[PATCH v7 05/12] arm64/boot: Factor out a macro to check SPE version

James Clark posted 12 patches 1 month, 3 weeks ago
There is a newer version of this series
[PATCH v7 05/12] arm64/boot: Factor out a macro to check SPE version
Posted by James Clark 1 month, 3 weeks ago
We check the version of SPE twice, and we'll add one more check in the
next commit so factor out a macro to do this. Change the #3 magic number
to the actual SPE version define (V1p2) to make it more readable.

No functional changes intended.

Tested-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
---
 arch/arm64/include/asm/el2_setup.h | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 46033027510c..3a4ca7f9acfb 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -103,8 +103,7 @@
 	csel	x2, xzr, x0, eq			// all PMU counters from EL1
 
 	/* Statistical profiling */
-	ubfx	x0, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
-	cbz	x0, .Lskip_spe_\@		// Skip if SPE not present
+	__spe_vers_imp .Lskip_spe_\@, ID_AA64DFR0_EL1_PMSVer_IMP, x0 // Skip if SPE not present
 
 	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
 	and	x0, x0, #(1 << PMBIDR_EL1_P_SHIFT)
@@ -255,6 +254,14 @@
 .Lskip_brbe_\@:
 .endm
 
+/* Branch to skip_label if SPE version is less than given version */
+.macro __spe_vers_imp skip_label, version, tmp
+    mrs    \tmp, id_aa64dfr0_el1
+    ubfx   \tmp, \tmp, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
+    cmp    \tmp, \version
+    b.lt   \skip_label
+.endm
+
 /* Disable any fine grained traps */
 .macro __init_el2_fgt
 	mrs	x1, id_aa64mmfr0_el1
@@ -263,10 +270,8 @@
 
 	mov	x0, xzr
 	mov	x2, xzr
-	mrs	x1, id_aa64dfr0_el1
-	ubfx	x1, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
-	cmp	x1, #3
-	b.lt	.Lskip_spe_fgt_\@
+	/* If SPEv1p2 is implemented, */
+	__spe_vers_imp .Lskip_spe_fgt_\@, #ID_AA64DFR0_EL1_PMSVer_V1P2, x1
 	/* Disable PMSNEVFR_EL1 read and write traps */
 	orr	x0, x0, #HDFGRTR_EL2_nPMSNEVFR_EL1_MASK
 	orr	x2, x2, #HDFGWTR_EL2_nPMSNEVFR_EL1_MASK

-- 
2.34.1
Re: [PATCH v7 05/12] arm64/boot: Factor out a macro to check SPE version
Posted by Leo Yan 1 month ago
On Thu, Aug 14, 2025 at 10:25:27AM +0100, James Clark wrote:
> We check the version of SPE twice, and we'll add one more check in the
> next commit so factor out a macro to do this. Change the #3 magic number
> to the actual SPE version define (V1p2) to make it more readable.
> 
> No functional changes intended.
> 
> Tested-by: Leo Yan <leo.yan@arm.com>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
>  arch/arm64/include/asm/el2_setup.h | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
> index 46033027510c..3a4ca7f9acfb 100644
> --- a/arch/arm64/include/asm/el2_setup.h
> +++ b/arch/arm64/include/asm/el2_setup.h
> @@ -103,8 +103,7 @@
>  	csel	x2, xzr, x0, eq			// all PMU counters from EL1
>  
>  	/* Statistical profiling */
> -	ubfx	x0, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
> -	cbz	x0, .Lskip_spe_\@		// Skip if SPE not present
> +	__spe_vers_imp .Lskip_spe_\@, ID_AA64DFR0_EL1_PMSVer_IMP, x0 // Skip if SPE not present
>  
>  	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
>  	and	x0, x0, #(1 << PMBIDR_EL1_P_SHIFT)
> @@ -255,6 +254,14 @@
>  .Lskip_brbe_\@:
>  .endm
>  
> +/* Branch to skip_label if SPE version is less than given version */
> +.macro __spe_vers_imp skip_label, version, tmp
> +    mrs    \tmp, id_aa64dfr0_el1
> +    ubfx   \tmp, \tmp, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
> +    cmp    \tmp, \version
> +    b.lt   \skip_label
> +.endm
> +

Just wondering if we need to move the macro to the beginning of the
file, so that we can define it first and call it afterwards.

