[PATCH v10 06/27] powerpc: helper functions to initialize AMR, IAMR and UAMOR registers
From: Ram Pai <hidden>
Date: 2018-01-19 01:52:33
Also in:
linux-arch, linux-kselftest, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted> Signed-off-by: Ram Pai <redacted> --- 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 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); +}
--
1.7.1