Sending IPI_CPU_STOP to a CPU causes it to execute a busy cpu_relax
loop forever. This makes it impossible to kexec successfully on an SMP
system since the secondary CPUs do not reset.
This patch adds a callback to platform_cpu_kill, defined when
CONFIG_HOTPLUG_CPU=y, from the ipi_cpu_stop handling code. This function
currently just returns 1 on all platforms that define it but allows them
to do something more sophisticated in the future.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tools such as kexec and CPU hotplug require a way to reset the processor
and branch to some code in physical space. This requires various bits of
jiggery pokery with the caches and MMU which, when it goes wrong, tends
to lock up the system.
This patch fleshes out the soft_restart implementation so that it
branches to the reset code using the identity mapping. This requires us
to change to a temporary stack, held within the kernel image as a static
array, to avoid conflicting with the new view of memory.
Signed-off-by: Will Deacon <will.deacon@arm.com>
arm_dma_zone_size is used by arm_bootmem_free() which is called by
paging_init(). Thus it needs to be set before calling it.
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Those two APIs were provided to optimize the calls of
tick_nohz_idle_enter() and rcu_idle_enter() into a single
irq disabled section. This way no interrupt happening in-between would
needlessly process any RCU job.
Now we are talking about an optimization for which benefits
have yet to be measured. Let's start simple and completely decouple
idle rcu and dyntick idle logics to simplify.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
It is assumed that rcu won't be used once we switch to tickless
mode and until we restart the tick. However this is not always
true, as in x86-64 where we dereference the idle notifiers after
the tick is stopped.
To prepare for fixing this, add two new APIs:
tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu().
If no use of RCU is made in the idle loop between
tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch
must instead call the new *_norcu() version such that the arch doesn't
need to call rcu_idle_enter() and rcu_idle_exit().
Otherwise the arch must call tick_nohz_enter_idle() and
tick_nohz_exit_idle() and also call explicitly:
- rcu_idle_enter() after its last use of RCU before the CPU is put
to sleep.
- rcu_idle_exit() before the first use of RCU after the CPU is woken
up.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The tick_nohz_stop_sched_tick() function, which tries to delay
the next timer tick as long as possible, can be called from two
places:
- From the idle loop to start the dytick idle mode
- From interrupt exit if we have interrupted the dyntick
idle mode, so that we reprogram the next tick event in
case the irq changed some internal state that requires this
action.
There are only few minor differences between both that
are handled by that function, driven by the ts->inidle
cpu variable and the inidle parameter. The whole guarantees
that we only update the dyntick mode on irq exit if we actually
interrupted the dyntick idle mode, and that we enter in RCU extended
quiescent state from idle loop entry only.
Split this function into:
- tick_nohz_idle_enter(), which sets ts->inidle to 1, enters
dynticks idle mode unconditionally if it can, and enters into RCU
extended quiescent state.
- tick_nohz_irq_exit() which only updates the dynticks idle mode
when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called).
To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed
into tick_nohz_idle_exit().
This simplifies the code and micro-optimize the irq exit path (no need
for local_irq_save there). This also prepares for the split between
dynticks and rcu extended quiescent state logics. We'll need this split to
further fix illegal uses of RCU in extended quiescent states in the idle
loop.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: David Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
24aa07882b (memblock, x86: Replace memblock_x86_reserve/free_range()
with generic ones) removed arch/x86/include/asm/memblock.h and dropped
its inclusion from include/linux/memblock.h which breaks other
architectures which depended on the generic memblock.h pulling in the
arch specific one.
However, the proper fix isn't adding back the asm inclusion. memblock
doesn't have any arch dependent part and doesn't need arch specific
header file and asm/memblock.h files are either practically empty or
contain mostly unrelated arch specific stuff.
* In microblaze, sh, powerpc, sparc and openrisc, asm/memblock.h is
either empty or just contains unused MEMBLOCK_DBG() macro. Remove
them.
* In arm and unicore32, asm/memblock.h contains arch specific stuff.
Include it directly from its users. It might be a good idea to
rename the header file to avoid confusion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
The DFSR and IFSR register format is different when LPAE is enabled. In
addition, DFSR and IFSR have similar definitions for the fault type.
This modifies the fault code to correctly handle the new format.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch adds the MMU initialisation for the LPAE page table format.
The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new
proc-v7-3level.S file contains the TTB initialisation, context switch
and PTE setting code with the LPAE. The TTBRx split is based on the
PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings
(supersections) and a few other memory types in mmu.c are conditionally
compiled.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Before we enable the MMU, we must ensure that the TTBR registers contain
sane values. After the MMU has been enabled, we jump to the *virtual*
address of the following function, so we also need to ensure that the
SCTLR write has taken effect.
This patch adds ISB instructions around the SCTLR write to ensure the
visibility of the above.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The ARM SMP booting code allocates a temporary set of page tables
containing an identity mapping of the kernel image and provides this
to secondary CPUs for initial booting.
In reality, we only need to include the __turn_mmu_on function in the
identity mapping since the rest of the kernel is executing from virtual
addresses after this point.
This patch adds __turn_mmu_on to the .idmap.text section, allowing the
SMP booting code to use the idmap_pgd directly and not have to populate
its own set of page table.
As a result of this patch, we can make the identity_mapping_add function
static (since it is only used within mm/idmap.c) and also remove the
identity_mapping_del function. The identity map population is moved to
an early initcall so that it is setup in time for secondary CPU bringup.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
__create_page_tables identity maps the region of memory from
__enable_mmu to the end of __turn_mmu_on.
In preparation for including __turn_mmu_on in the .idmap.text section,
this patch modifies the identity mapping so that it only includes the
__turn_mmu_on code.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped
in order to re-enable the MMU when coming out of suspend. Currently,
this is accomplished by maintaining a suspend_pgd with the relevant
mapping put in place at init time.
This patch replaces the use of suspend_pgd with the new idmap_pgd.
cpu_resume_mmu is placed in the .idmap.text section so that it is
included in the identity map.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
When disabling and re-enabling the MMU, it is necessary to take out an
identity mapping for the code that manipulates the SCTLR in order to
avoid it disappearing from under our feet. This is useful when soft
rebooting and returning from CPU suspend.
This patch allocates a set of page tables during boot and populates them
with an identity mapping for the .idmap.text section. This means that
users of the identity map do not need to manage their own pgd and can
instead annotate their functions with __idmap or, in the case of assembly
code, place them in the correct section.
Acked-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
In the unlikely case that a platform registers a PMU platform_device
when running on a CPU that is unsupported by perf, we will encounter a
NULL dereference when trying to assign the platform_device to the
cpu_pmu structure.
This patch checks that the CPU is supported by perf before assigning
the platform_device.
Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The linker places the unwind tables in readonly sections. So when using
an XIP kernel these are located in ROM and cannot be modified.
For that reason the current approach to convert the relative offsets in
the unwind index to absolute addresses early in the boot process doesn't
work with XIP.
The offsets in the unwind index section are signed 31 bit numbers and
the structs are sorted by this offset. So it first has offsets between
0x40000000 and 0x7fffffff (i.e. the negative offsets) and then offsets
between 0x00000000 and 0x3fffffff. When seperating these two blocks the
numbers are sorted even when interpreting the offsets as unsigned longs.
So determine the first non-negative entry once and track that using the
new origin pointer. The actual bisection can then use a plain unsigned
long comparison. The only thing that makes the new bisection more
complicated is that the offsets are relative to their position in the
index section, so the key to search needs to be adapted accordingly in
each step.
Moreover several consts are added to catch future writes and rename the
member "addr" of struct unwind_idx to "addr_offset" to better match the
new semantic. (This has the additional benefit of breaking eventual
users at compile time to make them aware of the change.)
In my tests the new algorithm was a tad faster than the original and has
the additional upside of not needing the initial conversion and so saves
some boot time and it's possible to unwind even earlier.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix loss of notification with multi-event
perf, x86: Force IBS LVT offset assignment for family 10h
perf, x86: Disable PEBS on SandyBridge chips
trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter
perf session: Fix crash with invalid CPU list
perf python: Fix undefined symbol problem
perf/x86: Enable raw event access to Intel offcore events
perf: Don't use -ENOSPC for out of PMU resources
perf: Do not set task_ctx pointer in cpuctx if there are no events in the context
perf/x86: Fix PEBS instruction unwind
oprofile, x86: Fix crash when unloading module (nmi timer mode)
oprofile: Fix crash when unloading module (hr timer mode)
This patch introduces .enable_irq and .disable_irq into
struct arm_pmu_platdata, so platform specific irq enablement
can be handled after request_irq, and platform specific irq
disablement can be handled before free_irq.
This patch is for support of pmu irq routed from CTI on omap4.
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
armpmu_get_max_events is only called from perf_num_counters, so we can
inline it there. It existed as a separate entity as a hangover from
the original perf-based oprofile implementation.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit 8f622422 ("perf events: Add generic front-end and back-end
stalled cycle event definitions") added two new ABI events for counting
stalled cycles.
This patch adds support for these new events to the ARM perf
implementation.
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch updates the ARMv7 perf event numbers so that:
(1) A consistent naming scheme is used between different CPUs.
(2) Only events actually used by Linux are described.
(3) Where possible, architected events are used in preference to
CPU-specific events.
This results in the removal of a load of unused, hardcoded data and
makes it more clear as to which events are supported on each PMU.
Cc: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
kernel/sched.c:7354:2: warning: initialization from incompatible pointer type
Align cpu_coregroup_mask prototype interface with sched_domain_mask_f typedef
use int cpu instead of unsigned int cpu
Cc: <stable@vger.kernel.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The SWP instruction is deprecated on ARMv6 and with ARMv7 it will be
UNDEFINED when CONFIG_SWP_EMULATE is selected. In this case, probing a
SWP instruction will cause an oops when the kprobes emulation code
executes an undefined instruction.
As the SWP instruction should be rare or non-existent in kernels for
ARMv6 and later, we can simply avoid these problems by not allowing
probing of these.
Reported-by: Leif Lindholm <leif.lindholm@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is a kprobes testcase for the instruction "strd r2, [r3], r4".
This has unpredictable behaviour as it uses r3 for register writeback
addressing and also stores it to memory.
On a cortex A9, this testcase would fail because the instruction writes
the updated value of r3 to memory, whereas the kprobes emulation code
writes the original value.
Fix this by changing testcase to used r5 instead of r3.
Reported-by: Leif Lindholm <leif.lindholm@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When compiling kprobes-test-thumb.c an error like below may occur:
/tmp/ccKcuJcG.s:19179: Error: offset out of range
This is caused by the compiler underestimating the size of the inline
assembler instructions containing ".space 0x1000" and failing to spill
the literal pool in time to prevent the generation of PC relative load
instruction with invalid offsets.
The fix implemented by this patch is to replace a single large .space
directive by a number of 4 byte .space's. This requires splitting the
macros which generate test cases for branch instructions into two forms:
one with, and one without support for inserting extra code between
branch and target.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Jon Medhurst <jon.medhurst@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix compilation failure, when Thumb support is not enabled:
arch/arm/kernel/entry-armv.S: Assembler messages:
arch/arm/kernel/entry-armv.S:501: Error: backward ref to unknown label "2:"
arch/arm/kernel/entry-armv.S:502: Error: backward ref to unknown label "3:"
make[2]: *** [arch/arm/kernel/entry-armv.o] Error 1
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Attempting to use a hardware counter on a platform with a supported PMU
but where the platform_device (defining the interrupts) has not been
registered results in a NULL pointer dereference.
This patch fixes the problem by checking that we actually have a platform
device registered before attempting to grab the interrupts.
Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Conflicts:
arch/arm/mach-omap2/board-4430sdp.c
arch/arm/mach-omap2/board-omap4panda.c
arch/arm/mach-omap2/include/mach/omap4-common.h
arch/arm/plat-omap/include/plat/irqs.h
The changes to omap4-common.h were moved to arch/arm/mach-omap2/common.h
and the other trivial conflicts resolved. The now empty ifdef in irqs.h
was also eliminated.
This patch implements a workaround for PL310 erratum 769419. On
revisions of the PL310 prior to r3p2, the Store Buffer does not
automatically drain. This can cause normal, non-cacheable writes to be
retained when the memory system is idle, leading to suboptimal I/O
performance for drivers using coherent DMA.
This patch adds an optional wmb() call to the cpu_idle loop. On systems
with an outer cache, this causes an explicit flush of the store buffer.
Cc: stable@vger.kernel.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We only need to set the system up for a soft-restart if we're going to
be doing a soft-restart. Provide a new function (soft_restart()) which
does the setup and final call for this, and make platforms use it.
Eliminate the call to setup_restart() from the default handler.
This means that platforms arch_reset() function is no longer called with
the page tables prepared for a soft-restart, and caches will still be
enabled.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Krzysztof Ha■asa <khc@pm.waw.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The meminfo array has to be sorted before sanity_check_meminfo() in
arch/arm/mm/mmu.c is called for it to work properly. This also allows
for a simpler find_limits() in arch/arm/mm/init.c.
The sort is moved to arch/arm/kernel/setup.c because that's where the
meminfo array is populated. Eventually this should be improved upon
to make the memory bank parser a bit more robust against problems
such as overlapping memory ranges.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These two syscalls were introduced during the last merge window.
Add the entries into the ARM call tables for them.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When validating an event group, we call pmu->get_event_idx for each
group member in order to check that the group can be scheduled as a
unit on an empty PMU.
As a result of 3fc2c830 ("ARM: perf: remove event limit from
pmu_hw_events"), the used_mask member of struct cpu_hw_events must be
setup explicitly, something which we don't do for the fake cpu_hw_events
used for validation.
This patch sets up an empty used_mask for the fake validation
cpu_hw_events, preventing NULL deferences when trying to get the event
index.
Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit b0e89590 ("ARM: PMU: move CPU PMU platform device handling and
init into perf") inadvertently removed the EXPORT_SYMBOL_GPL on
release_pmu, so out-of-tree modules can no longer play nice with perf,
even if they tried in the first place.
This patch re-exports the symbol.
Reported-by: Jon Medhurst (Tixy) <jon.medhurst@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Even when CONFIG_MULTI_IRQ_HANDLER is selected, the core code
requires the arch_irq_handler_default macro to be defined as
a fallback.
It turns out nobody is using that particular feature as both PXA
and shmobile have all their machine descriptors populated with
the interrupt handler, leaving unused code (or empty macros) in
their entry-macro.S file just to be able to compile entry-armv.S.
Make CONFIG_MULTI_IRQ_HANDLER exclusive wrt arch_irq_handler_default,
which allows to remove one test from the hot path. Also cleanup both
PXA and shmobile entry-macro.S.
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
People (Linus) objected to using -ENOSPC to signal not having enough
resources on the PMU to satisfy the request. Use -EINVAL.
Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-xv8geaz2zpbjhlx0svmpp28n@git.kernel.org
[ merged to newer kernel, fixed up MIPS impact ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
setup_processor copies the arch_name and elf_name fields out of the
selected proc_info_list into two fixed size buffers.
Since the proc_info_list structure is defined in a proc_*.S assembly
file, this can lead to subtle errors if the strings defined there are
too long (for example, corrupting the machine ID).
This patch uses snprintf instead of sprintf to ensure that these buffers
are not overrun.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
setup_mm_for_reboot() doesn't make use of its argument, so remove it.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the failure to reboot into machine_restart() to always catch
this condition, even if a platform decides to hook the restarting
via arm_pm_restart().
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Change 'soft_reboot' into a more generic 'restart_mode' variable,
allowing the default restart mode to be specified.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add a restart hook to the machine_desc record so we don't have to
populate all platforms with init_early methods to initialize the
arm_pm_restart function pointer.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Recent gcc versions generate unaligned accesses by default on ARMv6 and
later processors. This patch ensures that the SCTLR.A bit is always
cleared on such processors to avoid kernel traping before
alignment_init() is called.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: John Linn <John.Linn@xilinx.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This reverts commit 2b034922af.
Will Deacon reports:
This is causing kexec to fail.
The symptoms are that the .init.text section is not loaded as part of the
new kernel image, so when we try to do the SMP/UP fixups we hit a whole sea
of poison left there by the previous kernel.
So my guess is that machine_kexec_prepare *is* too early for preparing the
reboot_code_buffer and, unless anybody has a good reason not to, I'd like to
revert the patch causing these problems.
Reported-by: Will Deacon <will.deacon@arm.com>
These files will fail to compile if we dont clean them up in advance
and have them include the appropriate headers they need.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Many of the core ARM kernel files are not modules, but just
including module.h for exporting symbols. Now these files can
use the lighter footprint export.h for this role.
There are probably lots more, but ARM files of mach-* and plat-*
don't get coverage via a simple yesconfig build. They will have
to be cleaned up and tested via using their respective configs.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Building these files does not reveal a hidden need for
any of these. Since module.h brings in the whole kitchen
sink, it just needlessly adds 30k+ lines to the cpp burden.
There are probably lots more, but ARM files of mach-* and plat-*
don't get coverage via a simple yesconfig build. They will have
to be cleaned up and tested via using their respective configs.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
To fix things like this:
arch/arm/mach-omap2/usb-tusb6010.c:58: error: implicit declaration of function 'memset'
arch/arm/kernel/leds.c:40: error: implicit declaration of function 'strcspn'
arch/arm/kernel/leds.c:40: warning: incompatible implicit declaration of built-in function 'strcspn'
arch/arm/kernel/leds.c:45: error: implicit declaration of function 'strncmp'
arch/arm/kernel/leds.c:55: error: implicit declaration of function 'strlen'
arch/arm/kernel/leds.c:55: warning: incompatible implicit declaration of built-in function 'strlen'
arch/arm/mach-omap2/clockdomain.c:52: error: implicit declaration of function 'strcmp'
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
It was implicitly getting it via an implicit presence of module.h
but when we clean that up, we'll get a bunch of lines like this:
arch/arm/kernel/ptrace.c:764: error: 'NT_PRSTATUS' undeclared here (not in a function)
arch/arm/kernel/ptrace.c:765: error: 'ELF_NGREG' undeclared here (not in a function)
arch/arm/kernel/ptrace.c:776: error: 'NT_PRFPREG' undeclared here (not in a function)
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
rtmutex: Add missing rcu_read_unlock() in debug_rt_mutex_print_deadlock()
lockdep: Comment all warnings
lib: atomic64: Change the type of local lock to raw_spinlock_t
locking, lib/atomic64: Annotate atomic64_lock::lock as raw
locking, x86, iommu: Annotate qi->q_lock as raw
locking, x86, iommu: Annotate irq_2_ir_lock as raw
locking, x86, iommu: Annotate iommu->register_lock as raw
locking, dma, ipu: Annotate bank_lock as raw
locking, ARM: Annotate low level hw locks as raw
locking, drivers/dca: Annotate dca_lock as raw
locking, powerpc: Annotate uic->lock as raw
locking, x86: mce: Annotate cmci_discover_lock as raw
locking, ACPI: Annotate c3_lock as raw
locking, oprofile: Annotate oprofilefs lock as raw
locking, video: Annotate vga console lock as raw
locking, latencytop: Annotate latency_lock as raw
locking, timer_stats: Annotate table_lock as raw
locking, rwsem: Annotate inner lock as raw
locking, semaphores: Annotate inner lock as raw
locking, sched: Annotate thread_group_cputimer as raw
...
Fix up conflicts in kernel/posix-cpu-timers.c manually: making
cputimer->cputime a raw lock conflicted with the ABBA fix in commit
bcd5cff721 ("cputimer: Cure lock inversion").
The problem is related to the early enabling of interrupts and the
per cpu timer setup before the cpu is marked online. This doesn't
need to be done in order to call calibrate_delay().
calibrate_delay() monitors jiffies, which are updated from the CPU
which is waiting for the new CPU to set the online bit.
So simply calibrate_delay() can be called on the new CPU just from
the interrupt disabled region and move the local timer setup after
stored the cpu data and before enabling interrupts.
This solves both the cpu_online vs. cpu_active problem and the
affinity setting of the per cpu timers.
Signed-off-by: Thomas Gleinxer <tglx@linutronix.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch remove the hardcoded link between local timers and PPIs,
and convert the PPI users (TWD, MCT and MSM timers) to the new
*_percpu_irq interface. Also some collateral cleanup
(local_timer_ack() is gone, and the interrupt handler is strictly
private to each driver).
PPIs are now useable for more than just the local timers.
Additional testing by David Brown (msm8250 and msm8660) and
Shawn Guo (imx6q).
Cc: David Brown <davidb@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Brown <davidb@codeaurora.org>
Tested-by: David Brown <davidb@codeaurora.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
PPI handling is a bit of an odd beast. It uses its own low level
handling code and is hardwired to the local timers (hence lacking
a registration interface).
Instead, switch the low handling to the normal SPI handling code.
PPIs are handled by the handle_percpu_devid_irq flow.
This also allows the removal of some duplicated code.
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Brown <davidb@codeaurora.org>
Tested-by: David Brown <davidb@codeaurora.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Upon adding new board LL debug support, if the resultant code
addition would not cause PC relative offset of "hexbuf" from
"adr r2, hexbuf" (+2) instruction to be representable in a
shifted 8-bit value (hence indirectly putting higher aligment
requirement on larger offsets), following error occurs,
arch/arm/kernel/debug.S: Assembler messages:
arch/arm/kernel/debug.S:138: Error: invalid constant (428) after fixup
Fix it by bringing "hexbuf" closer so that "adr"
can have the offset.
