Flushing a large, non-faulting VMA from userspace can potentially result
in a long time spent flushing the cache line-by-line without preemption
occurring (in the case of CONFIG_PREEMPT=n).
Whilst this doesn't affect the stability of the system, it can certainly
affect the responsiveness and CPU availability for other tasks.
This patch splits up the user cacheflush code so that it flushes in
chunks of a page. After each chunk has been flushed, we may reschedule
if appropriate and, before processing the next chunk, we allow any
pending signals to be handled before resuming from where we left off.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Pull ARM fixes from Russell King:
"The usual collection of random fixes. Also some further fixes to the
last set of security fixes, and some more from Will (which you may
already have in a slightly different form)"
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7807/1: kexec: validate CPU hotplug support
ARM: 7812/1: rwlocks: retry trylock operation if strex fails on free lock
ARM: 7811/1: locks: use early clobber in arch_spin_trylock
ARM: 7810/1: perf: Fix array out of bounds access in armpmu_map_hw_event()
ARM: 7809/1: perf: fix event validation for software group leaders
ARM: Fix FIQ code on VIVT CPUs
ARM: Fix !kuser helpers case
ARM: Fix the world famous typo with is_gate_vma()
Ben Tebulin reported:
"Since v3.7.2 on two independent machines a very specific Git
repository fails in 9/10 cases on git-fsck due to an SHA1/memory
failures. This only occurs on a very specific repository and can be
reproduced stably on two independent laptops. Git mailing list ran
out of ideas and for me this looks like some very exotic kernel issue"
and bisected the failure to the backport of commit 53a59fc67f ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").
That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.
The real bug is that the TLB gather virtual memory range setup is subtly
buggered. It was introduced in commit 597e1c3580 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96c ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.
The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB. And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.
Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.
This makes the patch larger, but conceptually much simpler. And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.
Ben verified that this fixes his problem.
Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com>
Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au>
Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
From Tomasz Figa:
Here is the Samsung PWM cleanup series. Particular patches of the series
involve following modifications:
- fixing up few things in samsung_pwm_timer clocksource driver,
- moving remaining Samsung platforms to the new clocksource driver,
- removing old clocksource driver,
- adding new multiplatform- and DT-aware PWM driver,
- moving all Samsung platforms to use the new PWM driver,
- removing old PWM driver,
- removing all PWM-related code that is not used anymore.
* tag 'v3.12-pwm-cleanup-for-olof' of git://github.com/tom3q/linux: (684 commits)
ARM: SAMSUNG: Remove plat/regs-timer.h header
ARM: SAMSUNG: Remove remaining uses of plat/regs-timer.h header
ARM: SAMSUNG: Remove pwm-clock infrastructure
ARM: SAMSUNG: Remove old PWM timer platform devices
pwm: Remove superseded pwm-samsung-legacy driver
ARM: SAMSUNG: Modify board files to use new PWM platform device
ARM: SAMSUNG: Rework private data handling in dev-backlight
pwm: Add new pwm-samsung driver
pwm: samsung: Rename to pwm-samsung-legacy
ARM: SAMSUNG: Remove unused PWM timer IRQ chip code
ARM: SAMSUNG: Remove old samsung-time driver
ARM: SAMSUNG: Move all platforms to new clocksource driver
ARM: SAMSUNG: Set PWM platform data
ARM: SAMSUNG: Add new PWM platform device
ARM: SAMSUNG: Unify base address definitions of timer block
clocksource: samsung_pwm_timer: Handle suspend/resume correctly
clocksource: samsung_pwm_timer: Do not use clocksource_mmio
clocksource: samsung_pwm_timer: Cache clocksource register address
clocksource: samsung_pwm_timer: Correct definition of AUTORELOAD bit
clocksource: samsung_pwm_timer: Do not request PWM mem region
+ v3.11-rc4
Conflicts:
arch/arm/Kconfig.debug
Signed-off-by: Olof Johansson <olof@lixom.net>
From David Brown <davidb@codeaurora.org>:
* msm/cleanup:
ARM: msm: Only compile io.c on platforms that use it
iommu/msm: Move mach includes to iommu directory
ARM: msm: Remove devices-iommu.c
ARM: msm: Move mach/board.h contents to common.h
ARM: msm: Migrate msm_timer to CLOCKSOURCE_OF_DECLARE
ARM: msm: Remove TMR and TMR0 static mappings
ARM: msm: Move debug-macro.S to include/debug
ARM: msm: Don't compile __msm_ioremap_caller() unless used
ARM: msm: Remove unused and unmapped MSM_TLMM_BASE for 8x60
Signed-off-by: Kevin Hilman <khilman@linaro.org>
In order to specify a DMA zone size of 4GB on LPAE systems, the sizes need
to be 64-bit. So make machine_desc.dma_zone_size and arm_dma_zone_size be
phys_addr_t instead of unsigned long.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
THe L_PTE_USER actually has nothing to do with stage 2 mappings and the
L_PTE_S2_RDWR value sets the readable bit, which was what L_PTE_USER
was used for before proper handling of stage 2 memory defines.
