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alistair23-linux/arch/powerpc/kernel/entry_32.S

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Rewritten by Cort Dougan (cort@fsmlabs.com) for PReP
* Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com>
* 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 <linux/sys.h>
#include <linux/threads.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/ptrace.h>
#include <asm/export.h>
#include <asm/asm-405.h>
#include <asm/feature-fixups.h>
#include <asm/barrier.h>
#include <asm/kup.h>
#include <asm/bug.h>
#include "head_32.h"
/*
* Align to 4k in order to ensure that all functions modyfing srr0/srr1
* fit into one page in order to not encounter a TLB miss between the
* modification of srr0/srr1 and the associated rfi.
*/
.align 12
#ifdef CONFIG_BOOKE
.globl mcheck_transfer_to_handler
mcheck_transfer_to_handler:
mfspr r0,SPRN_DSRR0
stw r0,_DSRR0(r11)
mfspr r0,SPRN_DSRR1
stw r0,_DSRR1(r11)
/* fall through */
.globl debug_transfer_to_handler
debug_transfer_to_handler:
mfspr r0,SPRN_CSRR0
stw r0,_CSRR0(r11)
mfspr r0,SPRN_CSRR1
stw r0,_CSRR1(r11)
/* fall through */
.globl crit_transfer_to_handler
crit_transfer_to_handler:
#ifdef CONFIG_PPC_BOOK3E_MMU
mfspr r0,SPRN_MAS0
stw r0,MAS0(r11)
mfspr r0,SPRN_MAS1
stw r0,MAS1(r11)
mfspr r0,SPRN_MAS2
stw r0,MAS2(r11)
mfspr r0,SPRN_MAS3
stw r0,MAS3(r11)
mfspr r0,SPRN_MAS6
stw r0,MAS6(r11)
#ifdef CONFIG_PHYS_64BIT
mfspr r0,SPRN_MAS7
stw r0,MAS7(r11)
#endif /* CONFIG_PHYS_64BIT */
#endif /* CONFIG_PPC_BOOK3E_MMU */
#ifdef CONFIG_44x
mfspr r0,SPRN_MMUCR
stw r0,MMUCR(r11)
#endif
mfspr r0,SPRN_SRR0
stw r0,_SRR0(r11)
mfspr r0,SPRN_SRR1
stw r0,_SRR1(r11)
/* set the stack limit to the current stack */
mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)
stw r0,SAVED_KSP_LIMIT(r11)
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
#endif
#ifdef CONFIG_40x
.globl crit_transfer_to_handler
crit_transfer_to_handler:
lwz r0,crit_r10@l(0)
stw r0,GPR10(r11)
lwz r0,crit_r11@l(0)
stw r0,GPR11(r11)
mfspr r0,SPRN_SRR0
stw r0,crit_srr0@l(0)
mfspr r0,SPRN_SRR1
stw r0,crit_srr1@l(0)
/* set the stack limit to the current stack */
mfspr r8,SPRN_SPRG_THREAD
lwz r0,KSP_LIMIT(r8)
stw r0,saved_ksp_limit@l(0)
rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
stw r0,KSP_LIMIT(r8)
/* fall through */
#endif
/*
* This code finishes saving the registers to the exception frame
* and jumps to the appropriate handler for the exception, turning
* on address translation.
* Note that we rely on the caller having set cr0.eq iff the exception
* occurred in kernel mode (i.e. MSR:PR = 0).
*/
.globl transfer_to_handler_full
transfer_to_handler_full:
SAVE_NVGPRS(r11)
/* fall through */
.globl transfer_to_handler
transfer_to_handler:
stw r2,GPR2(r11)
stw r12,_NIP(r11)
stw r9,_MSR(r11)
andi. r2,r9,MSR_PR
mfctr r12
mfspr r2,SPRN_XER
stw r12,_CTR(r11)
stw r2,_XER(r11)
mfspr r12,SPRN_SPRG_THREAD
beq 2f /* if from user, fix up THREAD.regs */
addi r2, r12, -THREAD
addi r11,r1,STACK_FRAME_OVERHEAD
stw r11,PT_REGS(r12)
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
/* Check to see if the dbcr0 register is set up to debug. Use the
internal debug mode bit to do this. */
lwz r12,THREAD_DBCR0(r12)
andis. r12,r12,DBCR0_IDM@h
#endif
ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_lock r11, r12
#endif
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
beq+ 3f
/* From user and task is ptraced - load up global dbcr0 */
li r12,-1 /* clear all pending debug events */
mtspr SPRN_DBSR,r12
lis r11,global_dbcr0@ha
tophys(r11,r11)
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)
slwi r9,r9,3
add r11,r11,r9
#endif
lwz r12,0(r11)
mtspr SPRN_DBCR0,r12
lwz r12,4(r11)
addi r12,r12,-1
stw r12,4(r11)
#endif
b 3f
2: /* if from kernel, check interrupted DOZE/NAP mode and
* check for stack overflow
*/
powerpc/32s: Fix CPU wake-up from sleep mode commit 9933819099c4600b41a042f27a074470a43cf6b9 upstream. Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when _TLF_SLEEPING is set) by delaying the tovirt(r2, r2). This is because r2 is not restored by fast_exception_return. It used to work (by chance ?) because CPU wake-up interrupt never comes from user, so r2 is expected to point to 'current' on return. Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") broke it even more by clobbering r0 which is not restored by fast_exception_return either. Use r6 instead of r0. This is possible because r3-r6 are restored by fast_exception_return and only r3-r5 are used for exception arguments. For r2 it could be converted back to virtual address, but stay on the safe side and restore it from the stack instead. It should be live in the cache at that moment, so loading from the stack should make no difference compared to converting it from phys to virt. Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27 03:42:04 -07:00
kuap_save_and_lock r11, r12, r9, r2, r6
addi r2, r12, -THREAD
lwz r9,KSP_LIMIT(r12)
cmplw r1,r9 /* if r1 <= ksp_limit */
ble- stack_ovf /* then the kernel stack overflowed */
5:
#if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
lwz r12,TI_LOCAL_FLAGS(r2)
mtcrf 0x01,r12
bt- 31-TLF_NAPPING,4f
bt- 31-TLF_SLEEPING,7f
#endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */
.globl transfer_to_handler_cont
transfer_to_handler_cont:
3:
mflr r9
tovirt(r2, r2) /* set r2 to current */
lwz r11,0(r9) /* virtual address of handler */
lwz r9,4(r9) /* where to go when done */
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
powerpc/8xx: Perf events on PPC 8xx This patch has been reworked since RFC version. In the RFC, this patch was preceded by a patch clearing MSR RI for all PPC32 at all time at exception prologs. Now MSR RI clearing is done only when this 8xx perf events functionality is compiled in, it is therefore limited to 8xx and merged inside this patch. Other main changes have been to take into account detailed review from Peter Zijlstra. The instructions counter has been reworked to behave as a free running counter like the three other counters. The 8xx has no PMU, however some events can be emulated by other means. This patch implements the following events (as reported by 'perf list'): cpu-cycles OR cycles [Hardware event] instructions [Hardware event] dTLB-load-misses [Hardware cache event] iTLB-load-misses [Hardware cache event] 'cycles' event is implemented using the timebase clock. Timebase clock corresponds to CPU clock divided by 16, so number of cycles is approximatly 16 times the number of TB ticks On the 8xx, TLB misses are handled by software. It is therefore easy to count all TLB misses each time the TLB miss exception is called. 'instructions' is calculated by using instruction watchpoint counter. This patch sets counter A to count instructions at address greater than 0, hence we count all instructions executed while MSR RI bit is set. The counter is set to the maximum which is 0xffff. Every 65535 instructions, debug instruction breakpoint exception fires. The exception handler increments a counter in memory which then represent the upper part of the instruction counter. We therefore end up with a 48 bits counter. In order to avoid unnecessary overhead while no perf event is active, this counter is started when the first event referring to this counter is added, and the counter is stopped when the last event referring to it is deleted. In order to properly support breakpoint exceptions, MSR RI bit has to be unset in exception epilogs in order to avoid breakpoint exceptions during critical sections during changes to SRR0 and SRR1 would be problematic. All counters are handled as free running counters. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-12-15 05:42:18 -07:00
mtspr SPRN_NRI, r0
#endif
#ifdef CONFIG_TRACE_IRQFLAGS
/*
* When tracing IRQ state (lockdep) we enable the MMU before we call
* the IRQ tracing functions as they might access vmalloc space or
* perform IOs for console output.
