arch-independent code expects the arch to map
a pkey into the vma's protection bit setting.
The patch provides that ability.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch provides the implementation of execute-only pkey.
The architecture-independent layer expects the arch-dependent
layer, to support the ability to create and enable a special
key which has execute-only permission.
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Store and restore the AMR, IAMR and UAMOR register state of the task
before scheduling out and after scheduling in, respectively.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc has hardware support to disable execute on a pkey.
This patch enables the ability to create execute-disabled
keys.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch provides the detailed implementation for
a user to allocate a key and enable it in the hardware.
It provides the plumbing, but it cannot be used till
the system call is implemented. The next patch will
do so.
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Implements helper functions to read and write the key related
registers; AMR, IAMR, UAMOR.
AMR register tracks the read,write permission of a key
IAMR register tracks the execute permission of a key
UAMOR register enables and disables a key
Acked-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Total 32 keys are available on power7 and above. However
pkey 0,1 are reserved. So effectively we have 30 pkeys.
On 4K kernels, we do not have 5 bits in the PTE to
represent all the keys; we only have 3bits. Two of those
keys are reserved; pkey 0 and pkey 1. So effectively we
have 6 pkeys.
This patch keeps track of reserved keys, allocated keys
and keys that are currently free.
Also it adds skeletal functions and macros, that the
architecture-independent code expects to be available.
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Basic plumbing to initialize the pkey system.
Nothing is enabled yet. A later patch will enable it
once all the infrastructure is in place.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Rework copyrights to use SPDX tags]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Ram Pai