Otherwise, LGTM:

Reviewed-by: Leo Yan <leo.yan@arm.com>

>  /* Disable any fine grained traps */
>  .macro __init_el2_fgt
>  	mrs	x1, id_aa64mmfr0_el1
> @@ -263,10 +270,8 @@
>  
>  	mov	x0, xzr
>  	mov	x2, xzr
> -	mrs	x1, id_aa64dfr0_el1
> -	ubfx	x1, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
> -	cmp	x1, #3
> -	b.lt	.Lskip_spe_fgt_\@
> +	/* If SPEv1p2 is implemented, */
> +	__spe_vers_imp .Lskip_spe_fgt_\@, #ID_AA64DFR0_EL1_PMSVer_V1P2, x1
>  	/* Disable PMSNEVFR_EL1 read and write traps */
>  	orr	x0, x0, #HDFGRTR_EL2_nPMSNEVFR_EL1_MASK
>  	orr	x2, x2, #HDFGWTR_EL2_nPMSNEVFR_EL1_MASK
> 
> -- 
> 2.34.1
>
Re: [PATCH v7 05/12] arm64/boot: Factor out a macro to check SPE version
Posted by James Clark 1 month ago

On 01/09/2025 11:05 am, Leo Yan wrote:
> On Thu, Aug 14, 2025 at 10:25:27AM +0100, James Clark wrote:
>> We check the version of SPE twice, and we'll add one more check in the
>> next commit so factor out a macro to do this. Change the #3 magic number
>> to the actual SPE version define (V1p2) to make it more readable.
>>
>> No functional changes intended.
>>
>> Tested-by: Leo Yan <leo.yan@arm.com>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>>   arch/arm64/include/asm/el2_setup.h | 17 +++++++++++------
>>   1 file changed, 11 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
>> index 46033027510c..3a4ca7f9acfb 100644
>> --- a/arch/arm64/include/asm/el2_setup.h
>> +++ b/arch/arm64/include/asm/el2_setup.h
>> @@ -103,8 +103,7 @@
>>   	csel	x2, xzr, x0, eq			// all PMU counters from EL1
>>   
>>   	/* Statistical profiling */
>> -	ubfx	x0, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
>> -	cbz	x0, .Lskip_spe_\@		// Skip if SPE not present
>> +	__spe_vers_imp .Lskip_spe_\@, ID_AA64DFR0_EL1_PMSVer_IMP, x0 // Skip if SPE not present
>>   
>>   	mrs_s	x0, SYS_PMBIDR_EL1              // If SPE available at EL2,
>>   	and	x0, x0, #(1 << PMBIDR_EL1_P_SHIFT)
>> @@ -255,6 +254,14 @@
>>   .Lskip_brbe_\@:
>>   .endm
>>   
>> +/* Branch to skip_label if SPE version is less than given version */
>> +.macro __spe_vers_imp skip_label, version, tmp
>> +    mrs    \tmp, id_aa64dfr0_el1
>> +    ubfx   \tmp, \tmp, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
>> +    cmp    \tmp, \version
>> +    b.lt   \skip_label
>> +.endm
>> +
> 
> Just wondering if we need to move the macro to the beginning of the
> file, so that we can define it first and call it afterwards.
> 
> Otherwise, LGTM:
> 
> Reviewed-by: Leo Yan <leo.yan@arm.com>
> 

It's not required, but all the other macros are defined before use and 
it looks a bit weird to not do it, so I can move it.

>>   /* Disable any fine grained traps */
>>   .macro __init_el2_fgt
>>   	mrs	x1, id_aa64mmfr0_el1
>> @@ -263,10 +270,8 @@
>>   
>>   	mov	x0, xzr
>>   	mov	x2, xzr
>> -	mrs	x1, id_aa64dfr0_el1
>> -	ubfx	x1, x1, #ID_AA64DFR0_EL1_PMSVer_SHIFT, #4
>> -	cmp	x1, #3
>> -	b.lt	.Lskip_spe_fgt_\@
>> +	/* If SPEv1p2 is implemented, */
>> +	__spe_vers_imp .Lskip_spe_fgt_\@, #ID_AA64DFR0_EL1_PMSVer_V1P2, x1
>>   	/* Disable PMSNEVFR_EL1 read and write traps */
>>   	orr	x0, x0, #HDFGRTR_EL2_nPMSNEVFR_EL1_MASK
>>   	orr	x2, x2, #HDFGWTR_EL2_nPMSNEVFR_EL1_MASK
>>
>> -- 
>> 2.34.1
>>