*
* To speed up the syscall path where interrupts stay on, let's check
* first if we are changing the MSR value at all.
*/
tophys(r12, r1)
lwz r12,_MSR(r12)
andi. r12,r12,MSR_EE
bne 1f
/* MSR isn't changing, just transition directly */
#endif
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r10
mtlr r9
SYNC
RFI /* jump to handler, enable MMU */
#ifdef CONFIG_TRACE_IRQFLAGS
1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
* keep interrupts disabled at this point otherwise we might risk
* taking an interrupt before we tell lockdep they are enabled.
*/
lis r12,reenable_mmu@h
ori r12,r12,reenable_mmu@l
LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
mtspr SPRN_SRR0,r12
mtspr SPRN_SRR1,r0
SYNC
RFI
reenable_mmu:
powerpc/trace: Add a dummy stack frame for trace_hardirqs_off The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. If an exception occurs in user mode, there is only one stack frame on the stack and accessing the CALLER_ADDR1 will causes the following call trace. So we create a dummy stack frame to make trace_hardirqs_off happy. WARNING: at kernel/smp.c:459 Modules linked in: NIP: c0093280 LR: c00930a0 CTR: c0010780 REGS: edb87ae0 TRAP: 0700 Not tainted (3.1.0) MSR: 00021002 <ME,CE> CR: 28002888 XER: 00000000 TASK = edce2ac0[17658] 'mthread-lock-on' THREAD: edb86000 CPU: 5 GPR00: 00000001 edb87b90 edce2ac0 00000005 c0019594 edb87bd8 00000001 00000fe3 GPR08: 00041000 c084138c 4e20120d edb87b90 48002888 1001aa7c 00000000 00000000 GPR16: 48830000 10012a8c 00000000 10000af4 00000001 c0810000 00000000 00000000 GPR24: ee9aa920 c0816a18 00000000 00000005 c0019594 edb87bd8 ee20178c edb87b90 NIP [c0093280] smp_call_function_many+0x214/0x2b4 LR [c00930a0] smp_call_function_many+0x34/0x2b4 Call Trace: [edb87b90] [c00930a0] smp_call_function_many+0x34/0x2b4 (unreliable) [edb87bd0] [c00194ec] __flush_tlb_page+0xac/0x100 [edb87c00] [c001957c] flush_tlb_page+0x3c/0x54 [edb87c10] [c00180ac] ptep_set_access_flags+0x74/0x12c [edb87c40] [c0128068] handle_pte_fault+0x2f0/0x9ac [edb87cb0] [c0128c3c] handle_mm_fault+0x104/0x1dc [edb87ce0] [c05f40f4] do_page_fault+0x2dc/0x630 [edb87e50] [c001078c] handle_page_fault+0xc/0x80 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-10 09:04:17 -07:00
/*
* We save a bunch of GPRs,
* r3 can be different from GPR3(r1) at this point, r9 and r11
* contains the old MSR and handler address respectively,
* r4 & r5 can contain page fault arguments that need to be passed
* along as well. r12, CCR, CTR, XER etc... are left clobbered as
* they aren't useful past this point (aren't syscall arguments),
* the rest is restored from the exception frame.
