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Commit 945feb17 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Paul Mackerras
Browse files

[POWERPC] irqtrace support for 64-bit powerpc 



This adds the low level irq tracing hooks to the powerpc architecture
needed to enable full lockdep functionality.

This is partly based on Johannes Berg's initial version.  I removed
the asm trampoline that isn't needed (thus improving performance) and
modified all sorts of bits and pieces, reworking most of the assembly,
etc...

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent fd3e0bbc

arch/powerpc/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -53,6 +53,15 @@ config STACKTRACE_SUPPORT 
	bool

	default y



config TRACE_IRQFLAGS_SUPPORT

	bool

	depends on PPC64

	default y



config LOCKDEP_SUPPORT

	bool

	default y



config RWSEM_GENERIC_SPINLOCK

	bool

arch/powerpc/kernel/entry_64.S

+25 −2
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <asm/firmware.h>

#include <asm/bug.h>

#include <asm/ptrace.h>

#include <asm/irqflags.h>



/*

 * System calls.
@@ -89,6 +90,14 @@ system_call_common: 
	addi	r9,r1,STACK_FRAME_OVERHEAD

	ld	r11,exception_marker@toc(r2)

	std	r11,-16(r9)		/* "regshere" marker */

#ifdef CONFIG_TRACE_IRQFLAGS

	bl	.trace_hardirqs_on

	REST_GPR(0,r1)

	REST_4GPRS(3,r1)

	REST_2GPRS(7,r1)

	addi	r9,r1,STACK_FRAME_OVERHEAD

	ld	r12,_MSR(r1)

#endif /* CONFIG_TRACE_IRQFLAGS */

	li	r10,1

	stb	r10,PACASOFTIRQEN(r13)

	stb	r10,PACAHARDIRQEN(r13)
@@ -103,7 +112,7 @@ BEGIN_FW_FTR_SECTION 
	b	hardware_interrupt_entry

2:

END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

#endif

#endif /* CONFIG_PPC_ISERIES */

	mfmsr	r11

	ori	r11,r11,MSR_EE

	mtmsrd	r11,1
@@ -505,6 +514,10 @@ BEGIN_FW_FTR_SECTION 


	li	r3,0

	stb	r3,PACASOFTIRQEN(r13)	/* ensure we are soft-disabled */

#ifdef CONFIG_TRACE_IRQFLAGS

	bl	.trace_hardirqs_off

	mfmsr	r10

#endif

	ori	r10,r10,MSR_EE

	mtmsrd	r10			/* hard-enable again */

	addi	r3,r1,STACK_FRAME_OVERHEAD
@@ -513,7 +526,7 @@ BEGIN_FW_FTR_SECTION 
4:

END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

#endif

	stb	r5,PACASOFTIRQEN(r13)

	TRACE_AND_RESTORE_IRQ(r5);



	/* extract EE bit and use it to restore paca->hard_enabled */

	ld	r3,_MSR(r1)
@@ -581,6 +594,16 @@ do_work: 
	bne	restore

	/* here we are preempting the current task */

1:

#ifdef CONFIG_TRACE_IRQFLAGS

	bl	.trace_hardirqs_on

	/* Note: we just clobbered r10 which used to contain the previous

	 * MSR before the hard-disabling done by the caller of do_work.

	 * We don't have that value anymore, but it doesn't matter as

	 * we will hard-enable unconditionally, we can just reload the

	 * current MSR into r10

	 */

	mfmsr	r10

#endif /* CONFIG_TRACE_IRQFLAGS */

	li	r0,1

	stb	r0,PACASOFTIRQEN(r13)

	stb	r0,PACAHARDIRQEN(r13)

arch/powerpc/kernel/head_64.S

+32 −15
Original line number Diff line number Diff line
@@ -36,8 +36,7 @@ 
#include <asm/firmware.h>

#include <asm/page_64.h>

#include <asm/exception.h>



#define DO_SOFT_DISABLE

#include <asm/irqflags.h>



/*

 * We layout physical memory as follows:
@@ -450,8 +449,8 @@ bad_stack: 
 */

fast_exc_return_irq:			/* restores irq state too */

	ld	r3,SOFTE(r1)

	TRACE_AND_RESTORE_IRQ(r3);

	ld	r12,_MSR(r1)

	stb	r3,PACASOFTIRQEN(r13)	/* restore paca->soft_enabled */

	rldicl	r4,r12,49,63		/* get MSR_EE to LSB */

	stb	r4,PACAHARDIRQEN(r13)	/* restore paca->hard_enabled */

	b	1f
@@ -824,7 +823,7 @@ _STATIC(load_up_altivec) 
 * Hash table stuff

 */

	.align	7

_GLOBAL(do_hash_page)

_STATIC(do_hash_page)

	std	r3,_DAR(r1)

	std	r4,_DSISR(r1)
@@ -835,6 +834,27 @@ BEGIN_FTR_SECTION 
	bne-	do_ste_alloc		/* If so handle it */

END_FTR_SECTION_IFCLR(CPU_FTR_SLB)



	/*

	 * On iSeries, we soft-disable interrupts here, then

	 * hard-enable interrupts so that the hash_page code can spin on

	 * the hash_table_lock without problems on a shared processor.

