In some places, dump_backtrace() is called with a NULL tsk parameter,
e.g. in bug_handler() in arch/arm64, or indirectly via show_stack() in
core code. The expectation is that this is treated as if current were
passed instead of NULL. Similar is true of unwind_frame().

Commit a80a0eb7 ("arm64: make irq_stack_ptr more robust") didn't
take this into account. In dump_backtrace() it compares tsk against
current *before* we check if tsk is NULL, and in unwind_frame() we never
set tsk if it is NULL.

Due to this, we won't initialise irq_stack_ptr in either function. In
dump_backtrace() this results in calling dump_mem() for memory
immediately above the IRQ stack range, rather than for the relevant
range on the task stack. In unwind_frame we'll reject unwinding frames
on the IRQ stack.

In either case this results in incomplete or misleading backtrace
information, but is not otherwise problematic. The initial percpu areas
(including the IRQ stacks) are allocated in the linear map, and dump_mem
uses __get_user(), so we shouldn't access anything with side-effects,
and will handle holes safely.

This patch fixes the issue by having both functions handle the NULL tsk
case before doing anything else with tsk.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Fixes: a80a0eb7 ("arm64: make irq_stack_ptr more robust")
Acked-by: NJames Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yang Shi <yang.shi@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Instead of comparing the name to a magic string, use archdata to
explicitly communicate whether the arch timer is suitable for
direct vdso access.
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NScott Wood <oss@buserror.net>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Erratum A-008585 says that the ARM generic timer counter "has the
potential to contain an erroneous value for a small number of core
clock cycles every time the timer value changes".  Accesses to TVAL
(both read and write) are also affected due to the implicit counter
read.  Accesses to CVAL are not affected.

The workaround is to reread TVAL and count registers until successive
reads return the same value.  Writes to TVAL are replaced with an
equivalent write to CVAL.

The workaround is to reread TVAL and count registers until successive reads
return the same value, and when writing TVAL to retry until counter
reads before and after the write return the same value.

The workaround is enabled if the fsl,erratum-a008585 property is found in
the timer node in the device tree.  This can be overridden with the
clocksource.arm_arch_timer.fsl-a008585 boot parameter, which allows KVM
users to enable the workaround until a mechanism is implemented to
automatically communicate this information.

This erratum can be found on LS1043A and LS2080A.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NScott Wood <oss@buserror.net>
[will: renamed read macro to reflect that it's not usually unstable]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This erratum describes a bug in logic outside the core, so MIDR can't be
used to identify its presence, and reading an SoC-specific revision
register from common arch timer code would be awkward.  So, describe it
in the device tree.
Signed-off-by: NScott Wood <oss@buserror.net>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

virt_addr_valid is supposed to return true if and only if virt_to_page
returns a valid page structure. The current macro does math on whatever
address is given and passes that to pfn_valid to verify. vmalloc and
module addresses can happen to generate a pfn that 'happens' to be
valid. Fix this by only performing the pfn_valid check on addresses that
have the potential to be valid.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NLaura Abbott <labbott@redhat.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

These files were only including module.h for exception table
related functions.  We've now separated that content out into its
own file "extable.h" so now move over to that and avoid all the
extra header content in module.h that we don't really need to compile
these files.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Move the PMU name into a common header file so it may
be referenced by other users.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ARMv8 machines can identify the micro/arch defined counters
that are available on a machine. Add all these counters to the
default armv8 perf map. At run-time disable the counters which
are not available on the given PMU.
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In preparation for ACPI support, add a pmu_probe_info table to
the arm_pmu_device_probe() call. This table gets used when
probing in the absence of a devicetree node for PMU.
Signed-off-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NJeremy Linton <jeremy.linton@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

There are an increasing number of ARM SoC PMU drivers appearing for
things like interconnects, memory controllers and cache controllers.
Rather than have these handled on an ad-hoc basis, where SoC maintainers
each send their PMU drivers directly to arm-soc, let's take these into
drivers/perf/ and send a single pull request to arm-soc instead, much
like other subsystems.

This patch amends the ARM PMU MAINTAINERS entry to include all of
drivers/perf/ (currently just the ARM CPU PMU), changes Mark Rutland
from Reviewer to Maintainer, so that he can help with the new tree and
adds the device-tree binding to the list of maintained files.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Kprobes searches backwards a finite number of instructions to determine if
there is an attempt to probe a load/store exclusive sequence. It stops when
it hits the maximum number of instructions or a load or store exclusive.
However this means it can run up past the beginning of the function and
start looking at literal constants. This has been shown to cause a false
positive and blocks insertion of the probe. To fix this, further limit the
backwards search to stop if it hits a symbol address from kallsyms. The
presumption is that this is the entry point to this code (particularly for
the common case of placing probes at the beginning of functions).