powerpc/trace: Add a dummy stack frame for trace_hardirqs_off The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1. If an exception occurs in user mode, there is only one stack frame on the stack and accessing the CALLER_ADDR1 will causes the following call trace. So we create a dummy stack frame to make trace_hardirqs_off happy. WARNING: at kernel/smp.c:459 Modules linked in: NIP: c0093280 LR: c00930a0 CTR: c0010780 REGS: edb87ae0 TRAP: 0700 Not tainted (3.1.0) MSR: 00021002 <ME,CE> CR: 28002888 XER: 00000000 TASK = edce2ac0[17658] 'mthread-lock-on' THREAD: edb86000 CPU: 5 GPR00: 00000001 edb87b90 edce2ac0 00000005 c0019594 edb87bd8 00000001 00000fe3 GPR08: 00041000 c084138c 4e20120d edb87b90 48002888 1001aa7c 00000000 00000000 GPR16: 48830000 10012a8c 00000000 10000af4 00000001 c0810000 00000000 00000000 GPR24: ee9aa920 c0816a18 00000000 00000005 c0019594 edb87bd8 ee20178c edb87b90 NIP [c0093280] smp_call_function_many+0x214/0x2b4 LR [c00930a0] smp_call_function_many+0x34/0x2b4 Call Trace: [edb87b90] [c00930a0] smp_call_function_many+0x34/0x2b4 (unreliable) [edb87bd0] [c00194ec] __flush_tlb_page+0xac/0x100 [edb87c00] [c001957c] flush_tlb_page+0x3c/0x54 [edb87c10] [c00180ac] ptep_set_access_flags+0x74/0x12c [edb87c40] [c0128068] handle_pte_fault+0x2f0/0x9ac [edb87cb0] [c0128c3c] handle_mm_fault+0x104/0x1dc [edb87ce0] [c05f40f4] do_page_fault+0x2dc/0x630 [edb87e50] [c001078c] handle_page_fault+0xc/0x80 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-10 09:04:17 -07:00
*/
stwu r1,-32(r1)
stw r9,8(r1)
stw r11,12(r1)
stw r3,16(r1)
stw r4,20(r1)
stw r5,24(r1)
/* If we are disabling interrupts (normal case), simply log it with
* lockdep
*/
1: bl trace_hardirqs_off
2: lwz r5,24(r1)
lwz r4,20(r1)
lwz r3,16(r1)
lwz r11,12(r1)
lwz r9,8(r1)
addi r1,r1,32
lwz r0,GPR0(r1)
lwz r6,GPR6(r1)
lwz r7,GPR7(r1)
lwz r8,GPR8(r1)
mtctr r11
mtlr r9
bctr /* jump to handler */
#endif /* CONFIG_TRACE_IRQFLAGS */
#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
4: rlwinm r12,r12,0,~_TLF_NAPPING
stw r12,TI_LOCAL_FLAGS(r2)
b power_save_ppc32_restore
7: rlwinm r12,r12,0,~_TLF_SLEEPING
stw r12,TI_LOCAL_FLAGS(r2)
lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
rlwinm r9,r9,0,~MSR_EE
lwz r12,_LINK(r11) /* and return to address in LR */
kuap_restore r11, r2, r3, r4, r5
powerpc/32s: Fix CPU wake-up from sleep mode commit 9933819099c4600b41a042f27a074470a43cf6b9 upstream. Commit f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") broke the CPU wake-up from sleep mode (i.e. when _TLF_SLEEPING is set) by delaying the tovirt(r2, r2). This is because r2 is not restored by fast_exception_return. It used to work (by chance ?) because CPU wake-up interrupt never comes from user, so r2 is expected to point to 'current' on return. Commit e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") broke it even more by clobbering r0 which is not restored by fast_exception_return either. Use r6 instead of r0. This is possible because r3-r6 are restored by fast_exception_return and only r3-r5 are used for exception arguments. For r2 it could be converted back to virtual address, but stay on the safe side and restore it from the stack instead. It should be live in the cache at that moment, so loading from the stack should make no difference compared to converting it from phys to virt. Fixes: f7354ccac844 ("powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU") Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6d02c3ae6ad77af34392e98117e44c2bf6d13ba1.1580121710.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27 03:42:04 -07:00
lwz r2, GPR2(r11)
b fast_exception_return
#endif
/*
* On kernel stack overflow, load up an initial stack pointer
* and call StackOverflow(regs), which should not return.
*/
stack_ovf:
/* sometimes we use a statically-allocated stack, which is OK. */
lis r12,_end@h
ori r12,r12,_end@l
cmplw r1,r12
ble 5b /* r1 <= &_end is OK */
SAVE_NVGPRS(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
lis r1,init_thread_union@ha
addi r1,r1,init_thread_union@l
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
lis r9,StackOverflow@ha
addi r9,r9,StackOverflow@l
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
powerpc/8xx: Perf events on PPC 8xx This patch has been reworked since RFC version. In the RFC, this patch was preceded by a patch clearing MSR RI for all PPC32 at all time at exception prologs. Now MSR RI clearing is done only when this 8xx perf events functionality is compiled in, it is therefore limited to 8xx and merged inside this patch. Other main changes have been to take into account detailed review from Peter Zijlstra. The instructions counter has been reworked to behave as a free running counter like the three other counters. The 8xx has no PMU, however some events can be emulated by other means. This patch implements the following events (as reported by 'perf list'): cpu-cycles OR cycles [Hardware event] instructions [Hardware event] dTLB-load-misses [Hardware cache event] iTLB-load-misses [Hardware cache event] 'cycles' event is implemented using the timebase clock. Timebase clock corresponds to CPU clock divided by 16, so number of cycles is approximatly 16 times the number of TB ticks On the 8xx, TLB misses are handled by software. It is therefore easy to count all TLB misses each time the TLB miss exception is called. 'instructions' is calculated by using instruction watchpoint counter. This patch sets counter A to count instructions at address greater than 0, hence we count all instructions executed while MSR RI bit is set. The counter is set to the maximum which is 0xffff. Every 65535 instructions, debug instruction breakpoint exception fires. The exception handler increments a counter in memory which then represent the upper part of the instruction counter. We therefore end up with a 48 bits counter. In order to avoid unnecessary overhead while no perf event is active, this counter is started when the first event referring to this counter is added, and the counter is stopped when the last event referring to it is deleted. In order to properly support breakpoint exceptions, MSR RI bit has to be unset in exception epilogs in order to avoid breakpoint exceptions during critical sections during changes to SRR0 and SRR1 would be problematic. All counters are handled as free running counters. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-12-15 05:42:18 -07:00
mtspr SPRN_NRI, r0
#endif
mtspr SPRN_SRR0,r9
mtspr SPRN_SRR1,r10
SYNC
RFI
#ifdef CONFIG_TRACE_IRQFLAGS
trace_syscall_entry_irq_off:
/*
* Syscall shouldn't happen while interrupts are disabled,
* so let's do a warning here.
*/
0: trap
EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
bl trace_hardirqs_on
/* Now enable for real */
LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
mtmsr r10
REST_GPR(0, r1)
REST_4GPRS(3, r1)
REST_2GPRS(7, r1)
b DoSyscall
#endif /* CONFIG_TRACE_IRQFLAGS */
.globl transfer_to_syscall
transfer_to_syscall:
#ifdef CONFIG_TRACE_IRQFLAGS
andi. r12,r9,MSR_EE
beq- trace_syscall_entry_irq_off
#endif /* CONFIG_TRACE_IRQFLAGS */
/*
* Handle a system call.
*/
.stabs "arch/powerpc/kernel/",N_SO,0,0,0f
.stabs "entry_32.S",N_SO,0,0,0f
0:
_GLOBAL(DoSyscall)
stw r3,ORIG_GPR3(r1)
li r12,0
stw r12,RESULT(r1)
#ifdef CONFIG_TRACE_IRQFLAGS
/* Make sure interrupts are enabled */
mfmsr r11
andi. r12,r11,MSR_EE
/* We came in with interrupts disabled, we WARN and mark them enabled
* for lockdep now */
0: tweqi r12, 0
EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
#endif /* CONFIG_TRACE_IRQFLAGS */
lwz r11,TI_FLAGS(r2)
andi. r11,r11,_TIF_SYSCALL_DOTRACE
bne- syscall_dotrace
syscall_dotrace_cont:
cmplwi 0,r0,NR_syscalls
lis r10,sys_call_table@h
ori r10,r10,sys_call_table@l
slwi r0,r0,2
bge- 66f
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 .66f above has
* committed.
*/
lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
mtlr r10
addi r9,r1,STACK_FRAME_OVERHEAD
PPC440EP_ERR42
blrl /* Call handler */
.globl ret_from_syscall
ret_from_syscall:
powerpc: Add syscall detection for restartable sequences Syscalls are not allowed inside restartable sequences, so add a call to rseq_syscall() at the very beginning of system call exiting path for CONFIG_DEBUG_RSEQ=y kernel. This could help us to detect whether there is a syscall issued inside restartable sequences. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Watson <davejwatson@fb.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Chris Lameter <cl@linux.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Hunter <ahh@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Paul Turner <pjt@google.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Maurer <bmaurer@fb.com> Cc: linux-api@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lkml.kernel.org/r/20180602124408.8430-10-mathieu.desnoyers@efficios.com
2018-06-02 06:44:01 -06:00
#ifdef CONFIG_DEBUG_RSEQ
/* Check whether the syscall is issued inside a restartable sequence */
stw r3,GPR3(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl rseq_syscall
lwz r3,GPR3(r1)
#endif
mr r6,r3
/* disable interrupts so current_thread_info()->flags can't change */
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL) /* doesn't include MSR_EE */
/* Note: We don't bother telling lockdep about it */
SYNC
MTMSRD(r10)
lwz r9,TI_FLAGS(r2)
li r8,-MAX_ERRNO
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
bne- syscall_exit_work
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
cmplw 0,r3,r8
blt+ syscall_exit_cont
lwz r11,_CCR(r1) /* Load CR */
neg r3,r3
oris r11,r11,0x1000 /* Set SO bit in CR */
stw r11,_CCR(r1)
syscall_exit_cont:
lwz r8,_MSR(r1)
#ifdef CONFIG_TRACE_IRQFLAGS
/* If we are going to return from the syscall with interrupts
* off, we trace that here. It shouldn't normally happen.
*/
andi. r10,r8,MSR_EE
bne+ 1f
stw r3,GPR3(r1)
bl trace_hardirqs_off
lwz r3,GPR3(r1)
1:
#endif /* CONFIG_TRACE_IRQFLAGS */
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* If the process has its own DBCR0 value, load it up. The internal
debug mode bit tells us that dbcr0 should be loaded. */
lwz r0,THREAD+THREAD_DBCR0(r2)
andis. r10,r0,DBCR0_IDM@h
bnel- load_dbcr0
#endif
#ifdef CONFIG_44x
BEGIN_MMU_FTR_SECTION
lis r4,icache_44x_need_flush@ha
lwz r5,icache_44x_need_flush@l(r4)
cmplwi cr0,r5,0
bne- 2f
1:
END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x)
#endif /* CONFIG_44x */
BEGIN_FTR_SECTION
lwarx r7,0,r1
END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
stwcx. r0,0,r1 /* to clear the reservation */
ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_unlock r5, r7
#endif
kuap_check r2, r4
lwz r4,_LINK(r1)
lwz r5,_CCR(r1)
mtlr r4
mtcr r5
lwz r7,_NIP(r1)
lwz r2,GPR2(r1)
lwz r1,GPR1(r1)
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
powerpc/8xx: Perf events on PPC 8xx This patch has been reworked since RFC version. In the RFC, this patch was preceded by a patch clearing MSR RI for all PPC32 at all time at exception prologs. Now MSR RI clearing is done only when this 8xx perf events functionality is compiled in, it is therefore limited to 8xx and merged inside this patch. Other main changes have been to take into account detailed review from Peter Zijlstra. The instructions counter has been reworked to behave as a free running counter like the three other counters. The 8xx has no PMU, however some events can be emulated by other means. This patch implements the following events (as reported by 'perf list'): cpu-cycles OR cycles [Hardware event] instructions [Hardware event] dTLB-load-misses [Hardware cache event] iTLB-load-misses [Hardware cache event] 'cycles' event is implemented using the timebase clock. Timebase clock corresponds to CPU clock divided by 16, so number of cycles is approximatly 16 times the number of TB ticks On the 8xx, TLB misses are handled by software. It is therefore easy to count all TLB misses each time the TLB miss exception is called. 'instructions' is calculated by using instruction watchpoint counter. This patch sets counter A to count instructions at address greater than 0, hence we count all instructions executed while MSR RI bit is set. The counter is set to the maximum which is 0xffff. Every 65535 instructions, debug instruction breakpoint exception fires. The exception handler increments a counter in memory which then represent the upper part of the instruction counter. We therefore end up with a 48 bits counter. In order to avoid unnecessary overhead while no perf event is active, this counter is started when the first event referring to this counter is added, and the counter is stopped when the last event referring to it is deleted. In order to properly support breakpoint exceptions, MSR RI bit has to be unset in exception epilogs in order to avoid breakpoint exceptions during critical sections during changes to SRR0 and SRR1 would be problematic. All counters are handled as free running counters. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-12-15 05:42:18 -07:00
mtspr SPRN_NRI, r0
#endif
mtspr SPRN_SRR0,r7
mtspr SPRN_SRR1,r8
SYNC
RFI
#ifdef CONFIG_44x
2: li r7,0
iccci r0,r0
stw r7,icache_44x_need_flush@l(r4)
b 1b
#endif /* CONFIG_44x */
66: li r3,-ENOSYS
b ret_from_syscall
.globl ret_from_fork
ret_from_fork:
REST_NVGPRS(r1)
bl schedule_tail
li r3,0
b ret_from_syscall
.globl ret_from_kernel_thread
ret_from_kernel_thread:
REST_NVGPRS(r1)
bl schedule_tail
mtlr r14
mr r3,r15
PPC440EP_ERR42
blrl
li r3,0
b ret_from_syscall
/* Traced system call support */
syscall_dotrace:
SAVE_NVGPRS(r1)
li r0,0xc00
stw r0,_TRAP(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_syscall_trace_enter
/*
* Restore argument registers possibly just changed.
* We use the return value of do_syscall_trace_enter
* for call number to look up in the table (r0).