	 */

	DISABLE_INTS



	/*

	 * Currently, trace_hardirqs_off() will be called by DISABLE_INTS

	 * and will clobber volatile registers when irq tracing is enabled

	 * so we need to reload them. It may be possible to be smarter here

	 * and move the irq tracing elsewhere but let's keep it simple for

	 * now

	 */

#ifdef CONFIG_TRACE_IRQFLAGS

	ld	r3,_DAR(r1)

	ld	r4,_DSISR(r1)

	ld	r5,_TRAP(r1)

	ld	r12,_MSR(r1)

	clrrdi	r5,r5,4

#endif /* CONFIG_TRACE_IRQFLAGS */

	/*

	 * We need to set the _PAGE_USER bit if MSR_PR is set or if we are

	 * accessing a userspace segment (even from the kernel). We assume
@@ -847,13 +867,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_SLB) 
	ori	r4,r4,1			/* add _PAGE_PRESENT */

	rlwimi	r4,r5,22+2,31-2,31-2	/* Set _PAGE_EXEC if trap is 0x400 */



	/*

	 * On iSeries, we soft-disable interrupts here, then

	 * hard-enable interrupts so that the hash_page code can spin on

	 * the hash_table_lock without problems on a shared processor.

	 */

	DISABLE_INTS



	/*

	 * r3 contains the faulting address

	 * r4 contains the required access permissions
@@ -864,7 +877,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_SLB) 
	bl	.hash_page		/* build HPTE if possible */

	cmpdi	r3,0			/* see if hash_page succeeded */



#ifdef DO_SOFT_DISABLE

BEGIN_FW_FTR_SECTION

	/*

	 * If we had interrupts soft-enabled at the point where the
@@ -876,7 +888,7 @@ BEGIN_FW_FTR_SECTION 
	 */

	beq	13f

END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)

#endif



BEGIN_FW_FTR_SECTION

	/*

	 * Here we have interrupts hard-disabled, so it is sufficient
@@ -890,11 +902,12 @@ END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES) 


	/*

	 * hash_page couldn't handle it, set soft interrupt enable back

	 * to what it was before the trap.  Note that .local_irq_restore

	 * to what it was before the trap.  Note that .raw_local_irq_restore

	 * handles any interrupts pending at this point.

	 */

	ld	r3,SOFTE(r1)

	bl	.local_irq_restore

	TRACE_AND_RESTORE_IRQ_PARTIAL(r3, 11f)

	bl	.raw_local_irq_restore

	b	11f



/* Here we have a page fault that hash_page can't handle. */
@@ -1493,6 +1506,10 @@ _INIT_STATIC(start_here_multiplatform) 
	addi	r2,r2,0x4000

	add	r2,r2,r26



	/* Set initial ptr to current */

	LOAD_REG_IMMEDIATE(r4, init_task)

	std	r4,PACACURRENT(r13)



	/* Do very early kernel initializations, including initial hash table,

	 * stab and slb setup before we turn on relocation.	*/

arch/powerpc/kernel/irq.c

+2 −1
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ static inline void set_soft_enabled(unsigned long enable) 
	: : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled)));

}



void local_irq_restore(unsigned long en)

void raw_local_irq_restore(unsigned long en)

{

	/*

	 * get_paca()->soft_enabled = en;
@@ -174,6 +174,7 @@ void local_irq_restore(unsigned long en) 


	__hard_irq_enable();

}

EXPORT_SYMBOL(raw_local_irq_restore);

#endif /* CONFIG_PPC64 */



int show_interrupts(struct seq_file *p, void *v)

arch/powerpc/kernel/ppc_ksyms.c

+0 −4
Original line number Diff line number Diff line
@@ -45,10 +45,6 @@ 
#include <asm/signal.h>

#include <asm/dcr.h>



#ifdef CONFIG_PPC64

EXPORT_SYMBOL(local_irq_restore);

#endif



#ifdef CONFIG_PPC32

extern void transfer_to_handler(void);

extern void do_IRQ(struct pt_regs *regs);