Signed-off-by: Afzal Mohammed <afzal@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This copy really don't need to do at the very second before the kernel
would crash.
Signed-off-by: Lei Wen <leiwen@marvell.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Cache Type Register L1Ip field identifies I-caches with a PIPT
policy using the encoding 11b.
This patch extends the cache policy parsing to identify PIPT I-caches
correctly and prevent them from being treated as VIPT aliasing in cases
where they are sufficiently large.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Get rid of the mdesc pointer in the fixup function call. No one uses
the mdesc pointer, it shouldn't be modified anyway, and we can't wrap
it, so let's remove it.
Platform files found by:
$ regexp=$(git grep -h '\.fixup.*=' arch/arm |
sed 's!.*= *\([^,]*\),* *!\1!' | sort -u |
tr '\n' '|' | sed 's,|$,,;s,|,\\|,g')
$ git grep $regexp arch/arm
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM uses its own BUG() handler which makes its output slightly different
from other archtectures.
One of the problems is that the ARM implementation doesn't report the function
with the BUG() in it, but always reports the PC being in __bug(). The generic
implementation doesn't have this problem.
Currently we get something like:
kernel BUG at fs/proc/breakme.c:35!
Unable to handle kernel NULL pointer dereference at virtual address 00000000
...
PC is at __bug+0x20/0x2c
With this patch it displays:
kernel BUG at fs/proc/breakme.c:35!
Internal error: Oops - undefined instruction: 0 [#1] PREEMPT SMP
...
PC is at write_breakme+0xd0/0x1b4
This implementation uses an undefined instruction to implement BUG, and sets up
a bug table containing the relevant information. Many versions of gcc do not
support %c properly for ARM (inserting a # when they shouldn't) so we work
around this using distasteful macro magic.
v1: Initial version to replace existing ARM BUG() implementation with something
more similar to other architectures.
v2: Add Thumb support, remove backtrace whitespace output changes. Change to
use macros instead of requiring the asm %d flag to work (thanks to
Dave Martin <dave.martin@linaro.org>)
v3: Remove old BUG() implementation in favor of this one.
Remove the Backtrace: message (will submit this separately).
Use ARM_EXIT_KEEP() so that some architectures can dump exit text at link time
thanks to Stephen Boyd <sboyd@codeaurora.org> (although since we always
define GENERIC_BUG this might be academic.)
Rebase to linux-2.6.git master.
v4: Allow BUGS in modules (these were not reported correctly in v3)
(thanks to Stephen Boyd <sboyd@codeaurora.org> for suggesting that.)
Remove __bug() as this is no longer needed.
v5: Add %progbits as the section flags.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently, show_regs calls __backtrace which does
nothing if CONFIG_FRAME_POINTER is not set. Switch to
dump_stack which handles both CONFIG_FRAME_POINTER and
CONFIG_ARM_UNWIND correctly.
__backtrace is now superseded by dump_stack in general
and show_regs was the last caller so remove __backtrace
as well.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When v6 and >=v7 boards are supported in the same kernel, the
__und_usr code currently makes a build-time assumption that Thumb-2
instructions occurring in userspace don't need to be supported.
Strictly speaking this is incorrect.
This patch fixes the above case by doing a run-time check on the
CPU architecture in these cases. This only affects kernels which
support v6 and >=v7 CPUs together: plain v6 and plain v7 kernels
are unaffected.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When testing whether a Thumb-2 instruction is 32 bits long or not,
the masking done in order to test bits 11-15 of the first
instruction halfword won't affect the result of the comparison, so
remove it.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The CPU architecture really should not be changing at runtime, so
make it a global variable instead of a function.
The cpu_architecture() function declared in <asm/system.h> remains
the correct way to read this variable from C code.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
we save the l2x0 registers at the first initialization, and platform codes
can get them to restore l2x0 status after wakeup.
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The definition of __exception_irq_entry for
CONFIG_FUNCTION_GRAPH_TRACER=y needs linux/ftrace.h, but this creates a
circular dependency with it's current home in asm/system.h. Create
asm/exception.h and update all current users.
v4: - rebase to rmk/for-next
v3: - remove redundant includes of linux/ftrace.h
v2: - document the usage restricitions of __exception*
Cc: Zoltan Devai <zdevai@gmail.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In order to be able to handle localtimer directly from C code instead of
assembly code, introduce handle_local_timer(), which is modeled after
handle_IRQ().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In order to be able to handle IPI directly from C code instead of
assembly code, introduce handle_IPI(), which is modeled after handle_IRQ().
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When Cortex-A9 MPCore resumes from Dormant or Shutdown modes,
SCU needs to be re-enabled. This patch removes __init annotation
from function scu_enable(), so that platform resume procedure can
call it to re-enable SCU.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
To allow booting Linux on a CPU with physical ID != 0, we need to
provide a mapping from the logical CPU number to the physical CPU
number.
This patch adds such a mapping and populates it during boot.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The affinity between ARM processors is defined in the MPIDR register.
We can identify which processors are in the same cluster,
and which ones have performance interdependency. We can define the
cpu topology of ARM platform, that is then used by sched_mc and sched_smt.
The default state of sched_mc and sched_smt config is disable.
When enabled, the behavior of the scheduler can be modified with
sched_mc_power_savings and sched_smt_power_savings sysfs interfaces.
