powerpc/mm/radix: Setup AMOR in HV mode to allow key 0
Setup AMOR (Authority Mask Override Register) in HV mode so that the
host and guest kernel can in turn setup IAMR.
This allows us to enable key 0 in a following patch.
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 8d00ab4..29e5029 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -312,6 +312,18 @@ static void update_hid_for_radix(void)
cpu_relax();
}
+static void radix_init_amor(void)
+{
+ /*
+ * In HV mode, we init AMOR (Authority Mask Override Register) so that
+ * the hypervisor and guest can setup IAMR (Instruction Authority Mask
+ * Register), enable key 0 and set it to 1.
+ *
+ * AMOR = 0b1100 .... 0000 (Mask for key 0 is 11)
+ */
+ mtspr(SPRN_AMOR, (3ul << 62));
+}
+
void __init radix__early_init_mmu(void)
{
unsigned long lpcr;
@@ -368,6 +380,7 @@ void __init radix__early_init_mmu(void)
lpcr = mfspr(SPRN_LPCR);
mtspr(SPRN_LPCR, lpcr | LPCR_UPRT | LPCR_HR);
radix_init_partition_table();
+ radix_init_amor();
}
memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
@@ -387,6 +400,7 @@ void radix__early_init_mmu_secondary(void)
mtspr(SPRN_PTCR,
__pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
+ radix_init_amor();
}
}