From 78cdfb5cf15e0f9fb4c2a9176a13a907a1d024f0 Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Mon, 24 Jul 2017 21:55:16 +0900 Subject: [PATCH] openrisc: enable LOCKDEP_SUPPORT and irqflags tracing Lockdep is needed for proving the spinlocks and rwlocks work fine on our platform. It also requires calling the trace_hardirqs_off() and trace_hardirqs_on() pair of routines when entering and exiting an interrupt. For OpenRISC the interrupt stack frame does not support frame pointers, so to call trace_hardirqs_on() and trace_hardirqs_off() here the macro's build up a stack frame each time. There is one necessary small change in _sys_call_handler to move interrupt enabling later so they can get re-enabled during syscall restart. This was done to fix lockdep warnings that are now possible due to this patch. Signed-off-by: Stafford Horne --- arch/openrisc/Kconfig | 3 ++ arch/openrisc/kernel/entry.S | 74 ++++++++++++++++++++++++++++++++++-- 2 files changed, 74 insertions(+), 3 deletions(-) diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig index 399f55e82dcb..f8cfb3ba9e89 100644 --- a/arch/openrisc/Kconfig +++ b/arch/openrisc/Kconfig @@ -64,6 +64,9 @@ config GENERIC_CSUM config STACKTRACE_SUPPORT def_bool y +config LOCKDEP_SUPPORT + def_bool y + source "init/Kconfig" source "kernel/Kconfig.freezer" diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index 1b7160c79646..690d55272ba6 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -42,6 +42,61 @@ /* =========================================================[ macros ]=== */ +#ifdef CONFIG_TRACE_IRQFLAGS +/* + * Trace irq on/off creating a stack frame. + */ +#define TRACE_IRQS_OP(trace_op) \ + l.sw -8(r1),r2 /* store frame pointer */ ;\ + l.sw -4(r1),r9 /* store return address */ ;\ + l.addi r2,r1,0 /* move sp to fp */ ;\ + l.jal trace_op ;\ + l.addi r1,r1,-8 ;\ + l.ori r1,r2,0 /* restore sp */ ;\ + l.lwz r9,-4(r1) /* restore return address */ ;\ + l.lwz r2,-8(r1) /* restore fp */ ;\ +/* + * Trace irq on/off and save registers we need that would otherwise be + * clobbered. + */ +#define TRACE_IRQS_SAVE(t1,trace_op) \ + l.sw -12(r1),t1 /* save extra reg */ ;\ + l.sw -8(r1),r2 /* store frame pointer */ ;\ + l.sw -4(r1),r9 /* store return address */ ;\ + l.addi r2,r1,0 /* move sp to fp */ ;\ + l.jal trace_op ;\ + l.addi r1,r1,-12 ;\ + l.ori r1,r2,0 /* restore sp */ ;\ + l.lwz r9,-4(r1) /* restore return address */ ;\ + l.lwz r2,-8(r1) /* restore fp */ ;\ + l.lwz t1,-12(r1) /* restore extra reg */ + +#define TRACE_IRQS_OFF TRACE_IRQS_OP(trace_hardirqs_off) +#define TRACE_IRQS_ON TRACE_IRQS_OP(trace_hardirqs_on) +#define TRACE_IRQS_ON_SYSCALL \ + TRACE_IRQS_SAVE(r10,trace_hardirqs_on) ;\ + l.lwz r3,PT_GPR3(r1) ;\ + l.lwz r4,PT_GPR4(r1) ;\ + l.lwz r5,PT_GPR5(r1) ;\ + l.lwz r6,PT_GPR6(r1) ;\ + l.lwz r7,PT_GPR7(r1) ;\ + l.lwz r8,PT_GPR8(r1) ;\ + l.lwz r11,PT_GPR11(r1) +#define TRACE_IRQS_OFF_ENTRY \ + l.lwz r5,PT_SR(r1) ;\ + l.andi r3,r5,(SPR_SR_IEE|SPR_SR_TEE) ;\ + l.sfeq r5,r0 /* skip trace if irqs were already off */;\ + l.bf 1f ;\ + l.nop ;\ + TRACE_IRQS_SAVE(r4,trace_hardirqs_off) ;\ +1: +#else +#define TRACE_IRQS_OFF +#define TRACE_IRQS_ON +#define TRACE_IRQS_OFF_ENTRY +#define TRACE_IRQS_ON_SYSCALL +#endif + /* * We need to disable interrupts at beginning of RESTORE_ALL * since interrupt might come in after we've loaded EPC return address @@ -124,6 +179,7 @@ handler: ;\ /* r30 already save */ ;\ /* l.sw PT_GPR30(r1),r30*/ ;\ l.sw PT_GPR31(r1),r31 ;\ + TRACE_IRQS_OFF_ENTRY ;\ /* Store -1 in orig_gpr11 for non-syscall exceptions */ ;\ l.addi r30,r0,-1 ;\ l.sw PT_ORIG_GPR11(r1),r30 @@ -557,9 +613,6 @@ _string_syscall_return: .align 4 ENTRY(_sys_call_handler) - /* syscalls run with interrupts enabled */ - ENABLE_INTERRUPTS(r29) // enable interrupts, r29 is temp - /* r1, EPCR, ESR a already saved */ l.sw PT_GPR2(r1),r2 /* r3-r8 must be saved because syscall restart relies @@ -597,6 +650,10 @@ ENTRY(_sys_call_handler) /* l.sw PT_GPR30(r1),r30 */ _syscall_check_trace_enter: + /* syscalls run with interrupts enabled */ + TRACE_IRQS_ON_SYSCALL + ENABLE_INTERRUPTS(r29) // enable interrupts, r29 is temp + /* If TIF_SYSCALL_TRACE is set, then we want to do syscall tracing */ l.lwz r30,TI_FLAGS(r10) l.andi r30,r30,_TIF_SYSCALL_TRACE @@ -657,6 +714,7 @@ _syscall_check_trace_leave: _syscall_check_work: /* Here we need to disable interrupts */ DISABLE_INTERRUPTS(r27,r29) + TRACE_IRQS_OFF l.lwz r30,TI_FLAGS(r10) l.andi r30,r30,_TIF_WORK_MASK l.sfne r30,r0 @@ -871,6 +929,7 @@ UNHANDLED_EXCEPTION(_vector_0x1f00,0x1f00) _resume_userspace: DISABLE_INTERRUPTS(r3,r4) + TRACE_IRQS_OFF l.lwz r4,TI_FLAGS(r10) l.andi r13,r4,_TIF_WORK_MASK l.sfeqi r13,0 @@ -909,6 +968,15 @@ _work_pending: l.lwz r8,PT_GPR8(r1) _restore_all: +#ifdef CONFIG_TRACE_IRQFLAGS + l.lwz r4,PT_SR(r1) + l.andi r3,r4,(SPR_SR_IEE|SPR_SR_TEE) + l.sfeq r3,r0 /* skip trace if irqs were off */ + l.bf skip_hardirqs_on + l.nop + TRACE_IRQS_ON +skip_hardirqs_on: +#endif RESTORE_ALL /* This returns to userspace code */