*/
mr r0,r3
lwz r3,GPR3(r1)
lwz r4,GPR4(r1)
lwz r5,GPR5(r1)
lwz r6,GPR6(r1)
lwz r7,GPR7(r1)
lwz r8,GPR8(r1)
REST_NVGPRS(r1)
cmplwi r0,NR_syscalls
/* Return code is already in r3 thanks to do_syscall_trace_enter() */
bge- ret_from_syscall
b syscall_dotrace_cont
syscall_exit_work:
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
andi. r0,r9,_TIF_RESTOREALL
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
beq+ 0f
REST_NVGPRS(r1)
b 2f
0: cmplw 0,r3,r8
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
blt+ 1f
andi. r0,r9,_TIF_NOERROR
bne- 1f
lwz r11,_CCR(r1) /* Load CR */
neg r3,r3
oris r11,r11,0x1000 /* Set SO bit in CR */
stw r11,_CCR(r1)
1: stw r6,RESULT(r1) /* Save result */
stw r3,GPR3(r1) /* Update return value */
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
beq 4f
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
/* Clear per-syscall TIF flags if any are set. */
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
li r11,_TIF_PERSYSCALL_MASK
addi r12,r2,TI_FLAGS
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
3: lwarx r8,0,r12
andc r8,r8,r11
#ifdef CONFIG_IBM405_ERR77
dcbt 0,r12
#endif
stwcx. r8,0,r12
bne- 3b
4: /* Anything which requires enabling interrupts? */
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
beq ret_from_except
/* Re-enable interrupts. There is no need to trace that with
* lockdep as we are supposed to have IRQs on at this point
*/
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10)
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
/* Save NVGPRS if they're not saved already */
lwz r4,_TRAP(r1)
andi. r4,r4,1
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
beq 5f
SAVE_NVGPRS(r1)
li r4,0xc00
stw r4,_TRAP(r1)
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
5:
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_syscall_trace_leave
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
b ret_from_except_full
/*
[PATCH] syscall entry/exit revamp This cleanup patch speeds up the null syscall path on ppc64 by about 3%, and brings the ppc32 and ppc64 code slightly closer together. The ppc64 code was checking current_thread_info()->flags twice in the syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after disabling interrupts. Now we do the same as ppc32 -- check the flags only once in the fast path, and re-enable interrupts if necessary in the ptrace case. The patch abolishes the 'syscall_noerror' member of struct thread_info and replaces it with a TIF_NOERROR bit in the flags, which is handled in the slow path. This shortens the syscall entry code, which no longer needs to clear syscall_noerror. The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow path to save the non-volatile GPRs into a signal frame. This removes the need for the assembly wrappers around sys_sigsuspend(), sys_rt_sigsuspend(), et al which existed solely to save those registers in advance. It also means I don't have to add new wrappers for ppoll() and pselect(), which is what I was supposed to be doing when I got distracted into this... Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit directly into a signal handler (as required by sigsuspend et al) by introducing a TIF_RESTOREALL flag which causes _all_ the registers to be reloaded from the pt_regs by taking the ret_from_exception path, instead of the normal syscall exit path which stomps on the callee-saved GPRs. It appears to pass an LTP test run on ppc64, and passes basic testing on ppc32 too. Brief tests of ptrace functionality with strace and gdb also appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :) Signed-off-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-15 11:52:18 -07:00
* The fork/clone functions need to copy the full register set into
* the child process. Therefore we need to save all the nonvolatile
* registers (r13 - r31) before calling the C code.
*/
.globl ppc_fork
ppc_fork:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_fork
.globl ppc_vfork
ppc_vfork:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_vfork
.globl ppc_clone
ppc_clone:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_clone
.globl ppc_clone3
ppc_clone3:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_clone3
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
.globl ppc_swapcontext
ppc_swapcontext:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_swapcontext
/*
* Top-level page fault handling.
* This is in assembler because if do_page_fault tells us that
* it is a bad kernel page fault, we want to save the non-volatile
* registers before calling bad_page_fault.
*/
.globl handle_page_fault
handle_page_fault:
stw r4,_DAR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
#ifdef CONFIG_PPC_BOOK3S_32
andis. r0,r5,DSISR_DABRMATCH@h
bne- handle_dabr_fault
#endif
bl do_page_fault
cmpwi r3,0
beq+ ret_from_except
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
clrrwi r0,r0,1
stw r0,_TRAP(r1)
mr r5,r3
addi r3,r1,STACK_FRAME_OVERHEAD
lwz r4,_DAR(r1)
bl bad_page_fault
b ret_from_except_full
#ifdef CONFIG_PPC_BOOK3S_32
/* We have a data breakpoint exception - handle it */
handle_dabr_fault:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
clrrwi r0,r0,1
stw r0,_TRAP(r1)
bl do_break
b ret_from_except_full
#endif
/*
* 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.
* On entry, r3 points to the THREAD for the current task, r4
* points to the THREAD for the new task.
*
* This routine is always called with interrupts disabled.
*
* 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/ppc/kernel/process.c
*/
_GLOBAL(_switch)
stwu r1,-INT_FRAME_SIZE(r1)
mflr r0
stw r0,INT_FRAME_SIZE+4(r1)
/* r3-r12 are caller saved -- Cort */
SAVE_NVGPRS(r1)
stw r0,_NIP(r1) /* Return to switch caller */
mfmsr r11
li r0,MSR_FP /* Disable floating-point */
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
oris r0,r0,MSR_VEC@h /* Disable altivec */
mfspr r12,SPRN_VRSAVE /* save vrsave register value */
stw r12,THREAD+THREAD_VRSAVE(r2)
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_SPE
BEGIN_FTR_SECTION
oris r0,r0,MSR_SPE@h /* Disable SPE */
mfspr r12,SPRN_SPEFSCR /* save spefscr register value */
stw r12,THREAD+THREAD_SPEFSCR(r2)
END_FTR_SECTION_IFSET(CPU_FTR_SPE)
#endif /* CONFIG_SPE */
and. r0,r0,r11 /* FP or altivec or SPE enabled? */
beq+ 1f
andc r11,r11,r0
MTMSRD(r11)
isync
1: stw r11,_MSR(r1)
mfcr r10
stw r10,_CCR(r1)
stw r1,KSP(r3) /* Set old stack pointer */
kuap_check r2, r0
#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 */
tophys(r0,r4)
mtspr SPRN_SPRG_THREAD,r0 /* Update current THREAD phys addr */
lwz r1,KSP(r4) /* Load new stack pointer */
/* save the old current 'last' for return value */
mr r3,r2
addi r2,r4,-THREAD /* Update current */
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
lwz r0,THREAD+THREAD_VRSAVE(r2)
mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_SPE
BEGIN_FTR_SECTION
lwz r0,THREAD+THREAD_SPEFSCR(r2)
mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */
END_FTR_SECTION_IFSET(CPU_FTR_SPE)
#endif /* CONFIG_SPE */
lwz r0,_CCR(r1)
mtcrf 0xFF,r0
/* r3-r12 are destroyed -- Cort */
REST_NVGPRS(r1)
