On 16.02.2012, at 10:26, Liu Yu <yu.liu@xxxxxxxxxxxxx> wrote: > If the guest hypervisor node contains "has-idle" property. > > Signed-off-by: Liu Yu <yu.liu@xxxxxxxxxxxxx> > --- > v4: > 1. discard the CONFIG_E500 to make code for all powerpc platform > 2. code cleanup > > arch/powerpc/kernel/epapr.S | 29 +++++++++++++++++++++++++++++ > arch/powerpc/kernel/epapr_para.c | 13 ++++++++++++- > 2 files changed, 41 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/kernel/epapr.S b/arch/powerpc/kernel/epapr.S > index 697b390..f06d636 100644 > --- a/arch/powerpc/kernel/epapr.S > +++ b/arch/powerpc/kernel/epapr.S > @@ -15,6 +15,35 @@ > #include <asm/ppc_asm.h> > #include <asm/asm-offsets.h> > > +#define HC_VENDOR_EPAPR (1 << 16) > +#define HC_EV_IDLE 16 > + > +_GLOBAL(epapr_ev_idle) > +epapr_ev_idle: > + rlwinm r3,r1,0,0,31-THREAD_SHIFT /* current thread_info */ > + lwz r4,TI_LOCAL_FLAGS(r3) /* set napping bit */ > + ori r4,r4,_TLF_NAPPING /* so when we take an exception */ > + stw r4,TI_LOCAL_FLAGS(r3) /* it will return to our caller */ > + > + wrteei 1 > + > +idle_loop: > + LOAD_REG_IMMEDIATE(r11, HC_VENDOR_EPAPR | HC_EV_IDLE) > + > +.global epapr_ev_idle_start > +epapr_ev_idle_start: > + li r3, -1 > + nop > + nop > + nop Can't you just bl into epapr_hypercall_start? You don't even have to save the old lr. because we never return anyways :) Alex > + > + /* > + * Guard against spurious wakeups (e.g. from a hypervisor) -- > + * any real interrupt will cause us to return to LR due to > + * _TLF_NAPPING. > + */ > + b idle_loop > + > /* Hypercall entry point. Will be patched with device tree instructions. */ > .global epapr_hypercall_start > epapr_hypercall_start: > diff --git a/arch/powerpc/kernel/epapr_para.c b/arch/powerpc/kernel/epapr_para.c > index ea13cac..adee4f1 100644 > --- a/arch/powerpc/kernel/epapr_para.c > +++ b/arch/powerpc/kernel/epapr_para.c > @@ -20,6 +20,10 @@ > #include <linux/of.h> > #include <asm/epapr_hcalls.h> > #include <asm/cacheflush.h> > +#include <asm/machdep.h> > + > +extern void epapr_ev_idle(void); > +extern u32 epapr_ev_idle_start[]; > > bool epapr_para_enabled = false; > > @@ -35,10 +39,17 @@ static int __init epapr_para_init(void) > > insts = of_get_property(hyper_node, "hcall-instructions", &len); > if (!(len % 4) && (len >= (4 * 4))) { > - for (i = 0; i < (len / 4); i++) > + for (i = 0; i < (len / 4); i++) { > epapr_hypercall_start[i] = insts[i]; > + epapr_ev_idle_start[i] = insts[i]; > + } > flush_icache_range((ulong)epapr_hypercall_start, > (ulong)epapr_hypercall_start + len); > + flush_icache_range((ulong)epapr_ev_idle_start, > + (ulong)epapr_ev_idle_start + len); > + > + if (of_get_property(hyper_node, "has-idle", NULL)) > + ppc_md.power_save = epapr_ev_idle; > > epapr_para_enabled = true; > } > -- > 1.7.0.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html