When handling events, armv8pmu_handle_irq() calls perf_event_overflow(),
and subsequently calls irq_work_run() to handle any work queued by
perf_event_overflow(). As perf_event_overflow() raises IPI_IRQ_WORK when
queuing the work, this isn't strictly necessary and the work could be
handled as part of the IPI_IRQ_WORK handler.
In the common case the IPI handler will run immediately after the PMU IRQ
handler, and where the PE is heavily loaded with interrupts other handlers
may run first, widening the window where some counters are disabled.
In practice this window is unlikely to be a significant issue, and removing
the call to irq_work_run() would make the PMU IRQ handler NMI safe in
addition to making it simpler, so let's do that.
[Alexandru E.: Reworded commit message]
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200924110706.254996-5-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently we access the counter registers and their respective type
registers indirectly. This requires us to write to PMSELR, issue an ISB,
then access the relevant PMXEV* registers.
This is unfortunate, because:
* Under virtualization, accessing one register requires two traps to
the hypervisor, even though we could access the register directly with
a single trap.
* We have to issue an ISB which we could otherwise avoid the cost of.
* When we use NMIs, the NMI handler will have to save/restore the select
register in case the code it preempted was attempting to access a
counter or its type register.
We can avoid these issues by directly accessing the relevant registers.
This patch adds helpers to do so.
In armv8pmu_enable_event() we still need the ISB to prevent the PE from
reordering the write to PMINTENSET_EL1 register. If the interrupt is
enabled before we disable the counter and the new event is configured,
we might get an interrupt triggered by the previously programmed event
overflowing, but which we wrongly attribute to the event that we are
enabling. Execute an ISB after we disable the counter.
In the process, remove the comment that refers to the ARMv7 PMU.
[Julien T.: Don't inline read/write functions to avoid big code-size
increase, remove unused read_pmevtypern function,
fix counter index issue.]
[Alexandru E.: Removed comment, removed trailing semicolons in macros,
added ISB]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox)
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200924110706.254996-3-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
ARMv8.4-PMU introduces the PMMIR_EL1 registers and some new PMU events,
like STALL_SLOT etc, are related to it. Let's add a caps directory to
/sys/bus/event_source/devices/armv8_pmuv3_0/ and support slots from
PMMIR_EL1 registers in this entry. The user programs can get the slots
from sysfs directly.
/sys/bus/event_source/devices/armv8_pmuv3_0/caps/slots is exposed
under sysfs. Both ARMv8.4-PMU and STALL_SLOT event are implemented,
it returns the slots from PMMIR_EL1, otherwise it will return 0.
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/1600754025-53535-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
There was a request to preprocess the module linker script like we
do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)
The difference between vmlinux.lds and module.lds is that the latter
is needed for external module builds, thus must be cleaned up by
'make mrproper' instead of 'make clean'. Also, it must be created
by 'make modules_prepare'.
You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
scripts/module.lds.S.
scripts/module.lds is fine because 'make clean' keeps all the
build artifacts under scripts/.
You can add arch-specific sections in <asm/module.lds.h>.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Currently the code for displaying a stack trace on the console is located
in traps.c rather than stacktrace.c, using the unwinding code that is in
stacktrace.c. This can be confusing and make the code hard to find since
such output is often referred to as a stack trace which might mislead the
unwary. Due to this and since traps.c doesn't interact with this code
except for via the public interfaces move the code to stacktrace.c to
make it easier to find.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200921122341.11280-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Commit 73f3816609 ("arm64: Advertise mitigation of Spectre-v2, or lack
thereof") changed the way we deal with ARCH_WORKAROUND_1, by moving most
of the enabling code to the .matches() callback.
This has the unfortunate effect that the workaround gets only enabled on
the first affected CPU, and no other.
In order to address this, forcefully call the .matches() callback from a
.cpu_enable() callback, which brings us back to the original behaviour.
Fixes: 73f3816609 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof")
Cc: <stable@vger.kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
We seem to be pretending that we don't have any firmware mitigation
when KVM is not compiled in, which is not quite expected.
Bring back the mitigation in this case.
