powerpc: helper function to read, write AMR, IAMR, UAMOR registers

Implements helper functions to read and write the key related
registers; AMR, IAMR, UAMOR.

AMR register tracks the read,write permission of a key
IAMR register tracks the execute permission of a key
UAMOR register enables and disables a key

Acked-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index e68e367..afa6d0d 100644 (file)
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -67,3 +67,39 @@ void pkey_mm_init(struct mm_struct *mm)
                return;
        mm_pkey_allocation_map(mm) = initial_allocation_mask;
 }
+
+static inline u64 read_amr(void)
+{
+       return mfspr(SPRN_AMR);
+}
+
+static inline void write_amr(u64 value)
+{
+       mtspr(SPRN_AMR, value);
+}
+
+static inline u64 read_iamr(void)
+{
+       if (!likely(pkey_execute_disable_supported))
+               return 0x0UL;
+
+       return mfspr(SPRN_IAMR);
+}
+
+static inline void write_iamr(u64 value)
+{
+       if (!likely(pkey_execute_disable_supported))
+               return;
+
+       mtspr(SPRN_IAMR, value);
+}
+
+static inline u64 read_uamor(void)
+{
+       return mfspr(SPRN_UAMOR);
+}
+
+static inline void write_uamor(u64 value)
+{
+       mtspr(SPRN_UAMOR, value);
+}