Re: [PATCH 6/7] pc-bios: s390x: Use PSW constants in start.S

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 21.07.20 09:05, Thomas Huth wrote:
> On 15/07/2020 11.40, Janosch Frank wrote:
[..]
>>  #ifndef S390_ARCH_H
>>  #define S390_ARCH_H
>>  
>> +/* s390 psw bit masks */
>> +#define PSW_MASK_EXT        0x0100000000000000UL
>> +#define PSW_MASK_IOINT      0x0200000000000000ULL
>> +#define PSW_MASK_SHORTPSW   0x0008000000000000ULL
>> +#define PSW_MASK_WAIT       0x0002000000000000ULL
>> +#define PSW_MASK_EAMODE     0x0000000100000000ULL
>> +#define PSW_MASK_BAMODE     0x0000000080000000ULL
>> +#define PSW_MASK_SHORT_ADDR 0x000000007fffffffULL
>> +#define PSW_MASK_64         (PSW_MASK_EAMODE | PSW_MASK_BAMODE)
>> +#define PSW_MASK_DWAIT      (PSW_MASK_64 | PSW_MASK_WAIT)
>> +#define PSW_MASK_EWAIT      (PSW_MASK_DWAIT | PSW_MASK_IOINT | PSW_MASK_EXT)
>> +
>> +#ifndef __ASSEMBLER__
>> +
>>  typedef struct PSW {
>>      uint64_t mask;
>>      uint64_t addr;
>> @@ -24,15 +38,6 @@ typedef struct PSWLegacy {
>>  } __attribute__ ((aligned(8))) PSWLegacy;
>>  _Static_assert(sizeof(struct PSWLegacy) == 8, "PSWLegacy size incorrect");
>>  
>> -/* s390 psw bit masks */
>> -#define PSW_MASK_IOINT      0x0200000000000000ULL
>> -#define PSW_MASK_SHORTPSW   0x0008000000000000ULL
>> -#define PSW_MASK_WAIT       0x0002000000000000ULL
>> -#define PSW_MASK_EAMODE     0x0000000100000000ULL
>> -#define PSW_MASK_BAMODE     0x0000000080000000ULL
>> -#define PSW_MASK_SHORT_ADDR 0x000000007fffffffULL
>> -#define PSW_MASK_64         (PSW_MASK_EAMODE | PSW_MASK_BAMODE)
>> -
>>  /* Low core mapping */
>>  typedef struct LowCore {
>>      /* prefix area: defined by architecture */
>> @@ -107,5 +112,5 @@ static inline uint32_t store_prefix(void)
>>      asm volatile("stpx %0" : "=m" (address));
>>      return address;
>>  }
>> -
>> +#endif /* !__ASSEMBLER__ */
>>  #endif
>> diff --git a/pc-bios/s390-ccw/start.S b/pc-bios/s390-ccw/start.S
>> index ce519300a1..01c4c21b26 100644
>> --- a/pc-bios/s390-ccw/start.S
>> +++ b/pc-bios/s390-ccw/start.S
>> @@ -9,6 +9,7 @@
>>   * your option) any later version. See the COPYING file in the top-level
>>   * directory.
>>   */
>> +#include "s390-arch.h"
>>  
>>          .globl _start
>>  _start:
>> @@ -108,10 +109,10 @@ io_new_code:
>>  
>>          .align  8
>>  disabled_wait_psw:
>> -        .quad   0x0002000180000000,0x0000000000000000
>> +        .quad   PSW_MASK_DWAIT, 0x0000000000000000
>>  enabled_wait_psw:
>> -        .quad   0x0302000180000000,0x0000000000000000
>> +        .quad   PSW_MASK_EWAIT, 0x0000000000000000
>>  external_new_mask:
>> -        .quad   0x0000000180000000
>> +        .quad   PSW_MASK_64

I find the old numbers EASIER to parse (as I know how a PSW looks like) than a
macro that I first have to look up.

>>  io_new_mask:
>> -        .quad   0x0000000180000000
>> +        .quad   PSW_MASK_64
>>
> 
> This fails to compile with older versions of binutils (e.g. the ones in
> RHEL7):
> 
> pc-bios/s390-ccw/start.S: Assembler messages:
> pc-bios/s390-ccw/start.S:108: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:108: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:108: Error: junk at end of line, first
> unrecognized character is `L'
> pc-bios/s390-ccw/start.S:110: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:110: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:110: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:110: Error: junk at end of line, first
> unrecognized character is `L'
> pc-bios/s390-ccw/start.S:112: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:112: Error: junk at end of line, first
> unrecognized character is `L'
> pc-bios/s390-ccw/start.S:114: Error: found 'L', expected: ')'
> pc-bios/s390-ccw/start.S:114: Error: junk at end of line, first
> unrecognized character is `L'
> 
> You either need some macro-magic for this, or simply drop the patch.

So I suggest to drop this patch.