Changes since v4 :
* Remove unnecessary parentheses and blank lines
Changes since v3 :
* Update the format of printk message
* Remove blank line
Changes since v2 :
* Update the commit message and some comments
Changes since v1 :
* Update the commit message
* Add read_cpuid_mpidr in arch/arm/include/asm/cputype.h
* Modify header of arch/arm/kernel/topology.c
* Modify tests and manipulation of MPIDR's bitfields
* Modify the place and dependancy of the config
* Modify Noop functions
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Using COHERENT_LINE_{MISS,HIT} for cache misses and references
respectively is completely wrong. Instead, use the L1D events which
are a better and more useful approximation despite ignoring instruction
traffic.
Reported-by: Alasdair Grant <alasdair.grant@arm.com>
Reported-by: Matt Horsnell <matt.horsnell@arm.com>
Reported-by: Michael Williams <michael.williams@arm.com>
Cc: stable@kernel.org
Cc: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv6 cores do not implement the DBGOSLAR register, so we don't need to
try and clear it on boot. Furthermore, the VCR is zeroed out of reset,
so we don't need to zero it explicitly when a CPU comes online.
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some PCI drivers call pcibios_bus_to_resource directly,
but it is only exported when CONFIG_HOTPLUG is set,
because it was initially mean for pccard support.
Moving the export out of the #ifdef lets us avoid these
build errors:
ERROR: "pcibios_bus_to_resource" [drivers/video/vt8623fb.ko] undefined!
ERROR: "pcibios_bus_to_resource" [drivers/video/arkfb.ko] undefined!
ERROR: "pcibios_bus_to_resource" [drivers/video/s3fb.ko] undefined!
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Support for the cpu_suspend functions is only built-in
when CONFIG_PM_SLEEP is enabled, but omap3/4, exynos4
and pxa always call cpu_suspend when CONFIG_PM is enabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The rtc_lock is used by both the nvram and rtc drivers, so
we need to export it if at least one of the two is built,
not just for the rtc driver.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
When the CONFIG_NO_MACH_MEMORY_H symbol is selected by a particular
machine class, the machine specific memory.h include file is no longer
used and can be removed. In that case the equivalent information can
be obtained dynamically at runtime by enabling CONFIG_ARM_PATCH_PHYS_VIRT
or by specifying the physical memory address at kernel configuration time.
If/when all instances of mach/memory.h are removed then this symbol could
be removed.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Some platforms (like OMAP not to name it) are doing rather complicated
hacks just to determine the base UART address to use. Let's give their
addruart macro some slack by providing an extra work register which will
allow for much needed cleanups.
This is basically a no-op as this commit is only adding the extra argument
to the macro but no one is using it yet.
Signed-off-by: nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
We are seeing linker errors caused by sections being discarded, despite
the linker script trying to keep them. The result is (eg):
`.exit.text' referenced in section `.alt.smp.init' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o
`.exit.text' referenced in section `.alt.smp.init' of net/built-in.o: defined in discarded section `.exit.text' of net/built-in.o
This is the relevent part of the linker script (reformatted to make it
clearer):
| SECTIONS
| {
| /*
| * unwind exit sections must be discarded before the rest of the
| * unwind sections get included.
| */
| /DISCARD/ : {
| *(.ARM.exidx.exit.text)
| *(.ARM.extab.exit.text)
| }
| ...
| .exit.text : {
| *(.exit.text)
| *(.memexit.text)
| }
| ...
| /DISCARD/ : {
| *(.exit.text)
| *(.memexit.text)
| *(.exit.data)
| *(.memexit.data)
| *(.memexit.rodata)
| *(.exitcall.exit)
| *(.discard)
| *(.discard.*)
| }
| }
Now, this is what the linker manual says about discarded output sections:
| The special output section name `/DISCARD/' may be used to discard
| input sections. Any input sections which are assigned to an output
| section named `/DISCARD/' are not included in the output file.
No questions, no exceptions. It doesn't say "unless they are listed
before the /DISCARD/ section." Now, this is what asn-generic/vmlinux.lds.S
says:
| /*
| * Default discarded sections.
| *
| * Some archs want to discard exit text/data at runtime rather than
| * link time due to cross-section references such as alt instructions,
| * bug table, eh_frame, etc. DISCARDS must be the last of output
| * section definitions so that such archs put those in earlier section
| * definitions.
| */
And guess what - the list _always_ includes .exit.text etc.
Now, what's actually happening is that the linker is reading the script,
and it finds the first /DISCARD/ output section at the beginning of the
script. It continues reading the script, and finds the 'DISCARD' macro
at the end, which having been postprocessed results in another
/DISCARD/ output section. As the linker already contains the earlier
/DISCARD/ output section, it adds it to that existing section, so it
effectively is placed at the start. This can be seen by using the -M
option to ld:
| Linker script and memory map
|
| 0xc037c080 jiffies = jiffies_64
|
| /DISCARD/
| *(.ARM.exidx.exit.text)
| *(.ARM.extab.exit.text)
| *(.exit.text)
| *(.memexit.text)
| *(.exit.data)
| *(.memexit.data)
| *(.memexit.rodata)
| *(.exitcall.exit)
| *(.discard)
| *(.discard.*)
|
| 0xc0008000 . = 0xc0008000
|
| .head.text 0xc0008000 0x1d0
| 0xc0008000 _text = .
| *(.head.text)
| .head.text 0xc0008000 0x1d0 arch/arm/kernel/head.o
| 0xc0008000 stext
|
| .text 0xc0008200 0x2d78d0
| 0xc0008200 _stext = .
| 0xc0008200 __exception_text_start = .
| *(.exception.text)
| .exception.text
| ...
