Re: [Qemu-ppc] [PATCH v2 1/6] PPC 85xx: Detect e500v2 / e500mc during runtime

[Scott Wood]

On Fri, 2014-01-31 at 12:16 +0100, Alexander Graf wrote:
> With the qemu-ppce500 machine type we can run the same board with
> either an e500v2 or an e500mc core plugged in.
> 
> This means that the IVOR setup can't be based on compile time decisions,
> so instead we have to do a runtime check which CPU generation we're
> running on.
> 
> Signed-off-by: Alexander Graf <address@hidden>
> ---
>  arch/powerpc/cpu/mpc85xx/fixed_ivor.S |   21 ++++++++++++++++-----
>  1 file changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/powerpc/cpu/mpc85xx/fixed_ivor.S 
> b/arch/powerpc/cpu/mpc85xx/fixed_ivor.S
> index ebbb8c0..635a97e 100644
> --- a/arch/powerpc/cpu/mpc85xx/fixed_ivor.S
> +++ b/arch/powerpc/cpu/mpc85xx/fixed_ivor.S
> @@ -36,17 +36,25 @@
>       SET_IVOR(14, 0x1e0) /* Instruction TLB Error */
>       SET_IVOR(15, 0x040) /* Debug */
>  
> -/* e500v1 & e500v2 only */
> -#ifndef CONFIG_E500MC
> +     /* Check for CPU */
> +     mfpvr   r3
> +     srwi    r3, r3, 16
> +     /* Compare with e500mc PVR major number */
> +     li      r4, 0
> +     ori     r4, r4, 0x8023
> +     cmpw    r3, r4
> +
> +     /* e500v1 & e500v2 only */
> +     bge     1f
>       SET_IVOR(32, 0x200) /* SPE Unavailable */
>       SET_IVOR(33, 0x220) /* Embedded FP Data */
>       SET_IVOR(34, 0x240) /* Embedded FP Round */
> -#endif
> +1:
>  
>       SET_IVOR(35, 0x260) /* Performance monitor */
>  
> -/* e500mc only */
> -#ifdef CONFIG_E500MC
> +     /* e500mc only */
> +     blt     2f
>       SET_IVOR(36, 0x280) /* Processor doorbell */
>       SET_IVOR(37, 0x2a0) /* Processor doorbell critical */
>       SET_IVOR(38, 0x2c0) /* Guest Processor doorbell */
> @@ -54,6 +62,8 @@
>       SET_IVOR(40, 0x300) /* Hypervisor system call */
>       SET_IVOR(41, 0x320) /* Hypervisor Priviledge */
>  
> +#ifndef CONFIG_QEMU_E500
> +     /* QEMU guests runs in guest mode and can't access GIVORs */
>       SET_GIVOR(2, 0x060) /* Guest Data Storage */
>       SET_GIVOR(3, 0x080) /* Guest Instruction Storage */
>       SET_GIVOR(4, 0x0a0) /* Guest External Input */
> @@ -61,3 +71,4 @@
>       SET_GIVOR(13, 0x1c0) /* Guest Data TLB Error */
>       SET_GIVOR(14, 0x1e0) /* Guest Instruction TLB Error */
>  #endif
> +2:

Again, let's please just remove this entire file.

Besides, who's to say that (non-KVM) QEMU doesn't someday start
emulating GIVORs? :-)

-Scott