Changelog:
[v3]: Drop call to kvm_set_s2pte_writable in mmu.c
[v2]: Change default mappings to be r/w instead of r/o, as per Marc
Zyngier's suggestion.
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Architectures should fully validate whether kexec is possible as part of
machine_kexec_prepare(), so that user-space's kexec_load() operation can
report any problems. Performing validation in machine_kexec() itself is
too late, since it is not allowed to return.
Prior to this patch, ARM's machine_kexec() was testing after-the-fact
whether machine_kexec_prepare() was able to disable all but one CPU.
Instead, modify machine_kexec_prepare() to validate all conditions
necessary for machine_kexec_prepare()'s to succeed. BUG if the validation
succeeded, yet disabling the CPUs didn't actually work.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 15e7e5c1eb ("ARM: 7749/1: spinlock: retry trylock operation if
strex fails on free lock") modifying our arch_spin_trylock to retry the
acquisition if the lock appeared uncontended, but the strex failed.
This patch does the same for rwlocks, which were missed by the original
patch.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The res variable is written before we've finished with the input
operands (namely the lock address), so ensure that we mark it as `early
clobber' to avoid unintended register sharing.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some PCI drivers may need to adjust the pci_bus structure after it has
been allocated by the Linux PCI core. The PCI core allows
architectures to implement the pcibios_add_bus() and
pcibios_remove_bus() for this purpose. This commit therefore extends
the hw_pci and pci_sys_data structures of the ARM PCI core to allow
PCI drivers to register ->add_bus() and ->remove_bus() in hw_pci,
which will get called when a bus is added or removed from the system.
This will be used for example by the Marvell PCIe driver to connect a
particular PCI bus with its corresponding MSI chip to handle Message
Signaled Interrupts.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Daniel Price <daniel.price@gmail.com>
Tested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
flush_cache_vmap contains a dsb to ensure that any cacheflushing
operations to flush out newly written ptes have completed.
This patch adds the -ishst option to the dsb, since that is all that is
required for completing cacheflushing in the inner-shareable domain.
Signed-off-by: Will Deacon <will.deacon@arm.com>
When unlocking a spinlock, we use the sev instruction to signal other
CPUs waiting on the lock. Since sev is not a memory access instruction,
we require a dsb in order to ensure that the sev is not issued ahead
of the store placing the lock in an unlocked state.
However, as sev is only concerned with other processors in a
multiprocessor system, we can restrict the scope of the preceding dsb
to the inner-shareable domain. Furthermore, we can restrict the scope to
consider only stores, since there are no independent loads on the unlock
path.
A side-effect of this change is that a spin_unlock operation no longer
forces completion of pending TLB invalidation, something which we rely
on when unlocking runqueues to ensure that CPU migration during TLB
maintenance routines doesn't cause us to continue before the operation
has completed.
This patch adds the -ishst suffix to the ARMv7 definition of dsb_sev()
and adds an inner-shareable dsb to the context-switch path when running
a preemptible, SMP, v7 kernel.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Our TLB invalidation routines may require a barrier before the
maintenance (in order to ensure pending page table writes are visible to
the hardware walker) and barriers afterwards (in order to ensure
completion of the maintenance and visibility in the instruction stream).
Whilst this is expensive, the cost can be reduced somewhat by reducing
the scope of the barrier instructions:
- The barrier before only needs to apply to stores (pte writes)
- Local ops are required only to affect the non-shareable domain
- Global ops are required only to affect the inner-shareable domain
This patch makes these changes for the TLB flushing code.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
On ARMv7, the memory barrier instructions take an optional `option'
field which can be used to constrain the effects of a memory barrier
based on shareability and access type.
