Re: [kvm-unit-tests PATCH v6 02/10] s390x: Use PSW bits definitions in cstart

[Pierre Morel <pmorel@linux.ibm.com>]

On 2020-04-27 11:01, David Hildenbrand wrote:
> On 24.04.20 12:45, Pierre Morel wrote:
>> This patch defines the PSW bits EA/BA used to initialize the PSW masks
>> for exceptions.
>>
>> Since some PSW mask definitions exist already in arch_def.h we add these
>> definitions there.
>> We move all PSW definitions together and protect assembler code against
>> C syntax.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   lib/s390x/asm/arch_def.h | 16 ++++++++++++----
>>   s390x/cstart64.S         | 15 ++++++++-------
>>   2 files changed, 20 insertions(+), 11 deletions(-)
>>
>> diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
>> index 15a4d49..c54409a 100644
>> --- a/lib/s390x/asm/arch_def.h
>> +++ b/lib/s390x/asm/arch_def.h
>> @@ -10,15 +10,22 @@
>>   #ifndef _ASM_S390X_ARCH_DEF_H_
>>   #define _ASM_S390X_ARCH_DEF_H_
>>   
>> +#define PSW_MASK_EXT			0x0100000000000000UL
>> +#define PSW_MASK_DAT			0x0400000000000000UL
>> +#define PSW_MASK_SHORT_PSW		0x0008000000000000UL
>> +#define PSW_MASK_PSTATE			0x0001000000000000UL
>> +#define PSW_MASK_BA			0x0000000080000000UL
>> +#define PSW_MASK_EA			0x0000000100000000UL
>> +
>> +#define PSW_EXCEPTION_MASK	(PSW_MASK_EA | PSW_MASK_BA)
>> +#define PSW_RESET_MASK		(PSW_EXCEPTION_MASK | PSW_MASK_SHORT_PSW)
>> +
>> +#ifndef __ASSEMBLER__
>>   struct psw {
>>   	uint64_t	mask;
>>   	uint64_t	addr;
>>   };
>>   
>> -#define PSW_MASK_EXT			0x0100000000000000UL
>> -#define PSW_MASK_DAT			0x0400000000000000UL
>> -#define PSW_MASK_PSTATE			0x0001000000000000UL
>> -
>>   #define CR0_EXTM_SCLP			0X0000000000000200UL
>>   #define CR0_EXTM_EXTC			0X0000000000002000UL
>>   #define CR0_EXTM_EMGC			0X0000000000004000UL
>> @@ -297,4 +304,5 @@ static inline uint32_t get_prefix(void)
>>   	return current_prefix;
>>   }
>>   
>> +#endif /* __ASSEMBLER */
>>   #endif
>> diff --git a/s390x/cstart64.S b/s390x/cstart64.S
>> index ba2e67c..e394b3a 100644
>> --- a/s390x/cstart64.S
>> +++ b/s390x/cstart64.S
>> @@ -12,6 +12,7 @@
>>    */
>>   #include <asm/asm-offsets.h>
>>   #include <asm/sigp.h>
>> +#include <asm/arch_def.h>
>>   
>>   .section .init
>>   
>> @@ -225,19 +226,19 @@ svc_int:
>>   
>>   	.align	8
>>   reset_psw:
>> -	.quad	0x0008000180000000
>> +	.quad	PSW_RESET_MASK
> 
> I'd really prefer
> 
> .quad	PSW_EXCEPTION_MASK | PSW_MASK_SHORT_PSW
> 
> here instead and drop PSW_RESET_MASK. Makes it clearer that we are
> talking about a special short psw here.
> 
> Apart from that, looks good to me.
> 
> 

Thanks, I will do as you propose,

Regards,
Pierre


-- 
Pierre Morel
IBM Lab Boeblingen