Re: [PATCH v4 3/3] KVM: PPC: epapr: install ev_idle hcall for e500 guest
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From: Alexander Graf <hidden>
Date: 2012-02-16 10:23:48
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kvm
On 16.02.2012, at 10:26, Liu Yu [off-list ref] wrote:
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If the guest hypervisor node contains "has-idle" property. =20 Signed-off-by: Liu Yu <redacted> --- v4: 1. discard the CONFIG_E500 to make code for all powerpc platform 2. code cleanup =20 arch/powerpc/kernel/epapr.S | 29 +++++++++++++++++++++++++++++ arch/powerpc/kernel/epapr_para.c | 13 ++++++++++++- 2 files changed, 41 insertions(+), 1 deletions(-) =20diff --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> =20 +#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 th= e 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. *=
/
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.global epapr_hypercall_start epapr_hypercall_start:diff --git a/arch/powerpc/kernel/epapr_para.c b/arch/powerpc/kernel/epapr_=
para.c
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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[]; =20 bool epapr_para_enabled =3D false; =20@@ -35,10 +39,17 @@ static int __init epapr_para_init(void)=20 insts =3D of_get_property(hyper_node, "hcall-instructions", &len); if (!(len % 4) && (len >=3D (4 * 4))) { - for (i =3D 0; i < (len / 4); i++) + for (i =3D 0; i < (len / 4); i++) { epapr_hypercall_start[i] =3D insts[i]; + epapr_ev_idle_start[i] =3D 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 =3D epapr_ev_idle; =20 epapr_para_enabled =3D true; } --=20 1.7.0.4 =20 =20 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html