On 7/6/20 5:59 PM, Michael Ellerman wrote:
"Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> writes:
As we kexec across kernels that use AMR/IAMR for different purposes
we need to ensure that new kernels get kexec'd with a reset value
of AMR/IAMR. For ex: the new kernel can use key 0 for kernel mapping and the old
AMR value prevents access to key 0.
This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR
is not needed and the IAMR reset is partial (it doesn't do the reset
on secondary cpus) and is redundant with this patch.
I like the idea of cleaning this stuff up.
But I think tying it into kup/kuep/kuap and the MMU features and ifdefs
and so on is overly complicated.
We should just have eg:
void reset_sprs(void)
{
if (early_cpu_has_feature(CPU_FTR_ARCH_206)) {
mtspr(SPRN_AMR, 0);
mtspr(SPRN_UAMOR, 0);
}
if (early_cpu_has_feature(CPU_FTR_ARCH_207S)) {
mtspr(SPRN_IAMR, 0);
}
}
And call that from the kexec paths.
Will fix. Should that be early_cpu_has_feature()? cpu_has_feature()
should work there right?
-aneesh
