powerpc/book3s64/pkeys: Convert pkey_total to num_pkey

num_pkey now represents max number of keys supported such that we return
to userspace 0 - num_pkey - 1.

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/20200709032946.881753-11-aneesh.kumar@linux.ibm.com

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index f984bfa..26b2006 100644 (file)
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -12,7 +12,7 @@
 #include <asm/firmware.h>
 
 DECLARE_STATIC_KEY_FALSE(pkey_disabled);
-extern int pkeys_total; /* total pkeys as per device tree */
+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 */
 
@@ -44,7 +44,10 @@ static inline int vma_pkey(struct vm_area_struct *vma)
        return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
 }
 
-#define arch_max_pkey() pkeys_total
+static inline int arch_max_pkey(void)
+{
+       return num_pkey;
+}
 
 #define pkey_alloc_mask(pkey) (0x1 << pkey)
 

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 8bdb56c..65926c0 100644 (file)
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -13,7 +13,7 @@
 #include <linux/of_device.h>
 
 DEFINE_STATIC_KEY_FALSE(pkey_disabled);
-int  pkeys_total;              /* Total pkeys as per device tree */
+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
@@ -93,7 +93,7 @@ static int scan_pkey_feature(void)
 
 static int pkey_initialize(void)
 {
-       int os_reserved, i;
+       int pkeys_total, i;
 
        /*
         * We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral
@@ -133,12 +133,12 @@ static int pkey_initialize(void)
         * The OS can manage only 8 pkeys due to its inability to represent them
         * in the Linux 4K PTE. Mark all other keys reserved.
         */
-       os_reserved = pkeys_total - 8;
+       num_pkey = min(8, pkeys_total);
 #else
-       os_reserved = 0;
+       num_pkey = pkeys_total;
 #endif
 
-       if (unlikely((pkeys_total - os_reserved) <= execute_only_key)) {
+       if (unlikely(num_pkey <= execute_only_key)) {
                /*
                 * Insufficient number of keys to support
                 * execute only key. Mark it unavailable.
@@ -185,10 +185,10 @@ static int pkey_initialize(void)
        default_uamor &= ~(0x3ul << pkeyshift(1));
 
        /*
-        * Prevent the usage of OS reserved the keys. Update UAMOR
+        * Prevent the usage of OS reserved keys. Update UAMOR
         * for those keys.
         */
-       for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
+       for (i = num_pkey; i < pkeys_total; i++) {
                reserved_allocation_mask |= (0x1 << i);
                default_uamor &= ~(0x3ul << pkeyshift(i));
        }