On Mon, Jan 05, 2015 at 01:20:57PM +0000, David Laight wrote:

quoted

+/* simplify initialization of mask field */
+#define CYCLECOUNTER_MASK(bits) (cycle_t)((bits) < 64 ? ((1ULL<<(bits))-1) : -1)

That has me chasing through the C integer promotion rules.
Better might be:
	((bits) < 64 ? (1ULL << (bits)) - 1 : (((1ULL << 63) - 1) << 1) + 1)
I actually suspect there is a standard definition somewhere?

This is an exact copy of CLOCKSOURCE_MASK, and if wrong, then both are
wrong.  In any case, I can't see any issue here. Is not

	(some_int_type) -1

always equal to

	0xf...(width of type)

for all integer types, when using 2s compliment?

Thanks
Richard