Fixes: 4db61fef16 ("arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations")
Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
arch_scale_freq_invariant() is used by schedutil to determine whether
the scheduler's load-tracking signals are frequency invariant. Its
definition is overridable, though by default it is hardcoded to 'true'
if arch_scale_freq_capacity() is defined ('false' otherwise).
This behaviour is not overridden on arm, arm64 and other users of the
generic arch topology driver, which is somewhat precarious:
arch_scale_freq_capacity() will always be defined, yet not all cpufreq
drivers are guaranteed to drive the frequency invariance scale factor
setting. In other words, the load-tracking signals may very well *not*
be frequency invariant.
Now that cpufreq can be queried on whether the current driver is driving
the Frequency Invariance (FI) scale setting, the current situation can
be improved. This combines the query of whether cpufreq supports the
setting of the frequency scale factor, with whether all online CPUs are
counter-based FI enabled.
While cpufreq FI enablement applies at system level, for all CPUs,
counter-based FI support could also be used for only a subset of CPUs to
set the invariance scale factor. Therefore, if cpufreq-based FI support
is present, we consider the system to be invariant. If missing, we
require all online CPUs to be counter-based FI enabled in order for the
full system to be considered invariant.
If the system ends up not being invariant, a new condition is needed in
the counter initialization code that disables all scale factor setting
based on counters.
Precedence of counters over cpufreq use is not important here. The
invariant status is only given to the system if all CPUs have at least
one method of setting the frequency scale factor.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The passed cpumask arguments to arch_set_freq_scale() and
arch_freq_counters_available() are only iterated over, so reflect this
in the prototype. This also allows to pass system cpumasks like
cpu_online_mask without getting a warning.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When generating instructions at runtime, for example due to kernel text
patching or the BPF JIT, we can emit a trapping BRK instruction if we
are asked to encode an invalid instruction such as an out-of-range]
branch. This is indicative of a bug in the caller, and will result in a
crash on executing the generated code. Unfortunately, the message from
the crash is really unhelpful, and mumbles something about ptrace:
| Unexpected kernel BRK exception at EL1
| Internal error: ptrace BRK handler: f2000100 [#1] SMP
We can do better than this. Install a break handler for FAULT_BRK_IMM,
which is the immediate used to encode the "I've been asked to generate
an invalid instruction" error, and triage the faulting PC to determine
whether or not the failure occurred in the BPF JIT.
Link: https://lore.kernel.org/r/20200915141707.GB26439@willie-the-truck
Reported-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Fix the following warnings.
arch/arm64/kernel/fpsimd.c:935:6: warning: no previous prototype for
‘do_sve_acc’ [-Wmissing-prototypes]
arch/arm64/kernel/fpsimd.c:962:6: warning: no previous prototype for
‘do_fpsimd_acc’ [-Wmissing-prototypes]
arch/arm64/kernel/fpsimd.c:971:6: warning: no previous prototype for
‘do_fpsimd_exc’ [-Wmissing-prototypes]
arch/arm64/kernel/fpsimd.c:1266:6: warning: no previous prototype for
‘kernel_neon_begin’ [-Wmissing-prototypes]
arch/arm64/kernel/fpsimd.c:1292:6: warning: no previous prototype for
‘kernel_neon_end’ [-Wmissing-prototypes]
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/1600157999-14802-1-git-send-email-tiantao6@hisilicon.com
Signed-off-by: Will Deacon <will@kernel.org>
Historically architectures have had duplicated code in their stack trace
implementations for filtering what gets traced. In order to avoid this
duplication some generic code has been provided using a new interface
arch_stack_walk(), enabled by selecting ARCH_STACKWALK in Kconfig, which
factors all this out into the generic stack trace code. Convert arm64
to use this common infrastructure.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20200914153409.25097-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
As with the generic arch_stack_walk() code the arm64 stack walk code takes
a callback that is called per stack frame. Currently the arm64 code always
passes a struct stackframe to the callback and the generic code just passes
the pc, however none of the users ever reference anything in the struct
other than the pc value. The arm64 code also uses a return type of int
while the generic code uses a return type of bool though in both cases the
return value is a boolean value and the sense is inverted between the two.