As you can see, all the discarded sections are grouped together - and
as a result of it being the first output section, they all appear before
any other section.
The result is that not only is the unwind information discarded (as
intended), but also the .exit.text, despite us wanting to have the
.exit.text preserved.
We can't move the unwind information elsewhere, because it'll then be
included even when we do actually discard the .exit.text (and similar)
sections.
So, work around this by avoiding the generic DISCARDS macro, and instead
conditionalize the sections to be discarded ourselves. This avoids the
ambiguity in how the linker assigns input sections to output sections,
making our script less dependent on undocumented linker behaviour.
Reported-by: Rob Herring <robherring2@gmail.com>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to ensure that state is pushed out from the L2 cache when
suspending so that the resume paths can access their data before the
MMU and caches have been re-initialized. Add the necessary calls to
__cpu_suspend_save().
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Convert some of the sleep.S guts to C code, which makes it easier to
use our macros and to add L2 cache handling. We provide a helper
function, __cpu_suspend_save(), which deals with saving the common
state, setting up for resume, and flushing caches.
The remainder left as assembly code is the saving of the CPU general
purpose registers, and allocating space on the stack to save the CPU
specific registers and resume state.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We don't require cpu_resume_turn_mmu_on as we can combine the ldr
instruction with the following code provided we ensure that
cpu_resume_mmu is aligned for older CPUs. Note that we also align
to a 32-byte boundary to ensure that the code can't cross a section
boundary.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Only use the preallocated page table during the resume, not while
suspending. This avoids the overhead of having to switch unnecessarily
to the resume page table in the suspend path.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Preallocate a page table and setup an identity mapping for the MMU
enable code. This means we don't have to "borrow" a page table to
do this, avoiding complexities with L2 cache coherency.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure that the return value from __cpu_suspend is non-zero when
aborting. Zero indicates a successful suspend occurred.
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These benchmarks show the basic speed of kprobes and verify the success
of optimisations done to the emulation of typical function entry
instructions (i.e. push/stmdb).
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is used to verify that all combinations of CPU instructions
described by the kprobes decoding tables have a test case.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These check that the bitmask and match value used in the decoding tables
are self consistent.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The test code will be using kprobes' internal decoding tables so we
need to export these for when then the tests are compiled as a module.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
On ARM we have to simulate/emulate CPU instructions in order to
singlestep them. This patch adds a framework which can be used to
construct test cases for different instruction forms. It is described in
detail in the in-source comments of kprobes-test.c
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These test that the different kinds of probes can be successfully placed
into ARM and Thumb code and that the handlers are called correctly when
this code is executed.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch implements a workaround for erratum 764369 affecting
Cortex-A9 MPCore with two or more processors (all current revisions).
Under certain timing circumstances, a data cache line maintenance
operation by MVA targeting an Inner Shareable memory region may fail to
proceed up to either the Point of Coherency or to the Point of
Unification of the system. This workaround adds a DSB instruction before
the relevant cache maintenance functions and sets a specific bit in the
diagnostic control register of the SCU.
Cc: <stable@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Annotate the low level hardware locks which must not be preempted.
In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, armpmu_enable iterates through the events for a given
counter set, calling armpmu->enable on each before calling
armpmu->start to start the PMU's counters.
As armpmu->enable is called when each event is added, each event is
already configured in hardware. Due to this, calling armpmu->enable
in armpmu_enable is unnecessary and confusing.
This patch removes the unnecessary calls to armpmu->enable.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, struct arm_pmu and related functions are only visible to
{,arch/arm/}/kernel/perf_event.c. This prevents new drivers from using
the framework.
This patch moves declarations to asm/pmu.h, allowing new PMU drivers
to use the framework.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently struct cpu_hw_events stores data on events running on a
PMU associated with a CPU. As this data is general enough to be used
for system PMUs, this name is a misnomer, and may cause confusion when
it is used for system PMUs.
Additionally, 'armpmu' is commonly used as a parameter name for an
instance of struct arm_pmu. The name is also used for a global instance
which represents the CPU's PMU.
As cpu_hw_events is now not tied to CPU PMUs, it is renamed to
pmu_hw_events, with instances of it renamed similarly. As the global
'armpmu' is CPU-specfic, it is renamed to cpu_pmu. This should make it
clearer which code is generic, and which is coupled with the CPU.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently the event accounting data in pmu_hw_events is stored in
fixed-sized arrays within the structure.
This patch refactors the accounting data to allow any number of events
to be managed.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, a single static instance of struct pmu is used when
registering an ARM PMU with the main perf subsystem. This limits
the ARM perf code to supporting a single PMU.
This patch replaces the static struct pmu instance with a member
variable on struct arm_pmu. This provides bidirectional mapping
between the two structs, and therefore allows for support of multiple
PMUs. The function 'to_arm_pmu' is provided for convenience.
PMU-generic functions are also updated to use the new mapping, and
PMU-generic initialisation of the member variables is moved into a new
function: armpmu_init.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently mapping an event type to a hardware configuration value
depends on the data being pointed to from struct arm_pmu. These fields
(cache_map, event_map, raw_event_mask) are currently specific to CPU
PMUs, and do not serve the general case well.
This patch replaces the event map pointers on struct arm_pmu with a new
'map_event' function pointer. Small shim functions are used to reuse
the existing common code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, the ARM perf code assumes all PMUs it will handle are
CPU PMUs, having ARM_PMU_DEVICE_CPU hardcoded when reserving or
releasing hardware. This means that currently, the ARM perf code can't
support system PMUs.