lwz r4,_NIP(r1) /* Return to _switch caller in new task */
mtlr r4
addi r1,r1,INT_FRAME_SIZE
blr
.globl fast_exception_return
fast_exception_return:
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
andi. r10,r9,MSR_RI /* check for recoverable interrupt */
beq 1f /* if not, we've got problems */
#endif
2: REST_4GPRS(3, r11)
lwz r10,_CCR(r11)
REST_GPR(1, r11)
mtcr r10
lwz r10,_LINK(r11)
mtlr r10
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
li r10, 0
stw r10, 8(r11)
REST_GPR(10, r11)
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
powerpc/8xx: Perf events on PPC 8xx This patch has been reworked since RFC version. In the RFC, this patch was preceded by a patch clearing MSR RI for all PPC32 at all time at exception prologs. Now MSR RI clearing is done only when this 8xx perf events functionality is compiled in, it is therefore limited to 8xx and merged inside this patch. Other main changes have been to take into account detailed review from Peter Zijlstra. The instructions counter has been reworked to behave as a free running counter like the three other counters. The 8xx has no PMU, however some events can be emulated by other means. This patch implements the following events (as reported by 'perf list'): cpu-cycles OR cycles [Hardware event] instructions [Hardware event] dTLB-load-misses [Hardware cache event] iTLB-load-misses [Hardware cache event] 'cycles' event is implemented using the timebase clock. Timebase clock corresponds to CPU clock divided by 16, so number of cycles is approximatly 16 times the number of TB ticks On the 8xx, TLB misses are handled by software. It is therefore easy to count all TLB misses each time the TLB miss exception is called. 'instructions' is calculated by using instruction watchpoint counter. This patch sets counter A to count instructions at address greater than 0, hence we count all instructions executed while MSR RI bit is set. The counter is set to the maximum which is 0xffff. Every 65535 instructions, debug instruction breakpoint exception fires. The exception handler increments a counter in memory which then represent the upper part of the instruction counter. We therefore end up with a 48 bits counter. In order to avoid unnecessary overhead while no perf event is active, this counter is started when the first event referring to this counter is added, and the counter is stopped when the last event referring to it is deleted. In order to properly support breakpoint exceptions, MSR RI bit has to be unset in exception epilogs in order to avoid breakpoint exceptions during critical sections during changes to SRR0 and SRR1 would be problematic. All counters are handled as free running counters. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Scott Wood <oss@buserror.net>
2016-12-15 05:42:18 -07:00
mtspr SPRN_NRI, r0
#endif
mtspr SPRN_SRR1,r9
mtspr SPRN_SRR0,r12
REST_GPR(9, r11)
REST_GPR(12, r11)
lwz r11,GPR11(r11)
SYNC
RFI
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
/* check if the exception happened in a restartable section */
1: lis r3,exc_exit_restart_end@ha
addi r3,r3,exc_exit_restart_end@l
cmplw r12,r3
#ifdef CONFIG_PPC_BOOK3S_601
bge 2b
#else
bge 3f
#endif
lis r4,exc_exit_restart@ha
addi r4,r4,exc_exit_restart@l
cmplw r12,r4
#ifdef CONFIG_PPC_BOOK3S_601
blt 2b
#else
blt 3f
#endif
lis r3,fee_restarts@ha
tophys(r3,r3)
lwz r5,fee_restarts@l(r3)
addi r5,r5,1
stw r5,fee_restarts@l(r3)
mr r12,r4 /* restart at exc_exit_restart */
b 2b
.section .bss
.align 2
fee_restarts:
.space 4
.previous
/* aargh, a nonrecoverable interrupt, panic */
/* aargh, we don't know which trap this is */
/* but the 601 doesn't implement the RI bit, so assume it's OK */
3:
li r10,-1
stw r10,_TRAP(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
lis r10,MSR_KERNEL@h
ori r10,r10,MSR_KERNEL@l
bl transfer_to_handler_full
.long unrecoverable_exception
.long ret_from_except
#endif
.globl ret_from_except_full
ret_from_except_full:
REST_NVGPRS(r1)
/* fall through */
.globl ret_from_except
ret_from_except:
/* Hard-disable interrupts so that current_thread_info()->flags
* can't change between when we test it and when we return
* from the interrupt. */
/* Note: We don't bother telling lockdep about it */
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
SYNC /* Some chip revs have problems here... */
MTMSRD(r10) /* disable interrupts */
lwz r3,_MSR(r1) /* Returning to user mode? */
andi. r0,r3,MSR_PR
beq resume_kernel
user_exc_return: /* r10 contains MSR_KERNEL here */
/* Check current_thread_info()->flags */
lwz r9,TI_FLAGS(r2)
andi. r0,r9,_TIF_USER_WORK_MASK
bne do_work
restore_user:
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* Check whether this process has its own DBCR0 value. The internal
debug mode bit tells us that dbcr0 should be loaded. */
lwz r0,THREAD+THREAD_DBCR0(r2)
andis. r10,r0,DBCR0_IDM@h
bnel- load_dbcr0
#endif
ACCOUNT_CPU_USER_EXIT(r2, r10, r11)
#ifdef CONFIG_PPC_BOOK3S_32
kuep_unlock r10, r11
#endif
b restore
/* N.B. the only way to get here is from the beq following ret_from_except. */
resume_kernel:
/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
lwz r8,TI_FLAGS(r2)
andis. r0,r8,_TIF_EMULATE_STACK_STORE@h
beq+ 1f
addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
lwz 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/4 /* size: INT_FRAME_SIZE */
li r6,0 /* start offset: 0 */
mtctr r5
2: lwzx r0,r6,r4
stwx r0,r6,r3
addi r6,r6,4
bdnz 2b
/* Do real store operation to complete stwu */
lwz r5,GPR1(r1)
stw r8,0(r5)
/* Clear _TIF_EMULATE_STACK_STORE flag */
lis r11,_TIF_EMULATE_STACK_STORE@h
addi r5,r2,TI_FLAGS
0: lwarx r8,0,r5
andc r8,r8,r11
#ifdef CONFIG_IBM405_ERR77
dcbt 0,r5
#endif
stwcx. r8,0,r5
bne- 0b
1:
#ifdef CONFIG_PREEMPT
/* check current_thread_info->preempt_count */
lwz r0,TI_PREEMPT(r2)
cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
bne restore_kuap
andi. r8,r8,_TIF_NEED_RESCHED
beq+ restore_kuap
lwz r3,_MSR(r1)
andi. r0,r3,MSR_EE /* interrupts off? */
beq restore_kuap /* don't schedule if so */
#ifdef CONFIG_TRACE_IRQFLAGS
/* Lockdep thinks irqs are enabled, we need to call
* preempt_schedule_irq with IRQs off, so we inform lockdep
* now that we -did- turn them off already
*/
bl trace_hardirqs_off
#endif
bl preempt_schedule_irq
#ifdef CONFIG_TRACE_IRQFLAGS
/* And now, to properly rebalance the above, we tell lockdep they
* are being turned back on, which will happen when we return
*/
bl trace_hardirqs_on
#endif
#endif /* CONFIG_PREEMPT */
restore_kuap:
kuap_restore r1, r2, r9, r10, r0
/* interrupts are hard-disabled at this point */
restore:
#ifdef CONFIG_44x
BEGIN_MMU_FTR_SECTION
b 1f
END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
lis r4,icache_44x_need_flush@ha
lwz r5,icache_44x_need_flush@l(r4)
cmplwi cr0,r5,0
beq+ 1f
li r6,0
iccci r0,r0
stw r6,icache_44x_need_flush@l(r4)
1:
#endif /* CONFIG_44x */
lwz r9,_MSR(r1)
#ifdef CONFIG_TRACE_IRQFLAGS
/* Lockdep doesn't know about the fact that IRQs are temporarily turned
* off in this assembly code while peeking at TI_FLAGS() and such. However
* we need to inform it if the exception turned interrupts off, and we
* are about to trun them back on.
