From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Liu Yu <yu.liu@freescale.com>,
"<kvm-ppc@vger.kernel.org>" <kvm-ppc@vger.kernel.org>,
"<kvm@vger.kernel.org>" <kvm@vger.kernel.org>,
"<linuxppc-dev@ozlabs.org>" <linuxppc-dev@ozlabs.org>,
"<B07421@freescale.com>" <B07421@freescale.com>
Subject: Re: [PATCH v4 3/3] KVM: PPC: epapr: install ev_idle hcall for e500 guest
Date: Thu, 16 Feb 2012 16:58:06 +0000 [thread overview]
Message-ID: <4F3D359E.6030209@freescale.com> (raw)
In-Reply-To: <EAC043A1-A04F-4A27-8488-3C42D99D175E@suse.de>
On 02/16/2012 04:24 AM, Alexander Graf wrote:
> On 16.02.2012, at 10:26, Liu Yu <yu.liu@freescale.com> wrote:
>> +_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 :)
The interrupt will branch to LR, so no, we can't trash it or put it
anywhere else.
-scott
WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: "<linuxppc-dev@ozlabs.org>" <linuxppc-dev@ozlabs.org>,
Liu Yu <yu.liu@freescale.com>,
"<kvm@vger.kernel.org>" <kvm@vger.kernel.org>,
"<kvm-ppc@vger.kernel.org>" <kvm-ppc@vger.kernel.org>,
"<B07421@freescale.com>" <B07421@freescale.com>
Subject: Re: [PATCH v4 3/3] KVM: PPC: epapr: install ev_idle hcall for e500 guest
Date: Thu, 16 Feb 2012 10:58:06 -0600 [thread overview]
Message-ID: <4F3D359E.6030209@freescale.com> (raw)
In-Reply-To: <EAC043A1-A04F-4A27-8488-3C42D99D175E@suse.de>
On 02/16/2012 04:24 AM, Alexander Graf wrote:
> On 16.02.2012, at 10:26, Liu Yu <yu.liu@freescale.com> wrote:
>> +_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 :)
The interrupt will branch to LR, so no, we can't trash it or put it
anywhere else.
-scott
WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Liu Yu <yu.liu@freescale.com>,
"<kvm-ppc@vger.kernel.org>" <kvm-ppc@vger.kernel.org>,
"<kvm@vger.kernel.org>" <kvm@vger.kernel.org>,
"<linuxppc-dev@ozlabs.org>" <linuxppc-dev@ozlabs.org>,
"<B07421@freescale.com>" <B07421@freescale.com>
Subject: Re: [PATCH v4 3/3] KVM: PPC: epapr: install ev_idle hcall for e500 guest
Date: Thu, 16 Feb 2012 10:58:06 -0600 [thread overview]
Message-ID: <4F3D359E.6030209@freescale.com> (raw)
In-Reply-To: <EAC043A1-A04F-4A27-8488-3C42D99D175E@suse.de>
On 02/16/2012 04:24 AM, Alexander Graf wrote:
> On 16.02.2012, at 10:26, Liu Yu <yu.liu@freescale.com> wrote:
>> +_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 :)
The interrupt will branch to LR, so no, we can't trash it or put it
anywhere else.
-scott
next prev parent reply other threads:[~2012-02-16 16:58 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-16 9:26 [PATCH v4 1/3] KVM: PPC: epapr: Factor out the epapr init Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 9:26 ` [PATCH v4 2/3] KVM: PPC: epapr: Add idle hcall support for host Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 9:26 ` [PATCH v4 3/3] KVM: PPC: epapr: install ev_idle hcall for e500 guest Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 9:26 ` Liu Yu
2012-02-16 10:24 ` Alexander Graf
2012-02-16 10:24 ` Alexander Graf
2012-02-16 10:24 ` Alexander Graf
2012-02-16 16:58 ` Scott Wood [this message]
2012-02-16 16:58 ` Scott Wood
2012-02-16 16:58 ` Scott Wood
2012-02-16 17:18 ` Alexander Graf
2012-02-16 17:18 ` Alexander Graf
2012-02-16 17:18 ` Alexander Graf
2012-02-16 17:28 ` Scott Wood
2012-02-16 17:28 ` Scott Wood
2012-02-16 17:28 ` Scott Wood
2012-02-16 17:30 ` Alexander Graf
2012-02-16 17:30 ` Alexander Graf
2012-02-16 17:30 ` Alexander Graf
2012-02-16 17:36 ` Scott Wood
2012-02-16 17:36 ` Scott Wood
2012-02-16 17:36 ` Scott Wood
2012-02-16 17:39 ` Alexander Graf
2012-02-16 17:39 ` Alexander Graf
2012-02-16 17:39 ` Alexander Graf
2012-02-16 17:14 ` Scott Wood
2012-02-16 17:14 ` Scott Wood
2012-02-16 17:14 ` Scott Wood
2012-02-16 10:20 ` [PATCH v4 2/3] KVM: PPC: epapr: Add idle hcall support for host Alexander Graf
2012-02-16 10:20 ` Alexander Graf
2012-02-16 10:20 ` Alexander Graf
2012-02-17 2:13 ` Liu Yu-B13201
2012-02-17 2:13 ` Liu Yu-B13201
2012-02-17 2:20 ` Alexander Graf
2012-02-17 2:20 ` Alexander Graf
2012-02-17 2:20 ` Alexander Graf
2012-02-16 10:17 ` [PATCH v4 1/3] KVM: PPC: epapr: Factor out the epapr init Alexander Graf
2012-02-16 10:17 ` Alexander Graf
2012-02-16 10:17 ` Alexander Graf
2012-02-16 17:13 ` Scott Wood
2012-02-16 17:13 ` Scott Wood
2012-02-16 17:13 ` Scott Wood
2012-02-17 10:03 ` Liu Yu-B13201
2012-02-17 10:03 ` Liu Yu-B13201
2012-02-17 10:03 ` Liu Yu-B13201
2012-02-17 18:58 ` Scott Wood
2012-02-17 18:58 ` Scott Wood
2012-02-17 18:58 ` Scott Wood
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