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Commit 987ad70a authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

[S390] system call optimization. 



After the in-kernel system call has been remove the system call path
can be optimized. The problem state bit of the old psw is always set
between system_call and sysc_do_svc. SAVE_ALL_SVC uses this information
to avoid two instructions.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 3d62149f

arch/s390/kernel/entry.S

+6 −1
Original line number Diff line number Diff line
@@ -107,6 +107,11 @@ STACK_SIZE = 1 << STACK_SHIFT 
	l	%r13,__LC_SVC_NEW_PSW+4	# load &system_call to %r13

	.endm



	.macro	SAVE_ALL_SVC psworg,savearea

	la	%r12,\psworg

	l	%r15,__LC_KERNEL_STACK	# problem state -> load ksp

	.endm



	.macro	SAVE_ALL_SYNC psworg,savearea

	la	%r12,\psworg

	tm	\psworg+1,0x01		# test problem state bit
@@ -218,7 +223,7 @@ system_call: 
	STORE_TIMER __LC_SYNC_ENTER_TIMER

sysc_saveall:

	SAVE_ALL_BASE __LC_SAVE_AREA

	SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	lh	%r7,0x8a	  # get svc number from lowcore

#ifdef CONFIG_VIRT_CPU_ACCOUNTING

arch/s390/kernel/entry64.S

+6 −1
Original line number Diff line number Diff line
@@ -99,6 +99,11 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NEED_RESCHED | \ 
	larl	%r13,system_call

	.endm



	.macro	SAVE_ALL_SVC psworg,savearea

	la	%r12,\psworg

	lg	%r15,__LC_KERNEL_STACK	# problem state -> load ksp

	.endm



	.macro	SAVE_ALL_SYNC psworg,savearea

	la	%r12,\psworg

	tm	\psworg+1,0x01		# test problem state bit
@@ -207,7 +212,7 @@ system_call: 
	STORE_TIMER __LC_SYNC_ENTER_TIMER

sysc_saveall:

	SAVE_ALL_BASE __LC_SAVE_AREA

	SAVE_ALL_SYNC __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	SAVE_ALL_SVC __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	CREATE_STACK_FRAME __LC_SVC_OLD_PSW,__LC_SAVE_AREA

	llgh	%r7,__LC_SVC_INT_CODE	# get svc number from lowcore

#ifdef CONFIG_VIRT_CPU_ACCOUNTING