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Date: Tue, 24 Jun 2014 11:55:23 -0400
From: Christopher Covington <cov@codeaurora.org>
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Subject: Re: [Qemu-devel] [PATCH v1 7/7] target-arm: Call the pmccntr_sync
 function when swapping ELs
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To: Alistair Francis <alistair.francis@xilinx.com>
Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, qemu-devel@nongnu.org

On 06/23/2014 09:12 PM, Alistair Francis wrote:
> Call the new pmccntr_sync() function when there is a possibility
> of swapping ELs (I.E. when there is an exception)
> 
> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
> ---
> 
>  target-arm/helper-a64.c |    5 +++++
>  target-arm/helper.c     |    7 +++++++
>  target-arm/op_helper.c  |    6 ++++++
>  3 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c
> index 2b4ce6a..b61174f 100644
> --- a/target-arm/helper-a64.c
> +++ b/target-arm/helper-a64.c
> @@ -446,6 +446,8 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
>      target_ulong addr = env->cp15.vbar_el[1];
>      int i;
>  
> +    pmccntr_sync(env);
> +
>      if (arm_current_pl(env) == 0) {
>          if (env->aarch64) {
>              addr += 0x400;
> @@ -484,6 +486,7 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
>          addr += 0x100;
>          break;
>      default:
> +        pmccntr_sync(env);
>          cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
>      }
>  
> @@ -511,4 +514,6 @@ void aarch64_cpu_do_interrupt(CPUState *cs)
>  
>      env->pc = addr;
>      cs->interrupt_request |= CPU_INTERRUPT_EXITTB;
> +
> +    pmccntr_sync(env);
>  }

The double calls seem unwieldy. I think it could be made into a single
function call if there was access, perhaps as a second parameter or maybe as a
static variable, to both the previous and current state so the function could
tell whether there is no transition, enable->disable, or disable->enable.

Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
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