*/
andi. r10,r9,MSR_EE
beq 1f
stwu r1,-32(r1)
mflr r0
stw r0,4(r1)
bl trace_hardirqs_on
addi r1, r1, 32
lwz r9,_MSR(r1)
1:
#endif /* CONFIG_TRACE_IRQFLAGS */
lwz r0,GPR0(r1)
lwz r2,GPR2(r1)
REST_4GPRS(3, r1)
REST_2GPRS(7, r1)
lwz r10,_XER(r1)
lwz r11,_CTR(r1)
mtspr SPRN_XER,r10
mtctr r11
PPC405_ERR77(0,r1)
BEGIN_FTR_SECTION
lwarx r11,0,r1
END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
stwcx. r0,0,r1 /* to clear the reservation */
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
andi. r10,r9,MSR_RI /* check if this exception occurred */
beql nonrecoverable /* at a bad place (MSR:RI = 0) */
lwz r10,_CCR(r1)
lwz r11,_LINK(r1)
mtcrf 0xFF,r10
mtlr r11
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
li r10, 0
stw r10, 8(r1)
/*
* Once we put values in SRR0 and SRR1, we are in a state
* where exceptions are not recoverable, since taking an
* exception will trash SRR0 and SRR1. Therefore we clear the
* MSR:RI bit to indicate this. If we do take an exception,
* we can't return to the point of the exception but we
* can restart the exception exit path at the label
* exc_exit_restart below. -- paulus
*/
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL & ~MSR_RI)
SYNC
MTMSRD(r10) /* clear the RI bit */
.globl exc_exit_restart
exc_exit_restart:
lwz r12,_NIP(r1)
mtspr SPRN_SRR0,r12
mtspr SPRN_SRR1,r9
REST_4GPRS(9, r1)
lwz r1,GPR1(r1)
.globl exc_exit_restart_end
exc_exit_restart_end:
SYNC
RFI
#else /* !(CONFIG_4xx || CONFIG_BOOKE) */
/*
* This is a bit different on 4xx/Book-E because it doesn't have
* the RI bit in the MSR.
* The TLB miss handler checks if we have interrupted
* the exception exit path and restarts it if so
* (well maybe one day it will... :).
*/
lwz r11,_LINK(r1)
mtlr r11
lwz r10,_CCR(r1)
mtcrf 0xff,r10
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
li r10, 0
stw r10, 8(r1)
REST_2GPRS(9, r1)
.globl exc_exit_restart
exc_exit_restart:
lwz r11,_NIP(r1)
lwz r12,_MSR(r1)
exc_exit_start:
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
REST_2GPRS(11, r1)
lwz r1,GPR1(r1)
.globl exc_exit_restart_end
exc_exit_restart_end:
PPC405_ERR77_SYNC
rfi
b . /* prevent prefetch past rfi */
/*
* Returning from a critical interrupt in user mode doesn't need
* to be any different from a normal exception. For a critical
* interrupt in the kernel, we just return (without checking for
* preemption) since the interrupt may have happened at some crucial
* place (e.g. inside the TLB miss handler), and because we will be
* running with r1 pointing into critical_stack, not the current
* process's kernel stack (and therefore current_thread_info() will
* give the wrong answer).
* We have to restore various SPRs that may have been in use at the
* time of the critical interrupt.
*
*/
#ifdef CONFIG_40x
#define PPC_40x_TURN_OFF_MSR_DR \
/* avoid any possible TLB misses here by turning off MSR.DR, we \
* assume the instructions here are mapped by a pinned TLB entry */ \
li r10,MSR_IR; \
mtmsr r10; \
isync; \
tophys(r1, r1);
#else
#define PPC_40x_TURN_OFF_MSR_DR
#endif
#define RET_FROM_EXC_LEVEL(exc_lvl_srr0, exc_lvl_srr1, exc_lvl_rfi) \
REST_NVGPRS(r1); \
lwz r3,_MSR(r1); \
andi. r3,r3,MSR_PR; \
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL); \
bne user_exc_return; \
lwz r0,GPR0(r1); \
lwz r2,GPR2(r1); \
REST_4GPRS(3, r1); \
REST_2GPRS(7, r1); \
lwz r10,_XER(r1); \
lwz r11,_CTR(r1); \
mtspr SPRN_XER,r10; \
mtctr r11; \
PPC405_ERR77(0,r1); \
stwcx. r0,0,r1; /* to clear the reservation */ \
lwz r11,_LINK(r1); \
mtlr r11; \
lwz r10,_CCR(r1); \
mtcrf 0xff,r10; \
PPC_40x_TURN_OFF_MSR_DR; \
lwz r9,_DEAR(r1); \
lwz r10,_ESR(r1); \
mtspr SPRN_DEAR,r9; \
mtspr SPRN_ESR,r10; \
lwz r11,_NIP(r1); \
lwz r12,_MSR(r1); \
mtspr exc_lvl_srr0,r11; \
mtspr exc_lvl_srr1,r12; \
lwz r9,GPR9(r1); \
lwz r12,GPR12(r1); \
lwz r10,GPR10(r1); \
lwz r11,GPR11(r1); \
lwz r1,GPR1(r1); \
PPC405_ERR77_SYNC; \
exc_lvl_rfi; \
b .; /* prevent prefetch past exc_lvl_rfi */
#define RESTORE_xSRR(exc_lvl_srr0, exc_lvl_srr1) \
lwz r9,_##exc_lvl_srr0(r1); \
lwz r10,_##exc_lvl_srr1(r1); \
mtspr SPRN_##exc_lvl_srr0,r9; \
mtspr SPRN_##exc_lvl_srr1,r10;
#if defined(CONFIG_PPC_BOOK3E_MMU)
#ifdef CONFIG_PHYS_64BIT
#define RESTORE_MAS7 \
lwz r11,MAS7(r1); \
mtspr SPRN_MAS7,r11;
#else
#define RESTORE_MAS7
#endif /* CONFIG_PHYS_64BIT */
#define RESTORE_MMU_REGS \
lwz r9,MAS0(r1); \
lwz r10,MAS1(r1); \
lwz r11,MAS2(r1); \
mtspr SPRN_MAS0,r9; \
lwz r9,MAS3(r1); \
mtspr SPRN_MAS1,r10; \
lwz r10,MAS6(r1); \
mtspr SPRN_MAS2,r11; \
mtspr SPRN_MAS3,r9; \
mtspr SPRN_MAS6,r10; \
RESTORE_MAS7;
#elif defined(CONFIG_44x)
#define RESTORE_MMU_REGS \
lwz r9,MMUCR(r1); \
mtspr SPRN_MMUCR,r9;
#else
#define RESTORE_MMU_REGS
#endif
#ifdef CONFIG_40x
.globl ret_from_crit_exc
ret_from_crit_exc:
mfspr r9,SPRN_SPRG_THREAD
lis r10,saved_ksp_limit@ha;
lwz r10,saved_ksp_limit@l(r10);
tovirt(r9,r9);
stw r10,KSP_LIMIT(r9)
lis r9,crit_srr0@ha;
lwz r9,crit_srr0@l(r9);
lis r10,crit_srr1@ha;
lwz r10,crit_srr1@l(r10);
mtspr SPRN_SRR0,r9;
mtspr SPRN_SRR1,r10;
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
#endif /* CONFIG_40x */
#ifdef CONFIG_BOOKE
.globl ret_from_crit_exc
ret_from_crit_exc:
mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
.globl ret_from_debug_exc
ret_from_debug_exc:
mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_xSRR(CSRR0,CSRR1);
RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, PPC_RFDI)
.globl ret_from_mcheck_exc
ret_from_mcheck_exc:
mfspr r9,SPRN_SPRG_THREAD
lwz r10,SAVED_KSP_LIMIT(r1)
stw r10,KSP_LIMIT(r9)
RESTORE_xSRR(SRR0,SRR1);
RESTORE_xSRR(CSRR0,CSRR1);
RESTORE_xSRR(DSRR0,DSRR1);
RESTORE_MMU_REGS;
RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, PPC_RFMCI)
#endif /* CONFIG_BOOKE */
/*
* Load the DBCR0 value for a task that is being ptraced,
* having first saved away the global DBCR0. Note that r0
* has the dbcr0 value to set upon entry to this.