This patch allows the caller to pass these options if required, and
updates the smp_*() barriers to request inner-shareable barriers,
affecting only stores for the _wmb variant. wmb() is also changed to
use the -st version of dsb.
Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Now that the ASID allocator doesn't require inner-shareable maintenance,
we can convert the local_bp_flush_all function to perform only
non-shareable flushing, in a similar manner to the TLB invalidation
routines.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Branch predictor maintenance is only required when we are either
changing the kernel's view of memory (switching tables completely) or
dealing with ASID rollover.
Both of these use-cases require subsequent TLB invalidation, which has
the relevant barrier instructions to ensure completion and visibility
of the maintenance, so this patch removes the instruction barrier from
[local_]flush_bp_all.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Inner-shareable TLB invalidation is typically more expensive than local
(non-shareable) invalidation, so performing the broadcasting for
local_flush_tlb_* operations is a waste of cycles and needlessly
clobbers entries in the TLBs of other CPUs.
This patch introduces __flush_tlb_* versions for many of the TLB
invalidation functions, which only respect inner-shareable variants of
the invalidation instructions when presented with the TLB_V7_UIS_FULL
flag. The local version is also inlined to prevent SMP_ON_UP kernels
from missing flushes, where the __flush variant would be called with
the UP flags.
This gains us around 0.5% in hackbench scores for a dual-core A15, but I
would expect this to improve as more cores (and clusters) are added to
the equation.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Albin Tonnerre <Albin.Tonnerre@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
One more step to allowing MSM to participate in the
multi-platform defconfig.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
[davidb: Comment cleanup requested by sboyd]
Signed-off-by: David Brown <davidb@codeaurora.org>
Olof reports that noMMU builds error out with:
arch/arm/kernel/signal.c: In function 'setup_return':
arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member named 'sigpage'
This shows one of the evilnesses of IS_ENABLED(). Get rid of it here
and replace it with #ifdef's - and as no noMMU platform can make use
of sigpage, depend on CONIFG_MMU not CONFIG_ARM_MPU.
Reported-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If kuser helpers are not provided by the kernel, disable user access to
the vectors page. With the kuser helpers gone, there is no reason for
this page to be visible to userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the signal handlers into a VDSO page rather than keeping them in
the vectors page. This allows us to place them randomly within this
page, and also map the page at a random location within userspace
further protecting these code fragments from ROP attacks. The new
VDSO page is also poisoned in the same way as the vector page.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We're going to introduce support to read and write the memory
mapped timer registers in the next patch, so push the cp15
read/write functions one level deeper. This simplifies the next
patch and makes it clearer what's going on.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Using an enum for the register we wish to access allows newer
compilers to determine if we've forgotten a case in our switch
statement. This allows us to remove the BUILD_BUG() instances in
the arm64 port, avoiding problems where optimizations may not
happen.
To try and force better code generation we're currently marking
the accessor functions as inline, but newer compilers can ignore
the inline keyword unless it's marked __always_inline. Luckily on
arm and arm64 inline is __always_inline, but let's make
everything __always_inline to be explicit.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Commit 621a0147d5 ("ARM: 7757/1: mm:
don't flush icache in switch_mm with hardware broadcasting") breaks
the boot on OMAP2430SDP with omap2plus_defconfig. Tracked to an
undefined instruction abort from the CP15 read in
cache_ops_need_broadcast(). It turns out that gcc 4.5 reorders the
extended CP15 read above the is_smp() test. This breaks ARM1136 r0
cores, since they don't support several CP15 registers that later ARM
cores do. ARM1136JF-S TRM section 3.2.1 "Register allocation" has the
details.
So mark the extended CP15 read as clobbering memory, which prevents
the compiler from reordering it before the is_smp() test. Russell
states that the code generated from this approach is preferable to
marking the inline asm as volatile. Remove the existing condition
code clobber as it's obsolete, per Nico's post:
http://www.spinics.net/lists/arm-kernel/msg261208.html
This patch is a collaboration with Will Deacon and Russell King.
Comments from Paul Walmsley:
Russell, if you accept this one, might you also add Will's ack from the lists:
Comments from Paul Walmsley:
I'd also be obliged if you could add a Cc: line for Jonathan Austin, since he helped test:
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Tony Lindgren <tony@atomide.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The workqueues are problematic as they may be contended.