This also improves efficiency by not searching code that is not part of the
function. There may be some possibility that the label might not denote the
entry path to the probed instruction but the likelihood seems low and this
is just another example of how the kprobes user really needs to be
careful about what they are doing.
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NDavid A. Long <dave.long@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Make use of the new alternative_if and alternative_else_nop_endif and
get rid of our open-coded NOP sleds, making the code simpler to read.

Note that for __kvm_call_hyp the branch to __vhe_hyp_call has been moved
out of the alternative sequence, and in the default case there will be
four additional NOPs executed.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Make use of the new alternative_if and alternative_else_nop_endif and
get rid of our homebew NOP sleds, making the code simpler to read.

Note that for cpu_do_switch_mm the ret has been moved out of the
alternative sequence, and in the default case there will be three
additional NOPs executed.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In some cases, one side of an alternative sequence is simply a number of
NOPs used to balance the other side. Keeping track of this manually is
tedious, and the presence of large chains of NOPs makes the code more
painful to read than necessary.

To ameliorate matters, this patch adds a new alternative_else_nop_endif,
which automatically balances an alternative sequence with a trivial NOP
sled.

In many cases, we would like a NOP-sled in the default case, and
instructions patched in in the presence of a feature. To enable the NOPs
to be generated automatically for this case, this patch also adds a new
alternative_if, and updates alternative_else and alternative_endif to
work with either alternative_if or alternative_endif.

Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
[will: use new nops macro to generate nop sequences]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The LSE atomics are implemented using alternative code sequences of
different lengths, and explicit NOP padding is used to ensure the
patching works correctly.

This patch converts the bulk of the LSE code over to using the __nops
macro, which makes it slightly clearer as to what is going on and also
consolidates all of the padding at the end of the various sequences.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

NOP sequences tend to get used for padding out alternative sections
and uarch-specific pipeline flushes in errata workarounds.

This patch adds macros for generating these sequences as both inline
asm blocks, but also as strings suitable for embedding in other asm
blocks directly.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Similar to our {read,write}_sysreg accessors for architected, named
system registers, this patch introduces {read,write}_sysreg_s variants
that can take arbitrary sys_reg output and therefore access IMPDEF
registers or registers that unsupported by binutils.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We've grown our own versions of bug.h, ftrace.h, pci.h and topology.h,
so generating the generic ones as well is unnecessary and a potential
source of build hiccups. At the very least, having them present has
confused my source-indexing tool, and that simply will not do.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Systems with differing CPU i-cache/d-cache line sizes can cause
problems with the cache management by software when the execution
is migrated from one to another. Usually, the application reads
the cache size on a CPU and then uses that length to perform cache
operations. However, if it gets migrated to another CPU with a smaller
cache line size, things could go completely wrong. To prevent such
cases, always use the smallest cache line size among the CPUs. The
kernel CPU feature infrastructure already keeps track of the safe
value for all CPUID registers including CTR. This patch works around
the problem by :

For kernel, dynamically patch the kernel to read the cache size
from the system wide copy of CTR_EL0.

For applications, trap read accesses to CTR_EL0 (by clearing the SCTLR.UCT)
and emulate the mrs instruction to return the system wide safe value
of CTR_EL0.

For faster access (i.e, avoiding to lookup the system wide value of CTR_EL0
via read_system_reg), we keep track of the pointer to table entry for
CTR_EL0 in the CPU feature infrastructure.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Right now we trap some of the user space data cache operations
based on a few Errata (ARM 819472, 826319, 827319 and 824069).
We need to trap userspace access to CTR_EL0, if we detect mismatched
cache line size. Since both these traps share the EC, refactor
the handler a little bit to make it a bit more reader friendly.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

On systems with mismatched i/d cache min line sizes, we need to use
the smallest size possible across all CPUs. This will be done by fetching
the system wide safe value from CPU feature infrastructure.
However the some special users(e.g kexec, hibernate) would need the line
size on the CPU (rather than the system wide), when either the system
wide feature may not be accessible or it is guranteed that the caller
executes with a gurantee of no migration.
Provide another helper which will fetch cache line size on the current CPU.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NGeoff Levand <geoff@infradead.org>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

adrp uses PC-relative address offset to a page (of 4K size) of
a symbol. If it appears in an alternative code patched in, we
should adjust the offset to reflect the address where it will
be run from. This patch adds support for fixing the offset
for adrp instructions.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Adds helpers for decoding/encoding the PC relative addresses for adrp.
This will be used for handling dynamic patching of 'adrp' instructions
in alternative code patching.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The alternative code patching doesn't check if the replaced instruction
uses a pc relative literal. This could cause silent corruption in the
instruction stream as the instruction will be executed from a different
address than what it was compiled for. Catch all such cases.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Right now we run through the work around checks on a CPU
from __cpuinfo_store_cpu. There are some problems with that:

