powerpc/book3s64/pkeys: Make initial_allocation_mask static

initial_allocation_mask is not used outside this file.
Also mark reserved_allocation_mask and initial_allocation_mask __ro_after_init;
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709032946.881753-12-aneesh.kumar@linux.ibm.com

arch/powerpc/include/asm/pkeys.h

@@ -13,7 +13,6 @@
 
 DECLARE_STATIC_KEY_FALSE(pkey_disabled);
 extern int num_pkey;
-extern u32 initial_allocation_mask; /*  bits set for the initially allocated keys */
 extern u32 reserved_allocation_mask; /* bits set for reserved keys */
 
 #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \

arch/powerpc/mm/book3s64/pkeys.c

@@ -14,11 +14,14 @@
 
 DEFINE_STATIC_KEY_FALSE(pkey_disabled);
 int  num_pkey;		/* Max number of pkeys supported */
-u32  initial_allocation_mask;   /* Bits set for the initially allocated keys */
 /*
  *  Keys marked in the reservation list cannot be allocated by  userspace
  */
-u32  reserved_allocation_mask;
+u32 reserved_allocation_mask __ro_after_init;
+
+/* Bits set for the initially allocated keys */
+static u32 initial_allocation_mask __ro_after_init;
+
 static bool pkey_execute_disable_supported;
 /*
  * Even if we allocate keys with sys_pkey_alloc(), we need to make sure