They can't be scheduled with top priority either. Also the optimization
in bL_switch_request() to skip the workqueue entirely when the target CPU
and the calling CPU were the same didn't allow for bL_switch_request() to
be called from atomic context, as might be the case for some cpufreq
drivers.
Let's move to dedicated kthreads instead.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
This is the core code implementing big.LITTLE switcher functionality.
Rationale for this code is available here:
http://lwn.net/Articles/481055/
The main entry point for a switch request is:
void bL_switch_request(unsigned int cpu, unsigned int new_cluster_id)
If the calling CPU is not the wanted one, this wrapper takes care of
sending the request to the appropriate CPU with schedule_work_on().
At the moment the core switch operation is handled by bL_switch_to()
which must be called on the CPU for which a switch is requested.
What this code does:
* Return early if the current cluster is the wanted one.
* Close the gate in the kernel entry vector for both the inbound
and outbound CPUs.
* Wake up the inbound CPU so it can perform its reset sequence in
parallel up to the kernel entry vector gate.
* Migrate all interrupts in the GIC targeting the outbound CPU
interface to the inbound CPU interface, including SGIs. This is
performed by gic_migrate_target() in drivers/irqchip/irq-gic.c.
* Call cpu_pm_enter() which takes care of flushing the VFP state to
RAM and save the CPU interface config from the GIC to RAM.
* Modify the cpu_logical_map to refer to the inbound physical CPU.
* Call cpu_suspend() which saves the CPU state (general purpose
registers, page table address) onto the stack and store the
resulting stack pointer in an array indexed by the updated
cpu_logical_map, then call the provided shutdown function.
This happens in arch/arm/kernel/sleep.S.
At this point, the provided shutdown function executed by the outbound
CPU ungates the inbound CPU. Therefore the inbound CPU:
* Picks up the saved stack pointer in the array indexed by its MPIDR
in arch/arm/kernel/sleep.S.
* The MMU and caches are re-enabled using the saved state on the
provided stack, just like if this was a resume operation from a
suspended state.
* Then cpu_suspend() returns, although this is on the inbound CPU
rather than the outbound CPU which called it initially.
* The function cpu_pm_exit() is called which effect is to restore the
CPU interface state in the GIC using the state previously saved by
the outbound CPU.
* Exit of bL_switch_to() to resume normal kernel execution on the
new CPU.
However, the outbound CPU is potentially still running in parallel while
the inbound CPU is resuming normal kernel execution, hence we need
per CPU stack isolation to execute bL_do_switch(). After the outbound
CPU has ungated the inbound CPU, it calls mcpm_cpu_power_down() to:
* Clean its L1 cache.
* If it is the last CPU still alive in its cluster (last man standing),
it also cleans its L2 cache and disables cache snooping from the other
cluster.
* Power down the CPU (or whole cluster).
Code called from bL_do_switch() might end up referencing 'current' for
some reasons. However, 'current' is derived from the stack pointer.
With any arbitrary stack, the returned value for 'current' and any
dereferenced values through it are just random garbage which may lead to
segmentation faults.
The active page table during the execution of bL_do_switch() is also a
problem. There is no guarantee that the inbound CPU won't destroy the
corresponding task which would free the attached page table while the
outbound CPU is still running and relying on it.
To solve both issues, we borrow some of the task space belonging to
the init/idle task which, by its nature, is lightly used and therefore
is unlikely to clash with our usage. The init task is also never going
away.
Right now the logical CPU number is assumed to be equivalent to the
physical CPU number within each cluster. The kernel should also be
booted with only one cluster active. These limitations will be lifted
eventually.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
struct machine_desc records are defined everywhere as a 'const'
structure, but unfortuantely it loses its const-ness through the use of
linker magic - the symbols which surround the section are not declared
const so it becomes possible not to use 'const' for pointers to these
const structures.
Let's fix this oversight - all pointers to these structures should be
marked const too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
a.out support on ARM requires that argc, argv and envp are passed in
r0-r2 respectively, which requires hacking load_aout_binary to
prevent argc being clobbered by the return code. Whilst mainline kernels
do set the registers up in start_thread, the aout loader has never
carried the hack in mainline.