1) We initialise the system wide CPU feature registers only after the
Boot CPU updates its cpuinfo. Now, if a work around depends on the
variance of a CPU ID feature (e.g, check for Cache Line size mismatch),
we have no way of performing it cleanly for the boot CPU.

2) It is out of place, invoked from __cpuinfo_store_cpu() in cpuinfo.c. It
is not an obvious place for that.

This patch rearranges the CPU specific capability(aka work around) checks.

1) At the moment we use verify_local_cpu_capabilities() to check if a new
CPU has all the system advertised features. Use this for the secondary CPUs
to perform the work around check. For that we rename
  verify_local_cpu_capabilities() => check_local_cpu_capabilities()
which:

   If the system wide capabilities haven't been initialised (i.e, the CPU
   is activated at the boot), update the system wide detected work arounds.

   Otherwise (i.e a CPU hotplugged in later) verify that this CPU conforms to the
   system wide capabilities.

2) Boot CPU updates the work arounds from smp_prepare_boot_cpu() after we have
initialised the system wide CPU feature values.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This is a cosmetic change to rename the functions dealing with
the errata work arounds to be more consistent with their naming.

1) check_local_cpu_errata() => update_cpu_errata_workarounds()
check_local_cpu_errata() actually updates the system's errata work
arounds. So rename it to reflect the same.

2) verify_local_cpu_errata() => verify_local_cpu_errata_workarounds()
Use errata_workarounds instead of _errata.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Right now we use 0 as the safe value for CTR_EL0:L1Ip, which is
not defined at the moment. The safer value for the L1Ip should be
the weakest of the policies, which happens to be AIVIVT. While at it,
fix the comment about safe_val.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

1. Remove the old binding code.
2. Read the nid of cpu0 from dts.
3. Fallback the nid of cpu0 to 0 when numa=off is set in bootargs.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When the deleted code is executed, only the bit of cpu0 was set on
cpu_possible_mask. So that, only set_cpu_numa_node(0, NUMA_NO_NODE); will
be executed. And map_cpu_to_node(0, 0) will soon be called. So these code
can be safely removed.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

To make each percpu area allocated from its local numa node. Without this
patch, all percpu areas will be allocated from the node which cpu0 belongs
to.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Use pr_fmt to prefix kernel output, and remove duplicated msg
of NUMA turned off.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Use pr_fmt to prefix kernel output.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Use of_get_next_parent() instead of open-code.
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

numa_init may return error because of numa configuration error. So "No
NUMA configuration found" is inaccurate. In fact, specific configuration
error information should be immediately printed by the testing branch.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This warning has been printed in of_numa_parse_cpu_nodes before.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

If the numa-id which was configured in memory@ devicetree node is greater
than MAX_NUMNODES, we should report a warning. We have done this for cpus
and distance-map dt nodes, this patch help them to be consistent.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

For a normal memory@ devicetree node, its reg property can contains more
memory blocks.

Because we don't known how many memory blocks maybe contained, so we try
from index=0, increase 1 until error returned(the end).
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This information will be printed in the subfunction numa_add_memblk.
They are not the same, but very similar.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In systems with heterogeneous CPUs, there are multiple logical CPU PMUs,
each of which covers a subset of CPUs in the system. In some cases
userspace needs to know which CPUs a given logical PMU covers, so we'd
like to expose a cpumask under sysfs, similar to what is done for uncore
PMUs.

Unfortunately, prior to commit 00e727bb ("perf stat: Balance
opening and reading events"), perf stat only correctly handled a cpumask
holding a single CPU, and only when profiling in system-wide mode. In
other cases, the presence of a cpumask file could cause perf stat to
behave erratically.

Thus, exposing a cpumask file would break older perf binaries in cases
where they would otherwise work.

To avoid this issue while still providing userspace with the information
it needs, this patch exposes a differently-named file (cpus) under
sysfs. New tools can look for this and operate correctly, while older
tools will not be adversely affected by its presence.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Now that the 32-bit and 64-bit perf backends use the common groups
directly, remove the fallback and no longer allow the groups array to be
overridden.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>