[OpenBIOS] [RFC] libopenbios: Adapt CIF handling for ppc64

[Andreas Färber]

Am 18.12.2010 um 17:09 schrieb Blue Swirl:

> On Sat, Dec 18, 2010 at 1:09 AM, Andreas Färber <andreas.faerber at web.de 
> > wrote:
>> On ppc64 neither long nor pointers can be used for the client  
>> interface.
>> Introduce new types prom_[u]arg_t to abstract this and add helpers
>> get_service() and arg2pointer() as well as format strings.
>>
>> Signed-off-by: Andreas Färber <andreas.faerber at web.de>
>> ---
>>  libopenbios/client.c |  302 +++++++++++++++++++++++++++ 
>> +----------------------
>>  1 files changed, 170 insertions(+), 132 deletions(-)
>>
>> diff --git a/libopenbios/client.c b/libopenbios/client.c
>> index d8a9fdf..d986226 100644
>> --- a/libopenbios/client.c
>> +++ b/libopenbios/client.c
>> @@ -30,13 +30,47 @@
>>  * (it doesn't) or if the function is unimplemented.
>>  */
>>
>> +#ifdef CONFIG_PPC64
>> +typedef int             prom_arg_t;
>> +typedef unsigned int    prom_uarg_t;
>> +#define PRIdARG "d"
>> +#define PRIxARG "x"
>> +#define FMT_arg  "%" PRIdARG
>> +#define FMT_argx "%08" PRIxARG
>> +#else
>> +typedef long            prom_arg_t;
>> +typedef unsigned long   prom_uarg_t;
>> +#define PRIdARG "ld"
>> +#define PRIxARG "lx"
>> +#define FMT_arg  "%" PRIdARG
>> +#define FMT_argx "%08" PRIxARG
>
> This should be "%016" for Sparc64 since long is 64 bits.

The original code used %08 so I left it that way.
We could check #if BITS == 64.

> Maybe these
> should be moved to a common header instead.

In that case we need longer names - e.g., FMT_promarg.

>>  #define PROM_MAX_ARGS  10
>>  typedef struct prom_args {
>> -        const char     *service;
>> -        long           nargs;
>> -        long           nret;
>> -        unsigned long  args[PROM_MAX_ARGS];
>> -} prom_args_t;
>> +#ifdef CONFIG_PPC64
>> +    prom_uarg_t service;
>> +#else
>> +    const char  *service;
>> +#endif
>> +    prom_arg_t  nargs;
>> +    prom_arg_t  nret;
>> +    prom_uarg_t args[PROM_MAX_ARGS];
>> +} __attribute__((packed)) prom_args_t;
>> +
>> +static inline void* arg2pointer(prom_uarg_t value)
>> +{
>> +    return (void*)(uintptr_t)value;
>> +}
>
> Perhaps the the type of the return value should be const char *
> instead, that may reduce the number of casts.

Will try. I followed the cell2pointer() model.

>> +
>> +static inline const char* get_service(prom_args_t *pb)
>> +{
>> +#ifdef CONFIG_PPC64
>> +    return arg2pointer(pb->service);
>> +#else
>> +    return pb->service;
>> +#endif
>
> I don't think arg2pointer() has any effect for non-PPC64 hosts, so you
> could also unconditionally use arg2pointer().

OK.

>>                printk("of_client_interface return:");
>>                for (i = 0; i < pb->nret; i++) {
>> -                       printk(" %lx", pb->args[pb->nargs + i]);
>> +                       printk(" %" PRIxARG, pb->args[pb->nargs +  
>> i]);
>
> " " FMT_arg?

That would change the output to decimal. Intentional? If I used  
FMT_argx, we'd introduce zero-padding.

Andreas