On Fri, 8 Sep 2017 15:44:53 -0700 Ram Pai <linux...@us.ibm.com> wrote:
> Introduce helper functions that can initialize the bits in the AMR, > IAMR and UAMOR register; the bits that correspond to the given pkey. > > Signed-off-by: Ram Pai <linux...@us.ibm.com> > --- > arch/powerpc/include/asm/pkeys.h | 1 + > arch/powerpc/mm/pkeys.c | 46 > ++++++++++++++++++++++++++++++++++++++ > 2 files changed, 47 insertions(+), 0 deletions(-) > > diff --git a/arch/powerpc/include/asm/pkeys.h > b/arch/powerpc/include/asm/pkeys.h > index 133f8c4..5a83ed7 100644 > --- a/arch/powerpc/include/asm/pkeys.h > +++ b/arch/powerpc/include/asm/pkeys.h > @@ -26,6 +26,7 @@ > #define arch_max_pkey() pkeys_total > #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 > > #define pkey_alloc_mask(pkey) (0x1 << pkey) > > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > index ebc9e84..178aa33 100644 > --- a/arch/powerpc/mm/pkeys.c > +++ b/arch/powerpc/mm/pkeys.c > @@ -59,3 +59,49 @@ void __init pkey_initialize(void) > for (i = 2; i < (pkeys_total - os_reserved); i++) > initial_allocation_mask &= ~(0x1<<i); > } > + > +#define PKEY_REG_BITS (sizeof(u64)*8) > +#define pkeyshift(pkey) (PKEY_REG_BITS - ((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)); > + Do we need to check for reserved keys or that is at a layer above? > + 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_iamr(old_iamr | new_iamr_bits); Do we need to check for reserved keys here? > +} > + > +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); > +} Balbir Singh.