Add user APIs through ioctl to allocate, free, and be notified of an
AFU interrupt.
For opencapi, an AFU can trigger an interrupt on the host by sending a
specific command targeting a 64-bit object handle. On POWER9, this is
implemented by mapping a special page in the address space of a
process and a write to that page will trigger an interrupt.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In the opencapi protocol, host memory contexts are referenced by a
'actag'. During setup, a driver must tell the device how many actags
it can used, and what values are acceptable.
On POWER9, the NPU can handle 64 actags per link, so they must be
shared between all the PCI functions of the link. To get a global
picture of how many actags are used by each AFU of every function, we
capture some data at the end of PCI enumeration, so that actags can be
shared fairly if needed.
This is not powernv specific per say, but rather a consequence of the
opencapi configuration specification being quite general. The number
of available actags on POWER9 makes it more likely to be hit. This is
somewhat mitigated by the fact that existing AFUs are coded by
requesting a reasonable count of actags and existing devices carry
only one AFU.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Implement a few platform-specific calls which can be used by drivers:
- provide the Transaction Layer capabilities of the host, so that the
driver can find some common ground and configure the device and host
appropriately.
- provide the hw interrupt to be used for translation faults raised by
the NPU
- map/unmap some NPU mmio registers to get the fault context when the
NPU raises an address translation fault
The rest are wrappers around the previously-introduced opal calls.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add opal calls to interact with the NPU:
OPAL_NPU_SPA_SETUP: set the Shared Process Area (SPA)
The SPA is a table containing one entry (Process Element) per memory
context which can be accessed by the opencapi device.
OPAL_NPU_SPA_CLEAR_CACHE: clear the context cache
The NPU keeps a cache of recently accessed memory contexts. When a
Process Element is removed from the SPA, the cache for the link must
be cleared.
OPAL_NPU_TL_SET: configure the Transaction Layer
The Transaction Layer specification defines several templates for
messages to be exchanged on the link. During link setup, the host and
device must negotiate what templates are supported on both sides and
at what rates those messages can be sent.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The configuration space for opencapi devices doesn't have a PCI
Express capability, therefore confusing linux in thinking it's of an
old PCI type with a 256-byte configuration space size, instead of the
desired 4k. So add a PCI fixup to declare the correct size.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The NPU was already abstracted by opal as a virtual PHB for nvlink,
but it helps to be able to differentiate between a nvlink or opencapi
PHB, as it's not completely transparent to linux. In particular, PE
assignment differs and we'll also need the information in later
patches.
So rename existing PNV_PHB_NPU type to PNV_PHB_NPU_NVLINK and add a
new type PNV_PHB_NPU_OCAPI.
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The fallback RFI flush is used when firmware does not provide a way
to flush the cache. It's a "displacement flush" that evicts useful
data by displacing it with an uninteresting buffer.
The flush has to take care to work with implementation specific cache
replacment policies, so the recipe has been in flux. The initial
slow but conservative approach is to touch all lines of a congruence
class, with dependencies between each load. It has since been
determined that a linear pattern of loads without dependencies is
sufficient, and is significantly faster.
Measuring the speed of a null syscall with RFI fallback flush enabled
gives the relative improvement:
P8 - 1.83x
P9 - 1.75x
The flush also becomes simpler and more adaptable to different cache
geometries.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Platforms with a panic handler that halts the system can have problems
getting kernel messages out, because the panic notifiers are called
before kernel/panic.c does its flushing of printk buffers an console
etc.
This was attempted to be solved with commit a3b2cb30f2 ("powerpc: Do
not call ppc_md.panic in fadump panic notifier"), but that wasn't the
right approach and caused other problems, and was reverted by commit
ab9dbf771f.
Instead, the powernv shutdown paths have already had a similar
problem, fixed by taking the message flushing sequence from
kernel/panic.c. That's a little bit ugly, but while we have the code
duplicated, it will work for this case as well. So have ppc panic
handlers do the same flushing before they terminate.
Without this patch, a qemu pseries_le_defconfig guest stops silently
when issued the nmi command when xmon is off and no crash dumpers
enabled. Afterwards, an oops is printed by each CPU as expected.
Fixes: ab9dbf771f ("Revert "powerpc: Do not call ppc_md.panic in fadump panic notifier"")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently it's possible that a thread on PPC64 LE has its endianness
flipped inadvertently to Big-Endian resulting in a crash once the process
is back from the signal handler.
If giveup_all() is called when regs->msr has the bits MSR.FP and MSR.VEC
disabled (and hence MSR.VSX disabled too) it returns without calling
check_if_tm_restore_required() which copies regs->msr to ckpt_regs->msr if
the process caught a signal whilst in transactional mode. Then once in
setup_tm_sigcontexts() MSR from ckpt_regs.msr is used, but since
check_if_tm_restore_required() was not called previuosly, gp_regs[PT_MSR]
gets a copy of invalid MSR bits as MSR in ckpt_regs was not updated from
regs->msr and so is zeroed. Later when leaving the signal handler once in
sys_rt_sigreturn() the TS bits of gp_regs[PT_MSR] are checked to determine
if restore_tm_sigcontexts() must be called to pull in the correct MSR state
into the user context. Because TS bits are zeroed
restore_tm_sigcontexts() is never called and MSR restored from the user
context on returning from the signal handler has the MSR.LE (the endianness
bit) forced to zero (Big-Endian). That leads, for instance, to 'nop' being
treated as an illegal instruction in the following sequence:
tbegin.
beq 1f
trap
tend.
1: nop
on PPC64 LE machines and the process dies just after returning from the
signal handler.
PPC64 BE is also affected but in a subtle way since forcing Big-Endian on
a BE machine does not change the endianness.
This commit fixes the issue described above by ensuring that once in
setup_tm_sigcontexts() the MSR used is from regs->msr instead of from
ckpt_regs->msr and by ensuring that we pull in only the MSR.FP, MSR.VEC,
and MSR.VSX bits from ckpt_regs->msr.
The fix was tested both on LE and BE machines and no regression regarding
the powerpc/tm selftests was observed.
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The thread switch control register (TSCR) is a per core register
that configures how the CPU shares resources between SMT threads.
Exposing it via sysfs allows us to tune it at run time.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
radix__flush_tlb_all() is called only in kexec path in real mode and any
tracepoints at this stage will make kexec to fail if enabled.
To verify enable tlbie trace before kexec.
$ echo 1 > /sys/kernel/debug/tracing/events/powerpc/tlbie/enable
== kexec into new kernel and kexec fails.
Fix this by not calling trace_tlbie from radix__flush_tlb_all().
Fixes: 0428491cba ("powerpc/mm: Trace tlbie(l) instructions")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
During a kdump kernel boot in PowerPC, we request a reset of the PHBs
to the FW. It makes sense, since if we are booting a kdump kernel it
means we had some trouble before and we cannot rely in the adapters'
health; they could be in a bad state, hence the reset is needed.
But this reset is useful not only in kdump - there are situations,
specially when debugging drivers, that we could break an adapter in
a way it requires such reset. One can tell to just go ahead and
reboot the machine, but happens that many times doing kexec is much
faster, and so preferable than a full power cycle.
This patch adds the ppc_pci_reset_phbs parameter to perform such reset.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As of 438cc81a41 "powerpc/pseries: Automatically resize HPT for memory hot
add/remove" when running on the pseries platform, we always attempt to
use the PAPR extension to resize the hashed page table (HPT) when we add
or remove memory.
This is fine, but when the extension is available we'll give a harmless,
but scary warning. This patch suppresses the warning in this case. It
will still warn if the feature is supposed to be available, but didn't
work.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Symbolic macros are unintuitive and hard to read, whereas octal constants
are much easier to interpret. Replace macros for the basic permission
flags (user/group/other read/write/execute) with numeric constants
instead, across the whole powerpc tree.
Introducing a significant number of changes across the tree for no runtime
benefit isn't exactly desirable, but so long as these macros are still
used in the tree people will keep sending patches that add them. Not only
are they hard to parse at a glance, there are multiple ways of coming to
the same value (as you can see with 0444 and 0644 in this patch) which
hurts readability.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Improve the DTS files by removing all the leading "0x" and zeros to
fix the following dtc warnings:
Warning (unit_address_format): Node /XXX unit name should not have leading "0x"
and:
Warning (unit_address_format): Node /XXX unit name should not have leading 0s
Converted using the following command:
find . -type f \( -iname *.dts -o -iname *.dtsi \) -exec sed -E -i -e "s/@0x([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" -e "s/@0+([0-9a-fA-F\.]+)\s?\{/@\L\1 \{/g" {} +
For simplicity, two sed expressions were used to solve each warnings
separately.
To make the regex expression more robust a few other issues were
resolved, namely setting unit-address to lower case, and adding a
whitespace before the the opening curly brace:
https://elinux.org/Device_Tree_Linux#Linux_conventions
This is a follow up to commit 4c9847b737 ("dt-bindings: Remove
leading 0x from bindings notation")
Reported-by: David Daney <ddaney@caviumnetworks.com>
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix warnings such as:
arch/powerpc/platforms/powermac/backlight.c: In function ‘pmac_backlight_get_legacy_brightness’:
arch/powerpc/platforms/powermac/backlight.c:189:5: error: old-style function definition [-Werror=old-style-definition]
int pmac_backlight_get_legacy_brightness()
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit 5b102782c7 ("powerpc/xmon: Enable disassembly files (compilation
changes)") usage of variable `op` has been removed. Completely remove opcode
computation since not used anymore.
Fix fatal warning:
arch/powerpc/xmon/ppc-dis.c: In function ‘lookup_powerpc’:
arch/powerpc/xmon/ppc-dis.c:96:17: error: variable ‘op’ set but not used [-Werror=unused-but-set-variable]
unsigned long op;
^~
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix fatal warning during compilation:
In file included from arch/powerpc/xmon/xmon.c:54:0:
./arch/powerpc/include/asm/xive.h:157:20: error: no previous prototype for ‘xive_smp_prepare_cpu’ [-Werror=missing-prototypes]
extern inline int xive_smp_prepare_cpu(unsigned int cpu) { return -EINVAL; }
^
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
One of the easiest way to test config with 4K HPTE is to disable 64K hardware
page size like below.
int __init htab_dt_scan_page_sizes(unsigned long node,
size -= 3; prop += 3;
base_idx = get_idx_from_shift(base_shift);
- if (base_idx < 0) {
+ if (base_idx < 0 || base_idx == MMU_PAGE_64K) {
/* skip the pte encoding also */
prop += lpnum * 2; size -= lpnum * 2;
But then this results in error in other part of the code such as MPSS parsing
where we look at 4K base page size and 64K actual page size support.
This patch fix MPSS parsing by ignoring the actual page sizes marked
unsupported. In reality this can happen only with a corrupt device tree. But it
is good to tighten the error check.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge our fixes branch from the 4.15 cycle.
Unusually the fixes branch saw some significant features merged,
notably the RFI flush patches, so we want the code in next to be
tested against that, to avoid any surprises when the two are merged.
There's also some other work on the panic handling that was reverted
in fixes and we now want to do properly in next, which would conflict.
And we also fix a few other minor merge conflicts.
Merge the topic branch we share with kvm-ppc, this brings in two xive
commits, one from Paul to rework HMI handling, and a minor cleanup to
drop an unused flag.
Since commit 9427ecbed4 ("gpio: Rework of_gpiochip_set_names()
to use device property accessors"), gpio chips have to have a
parent, otherwise devprop_gpiochip_set_names() prematurely exists
with message "GPIO chip parent is NULL" and doesn't proceed
'gpio-line-names' DT property.
This patch wraps the CPM GPIO into a platform driver to allow
assignment of the parent device.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
To: linuxppc-dev@lists.ozlabs.org
From: Michael Bringmann <mwb@linux.vnet.ibm.com>
Cc: Michael Bringmann <mwb@linux.vnet.ibm.com>
Cc: nfont@linux.vnet.ibm.com
Subject: [PATCH V6 4/4] powerpc: Enable support for ibm,drc-info devtree property
prom_init.c: Enable support for new DRC device tree property
"ibm,drc-info" in initial handshake between the Linux kernel and
the front end processor.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pseries/drc-info: Provide parallel routines to convert between
drc_index and CPU numbers at runtime, using the older device-tree
properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
and "ibm,drc-power-domains"), or the new property "ibm,drc-info".
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Firmware Features: Define new bit flag representing the presence of
new device tree property "ibm,drc-info". The flag is used to tell
the front end processor whether the Linux kernel supports the new
property, and by the front end processor to tell the Linux kernel
that the new property is present in the device tree.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/sysdev/fsl_pci.c:1307:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: Scott Wood <oss@buserror.net>
get_user() had it args reversed causing NIP to be NULL:ed instead
of fixing up the PCI access.
Note: This still hangs my P1020 Freescale CPU hard, but at least
I get a NIP now.
Signed-off-by: Joakim Tjernlund <joakim.tjernlund@infinera.com>
Acked-by: Li Yang <leoyang.li@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
The overview comments in the powerpc watchdog are out of date after
several iterations and changes of the code. Bring them up to date.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
feature fixups need to use patch_instruction() early in the boot,
even before the code is relocated to its final address, requiring
patch_instruction() to use PTRRELOC() in order to address data.
But feature fixups applies on code before it is set to read only,
even for modules. Therefore, feature fixups can use
raw_patch_instruction() instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
patch_instruction() uses almost the same sequence as
__patch_instruction()
This patch refactor it so that patch_instruction() uses
__patch_instruction() instead of duplicating code.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch restores the alphabetic order which was broken by
commit 1e0fc9d1eb ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX
for some configs")
Fixes: 1e0fc9d1eb ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The switch log prints the tv_sec portion of timespec as a 32-bit
number, while overflows in 2106. It also uses the timespec type,
which is safe on 64-bit architectures, but deprecated because
it causes overflows in 2038 elsewhere.
This changes it to timespec64 and printing a 64-bit number for
consistency.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In an effort to remove all instances of 'struct timeval'
from the kernel, I'm changing the powerpc mpic_timer interface
to use plain seconds instead. There is only one user of this
interface, and that doesn't use the microseconds portion, so
the code gets noticeably simpler in the process.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
9003a2498 removed checn from the DMA window pages allocator, however
the VFIO driver tests limits before doing so by calling
the get_table_size hook which was left behind; this fixes it.
Fixes: 9003a2498 "powerpc/powernv/ioda: Remove explicit max window size check"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Radix enabled platforms don't support subpage_prot() system calls. But
at present the system call goes through without an error and fails
later on while validating expected subpage accesses. Lets not allow
the system call on powerpc radix platforms to begin with to prevent
this confusion in user space.
Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Patch provides the ability for a process to
associate a pkey with a address range.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Finally this patch provides the ability for a process to
allocate and free a protection key.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PAPR defines 'ibm,processor-storage-keys' property. It exports two
values. The first value holds the number of data-access keys and the
second holds the number of instruction-access keys. Due to a bug in
the firmware, instruction-access keys is always reported as zero.
However any key can be configured to disable data-access and/or
disable execution-access. The inavailablity of the second value is not
a big handicap, though it could have been used to determine if the
platform supported disable-execution-access.
Non-PAPR platforms do not define this property in the device tree yet.
Fortunately power8 is the only released Non-PAPR platform that is
supported. Here, we hardcode the number of supported pkey to 32, by
consulting the PowerISA3.0
This patch calculates the number of keys supported by the platform.
Also it determines the platform support for read/write/execution
access support for pkeys.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Use a PVR check instead of CPU_FTR for execute. Restrict to
Power7/8/9 for now until older CPUs are tested.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The AMR/IAMR/UAMOR are part of the program context.
Allow it to be accessed via ptrace and through core files.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The value of the pkey, whose protection got violated,
is made available in si_pkey field of the siginfo structure.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
get_mm_addr_key() helper returns the pkey associated with
an address corresponding to a given mm_struct.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Handle Data and Instruction exceptions caused by memory
protection-key.
The CPU will detect the key fault if the HPTE is already
programmed with the key.
However if the HPTE is not hashed, a key fault will not
be detected by the hardware. The software will detect
pkey violation in such a case.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch provides the implementation for
arch_vma_access_permitted(). Returns true if the
requested access is allowed by pkey associated with the
vma.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Make sure that the kernel does not access user pages without
checking their key-protection.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[mpe: Integrate with upstream version of pte_access_permitted()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
helper function that checks if the read/write/execute is allowed
on the pte.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Map the PTE protection key bits to the HPTE key protection bits,
while creating HPTE entries.
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>
Map the key protection bits of the vma to the pkey bits in
the PTE.
The PTE bits used for pkey are 3,4,5,6 and 57. The first
four bits are the same four bits that were freed up initially
in this patch series. remember? :-) Without those four bits
this patch wouldn't be possible.
BUT, on 4k kernel, bit 3, and 4 could not be freed up. remember?
Hence we have to be satisfied with 5, 6 and 7.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch independent code calls arch_override_mprotect_pkey()
to return a pkey that best matches the requested protection.
This patch provides the implementation.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
