From: Jesper Nilsson Date: Mon, 2 Aug 2010 16:09:56 +0000 (+0200) Subject: CRIS: Simple insn reschedule to avoid interlocks. X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=43f6cdd7693ddddb4db17a1ab591d506cb1fc110;p=linux.git CRIS: Simple insn reschedule to avoid interlocks. Brings down the CPI from ~1.5 to ~1.1. Signed-off-by: Edgar Iglesias Signed-off-by: Jesper Nilsson --- diff --git a/arch/cris/arch-v32/kernel/entry.S b/arch/cris/arch-v32/kernel/entry.S index 7c14acb754a1d..ce121df3aaefa 100644 --- a/arch/cris/arch-v32/kernel/entry.S +++ b/arch/cris/arch-v32/kernel/entry.S @@ -348,40 +348,40 @@ _syscall_trace_entry: .type resume,@function resume: - subq 4, $sp - move $srp, [$sp] ; Keep old/new PC on the stack. + subq 4, $sp ; Make space for srp. + add.d $r12, $r10 ; R10 = current tasks tss. addoq +THREAD_ccs, $r10, $acr + move $srp, [$sp] ; Keep old/new PC on the stack. move $ccs, [$acr] ; Save IRQ enable state. di addoq +THREAD_usp, $r10, $acr + subq 10*4, $sp ; Make room for R9. move $usp, [$acr] ; Save user-mode stackpointer. ;; See copy_thread for the reason why register R9 is saved. - subq 10*4, $sp movem $r9, [$sp] ; Save non-scratch registers and R9. addoq +THREAD_ksp, $r10, $acr + move.d $sp, $r10 ; Return last running task in R10. move.d $sp, [$acr] ; Save kernel SP for old task. - move.d $sp, $r10 ; Return last running task in R10. and.d -8192, $r10 ; Get thread_info from stackpointer. addoq +TI_task, $r10, $acr - move.d [$acr], $r10 ; Get task. add.d $r12, $r11 ; Find the new tasks tss. + move.d [$acr], $r10 ; Get task. addoq +THREAD_ksp, $r11, $acr move.d [$acr], $sp ; Switch to new stackframe. + addoq +THREAD_usp, $r11, $acr movem [$sp+], $r9 ; Restore non-scratch registers and R9. - addoq +THREAD_usp, $r11, $acr move [$acr], $usp ; Restore user-mode stackpointer. addoq +THREAD_ccs, $r11, $acr + move.d [$sp+], $r11 + jump $r11 ; Restore PC. move [$acr], $ccs ; Restore IRQ enable status. - move.d [$sp+], $acr - jump $acr ; Restore PC. - nop .size resume, . - resume nmi_interrupt: