From: David S. Miller Date: Mon, 6 Feb 2006 04:47:26 +0000 (-0800) Subject: [SPARC64]: Fill dead cycles on trap entry with real work. X-Git-Tag: v2.6.17-rc1~1184^2~189 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e02493a7f33ac89e698b980a657d77ab2749eaf;p=linux-2.6 [SPARC64]: Fill dead cycles on trap entry with real work. As we save trap state onto the stack, the store buffer fills up mid-way through and we stall for several cycles as the store buffer trickles out to the L2 cache. Meanwhile we can do some privileged register reads and other calculations, essentially for free. Signed-off-by: David S. Miller --- diff --git a/arch/sparc64/kernel/etrap.S b/arch/sparc64/kernel/etrap.S index 4a0e01b140..f2556146a7 100644 --- a/arch/sparc64/kernel/etrap.S +++ b/arch/sparc64/kernel/etrap.S @@ -98,37 +98,40 @@ etrap_save: save %g2, -STACK_BIAS, %sp stxa %g3, [%l4] ASI_DMMU sethi %hi(KERNBASE), %l4 flush %l4 - wr %g0, ASI_AIUS, %asi -2: wrpr %g0, 0x0, %tl - mov %g4, %l4 + mov ASI_AIUS, %l7 +2: mov %g4, %l4 mov %g5, %l5 - - mov %g7, %l2 + add %g7, 4, %l2 wrpr %g0, ETRAP_PSTATE1, %pstate stx %g1, [%sp + PTREGS_OFF + PT_V9_G1] stx %g2, [%sp + PTREGS_OFF + PT_V9_G2] + sllx %l7, 24, %l7 stx %g3, [%sp + PTREGS_OFF + PT_V9_G3] + rdpr %cwp, %l0 stx %g4, [%sp + PTREGS_OFF + PT_V9_G4] stx %g5, [%sp + PTREGS_OFF + PT_V9_G5] stx %g6, [%sp + PTREGS_OFF + PT_V9_G6] - stx %g7, [%sp + PTREGS_OFF + PT_V9_G7] + or %l7, %l0, %l7 + sethi %hi(TSTATE_RMO | TSTATE_PEF), %l0 + or %l7, %l0, %l7 + wrpr %l2, %tnpc + wrpr %l7, (TSTATE_PRIV | TSTATE_IE), %tstate stx %i0, [%sp + PTREGS_OFF + PT_V9_I0] stx %i1, [%sp + PTREGS_OFF + PT_V9_I1] stx %i2, [%sp + PTREGS_OFF + PT_V9_I2] stx %i3, [%sp + PTREGS_OFF + PT_V9_I3] stx %i4, [%sp + PTREGS_OFF + PT_V9_I4] stx %i5, [%sp + PTREGS_OFF + PT_V9_I5] - stx %i6, [%sp + PTREGS_OFF + PT_V9_I6] - stx %i7, [%sp + PTREGS_OFF + PT_V9_I7] - wrpr %g0, ETRAP_PSTATE2, %pstate mov %l6, %g6 + stx %i7, [%sp + PTREGS_OFF + PT_V9_I7] LOAD_PER_CPU_BASE(%g5, %g6, %g4, %g3, %l1) - jmpl %l2 + 0x4, %g0 - ldx [%g6 + TI_TASK], %g4 + ldx [%g6 + TI_TASK], %g4 + done -3: ldub [%l6 + TI_FPDEPTH], %l5 +3: mov ASI_P, %l7 + ldub [%l6 + TI_FPDEPTH], %l5 add %l6, TI_FPSAVED + 1, %l4 srl %l5, 1, %l3 add %l5, 2, %l5