Hi,
> On 24 Aug 2020, at 04:28, Wei Chen <wei.c...@arm.com> wrote:
>
> Arm ID_AA64PFR0_EL1 register provides two fields to describe CPU
> FP/SIMD implementations. Currently, we exactly know the meaning of
> 0x0, 0x1 and 0xf of these fields. Xen treats value < 8 as FP/SIMD
> features presented. If there is a value 0x2 bumped in the future,
> Xen behaviors for value <= 0x1 can also take effect. But what Xen
> done for value <= 0x1 may not always cover new value 0x2 required.
> We throw these messages to break the silence when Xen detected
> unknown FP/SIMD IDs to notice user to check.
>
> Signed-off-by: Wei Chen <wei.c...@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marq...@arm.com>
> ---
> xen/arch/arm/setup.c | 26 ++++++++++++++++++++++++--
> 1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index 7968cee47d..c7802d0e49 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -99,6 +99,28 @@ static const char * __initdata processor_implementers[] = {
> ['i'] = "Intel Corporation",
> };
>
> +static const char * __initdata fp_implements[] = {
> + "Floating-point",
> + "Floating-point + half-precision floating-point arithmetic",
> + "Floating-point Unknown ID 0x2",
> + "Floating-point Unknown ID 0x3",
> + "Floating-point Unknown ID 0x4",
> + "Floating-point Unknown ID 0x5",
> + "Floating-point Unknown ID 0x6",
> + "Floating-point Unknown ID 0x7",
> +};
> +
> +static const char * __initdata advsimd_implements[] = {
> + "AdvancedSIMD",
> + "AdvancedSIMD + half-precision floating-point arithmetic",
> + "AdvancedSIMD Unknown ID 0x2",
> + "AdvancedSIMD Unknown ID 0x3",
> + "AdvancedSIMD Unknown ID 0x4",
> + "AdvancedSIMD Unknown ID 0x5",
> + "AdvancedSIMD Unknown ID 0x6",
> + "AdvancedSIMD Unknown ID 0x7",
> +};
> +
> static void __init processor_id(void)
> {
> const char *implementer = "Unknown";
> @@ -129,8 +151,8 @@ static void __init processor_id(void)
> cpu_has_el1_32 ? "64+32" : cpu_has_el1_64 ? "64" : "No",
> cpu_has_el0_32 ? "64+32" : cpu_has_el0_64 ? "64" : "No");
> printk(" Extensions:%s%s%s\n",
> - cpu_has_fp ? " FloatingPoint" : "",
> - cpu_has_simd ? " AdvancedSIMD" : "",
> + cpu_has_fp ? fp_implements[boot_cpu_feature64(fp)] : "",
> + cpu_has_simd ? advsimd_implements[boot_cpu_feature64(simd)] : "",
> cpu_has_gicv3 ? " GICv3-SysReg" : "");
>
> printk(" Debug Features: %016"PRIx64" %016"PRIx64"\n",
> --
> 2.17.1
>
