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Subject[RFC v6 15/62] powerpc: helper functions to initialize AMR, IAMR and UMOR registers
Date
Introduce helper functions that can initialize the bits in the AMR,
IAMR and UMOR register; the bits that correspond to the given pkey.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
arch/powerpc/include/asm/pkeys.h | 1 +
arch/powerpc/mm/pkeys.c | 44 ++++++++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
index 09b268e..4327842 100644
--- a/arch/powerpc/include/asm/pkeys.h
+++ b/arch/powerpc/include/asm/pkeys.h
@@ -5,6 +5,7 @@
#define arch_max_pkey() 32
#define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \
VM_PKEY_BIT3 | VM_PKEY_BIT4)
+#define AMR_BITS_PER_PKEY 2
/*
* Bits are in BE format.
* NOTE: key 31, 1, 0 are not used.
diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index c3acee1..04ee361 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -16,3 +16,47 @@
#include <linux/pkeys.h> /* PKEY_* */

bool pkey_inited;
+#define pkeyshift(pkey) ((arch_max_pkey()-pkey-1) * AMR_BITS_PER_PKEY)
+
+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 & 0x3UL) << pkeyshift(pkey));
+ u64 old_iamr = read_iamr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+
+ write_amr(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);
+}
--
1.7.1
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