thr3ads.net - Xen devel - [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd

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Jan Beulich

2011-Dec-16 15:23 UTC

[PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

The boolean ''osvw'' indicator and ''osvw_id''
can be folded - the function
can as well distinguish the non-OSVW case by checking for a negative
''osvw_id''. That way the whole variable argument list
processing is only
needed on the legacy code path.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -186,7 +186,7 @@ static void __devinit set_cpuidmask(cons
  * Check for the presence of an AMD erratum. Arguments are defined in amd.h 
  * for each known erratum. Return 1 if erratum is found.
  */
-int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw, ...) 
+int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw_id, ...)
 {
 	va_list ap;
 	u32 range;
@@ -195,27 +195,24 @@ int cpu_has_amd_erratum(const struct cpu
 	if (cpu->x86_vendor != X86_VENDOR_AMD)
 		return 0;
 
-	va_start(ap, osvw);
+	if (osvw_id >= 0 && cpu_has(cpu, X86_FEATURE_OSVW)) {
+		u64 osvw_len;
 
-	if (osvw) {
-		u16 osvw_id = va_arg(ap, int);
+		rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
 
-		if (cpu_has(cpu, X86_FEATURE_OSVW)) {
-			u64 osvw_len;
-			rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
-
-			if (osvw_id < osvw_len) {
-				u64 osvw_bits;
-				rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id >> 6), 
-				       osvw_bits);
+		if (osvw_id < osvw_len) {
+			u64 osvw_bits;
 
-				va_end(ap);
-				return (osvw_bits >> (osvw_id & 0x3f)) & 0x01;
-			}
+			rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id >> 6),
+			       osvw_bits);
+
+			return (osvw_bits >> (osvw_id & 0x3f)) & 1;
 		}
 	}
 
 	/* OSVW unavailable or ID unknown, match family-model-stepping range */
+	va_start(ap, osvw_id);
+
 	ms = (cpu->x86_model << 4) | cpu->x86_mask;
 	while ((range = va_arg(ap, int))) {
 		if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range)) &&
--- a/xen/include/asm-x86/amd.h
+++ b/xen/include/asm-x86/amd.h
@@ -119,8 +119,8 @@
  *   
  */
 
-#define AMD_LEGACY_ERRATUM(...)         0 /* legacy */, __VA_ARGS__, 0
-#define AMD_OSVW_ERRATUM(osvw_id, ...)  1 /* osvw */, osvw_id, __VA_ARGS__, 0
+#define AMD_LEGACY_ERRATUM(...)         -1 /* legacy */, __VA_ARGS__, 0
+#define AMD_OSVW_ERRATUM(osvw_id, ...)  osvw_id, __VA_ARGS__, 0
 #define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end)              \
     ((f << 24) | (m_start << 16) | (s_start << 12) | (m_end
<< 4) | (s_end))
 #define AMD_MODEL_RANGE_FAMILY(range)   (((range) >> 24) & 0xff)





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Boris Ostrovsky

2011-Dec-16 16:55 UTC

head link

Re: [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

On 12/16/11 10:23, Jan Beulich wrote:> The boolean ''osvw'' indicator and
''osvw_id'' can be folded - the function
> can as well distinguish the non-OSVW case by checking for a negative
> ''osvw_id''. That way the whole variable argument list
processing is only
> needed on the legacy code path.
>
> Signed-off-by: Jan Beulich<jbeulich@suse.com>
Acked-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
>
> --- a/xen/arch/x86/cpu/amd.c
> +++ b/xen/arch/x86/cpu/amd.c
> @@ -186,7 +186,7 @@ static void __devinit set_cpuidmask(cons
>    * Check for the presence of an AMD erratum. Arguments are defined in
amd.h
>    * for each known erratum. Return 1 if erratum is found.
>    */
> -int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw, ...)
> +int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw_id, ...)
>   {
>   	va_list ap;
>   	u32 range;
> @@ -195,27 +195,24 @@ int cpu_has_amd_erratum(const struct cpu
>   	if (cpu->x86_vendor != X86_VENDOR_AMD)
>   		return 0;
>
> -	va_start(ap, osvw);
> +	if (osvw_id>= 0&&  cpu_has(cpu, X86_FEATURE_OSVW)) {
> +		u64 osvw_len;
>
> -	if (osvw) {
> -		u16 osvw_id = va_arg(ap, int);
> +		rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
>
> -		if (cpu_has(cpu, X86_FEATURE_OSVW)) {
> -			u64 osvw_len;
> -			rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
> -
> -			if (osvw_id<  osvw_len) {
> -				u64 osvw_bits;
> -				rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id>>  6),
> -				       osvw_bits);
> +		if (osvw_id<  osvw_len) {
> +			u64 osvw_bits;
>
> -				va_end(ap);
> -				return (osvw_bits>>  (osvw_id&  0x3f))&  0x01;
> -			}
> +			rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id>>  6),
> +			       osvw_bits);
> +
> +			return (osvw_bits>>  (osvw_id&  0x3f))&  1;
>   		}
>   	}
>
>   	/* OSVW unavailable or ID unknown, match family-model-stepping range */
> +	va_start(ap, osvw_id);
> +
>   	ms = (cpu->x86_model<<  4) | cpu->x86_mask;
>   	while ((range = va_arg(ap, int))) {
>   		if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range))&&
> --- a/xen/include/asm-x86/amd.h
> +++ b/xen/include/asm-x86/amd.h
> @@ -119,8 +119,8 @@
>    *
>    */
>
> -#define AMD_LEGACY_ERRATUM(...)         0 /* legacy */, __VA_ARGS__, 0
> -#define AMD_OSVW_ERRATUM(osvw_id, ...)  1 /* osvw */, osvw_id,
__VA_ARGS__, 0
> +#define AMD_LEGACY_ERRATUM(...)         -1 /* legacy */, __VA_ARGS__, 0
> +#define AMD_OSVW_ERRATUM(osvw_id, ...)  osvw_id, __VA_ARGS__, 0
>   #define AMD_MODEL_RANGE(f, m_start, s_start, m_end, s_end)              \
>       ((f<<  24) | (m_start<<  16) | (s_start<<  12) |
(m_end<<  4) | (s_end))
>   #define AMD_MODEL_RANGE_FAMILY(range)   (((range)>>  24)& 
0xff)
>
>
>