In order to reduce code duplication when arm64 is converted to use
arch_stack_walk() change the signature and return sense of the arm64
specific callback to match that of the generic code.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20200914153409.25097-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Steal time initialization requires mapping a memory region which
invokes a memory allocation. Doing this at CPU starting time results
in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled:
BUG: sleeping function called from invalid context at mm/slab.h:498
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1
Call trace:
dump_backtrace+0x0/0x208
show_stack+0x1c/0x28
dump_stack+0xc4/0x11c
___might_sleep+0xf8/0x130
__might_sleep+0x58/0x90
slab_pre_alloc_hook.constprop.101+0xd0/0x118
kmem_cache_alloc_node_trace+0x84/0x270
__get_vm_area_node+0x88/0x210
get_vm_area_caller+0x38/0x40
__ioremap_caller+0x70/0xf8
ioremap_cache+0x78/0xb0
memremap+0x9c/0x1a8
init_stolen_time_cpu+0x54/0xf0
cpuhp_invoke_callback+0xa8/0x720
notify_cpu_starting+0xc8/0xd8
secondary_start_kernel+0x114/0x180
CPU1: Booted secondary processor 0x0000000001 [0x431f0a11]
However we don't need to initialize steal time at CPU starting time.
We can simply wait until CPU online time, just sacrificing a bit of
accuracy by returning zero for steal time until we know better.
While at it, add __init to the functions that are only called by
pv_time_init() which is __init.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Fixes: e0685fa228 ("arm64: Retrieve stolen time as paravirtualized guest")
Cc: stable@vger.kernel.org
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The function __{pgd, pud, pmd, pte}_error() are introduced so that
they can be called by {pgd, pud, pmd, pte}_ERROR(). However, some
of the functions could never be called when the corresponding page
table level isn't enabled. For example, __{pud, pmd}_error() are
unused when PUD and PMD are folded to PGD.
This removes __{pgd, pud, pmd, pte}_error() and call pr_err() from
{pgd, pud, pmd, pte}_ERROR() directly, similar to what x86/powerpc
are doing. With this, the code looks a bit simplified either.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20200913234730.23145-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
With the addition of ARMv8.3-FPAC feature, the probe of authenticate
ptrauth instructions (AUT*) may cause ptrauth fault exception in case of
authenticate failure so they cannot be safely single stepped.
Hence the probe of authenticate instructions is disallowed but the
corresponding pac ptrauth instruction (PAC*) is not affected and they can
still be probed. Also AUTH* instructions do not make sense at function
entry points so most realistic probes would be unaffected by this change.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-6-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
The current address authentication cpufeature levels are set as LOWER_SAFE
which is not compatible with the different configurations added for Armv8.3
ptrauth enhancements as the different levels have different behaviour and
there is no tunable to enable the lower safe versions. This is rectified
by setting those cpufeature type as EXACT.
The current cpufeature framework also does not interfere in the booting of
non-exact secondary cpus but rather marks them as tainted. As a workaround
this is fixed by replacing the generic match handler with a new handler
specific to ptrauth.
After this change, if there is any variation in ptrauth configurations in
secondary cpus from boot cpu then those mismatched cpus are parked in an
infinite loop.
Following ptrauth crash log is observed in Arm fastmodel with simulated
mismatched cpus without this fix,
CPU features: SANITY CHECK: Unexpected variation in SYS_ID_AA64ISAR1_EL1. Boot CPU: 0x11111110211402, CPU4: 0x11111110211102
CPU features: Unsupported CPU feature variation detected.
