Re: [PATCH 07/28] nios2: I/O Mapping

[Ley Foon Tan]

On Thu, Apr 24, 2014 at 2:02 PM, Ley Foon Tan <lftan@xxxxxxxxxx> wrote:
> On Tue, Apr 22, 2014 at 9:59 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> On Friday 18 April 2014, Ley Foon Tan wrote:
>>
>>> +
>>> +#include <asm/pgtable-bits.h>
>>> +
>>> +#define IO_SPACE_LIMIT 0xffffffff
>>
>> Please use 0xffff here, this should work for almost any PCI bus.
> Ah, CONFIG_PCI is not enable in nios2. So, I think IO_SPACE_LIMIT
> should set to 0.
>
>
>>> +
>>> +/* Use "Duff's Device" to unroll the loops. */
>>> +#define __IO_OUT_LOOP(a, b, l)                               \
>>> +     do {                                            \
>>> +             if (l > 0) {                            \
>>> +                     int _n = (l + 7) / 8;           \
>>> +                     switch (l % 8) {                \
>>> +                     case 0:                         \
>>> +                             do {                    \
>>> +                                     *a = *b++;      \
>>
>> I would recommend just doing all of this in out-of-line implementations
>> rather than macros and inline functions.
> Okay. Will move the macros to out-of-line function.
I'm start working on this and found that it is better to keep it as
macros. This is because the input arguments "a" and "b" can be
byte/short/int pointers. Otherwise, we need to have separate function
calls for byte/short/int.

Regards
Ley Foon
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