From: Wang Dongsheng <dongsheng.w...@freescale.com> Using hardware features make core automatically enter PW20 state. Set a TB count to hardware, the effective count begins when PW10 is entered. When the effective period has expired, the core will proceed from PW10 to PW20 if no exit conditions have occurred during the period.
Signed-off-by: Wang Dongsheng <dongsheng.w...@freescale.com> --- *v3: Assembly code instead of C code. *v2: Remove: delete setup_idle_hw_governor function. delete "Fix erratum" for rev1. Move: move setup_* into __setup/restore_cpu_e6500. arch/powerpc/kernel/cpu_setup_fsl_booke.S | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/powerpc/kernel/cpu_setup_fsl_booke.S b/arch/powerpc/kernel/cpu_setup_fsl_booke.S index 4789056..49e738e 100644 --- a/arch/powerpc/kernel/cpu_setup_fsl_booke.S +++ b/arch/powerpc/kernel/cpu_setup_fsl_booke.S @@ -55,6 +55,25 @@ _GLOBAL(__e500_dcache_setup) /* * FIXME - we haven't yet done testing to determine a reasonable default + * value for PW20_WAIT_IDLE_BIT. + */ +#define PW20_WAIT_IDLE_BIT 50 /* 1ms, TB frequency is 41.66MHZ */ +_GLOBAL(setup_pw20_idle) + mfspr r3, SPRN_PWRMGTCR0 + + /* Set PW20_WAIT bit, enable pw20 state*/ + ori r3, r3, PWRMGTCR0_PW20_WAIT + li r11, PW20_WAIT_IDLE_BIT + + /* Set Automatic PW20 Core Idle Count */ + rlwimi r3, r11, PWRMGTCR0_PW20_ENT_SHIFT, PWRMGTCR0_PW20_ENT + + mtspr SPRN_PWRMGTCR0, r3 + + blr + +/* + * FIXME - we haven't yet done testing to determine a reasonable default * value for AV_WAIT_IDLE_BIT. */ #define AV_WAIT_IDLE_BIT 50 /* 1ms, TB frequency is 41.66MHZ */ @@ -77,6 +96,7 @@ _GLOBAL(__setup_cpu_e6500) #ifdef CONFIG_PPC64 bl .setup_altivec_ivors #endif + bl setup_pw20_idle bl setup_altivec_idle bl __setup_cpu_e5500 mtlr r6 @@ -139,6 +159,7 @@ _GLOBAL(__setup_cpu_e5500) _GLOBAL(__restore_cpu_e6500) mflr r5 bl .setup_altivec_ivors + bl .setup_pw20_idle bl .setup_altivec_idle bl __restore_cpu_e5500 mtlr r5 -- 1.8.0 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev