Add a macro and some helper C functions for patching single asm
instructions.
The gas macro means we can do something like:
1: nop
patch_site 1b, patch__foo
Which is less visually distracting than defining a GLOBAL symbol at 1,
and also doesn't pollute the symbol table which can confuse eg. perf.
These are obviously similar to our existing feature sections, but are
not automatically patched based on CPU/MMU features, rather they are
designed to be manually patched by C code at some arbitrary point.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Used barrier_nospec to sanitize the syscall table.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Implement the barrier_nospec as a isync;sync instruction sequence.
The implementation uses the infrastructure built for BOOK3S 64.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In a subsequent patch we will enable building security.c for Book3E.
However the NXP platforms are not vulnerable to Meltdown, so make the
Meltdown vulnerability reporting PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we require platform code to call setup_barrier_nospec(). But
if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case
then we can call it in setup_arch().
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a config symbol to encode which platforms support the
barrier_nospec speculation barrier. Currently this is just Book3S 64
but we will add Book3E in a future patch.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
NXP Book3E platforms are not vulnerable to speculative store
bypass, so make the mitigations PPC_BOOK3S_64 specific.
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The speculation barrier can be disabled from the command line
with the parameter: "nospectre_v1".
Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We only need to use __MASKABLE_EXCEPTION in one of the four cases for
hardware interrupt, so use the helper macros in the other cases.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We pass the "loc" (location) parameter to MASKABLE_EXCEPTION and
friends, but it's not used, so drop it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
_MASKABLE_RELON_EXCEPTION_PSERIES() does nothing useful, update all
callers to use __MASKABLE_RELON_EXCEPTION_PSERIES() directly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
_MASKABLE_EXCEPTION_PSERIES() does nothing useful, update all callers
to use __MASKABLE_EXCEPTION_PSERIES() directly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The EXCEPTION_RELON_PROLOG_PSERIES_1() macro does the same job as
EXCEPTION_PROLOG_2 (which we just recently created), except for
"RELON" (relocation on) exceptions.
So rename it as such.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As with the other patches in this series, we are removing the
"PSERIES" from the name as it's no longer meaningful.
In this case it's not simply a case of removing the "PSERIES" as that
would result in a clash with the existing EXCEPTION_PROLOG_1.
Instead we name this one EXCEPTION_PROLOG_2, as it's usually used in
sequence after 0 and 1.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The "PSERIES" in STD_EXCEPTION_PSERIES is to differentiate the macros
from the legacy iSeries versions, which are called
STD_EXCEPTION_ISERIES. It is not anything to do with pseries vs
powernv or powermac etc.
We removed the legacy iSeries code in 2012, in commit 8ee3e0d69623x
("powerpc: Remove the main legacy iSerie platform code").
So remove "PSERIES" from the macros.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
EXCEPTION_RELON_PROLOG_PSERIES() only has two users,
STD_RELON_EXCEPTION_PSERIES() and STD_RELON_EXCEPTION_HV() both of
which "call" SET_SCRATCH0(), so just move SET_SCRATCH0() into
EXCEPTION_RELON_PROLOG_PSERIES().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
EXCEPTION_PROLOG_PSERIES() only has two users, STD_EXCEPTION_PSERIES()
and STD_EXCEPTION_HV() both of which "call" SET_SCRATCH0(), so just
move SET_SCRATCH0() into EXCEPTION_PROLOG_PSERIES().
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pasemi arch code finds the root of the PCI-e bus by searching the
device-tree for a node called 'pxp'. But the root bus has a compatible
property of 'pasemi,rootbus' so search for that instead.
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The generic implementation of strlen() reads strings byte per byte.
This patch implements strlen() in assembly based on a read of entire
words, in the same spirit as what some other arches and glibc do.