GICv3: CPU4: found redistributor 100 region 0:0x000000002f180000
CPU4: Booted secondary processor 0x0000000100 [0x410fd0f0]
Unable to handle kernel paging request at virtual address bfff800010dadf3c
Mem abort info:
ESR = 0x86000004
EC = 0x21: IABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
[bfff800010dadf3c] address between user and kernel address ranges
Internal error: Oops: 86000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 4 PID: 29 Comm: migration/4 Tainted: G S 5.8.0-rc4-00005-ge658591d66d1-dirty #158
Hardware name: Foundation-v8A (DT)
pstate: 60000089 (nZCv daIf -PAN -UAO BTYPE=--)
pc : 0xbfff800010dadf3c
lr : __schedule+0x2b4/0x5a8
sp : ffff800012043d70
x29: ffff800012043d70 x28: 0080000000000000
x27: ffff800011cbe000 x26: ffff00087ad37580
x25: ffff00087ad37000 x24: ffff800010de7d50
x23: ffff800011674018 x22: 0784800010dae2a8
x21: ffff00087ad37000 x20: ffff00087acb8000
x19: ffff00087f742100 x18: 0000000000000030
x17: 0000000000000000 x16: 0000000000000000
x15: ffff800011ac1000 x14: 00000000000001bd
x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 71519a147ddfeb82
x9 : 825d5ec0fb246314 x8 : ffff00087ad37dd8
x7 : 0000000000000000 x6 : 00000000fffedb0e
x5 : 00000000ffffffff x4 : 0000000000000000
x3 : 0000000000000028 x2 : ffff80086e11e000
x1 : ffff00087ad37000 x0 : ffff00087acdc600
Call trace:
0xbfff800010dadf3c
schedule+0x78/0x110
schedule_preempt_disabled+0x24/0x40
__kthread_parkme+0x68/0xd0
kthread+0x138/0x160
ret_from_fork+0x10/0x34
Code: bad PC value
After this fix, the mismatched CPU4 is parked as,
CPU features: CPU4: Detected conflict for capability 39 (Address authentication (IMP DEF algorithm)), System: 1, CPU: 0
CPU4: will not boot
CPU4: failed to come online
CPU4: died during early boot
[Suzuki: Introduce new matching function for address authentication]
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-5-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Some Armv8.3 Pointer Authentication enhancements have been introduced
which are mandatory for Armv8.6 and optional for Armv8.3. These features
are,
* ARMv8.3-PAuth2 - An enhanced PAC generation logic is added which hardens
finding the correct PAC value of the authenticated pointer.
* ARMv8.3-FPAC - Fault is generated now when the ptrauth authentication
instruction fails in authenticating the PAC present in the address.
This is different from earlier case when such failures just adds an
error code in the top byte and waits for subsequent load/store to abort.
The ptrauth instructions which may cause this fault are autiasp, retaa
etc.
The above features are now represented by additional configurations
for the Address Authentication cpufeature and a new ESR exception class.
The userspace fault received in the kernel due to ARMv8.3-FPAC is treated
as Illegal instruction and hence signal SIGILL is injected with ILL_ILLOPN
as the signal code. Note that this is different from earlier ARMv8.3
ptrauth where signal SIGSEGV is issued due to Pointer authentication
failures. The in-kernel PAC fault causes kernel to crash.
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-4-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Currently the ARMv8.3-PAuth combined branch instructions (braa, retaa
etc.) are not simulated for out-of-line execution with a handler. Hence the
uprobe of such instructions leads to kernel warnings in a loop as they are
not explicitly checked and fall into INSN_GOOD categories. Other combined
instructions like LDRAA and LDRBB can be probed.
The issue of the combined branch instructions is fixed by adding
group definitions of all such instructions and rejecting their probes.
The instruction groups added are br_auth(braa, brab, braaz and brabz),
blr_auth(blraa, blrab, blraaz and blrabz), ret_auth(retaa and retab) and
eret_auth(eretaa and eretab).
Warning log:
WARNING: CPU: 0 PID: 156 at arch/arm64/kernel/probes/uprobes.c:182 uprobe_single_step_handler+0x34/0x50
Modules linked in:
CPU: 0 PID: 156 Comm: func Not tainted 5.9.0-rc3 #188
Hardware name: Foundation-v8A (DT)
pstate: 804003c9 (Nzcv DAIF +PAN -UAO BTYPE=--)
pc : uprobe_single_step_handler+0x34/0x50
lr : single_step_handler+0x70/0xf8
sp : ffff800012af3e30
x29: ffff800012af3e30 x28: ffff000878723b00
x27: 0000000000000000 x26: 0000000000000000
x25: 0000000000000000 x24: 0000000000000000
x23: 0000000060001000 x22: 00000000cb000022
x21: ffff800012065ce8 x20: ffff800012af3ec0
x19: ffff800012068d50 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000
x15: 0000000000000000 x14: 0000000000000000
x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000
x9 : ffff800010085c90 x8 : 0000000000000000
x7 : 0000000000000000 x6 : ffff80001205a9c8
x5 : ffff80001205a000 x4 : ffff80001233db80
x3 : ffff8000100a7a60 x2 : 0020000000000003
x1 : 0000fffffffff008 x0 : ffff800012af3ec0
Call trace:
uprobe_single_step_handler+0x34/0x50
single_step_handler+0x70/0xf8
do_debug_exception+0xb8/0x130
el0_sync_handler+0x138/0x1b8
el0_sync+0x158/0x180
Fixes: 74afda4016 ("arm64: compile the kernel with ptrauth return address signing")
Fixes: 04ca3204fa ("arm64: enable pointer authentication")
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-2-amit.kachhap@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
The GIC's internal view of the priority mask register and the assigned
interrupt priorities are based on whether GIC security is enabled and
whether firmware routes Group 0 interrupts to EL3. At the moment, we
support priority masking when ICC_PMR_EL1 and interrupt priorities are
either both modified by the GIC, or both left unchanged.