Wei Huang

2011-Dec-16 17:16 UTC

head link

Re: [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

Acked-by: Wei Huang <wei.huang2@amd.com>

On 12/16/2011 10:55 AM, Boris Ostrovsky wrote:> On 12/16/11 10:23, Jan Beulich wrote:
>> The boolean ''osvw'' indicator and
''osvw_id'' can be folded - the function
>> can as well distinguish the non-OSVW case by checking for a negative
>> ''osvw_id''. That way the whole variable argument list
processing is only
>> needed on the legacy code path.
>>
>> Signed-off-by: Jan Beulich<jbeulich@suse.com>
>
> Acked-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
>
>>
>> --- a/xen/arch/x86/cpu/amd.c
>> +++ b/xen/arch/x86/cpu/amd.c
>> @@ -186,7 +186,7 @@ static void __devinit set_cpuidmask(cons
>>    * Check for the presence of an AMD erratum. Arguments are defined 
>> in amd.h
>>    * for each known erratum. Return 1 if erratum is found.
>>    */
>> -int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw, ...)
>> +int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int osvw_id, 
>> ...)
>>   {
>>       va_list ap;
>>       u32 range;
>> @@ -195,27 +195,24 @@ int cpu_has_amd_erratum(const struct cpu
>>       if (cpu->x86_vendor != X86_VENDOR_AMD)
>>           return 0;
>>
>> -    va_start(ap, osvw);
>> +    if (osvw_id>= 0&&  cpu_has(cpu, X86_FEATURE_OSVW)) {
>> +        u64 osvw_len;
>>
>> -    if (osvw) {
>> -        u16 osvw_id = va_arg(ap, int);
>> +        rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
>>
>> -        if (cpu_has(cpu, X86_FEATURE_OSVW)) {
>> -            u64 osvw_len;
>> -            rdmsrl(MSR_AMD_OSVW_ID_LENGTH, osvw_len);
>> -
>> -            if (osvw_id<  osvw_len) {
>> -                u64 osvw_bits;
>> -                rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id>>  6),
>> -                       osvw_bits);
>> +        if (osvw_id<  osvw_len) {
>> +            u64 osvw_bits;
>>
>> -                va_end(ap);
>> -                return (osvw_bits>>  (osvw_id&  0x3f))& 
0x01;
>> -            }
>> +            rdmsrl(MSR_AMD_OSVW_STATUS + (osvw_id>>  6),
>> +                   osvw_bits);
>> +
>> +            return (osvw_bits>>  (osvw_id&  0x3f))&  1;
>>           }
>>       }
>>
>>       /* OSVW unavailable or ID unknown, match family-model-stepping 
>> range */
>> +    va_start(ap, osvw_id);
>> +
>>       ms = (cpu->x86_model<<  4) | cpu->x86_mask;
>>       while ((range = va_arg(ap, int))) {
>>           if ((cpu->x86 == AMD_MODEL_RANGE_FAMILY(range))&&
>> --- a/xen/include/asm-x86/amd.h
>> +++ b/xen/include/asm-x86/amd.h
>> @@ -119,8 +119,8 @@
>>    *
>>    */
>>
>> -#define AMD_LEGACY_ERRATUM(...)         0 /* legacy */, __VA_ARGS__, 0
>> -#define AMD_OSVW_ERRATUM(osvw_id, ...)  1 /* osvw */, osvw_id, 
>> __VA_ARGS__, 0
>> +#define AMD_LEGACY_ERRATUM(...)         -1 /* legacy */, __VA_ARGS__,
0
>> +#define AMD_OSVW_ERRATUM(osvw_id, ...)  osvw_id, __VA_ARGS__, 0
>>   #define AMD_MODEL_RANGE(f, m_start, s_start, m_end, 
>> s_end)              \
>>       ((f<<  24) | (m_start<<  16) | (s_start<<  12)
| (m_end<<  4) |
>> (s_end))
>>   #define AMD_MODEL_RANGE_FAMILY(range)   (((range)>>  24)& 
0xff)
>>
>>
>>
>

Xen devel - Dec 2011 - [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

[PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

Re: [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()

Re: [PATCH] x86/AMD: fold redundant parameters of cpu_has_amd_erratum()