always be set here, so set it now - * to reconcile the IRQ state. Tracing is already accounted for. - */ - lbz r4,PACAIRQHAPPENED(r13) - ori r4,r4,PACA_IRQ_HARD_DIS - stb r4,PACAIRQHAPPENED(r13) - - /* - * Then find the right handler and call it. Interrupts are - * still soft-disabled and we keep them that way. - */ - cmpwi cr0,r3,0x500 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl do_IRQ - b ret_from_except -1: cmpwi cr0,r3,0xf00 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl performance_monitor_exception - b ret_from_except -1: cmpwi cr0,r3,0xe60 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl handle_hmi_exception - b ret_from_except -1: cmpwi cr0,r3,0x900 - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl timer_interrupt - b ret_from_except -#ifdef CONFIG_PPC_DOORBELL -1: -#ifdef CONFIG_PPC_BOOK3E - cmpwi cr0,r3,0x280 -#else - cmpwi cr0,r3,0xa00 -#endif /* CONFIG_PPC_BOOK3E */ - bne 1f - addi r3,r1,STACK_FRAME_OVERHEAD; - bl doorbell_exception -#endif /* CONFIG_PPC_DOORBELL */ -1: b ret_from_except /* What else to do here ? */ - -.Lunrecov_restore: - addi r3,r1,STACK_FRAME_OVERHEAD - bl unrecoverable_exception - b .Lunrecov_restore - -_ASM_NOKPROBE_SYMBOL(ret_from_except); -_ASM_NOKPROBE_SYMBOL(ret_from_except_lite); -_ASM_NOKPROBE_SYMBOL(resume_kernel); -_ASM_NOKPROBE_SYMBOL(fast_exc_return_irq); -_ASM_NOKPROBE_SYMBOL(restore); -_ASM_NOKPROBE_SYMBOL(fast_exception_return); - - -#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,-SWITCH_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) - - /* Temporary workaround to clear CR until RTAS can be modified to - * ignore all bits. - */ - li r0,0 - mtcr r0 - -#ifdef CONFIG_BUG - /* There is no way it is acceptable to get here with interrupts enabled, - * check it with the asm equivalent of WARN_ON - */ - lbz r0,PACAIRQSOFTMASK(r13) -1: tdeqi r0,IRQS_ENABLED - EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - - /* Hard-disable interrupts */ - mfmsr r6 - rldicl r7,r6,48,1 - rotldi r7,r7,16 - mtmsrd r7,1 - - /* 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 */ - LOAD_REG_ADDR(r4,rtas_return_loc) - clrldi r4,r4,2 /* convert to realmode address */ - 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|MSR_LE - andc r6,r0,r9 - -__enter_rtas: - sync /* disable interrupts so SRR0/1 */ - mtmsrd r0 /* don't get trashed */ - - LOAD_REG_ADDR(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 - RFI_TO_KERNEL - b . /* prevent speculative execution */ - -rtas_return_loc: - FIXUP_ENDIAN - - /* - * Clear RI and set SF before anything. - */ - mfmsr r6 - li r0,MSR_RI - andc r6,r6,r0 - sldi r0,r0,(MSR_SF_LG - MSR_RI_LG) - or r6,r6,r0 - sync - mtmsrd r6 - - /* relocation is off at this point */ - GET_PACA(r4) - clrldi r4,r4,2 /* convert to realmode address */ - - bcl 20,31,$+4 -0: mflr r3 - ld r3,(1f-0b)(r3) /* get &rtas_restore_regs */ - - ld r1,PACAR1(r4) /* Restore our SP */ - ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ - - mtspr SPRN_SRR0,r3 - mtspr SPRN_SRR1,r4 - RFI_TO_KERNEL - b . /* prevent speculative execution */ -_ASM_NOKPROBE_SYMBOL(__enter_rtas) -_ASM_NOKPROBE_SYMBOL(rtas_return_loc) - - .align 3 -1: .8byte rtas_restore_regs - -rtas_restore_regs: - /* relocation is on at this point */ - REST_GPR(2, r1) /* Restore the TOC */ - REST_GPR(13, r1) /* Restore paca */ - REST_8GPRS(14, r1) /* Restore the non-volatiles */ - REST_10GPRS(22, r1) /* ditto */ - - GET_PACA(r13) - - ld r4,_CCR(r1) - mtcr r4 - ld r5,_CTR(r1) - mtctr r5 - ld r6,_XER(r1) - mtspr SPRN_XER,r6 - ld r7,_DAR(r1) - mtdar r7 - ld r8,_DSISR(r1) - mtdsisr r8 - - addi r1,r1,SWITCH_FRAME_SIZE /* Unstack our frame */ - ld r0,16(r1) /* get return address */ - - mtlr r0 - blr /* return to caller */ - -#endif /* CONFIG_PPC_RTAS */ - -_GLOBAL(enter_prom) - mflr r0 - std r0,16(r1) - stdu r1,-SWITCH_FRAME_SIZE(r1) /* Save SP and create stack space */ - - /* Because PROM is running in 32b mode, it clobbers the high order half - * of all registers that it saves. We therefore save those registers - * PROM might touch to the stack. (r0, r3-r13 are caller saved) - */ - SAVE_GPR(2, r1) - SAVE_GPR(13, r1) - SAVE_8GPRS(14, r1) - SAVE_10GPRS(22, r1) - mfcr r10 - mfmsr r11 - std r10,_CCR(r1) - std r11,_MSR(r1) - - /* Put PROM address in SRR0 */ - mtsrr0 r4 - - /* Setup our trampoline return addr in LR */ - bcl 20,31,$+4 -0: mflr r4 - addi r4,r4,(1f - 0b) - mtlr r4 - - /* Prepare a 32-bit mode big endian MSR - */ -#ifdef CONFIG_PPC_BOOK3E - rlwinm r11,r11,0,1,31 - mtsrr1 r11 - rfi -#else /* CONFIG_PPC_BOOK3E */ - LOAD_REG_IMMEDIATE(r12, MSR_SF | MSR_ISF | MSR_LE) - andc r11,r11,r12 - mtsrr1 r11 - RFI_TO_KERNEL -#endif /* CONFIG_PPC_BOOK3E */ - -1: /* Return from OF */ - FIXUP_ENDIAN - - /* 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 - - addi r1,r1,SWITCH_FRAME_SIZE - ld r0,16(r1) - mtlr r0 - blr |