Trusted Firmware-A's default interrupt routing model allows Group 0
interrupts to be delivered to the non-secure world (SCR_EL3.FIQ == 0).
Unfortunately, this is precisely the case that the GIC driver doesn't
support: ICC_PMR_EL1 remains unchanged, but the GIC's view of interrupt
priorities is different from the software programmed values.
Support pseudo-NMIs when SCR_EL3.FIQ == 0 by using a different value to
mask regular interrupts. All the other values remain the same.
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200912153707.667731-3-alexandru.elisei@arm.com
In order to deal with IPIs as normal interrupts, let's add
a new way to register them with the architecture code.
set_smp_ipi_range() takes a range of interrupts, and allows
the arch code to request them as if the were normal interrupts.
A standard handler is then called by the core IRQ code to deal
with the IPI.
This means that we don't need to call irq_enter/irq_exit, and
that we don't need to deal with set_irq_regs either. So let's
move the dispatcher into its own function, and leave handle_IPI()
as a compatibility function.
On the sending side, let's make use of ipi_send_mask, which
already exists for this purpose.
One of the major difference is that we end up, in some cases
(such as when performing IRQ time accounting on the scheduler
IPI), end up with nested irq_enter()/irq_exit() pairs.
Other than the (relatively small) overhead, there should be
no consequences to it (these pairs are designed to nest
correctly, and the accounting shouldn't be off).
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Now that we allow CPUs affected by erratum 1418040 to come in late,
this prevents their unaffected sibblings from coming in late (or
coming back after a suspend or hotplug-off, which amounts to the
same thing).
To allow this, we need to add ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU,
which amounts to set .type to ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE.
Fixes: bf87bb0881 ("arm64: Allow booting of late CPUs affected by erratum 1418040")
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200911181611.2073183-1-maz@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Kernel startup entry point requires disabling MMU and D-cache.
As for kexec-reboot, taking a close look at "msr sctlr_el1, x12" in
__cpu_soft_restart as the following:
-1. booted at EL1
The instruction is enough to disable MMU and I/D cache for
EL1 regime.
-2. booted at EL2, using VHE
Access to SCTLR_EL1 is redirected to SCTLR_EL2 in EL2. So the instruction
is enough to disable MMU and clear I+C bits for EL2 regime.
-3. booted at EL2, not using VHE
The instruction itself can not affect EL2 regime. But The hyp-stub doesn't
enable the MMU and I/D cache for EL2 regime. And KVM also disable them for EL2
regime when its unloaded, or execute a HVC_SOFT_RESTART call. So when
kexec-reboot, the code in KVM has prepare the requirement.
As a conclusion, disabling MMU and clearing I+C bits in
SYM_CODE_START(arm64_relocate_new_kernel) is redundant, and can be removed
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: kvmarm@lists.cs.columbia.edu
Link: https://lore.kernel.org/r/1598621998-20563-1-git-send-email-kernelfans@gmail.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Will Deacon <will@kernel.org>
In the absence of ACPI or DT topology data, we fallback to haphazardly
decoding *something* out of MPIDR. Sadly, the contents of that register are
mostly unusable due to the implementation leniancy and things like Aff0
having to be capped to 15 (despite being encoded on 8 bits).
