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Commit 266de3a8 authored by Naveen N. Rao's avatar Naveen N. Rao Committed by Michael Ellerman
Browse files

powerpc/64s: Move system_call() symbol to just after setting MSR_EE 



It is common to get a PMU interrupt right after the mtmsr instruction that
enables interrupts. Due to this, the stack trace profile gets needlessly split
across system_call_common() and system_call().

Previously, system_call() symbol was at the current place to hide a few
earlier symbols which have since been made private or removed entirely.

So, let's move system_call() slightly higher up, right after the mtmsr
instruction that enables interrupts. Convert existing references to
system_call to a local syscall symbol.

Suggested-by: default avatarNicholas Piggin <npiggin@gmail.com>
Reviewed-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent cf7d6fb0

arch/powerpc/kernel/entry_64.S

+4 −3
Original line number Diff line number Diff line
@@ -143,6 +143,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) 
	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

	 */
@@ -156,7 +157,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) 
	cmpldi	0,r0,NR_syscalls

	bge-	.Lsyscall_enosys



system_call:			/* label this so stack traces look sane */

.Lsyscall:

/*

 * Need to vector to 32 Bit or default sys_call_table here,

 * based on caller's run-mode / personality.
@@ -310,13 +311,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR) 
	ld	r7,GPR7(r1)

	ld	r8,GPR8(r1)



	/* Repopulate r9 and r10 for the system_call path */

	/* Repopulate r9 and r10 for the syscall path */

	addi	r9,r1,STACK_FRAME_OVERHEAD

	CURRENT_THREAD_INFO(r10, r1)

	ld	r10,TI_FLAGS(r10)



	cmpldi	r0,NR_syscalls

	blt+	system_call

	blt+	.Lsyscall



	/* Return code is already in r3 thanks to do_syscall_trace_enter() */

	b	.Lsyscall_exit