Le 12/01/2011 10:08, Aneesh V a écrit :
On Saturday 08 January 2011 07:36 PM, Albert ARIBAUD wrote:
Le 08/01/2011 14:17, Aneesh V a écrit :
<snip..>
+/* some utility macros */ +#define mask(start, end) \
- (((1<< ((end) - (start) + 1)) - 1)<< (start))
+#define mask_n_get(reg, start, end) \
- (((reg)& mask(start, end))>> (start))
Seeing as these functions are only used in the ARMv7 cache C file, they should be moved there.
I plan to use a modified version of mask_n_get() and its set couterpart mask_n_set() in my subsequent works in more files.
Can I keep it here itself or should I move it to an OMAP specific header file or can I move it to a more generic header file? Please suggest.
They're very generic actually. I think they should go to a gereric bit manipulation header, and be named a... bit... more explicitly. For instance, the name 'mask' does not show that the macro creates a range of 'one' bits from start to end.
What I need is something like below:
#define get_bit_field(nr, start, mask)\ (((nr) & (mask)) >> (start))
#define set_bit_field(nr, start, mask, val)\ (nr) = ((nr) & ~(mask)) | (((val) << (start)) & (mask))
Can these go in a generic header? If so, can I add them to "include/linux/bitops.h"
After some more thought, I am wondering if a *generic* field setting and getting macro is really useful. So far everyone is fine with at most defining field-specific macros.
Best regards, Aneesh
Amicalement,