On a 8xx the time spent in strlen is reduced by 3/4 for long strings.
strlen() selftest on an 8xx provides the following values:
Before the patch (ie with the generic strlen() in lib/string.c):
len 256 : time = 1.195055
len 016 : time = 0.083745
len 008 : time = 0.046828
len 004 : time = 0.028390
After the patch:
len 256 : time = 0.272185 ==> 78% improvment
len 016 : time = 0.040632 ==> 51% improvment
len 008 : time = 0.033060 ==> 29% improvment
len 004 : time = 0.029149 ==> 2% degradation
On a 832x:
Before the patch:
len 256 : time = 0.236125
len 016 : time = 0.018136
len 008 : time = 0.011000
len 004 : time = 0.007229
After the patch:
len 256 : time = 0.094950 ==> 60% improvment
len 016 : time = 0.013357 ==> 26% improvment
len 008 : time = 0.010586 ==> 4% improvment
len 004 : time = 0.008784
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
rtas_log_buf is a buffer to hold RTAS event data that are communicated
to kernel by hypervisor. This buffer is then used to pass RTAS event
data to user through proc fs. This buffer is allocated from
vmalloc (non-linear mapping) area.
On Machine check interrupt, register r3 points to RTAS extended event
log passed by hypervisor that contains the MCE event. The pseries
machine check handler then logs this error into rtas_log_buf. The
rtas_log_buf is a vmalloc-ed (non-linear) buffer we end up taking up a
page fault (vector 0x300) while accessing it. Since machine check
interrupt handler runs in NMI context we can not afford to take any
page fault. Page faults are not honored in NMI context and causes
kernel panic. Apart from that, as Nick pointed out,
pSeries_log_error() also takes a spin_lock while logging error which
is not safe in NMI context. It may endup in deadlock if we get another
MCE before releasing the lock. Fix this by deferring the logging of
rtas error to irq work queue.
Current implementation uses two different buffers to hold rtas error
log depending on whether extended log is provided or not. This makes
bit difficult to identify which buffer has valid data that needs to
logged later in irq work. Simplify this using single buffer, one per
paca, and copy rtas log to it irrespective of whether extended log is
provided or not. Allocate this buffer below RMA region so that it can
be accessed in real mode mce handler.
Fixes: b96672dd84 ("powerpc: Machine check interrupt is a non-maskable interrupt")
Cc: stable@vger.kernel.org # v4.14+
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The global mce data buffer that used to copy rtas error log is of 2048
(RTAS_ERROR_LOG_MAX) bytes in size. Before the copy we read
extended_log_length from rtas error log header, then use max of
extended_log_length and RTAS_ERROR_LOG_MAX as a size of data to be copied.
Ideally the platform (phyp) will never send extended error log with
size > 2048. But if that happens, then we have a risk of buffer overrun
and corruption. Fix this by using min_t instead.
Fixes: d368514c30 ("powerpc: Fix corruption when grabbing FWNMI data")
Reported-by: Michal Suchanek <msuchanek@suse.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It's identical to xive_teardown_cpu() so just use the latter
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Those overly verbose statement in the setup of the pool VP
aren't particularly useful (esp. considering we don't actually
use the pool, we configure it bcs HW requires it only). So
remove them which improves the code readability.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The kernel page table caches are tied to init_mm, so there is no
more need for them after userspace is finished.
destroy_context() gets called when we drop the last reference for an
mm, which can be much later than the task exit due to other lazy mm
references to it. We can free the page table cache pages on task exit
because they only cache the userspace page tables and kernel threads
should not access user space addresses.
The mapping for kernel threads itself is maintained in init_mm and
page table cache for that is attached to init_mm.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Merge change log additions from Aneesh]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the mm is being torn down there will be a full PID flush so
there is no need to flush the TLB on page size changes.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This makes it easy to run checkpatch with settings that I like.
Usage is eg:
$ ./arch/powerpc/tools/checkpatch.sh -g origin/master..
To check all commits since origin/master.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Russell Currey <ruscur@russell.cc>
We recently added a warning in arch_local_irq_restore() to check that
the soft masking state matches reality.
Unfortunately it trips in a few places, which are not entirely trivial
to fix. The key problem is if we're doing function_graph tracing of
restore_math(), the warning pops and then seems to recurse. It's not
entirely clear because the system continuously oopses on all CPUs,
with the output interleaved and unreadable.
It's also been observed on a G5 coming out of idle.
Until we can fix those cases disable the warning for now.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch is to add clocks property for fman ptp timer node.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull powerpc fixes from Michael Ellerman:
"One fix for a regression in a recent TLB flush optimisation, which
caused us to incorrectly not send TLB invalidations to coprocessors.
Thanks to Frederic Barrat, Nicholas Piggin, Vaibhav Jain"
* tag 'powerpc-4.18-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/64s/radix: Fix missing global invalidations when removing copro
We've encountered a performance issue when multiple processors stress
{get,put}_mmio_atsd_reg(). These functions contend for
mmio_atsd_usage, an unsigned long used as a bitmask.
The accesses to mmio_atsd_usage are done using test_and_set_bit_lock()
and clear_bit_unlock(). As implemented, both of these will require
a (successful) stwcx to that same cache line.
What we end up with is thread A, attempting to unlock, being slowed by
other threads repeatedly attempting to lock. A's stwcx instructions
fail and retry because the memory reservation is lost every time a
different thread beats it to the punch.
There may be a long-term way to fix this at a larger scale, but for
now resolve the immediate problem by gating our call to
test_and_set_bit_lock() with one to test_bit(), which is obviously
implemented without using a store.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Acked-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
kernel/dma/Kconfig already defines NEED_DMA_MAP_STATE, just select it
from CONFIG_PPC using the same condition as an if guard.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[mpe: Move it under PPC]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 9c7b185ab2 ("powernv/cpuidle: Parse dt idle properties into
global structure") parses dt idle states into structs, but never marks
them valid. This results in all idle states being lost.
Fixes: 9c7b185ab2 ("powernv/cpuidle: Parse dt idle properties into global structure")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Almost all architectures include it. Add a ARCH_NO_PREEMPT symbol to
disable preempt support for alpha, hexagon, non-coldfire m68k and
user mode Linux.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Move the source of lib/Kconfig.debug and arch/$(ARCH)/Kconfig.debug to
the top-level Kconfig. For two architectures that means moving their
arch-specific symbols in that menu into a new arch Kconfig.debug file,
and for a few more creating a dummy file so that we can include it
unconditionally.
Also move the actual 'Kernel hacking' menu to lib/Kconfig.debug, where
it belongs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Instead of duplicating the source statements in every architecture just
do it once in the toplevel Kconfig file.
Note that with this the inclusion of arch/$(SRCARCH/Kconfig moves out of
the top-level Kconfig into arch/Kconfig so that don't violate ordering
constraits while keeping a sensible menu structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
With the optimizations for TLB invalidation from commit 0cef77c779
("powerpc/64s/radix: flush remote CPUs out of single-threaded
mm_cpumask"), the scope of a TLBI (global vs. local) can now be
influenced by the value of the 'copros' counter of the memory context.
When calling mm_context_remove_copro(), the 'copros' counter is
decremented first before flushing. It may have the unintended side
effect of sending local TLBIs when we explicitly need global
invalidations in this case. Thus breaking any nMMU user in a bad and
unpredictable way.
Fix it by flushing first, before updating the 'copros' counter, so
that invalidations will be global.
Fixes: 0cef77c779 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask")
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When a PCI device is detected, pdev->is_added is set to 1 and proc and
sysfs entries are created.
When the device is removed, pdev->is_added is checked for one and then
device is detached with clearing of proc and sys entries and at end,
pdev->is_added is set to 0.
is_added and is_busmaster are bit fields in pci_dev structure sharing same
memory location.
A strange issue was observed with multiple removal and rescan of a PCIe
NVMe device using sysfs commands where is_added flag was observed as zero
instead of one while removing device and proc,sys entries are not cleared.
This causes issue in later device addition with warning message
"proc_dir_entry" already registered.
Debugging revealed a race condition between the PCI core setting the
is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue
setting the is_busmaster bit in pci_set_master(). As these fields are not
handled atomically, that clears the is_added bit.
Move the is_added bit to a separate private flag variable and use atomic
functions to set and retrieve the device addition state. This avoids the
race because is_added no longer shares a memory location with is_busmaster.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283
Signed-off-by: Hari Vyas <hari.vyas@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
