Messages in this thread | | | Date | Mon, 3 Feb 2014 15:55:42 +0000 | From | Leif Lindholm <> | Subject | Re: [PATCH v4 2/5] arm: add new asm macro update_sctlr |
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On Mon, Feb 03, 2014 at 10:34:15AM +0000, Will Deacon wrote: > On Thu, Jan 30, 2014 at 01:12:47PM +0000, Leif Lindholm wrote: > > Oh, that's neat - thanks! > > > > Well, given that, I can think of two less horrible options: > > 1) > > .macro update_sctlr, tmp:req, set=, clear= > > mrc p15, 0, \tmp, c1, c0, 0 > > .ifnc \set, > > orr \tmp, \set > > .endif > > .ifnc \clear, > > mvn \clear, \clear > > and \tmp, \tmp, \clear > > Can't you use bic here?
Yeah.
> > .endif > > mcr p15, 0, \tmp, c1, c0, 0 > > .endm > > > > With the two call sites in uefi_phys.S as: > > > > ldr r5, =(CR_M) > > update_sctlr r12, , r5 > > and > > ldr r4, =(CR_I | CR_C | CR_M) > > update_sctlr r12, r4 > > These ldr= could be movs, right?
The first one could. The second one could be movw on armv7+.
> If so, I definitely prefer this to putting an ldr = into the macro itself > (option 2).
And your preference between 1) and 2) is?
/ Leif
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