Messages in this thread | | | Subject | Re: [PATCH v4 01/17] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long | From | Paolo Bonzini <> | Date | Mon, 4 Mar 2019 11:48:18 +0100 |
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On 04/03/19 11:17, Peter Zijlstra wrote: > On Mon, Mar 04, 2019 at 09:33:16AM +0100, Paolo Bonzini wrote: >> Why not instead change set_bit/clear_bit to use btsl/btrl instead of >> btsq/btrq? > > At least one of the faulty users (wireless) is in generic code and needs > fixing regardless. > > For better or worse; the bitmap stuff is defined to work on unsigned > long. Using it on smaller types already relies on small endian; but > further enabling just makes it worse I feel. Better have the rules be > uniform.
True that. On the other hand btsl/btrl is also one byte smaller if no operand is %r8-%r15.
In any case, /me wonders if we should have a macro like
#define DECLARE_LE_BITMAP(name,bits) \ u32 name[DIV_ROUND_UP(bits, 32)] __aligned(sizeof(unsigned long))
Paolo
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