On Wed, Nov 14, 2012 at 02:21:59PM -0800, Tony Lindgren wrote: > No idea if assuming that zero value for the diagnostic register > is safe.. What's the default value of the diagnostic register supposed > to be?
No, that's not safe. What if your pre-kernel code has asked the secure monitor to set the work-around bit already? > #if defined(CONFIG_ARM_ERRATA_751472) && defined(CONFIG_SMP) > ALT_SMP(cmp r6, #0x30) @ present prior to r3p0 > ALT_UP_B(1f) > - mrclt p15, 0, r10, c15, c0, 1 @ read diagnostic register > - orrlt r10, r10, #1 << 11 @ set bit #11 > - mcrlt p15, 0, r10, c15, c0, 1 @ write diagnostic register > + bge 1f @ not needed for r3p0 and later > + mrc p15, 0, r10, c15, c0, 1 @ read diagnostic register > + teq r10, #0 @ zero for secure mode? > + beq 1f @ bail out for secure mode This test for zero is pointless. What if some other work-around has been enabled but not this one? > + tst r10, #1 << 11 @ bit #11 already set? > + orreq r10, r10, #1 << 11 @ set bit #11 if not set > + mcreq p15, 0, r10, c15, c0, 1 @ write diagnostic register > 1: > #endif > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