*/
load_dbcr0:
mfmsr r10 /* first disable debug exceptions */
rlwinm r10,r10,0,~MSR_DE
mtmsr r10
isync
mfspr r10,SPRN_DBCR0
lis r11,global_dbcr0@ha
addi r11,r11,global_dbcr0@l
#ifdef CONFIG_SMP
lwz r9,TASK_CPU(r2)
slwi r9,r9,3
add r11,r11,r9
#endif
stw r10,0(r11)
mtspr SPRN_DBCR0,r0
lwz r10,4(r11)
addi r10,r10,1
stw r10,4(r11)
li r11,-1
mtspr SPRN_DBSR,r11 /* clear all pending debug events */
blr
.section .bss
.align 4
.global global_dbcr0
global_dbcr0:
.space 8*NR_CPUS
.previous
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
do_work: /* r10 contains MSR_KERNEL here */
andi. r0,r9,_TIF_NEED_RESCHED
beq do_user_signal
do_resched: /* r10 contains MSR_KERNEL here */
#ifdef CONFIG_TRACE_IRQFLAGS
bl trace_hardirqs_on
mfmsr r10
#endif
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10) /* hard-enable interrupts */
bl schedule
recheck:
/* Note: And we don't tell it we are disabling them again
* neither. Those disable/enable cycles used to peek at
* TI_FLAGS aren't advertised.
*/
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
SYNC
MTMSRD(r10) /* disable interrupts */
lwz r9,TI_FLAGS(r2)
andi. r0,r9,_TIF_NEED_RESCHED
bne- do_resched
andi. r0,r9,_TIF_USER_WORK_MASK
beq restore_user
do_user_signal: /* r10 contains MSR_KERNEL here */
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10) /* hard-enable interrupts */
/* save r13-r31 in the exception frame, if not already done */
lwz r3,_TRAP(r1)
andi. r0,r3,1
beq 2f
SAVE_NVGPRS(r1)
rlwinm r3,r3,0,0,30
stw r3,_TRAP(r1)
2: addi r3,r1,STACK_FRAME_OVERHEAD
mr r4,r9
bl do_notify_resume
REST_NVGPRS(r1)
b recheck
/*
* We come here when we are at the end of handling an exception
* that occurred at a place where taking an exception will lose
* state information, such as the contents of SRR0 and SRR1.
*/
nonrecoverable:
lis r10,exc_exit_restart_end@ha
addi r10,r10,exc_exit_restart_end@l
cmplw r12,r10
#ifdef CONFIG_PPC_BOOK3S_601
bgelr
#else
bge 3f
#endif
lis r11,exc_exit_restart@ha
addi r11,r11,exc_exit_restart@l
cmplw r12,r11
#ifdef CONFIG_PPC_BOOK3S_601
bltlr
#else
blt 3f
#endif
lis r10,ee_restarts@ha
lwz r12,ee_restarts@l(r10)
addi r12,r12,1
stw r12,ee_restarts@l(r10)
mr r12,r11 /* restart at exc_exit_restart */
blr
3: /* OK, we can't recover, kill this process */
/* but the 601 doesn't implement the RI bit, so assume it's OK */
lwz r3,_TRAP(r1)
andi. r0,r3,1
beq 5f
SAVE_NVGPRS(r1)
rlwinm r3,r3,0,0,30
stw r3,_TRAP(r1)
5: mfspr r2,SPRN_SPRG_THREAD
addi r2,r2,-THREAD
tovirt(r2,r2) /* set back r2 to current */
4: addi r3,r1,STACK_FRAME_OVERHEAD
bl unrecoverable_exception
/* shouldn't return */
b 4b
.section .bss
.align 2
ee_restarts:
.space 4
.previous
/*
* PROM code for specific machines follows. Put it
* here so it's easy to add arch-specific sections later.
* -- Cort
*/
#ifdef CONFIG_PPC_RTAS
/*
* On CHRP, the Run-Time Abstraction Services (RTAS) have to be
* called with the MMU off.
*/
_GLOBAL(enter_rtas)
stwu r1,-INT_FRAME_SIZE(r1)
mflr r0
stw r0,INT_FRAME_SIZE+4(r1)
LOAD_REG_ADDR(r4, rtas)
lis r6,1f@ha /* physical return address for rtas */
addi r6,r6,1f@l
tophys(r6,r6)
tophys(r7,r1)
lwz r8,RTASENTRY(r4)
lwz r4,RTASBASE(r4)
mfmsr r9
stw r9,8(r1)
LOAD_REG_IMMEDIATE(r0,MSR_KERNEL)
SYNC /* disable interrupts so SRR0/1 */
MTMSRD(r0) /* don't get trashed */
li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
mtlr r6
stw r7, THREAD + RTAS_SP(r2)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI
1: tophys(r9,r1)
lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */
lwz r9,8(r9) /* original msr value */
addi r1,r1,INT_FRAME_SIZE
li r0,0
tophys(r7, r2)
stw r0, THREAD + RTAS_SP(r7)
mtspr SPRN_SRR0,r8
mtspr SPRN_SRR1,r9
RFI /* return to caller */
.globl machine_check_in_rtas
machine_check_in_rtas:
twi 31,0,0
/* XXX load up BATs and panic */
#endif /* CONFIG_PPC_RTAS */