Initialising the registers in this way actually goes against the libc
expectations for ELF binaries, where argc, argv and envp are passed on
the stack, with r0 being used to hold a pointer to an exit function for
cleaning up after the dynamic linker if required. If the pointer is
NULL, then it is ignored. When execing an ELF binary, Linux currently
zeroes r0, then sets it to argc and then finally clobbers it with the
return value of the execve syscall, so we actually end up with:
r0 = 0
stack[0] = argc
r1 = stack[1] = argv
r2 = stack[2] = envp
libc treats r1 and r2 as undefined. The clobbering of r0 by sys_execve
works for user-spawned threads, but when executing an ELF binary from a
kernel thread (via call_usermodehelper), the execve is performed on the
ret_from_fork path, which restores r0 from the saved pt_regs, resulting
in argc being presented to the C library. This has horrible consequences
when the application exits, since we have an exit function registered
using argc, resulting in a jump to hyperspace.
This patch solves the problem by removing the partial a.out support from
arch/arm/ altogether.
Cc: <stable@vger.kernel.org>
Cc: Ashish Sangwan <ashishsangwan2@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As of commit b9d4d42ad9 (ARM: Remove __ARCH_WANT_INTERRUPTS_ON_CTXSW on
pre-ARMv6 CPUs), the mm switching on VIVT processors is done in the
finish_arch_post_lock_switch() function to avoid whole cache flushing
with interrupts disabled. The need for deferred mm switch is stored as a
thread flag (TIF_SWITCH_MM). However, with preemption enabled, we can
have another thread switch before finish_arch_post_lock_switch(). If the
new thread has the same mm as the previous 'next' thread, the scheduler
will not call switch_mm() and the TIF_SWITCH_MM flag won't be set for
the new thread.
This patch moves the switch pending flag to the mm_context_t structure
since this is specific to the mm rather than thread.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: <stable@vger.kernel.org> # 3.5+
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 93dc688 (ARM: 7684/1: errata: Workaround for Cortex-A15 erratum 798181 (TLBI/DSB operations)) causes the following undefined instruction error on a mx53 (Cortex-A8):
Internal error: Oops - undefined instruction: 0 [#1] SMP ARM
CPU: 0 PID: 275 Comm: modprobe Not tainted 3.11.0-rc2-next-20130722-00009-g9b0f371 #881
task: df46cc00 ti: df48e000 task.ti: df48e000
PC is at check_and_switch_context+0x17c/0x4d0
LR is at check_and_switch_context+0xdc/0x4d0
This problem happens because check_and_switch_context() calls dummy_flush_tlb_a15_erratum() without checking if we are really running on a Cortex-A15 or not.
To avoid this issue, only call dummy_flush_tlb_a15_erratum() inside
check_and_switch_context() if erratum_a15_798181() returns true, which means that we are really running on a Cortex-A15.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a
cached value of __boot_cpu_mode may be incoherent with that in memory.
This could lead to a failure to detect mismatched boot modes.
This patch adds flushing to ensure that writes by secondaries to
__boot_cpu_mode are made visible before we test against it.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
From Stephen Boyd:
Now that we have a generic arch hook for broadcast we can remove the
local timer API entirely. Doing so will reduce code in ARM core, reduce
the architecture dependencies of our timer drivers, and simplify the code
because we no longer go through an architecture layer that is essentially
a hotplug notifier.
* tag 'remove-local-timers' of git://git.kernel.org/pub/scm/linux/kernel/git/davidb/linux-msm:
ARM: smp: Remove local timer API
clocksource: time-armada-370-xp: Divorce from local timer API
clocksource: time-armada-370-xp: Fix sparse warning
ARM: msm: Divorce msm_timer from local timer API
ARM: PRIMA2: Divorce timer-marco from local timer API
ARM: EXYNOS4: Divorce mct from local timer API
ARM: OMAP2+: Divorce from local timer API
ARM: smp_twd: Divorce smp_twd from local timer API
ARM: smp: Remove duplicate dummy timer implementation
Resolved a large number of conflicts due to __cpuinit cleanups, etc.
Signed-off-by: Olof Johansson <olof@lixom.net>
Comments from Ard Biesheuvel:
I have included two use cases that I have been using, XOR and RAID-6
checksumming. The former gets a 60% performance boost on the NEON, the
latter over 400%.
ARM: add support for kernel mode NEON
Adds kernel_neon_begin/end (renamed from kernel_vfp_begin/end in the
previous version to de-emphasize the VFP part as VFP code that needs
software assistance is not supported currently.)
Introduces <asm/neon.h> and the Kconfig symbol KERNEL_MODE_NEON. This
has been aligned with Catalin for arm64, so any NEON code that does
not use assembly but intrinsics or the GCC vectorizer (such as my
examples) can potentially be shared between arm and arm64 archs.
