diff mbox series

[v10,06/27] powerpc: helper functions to initialize AMR, IAMR and UAMOR registers

Message ID 1516326648-22775-7-git-send-email-linuxram@us.ibm.com (mailing list archive)
State Accepted
Commit 4d70b698f9575cea7fa52e1d8f5020beca869907
Headers show
Series powerpc, mm: Memory Protection Keys | expand

Commit Message

Ram Pai Jan. 19, 2018, 1:50 a.m. UTC 
Introduce  helper functions that can initialize the bits in the AMR,
IAMR and UAMOR register; the bits that correspond to the given pkey.

Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/mm/pkeys.c |   47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 47 insertions(+), 0 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index 6e8df6e..e1dc45b 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -16,6 +16,10 @@ 
 int  pkeys_total;		/* Total pkeys as per device tree */
 u32  initial_allocation_mask;	/* Bits set for reserved keys */
 
+#define AMR_BITS_PER_PKEY 2
+#define PKEY_REG_BITS (sizeof(u64)*8)
+#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
+
 int pkey_initialize(void)
 {
 	int os_reserved, i;
@@ -107,3 +111,46 @@  static inline void write_uamor(u64 value)
 {
 	mtspr(SPRN_UAMOR, value);
 }
+
+static inline void init_amr(int pkey, u8 init_bits)
+{
+	u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
+	u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+
+	write_amr(old_amr | new_amr_bits);
+}
+
+static inline void init_iamr(int pkey, u8 init_bits)
+{
+	u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
+	u64 old_iamr = read_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
+
+	write_iamr(old_iamr | new_iamr_bits);
+}
+
+static void pkey_status_change(int pkey, bool enable)
+{
+	u64 old_uamor;
+
+	/* Reset the AMR and IAMR bits for this key */
+	init_amr(pkey, 0x0);
+	init_iamr(pkey, 0x0);
+
+	/* Enable/disable key */
+	old_uamor = read_uamor();
+	if (enable)
+		old_uamor |= (0x3ul << pkeyshift(pkey));
+	else
+		old_uamor &= ~(0x3ul << pkeyshift(pkey));
+	write_uamor(old_uamor);
+}
+
+void __arch_activate_pkey(int pkey)
+{
+	pkey_status_change(pkey, true);
+}
+
+void __arch_deactivate_pkey(int pkey)
+{
+	pkey_status_change(pkey, false);
+}