From mboxrd@z Thu Jan  1 00:00:00 1970
From: Vijay Kilari <vijay.kilari@gmail.com>
Subject: Re: [PATCH v2 03/15] arm/xen: move gic save and restore
 registers to gic driver
Date: Thu, 10 Apr 2014 10:20:04 +0530
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To: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Prasun Kapoor <Prasun.Kapoor@caviumnetworks.com>, Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>, Julien Grall <julien.grall@linaro.org>, xen-devel@lists.xen.org, Stefano Stabellini <stefano.stabellini@citrix.com>
List-Id: xen-devel@lists.xenproject.org

On Wed, Apr 9, 2014 at 10:21 PM, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Fri, 2014-04-04 at 17:26 +0530, vijay.kilari@gmail.com wrote:
>
>> gic saved registers are moved to gic driver.
>> This required structure is allocated at runtime
>> and is saved & restored.
>
> I don't follow why this change required switch to allocating them
> dynamically. If it is a v2 vs v3 thing then I think a union in struct
> arch_vcpu would be fine, unless the v3 stuff is relatively enormous.
>
v2:
struct gic_state_data {
    uint32_t gic_hcr, gic_vmcr;
    uint32_t gic_apr;
    uint32_t gic_lr[64];
};

v3:
 struct gic_state_data {
     uint32_t gic_hcr, gic_vmcr;
     uint32_t gic_apr0[4];
      uint32_t gic_apr1[4];
      uint64_t gic_lr[16];
  };

Except hcr & vmcr registers, v2 & v3 are different.
Does static allocation helps in caching the domain struct and
is this the reason for not choosing dynamic allocation?
If so, I would suggest to move this structure to gic.h without
dynamic allocation?

>> -    v->arch.gic_apr = GICH[GICH_APR];
>> -    v->arch.gic_vmcr = GICH[GICH_VMCR];
>> +    v->arch.gic_state->gic_apr = GICH[GICH_APR];
>> +    v->arch.gic_state->gic_vmcr = GICH[GICH_VMCR];
>
> I think the gic on the field name is now redundant, at I reckon you can
> drop _state too.
>
> IOW v->arch.gic->apr, v->arch.gic->vmcr, etc.
>
> (or v->arch.gic.v2.apr / v->arch.gic_v2.apr based on the first comment)
>
> Ian.
>