ARM: move VFP init to an earlier boot stage
This is needed so the NEON is enabled when the XOR and RAID-6 algo
boot time benchmarks are run.
ARM: be strict about FP exceptions in kernel mode
This adds a check to vfp_support_entry() to flag unsupported uses of
the NEON/VFP in kernel mode. FP exceptions (bounces) are flagged as
a bug, this is because of their potentially intermittent nature.
Exceptions caused by the fact that kernel_neon_begin has not been
called are just routed through the undef handler.
ARM: crypto: add NEON accelerated XOR implementation
This is the xor_blocks() implementation built with -ftree-vectorize,
60% faster than optimized ARM code. It calls in_interrupt() to check
whether the NEON flavor can be used: this should really not be
necessary, but due to xor_blocks'squite generic nature, there is no
telling how exactly people may be using it in the real world.
lib/raid6: add ARM-NEON accelerated syndrome calculation
This is a port of the RAID-6 checksumming code in altivec.uc ported
to use NEON intrinsics. It is about 4x faster than the sequential
code.
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.
This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code. It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Pull ARM SoC fixes from Olof Johansson:
"This is our first set of fixes from arm-soc for 3.11.
- A handful of build and warning fixes from Arnd
- A collection of OMAP fixes
- defconfig updates to make the default configs more useful for real
use (and testing) out of the box on hardware
And a couple of other small fixes. Some of these have been recently
applied but it's normally how we deal with fixes, with less bake time
in -next needed"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (32 commits)
arm: multi_v7_defconfig: Tweaks for omap and sunxi
arm: multi_v7_defconfig: add i.MX options and NFS root
ARM: omap2: add select of TI_PRIV_EDMA
ARM: exynos: select PM_GENERIC_DOMAINS only when used
ARM: ixp4xx: avoid circular header dependency
ARM: OMAP: omap_common_late_init may be unused
ARM: sti: move DEBUG_STI_UART into alphabetical order
ARM: OMAP: build mach-omap code only if needed
ARM: zynq: use DT_MACHINE_START
ARM: omap5: omap5 has SCU and TWD
ARM: OMAP2+: omap2plus_defconfig: Enable appended DTB support
ARM: OMAP2+: Enable TI_EDMA in omap2plus_defconfig
ARM: OMAP2+: omap2plus_defconfig: enable DRA752 thermal support by default
ARM: OMAP2+: omap2plus_defconfig: enable TI bandgap driver
ARM: OMAP2+: devices: remove duplicated include from devices.c
ARM: OMAP3: igep0020: Set DSS pins in correct mux mode.
ARM: OMAP2+: N900: enable N900-specific drivers even if device tree is enabled
ARM: OMAP2+: Cocci spatch "ptr_ret.spatch"
ARM: OMAP2+: Remove obsolete Makefile line
ARM: OMAP5: Enable Cortex A15 errata 798181
...
Preparing to move the parsing of reboot= to generic kernel code forces
the change in reboot_mode handling to use the enum.
[akpm@linux-foundation.org: fix arch/arm/mach-socfpga/socfpga.c]
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a source file xor-neon.c (which is really just the reference
C implementation passed through the GCC vectorizer) and hook it
up to the XOR framework.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
In order to safely support the use of NEON instructions in
kernel mode, some precautions need to be taken:
- the userland context that may be present in the registers (even
if the NEON/VFP is currently disabled) must be stored under the
correct task (which may not be 'current' in the UP case),
- to avoid having to keep track of additional vfpstates for the
kernel side, disallow the use of NEON in interrupt context
and run with preemption disabled,
- after use, re-enable preemption and re-enable the lazy restore
machinery by disabling the NEON/VFP unit.
This patch adds the functions kernel_neon_begin() and
kernel_neon_end() which take care of the above. It also adds
the Kconfig symbol KERNEL_MODE_NEON to enable it.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Pull timer core updates from Thomas Gleixner:
"The timer changes contain:
- posix timer code consolidation and fixes for odd corner cases
- sched_clock implementation moved from ARM to core code to avoid
duplication by other architectures
- alarm timer updates
- clocksource and clockevents unregistration facilities
- clocksource/events support for new hardware
- precise nanoseconds RTC readout (Xen feature)
- generic support for Xen suspend/resume oddities
- the usual lot of fixes and cleanups all over the place
The parts which touch other areas (ARM/XEN) have been coordinated with
the relevant maintainers. Though this results in an handful of
trivial to solve merge conflicts, which we preferred over nasty cross
tree merge dependencies.