Consider a simple system with a single package of 32 cores, all under the
same LLC. We ought to be shoving them in the same core_sibling mask, but
MPIDR is going to look like:
| CPU | 0 | ... | 15 | 16 | ... | 31 |
|------+---+-----+----+----+-----+----+
| Aff0 | 0 | ... | 15 | 0 | ... | 15 |
| Aff1 | 0 | ... | 0 | 1 | ... | 1 |
| Aff2 | 0 | ... | 0 | 0 | ... | 0 |
Which will eventually yield
core_sibling(0-15) == 0-15
core_sibling(16-31) == 16-31
NUMA woes
=========
If we try to play games with this and set up NUMA boundaries within those
groups of 16 cores via e.g. QEMU:
# Node0: 0-9; Node1: 10-19
$ qemu-system-aarch64 <blah> \
-smp 20 -numa node,cpus=0-9,nodeid=0 -numa node,cpus=10-19,nodeid=1
The scheduler's MC domain (all CPUs with same LLC) is going to be built via
arch_topology.c::cpu_coregroup_mask()
In there we try to figure out a sensible mask out of the topology
information we have. In short, here we'll pick the smallest of NUMA or
core sibling mask.
node_mask(CPU9) == 0-9
core_sibling(CPU9) == 0-15
MC mask for CPU9 will thus be 0-9, not a problem.
node_mask(CPU10) == 10-19
core_sibling(CPU10) == 0-15
MC mask for CPU10 will thus be 10-19, not a problem.
node_mask(CPU16) == 10-19
core_sibling(CPU16) == 16-19
MC mask for CPU16 will thus be 16-19... Uh oh. CPUs 16-19 are in two
different unique MC spans, and the scheduler has no idea what to make of
that. That triggers the WARN_ON() added by commit
ccf74128d6 ("sched/topology: Assert non-NUMA topology masks don't (partially) overlap")
Fixing MPIDR-derived topology
=============================
We could try to come up with some cleverer scheme to figure out which of
the available masks to pick, but really if one of those masks resulted from
MPIDR then it should be discarded because it's bound to be bogus.
I was hoping to give MPIDR a chance for SMT, to figure out which threads are
in the same core using Aff1-3 as core ID, but Sudeep and Robin pointed out
to me that there are systems out there where *all* cores have non-zero
values in their higher affinity fields (e.g. RK3288 has "5" in all of its
cores' MPIDR.Aff1), which would expose a bogus core ID to userspace.
Stop using MPIDR for topology information. When no other source of topology
information is available, mark each CPU as its own core and its NUMA node
as its LLC domain.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200829130016.26106-1-valentin.schneider@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
TEXT_OFFSET serves no purpose, and for this reason, it was redefined
as 0x0 in the v5.8 timeframe. Since this does not appear to have caused
any issues that require us to revisit that decision, let's get rid of the
macro entirely, along with any references to it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
The vdso linker script is preprocessed on demand.
Adding it to 'targets' is enough to include the .cmd file.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
This patch is to add the general hardware last level cache (LLC) events
for PMUv3: one event is for LLC access and another is for LLC miss.
With this change, perf tool can support last level cache profiling,
below is an example to demonstrate the usage on Arm64:
$ perf stat -e LLC-load-misses -e LLC-loads -- \
perf bench mem memcpy -s 1024MB -l 100 -f default
[...]
Performance counter stats for 'perf bench mem memcpy -s 1024MB -l 100 -f default':
35,534,262 LLC-load-misses # 2.16% of all LL-cache hits
1,643,946,443 LLC-loads
[...]
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20200811053505.21223-1-leo.yan@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
Currently, there are different description strings in die() such as
die("Oops",,), die("Oops - BUG",,). And panic() called by die() will
always show "Fatal exception" or "Fatal exception in interrupt".
Note that panic() will run any panic handler via panic_notifier_list.
And the string above will be formatted and placed in static buf[]
which will be passed to handler.
So panic handler can not distinguish which Oops it is from the buf if
we want to do some things like reserve the string in memory or panic
statistics. It's not benefit to debug. We need to add more codes to
troubleshoot. Let's utilize existing resource to make debug much simpler.
Signed-off-by: Yue Hu <huyue2@yulong.com>
Link: https://lore.kernel.org/r/20200804085347.10720-1-zbestahu@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
