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Re: [Qemu-devel] [Qemu-ppc] [PATCH v2] PPC: Introduce the Virtual Time B
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From: |
Alexander Graf |
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Subject: |
Re: [Qemu-devel] [Qemu-ppc] [PATCH v2] PPC: Introduce the Virtual Time Base (VTB) SPR register |
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Date: |
Fri, 27 Feb 2015 16:28:09 +0100 |
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User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 |
On 27.02.15 00:19, Cyril Bur wrote:
> This patch adds basic support for the VTB.
>
> PowerISA:
> The Virtual Time Base (VTB) is a 64-bit incrementing counter.
> Virtual Time Base increments at the same rate as the Time Base until its value
> becomes 0xFFFF_FFFF_FFFF_FFFF (2 64 - 1); at the next increment its value
> becomes 0x0000_0000_0000_0000. There is no interrupt or other indication when
> this occurs.
>
> The operation of the Virtual Time Base has the following additional
> properties.
> 1. Loading a GPR from the Virtual Time Base has no effect on the accuracy of
> the Virtual Time Base.
> 2. Copying the contents of a GPR to the Virtual Time Base replaces the
> contents of the Virtual Time Base with the contents of the GPR.
>
> Signed-off-by: Cyril Bur <address@hidden>
Thanks, applied to ppc-next.
Alex