From c742b31c03f37c5c499178f09f57381aa6c70131 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 31 Dec 2008 15:11:42 +0100 Subject: [PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_ID The extract cpu time instruction (ectg) instruction allows the user process to get the current thread cputime without calling into the kernel. The code that uses the instruction needs to switch to the access registers mode to get access to the per-cpu info page that contains the two base values that are needed to calculate the current cputime from the CPU timer with the ectg instruction. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry64.S | 45 ++++++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 21 deletions(-) (limited to 'arch/s390/kernel/entry64.S') diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index ae83c195171..c6fbde13971 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -177,8 +177,11 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ .if !\sync ni \psworg+1,0xfd # clear wait state bit .endif - lmg %r0,%r15,SP_R0(%r15) # load gprs 0-15 of user + lg %r14,__LC_VDSO_PER_CPU + lmg %r0,%r13,SP_R0(%r15) # load gprs 0-13 of user stpt __LC_EXIT_TIMER + mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER + lmg %r14,%r15,SP_R14(%r15) # load grps 14-15 of user lpswe \psworg # back to caller .endm @@ -980,23 +983,23 @@ cleanup_sysc_return: cleanup_sysc_leave: clc 8(8,%r12),BASED(cleanup_sysc_leave_insn) - je 2f - mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER + je 3f clc 8(8,%r12),BASED(cleanup_sysc_leave_insn+8) - je 2f - mvc __LC_RETURN_PSW(16),SP_PSW(%r15) + jhe 0f + mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER +0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15) cghi %r12,__LC_MCK_OLD_PSW - jne 0f + jne 1f mvc __LC_SAVE_AREA+64(32),SP_R12(%r15) - j 1f -0: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15) -1: lmg %r0,%r11,SP_R0(%r15) + j 2f +1: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15) +2: lmg %r0,%r11,SP_R0(%r15) lg %r15,SP_R15(%r15) -2: la %r12,__LC_RETURN_PSW +3: la %r12,__LC_RETURN_PSW br %r14 cleanup_sysc_leave_insn: .quad sysc_done - 4 - .quad sysc_done - 8 + .quad sysc_done - 16 cleanup_io_return: mvc __LC_RETURN_PSW(8),0(%r12) @@ -1006,23 +1009,23 @@ cleanup_io_return: cleanup_io_leave: clc 8(8,%r12),BASED(cleanup_io_leave_insn) - je 2f - mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER + je 3f clc 8(8,%r12),BASED(cleanup_io_leave_insn+8) - je 2f - mvc __LC_RETURN_PSW(16),SP_PSW(%r15) + jhe 0f + mvc __LC_EXIT_TIMER(8),__LC_ASYNC_ENTER_TIMER +0: mvc __LC_RETURN_PSW(16),SP_PSW(%r15) cghi %r12,__LC_MCK_OLD_PSW - jne 0f + jne 1f mvc __LC_SAVE_AREA+64(32),SP_R12(%r15) - j 1f -0: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15) -1: lmg %r0,%r11,SP_R0(%r15) + j 2f +1: mvc __LC_SAVE_AREA+32(32),SP_R12(%r15) +2: lmg %r0,%r11,SP_R0(%r15) lg %r15,SP_R15(%r15) -2: la %r12,__LC_RETURN_PSW +3: la %r12,__LC_RETURN_PSW br %r14 cleanup_io_leave_insn: .quad io_done - 4 - .quad io_done - 8 + .quad io_done - 16 /* * Integer constants -- cgit v1.2.3