The patches which have been committed in the last few days are bug
fixes plus the posix timer lot. The latter was in akpms queue and
next for quite some time; they just got forgotten and Frederic
collected them last minute."
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (59 commits)
hrtimer: Remove unused variable
hrtimers: Move SMP function call to thread context
clocksource: Reselect clocksource when watchdog validated high-res capability
posix-cpu-timers: don't account cpu timer after stopped thread runtime accounting
posix_timers: fix racy timer delta caching on task exit
posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()
selftests: add basic posix timers selftests
posix_cpu_timers: consolidate expired timers check
posix_cpu_timers: consolidate timer list cleanups
posix_cpu_timer: consolidate expiry time type
tick: Sanitize broadcast control logic
tick: Prevent uncontrolled switch to oneshot mode
tick: Make oneshot broadcast robust vs. CPU offlining
x86: xen: Sync the CMOS RTC as well as the Xen wallclock
x86: xen: Sync the wallclock when the system time is set
timekeeping: Indicate that clock was set in the pvclock gtod notifier
timekeeping: Pass flags instead of multiple bools to timekeeping_update()
xen: Remove clock_was_set() call in the resume path
hrtimers: Support resuming with two or more CPUs online (but stopped)
timer: Fix jiffies wrap behavior of round_jiffies_common()
...
Pull Xen ARM update rom Stefano Stabellini:
"Just one commit this time: the implementation of the tmem hypercall
for arm and arm64"
* tag 'xenarm-for-3.11-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/sstabellini/xen:
xen/arm and xen/arm64: implement HYPERVISOR_tmem_op
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into timers/core
Frederic sayed: "Most of these patches have been hanging around for
several month now, in -mmotm for a significant chunk. They already
missed a few releases."
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On platforms such as Cortex-A15 based OMAP5, SCU is not used, however
since much code is shared between Cortex-A9 based OMAP4 (which uses
SCU) and OMAP5, It does help to have inline functions returning error
values when SCU is not present on the platform.
arch/arm/mach-omap2/omap-smp.c which is common between OMAP4 and 5
handles the SCU usage only for OMAP4.
This fixes the following build failure with OMAP5 only build:
arch/arm/mach-omap2/built-in.o: In function `omap4_smp_init_cpus':
arch/arm/mach-omap2/omap-smp.c:185: undefined reference to `scu_get_core_count'
arch/arm/mach-omap2/built-in.o: In function `omap4_smp_prepare_cpus':
arch/arm/mach-omap2/omap-smp.c:211: undefined reference to `scu_enable'
Reported-by: Pekon Gupta <pekon@ti.com>
Reported-by: Vincent Stehlé <v-stehle@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Merge first patch-bomb from Andrew Morton:
- various misc bits
- I'm been patchmonkeying ocfs2 for a while, as Joel and Mark have been
distracted. There has been quite a bit of activity.
- About half the MM queue
- Some backlight bits
- Various lib/ updates
- checkpatch updates
- zillions more little rtc patches
- ptrace
- signals
- exec
- procfs
- rapidio
- nbd
- aoe
- pps
- memstick
- tools/testing/selftests updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (445 commits)
tools/testing/selftests: don't assume the x bit is set on scripts
selftests: add .gitignore for kcmp
selftests: fix clean target in kcmp Makefile
selftests: add .gitignore for vm
selftests: add hugetlbfstest
self-test: fix make clean
selftests: exit 1 on failure
kernel/resource.c: remove the unneeded assignment in function __find_resource
aio: fix wrong comment in aio_complete()
drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test mode
drivers/memstick/host/r592.c: convert to module_pci_driver
drivers/memstick/host/jmb38x_ms: convert to module_pci_driver
pps-gpio: add device-tree binding and support
drivers/pps/clients/pps-gpio.c: convert to module_platform_driver
drivers/pps/clients/pps-gpio.c: convert to devm_* helpers
drivers/parport/share.c: use kzalloc
Documentation/accounting/getdelays.c: avoid strncpy in accounting tool
aoe: update internal version number to v83
aoe: update copyright date
aoe: perform I/O completions in parallel
...
