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Subject[PATCH v9 06/51] powerpc: helper functions to initialize AMR, IAMR and UAMOR registers
Date
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 --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c
index b6bdfdf..f3bf661 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))
+
void __init pkey_initialize(void)
{
int os_reserved, i;
@@ -97,3 +101,46 @@ 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);
+}
--
1.7.1
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