This patch adds a 'type' field to struct arm_pmu, which allows the code
to reserve & release the hardware regardless of the PMU type.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, a single lock serialises access to CPU PMU registers. This
global locking is unnecessary as PMU registers are local to the CPU
they monitor.
This patch replaces the global lock with a per-CPU lock. As the lock is
in struct cpu_hw_events, PMUs providing a single cpu_hw_events instance
can be locked globally.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
As armpmu_disable will call armpmu->stop when the last event has been
removed, this is pointless and simply adds to the noise when debugging.
Additionally, due to this call occurring in a preemptible context, this
is problematic for per-cpu locking of PMU registers (where we will
attempt to access per-cpu spinlock for use with raw_spin_lock_irqsave).
This patch removes the call to armpmu->stop.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, cpu_hw_events is a global per-CPU variable. To enable
support for multiple PMUs, there needs to be a mapping from an instance
of arm_pmu to its cpu_hw_events. Additionally, as system PMUs are not
CPU-affine, they should not have this stored per-CPU.
This patch moves access to the hardware events data behind an accessor
function (arm_pmu::get_hw_events). This allows each instance to have
its own hardware event data, which can be stored per-CPU or globally as
required.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently the ARM perf code supports having a single struct
platform_device to supply IRQ numbers, limiting it to supporting a
single PMU.
This patch makes a platform_device instance variable on struct arm_pmu.
This should allow for multiple PMUs to be supported in future.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch moves the active_events counter into struct arm_pmu, in
preparation for supporting multiple PMUs. This also moves
pmu_reserve_mutex, as it is used to guard accesses to active_events.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, pmu_hw_events::active_mask is used to keep track of which
events are active in hardware. As we can stop counters and their
interrupts, this is unnecessary.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, event group validation compares each event's 'pmu' pointer
against the static 'pmu' pointer. This limits the code to supporting
only 1 PMU.
This patch changes the behaviour to consider an event's group leader's
'pmu' pointer as canonical for validation. This should ease later
generalisation of the code to support multiple PMUs at once.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, an "empty" struct pmu is registered as the CPU PMU,
regardless of whether there is a physical PMU. This burdens the
accessor functions with checks to see whether a PMU is actually
present.
This patch changes initialisation to register a PMU only if there is a
supported PMU present, and removes the checks that this change makes
redundant.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Ashwin Chaugule <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ARM hw_breakpoint backend is currently a bit too noisy when things
start to go awry.
This patch removes a couple of over-zealous WARN_ONCE invocations and
replaces then with pr_warnings instead.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ARM debug registers can only be accessed if the DBGSWENABLE signal
to the core is driven HIGH by the DAP. The architecture does not provide
a way to detect the value of this signal, so the best we can do is
register an undef_hook to trap debug register co-processor accesses and
then fail if the trap is taken.
Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM debug architecture 7.1 mandates that the DFAR is updated on a
watchpoint debug exception to contain the faulting virtual address
of the memory access. This allows us to determine which watchpoints
have fired and therefore report useful information to userspace.
This patch adds support for using the DFAR in the watchpoint handler,
which allows us to support multiple watchpoints on CPUs implementing
the new debug architecture.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The current hw_breakpoint code on ARM reserves 1 breakpoint for each
watchpoint that is available. Since debug architectures prior to 7.1
are restricted to 1 watchpoint anyway, only one breakpoint was ever
reserved.
This patch changes the reservation strategy so that a single breakpoint
is reserved, regardless of the number of watchpoints. This is in
preparation for multiple-watchpoint support on debug architectures
from 7.1 onwards.
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch adds initial support for Cortex-A15 (debug architecture v7.1)
to the hw_breakpoint ARM backend.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The Cortex-A15 PMU implements the PMUv2 specification and therefore
has support for some mode exclusion.
This patch adds support for excluding user, kernel and hypervisor counts
from a given event.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Modern PMUs allow for mode exclusion, so we no longer wish to return
-EPERM if it is requested.
This patch provides a hook in the armpmu structure for implementing
mode exclusion. The hw_perf_event initialisation is slightly delayed so
that the backend code can update the structure if required.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM PMU code used to use 1-based indices for PMU registers. This caused
several data structures (pmu_hw_events::{active_events, used_mask, events})
to have an unused element at index zero. ARMPMU_MAX_HWEVENTS still takes
this indexing into account, and currently equates to 33.
This patch updates the core ARM perf code to use the 0th index again.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Now that the ARMv7 PMU backend indexes event counters from zero, follow
suit and do the same for ARMv6 and Xscale.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The current ARMv7 PMU backend indexes event counters from two, with
index zero being reserved and index one being used to represent the
cycle counter.
This patch tidies up the code by indexing from one instead (with zero
for the cycle counter). This allows us to remove many of the accessor
macros along with the counter enumeration and makes the code much more
readable.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch ensures that integers are used to represent event indices in
the ARMv7 PMU backend. This ensures consistency between functions and
also with the arm_pmu structure.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
The ARMv7 perf backend mixes up u32 and unsigned long, which is rather
ugly.
This patch makes the ARMv7 PMU code consistently use the u32 type
instead.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit 5dfc54e0 ("ARM: GIC: avoid routing interrupts to offline CPUs")
prevents the GIC from setting the affinity of an IRQ to a CPU with
id >= nr_cpu_ids. This was previously abused by perf on some platforms
where more IRQs were registered than possible CPUs.
This patch fixes the problem by using a cpumask_t to keep track of the
active (requested) interrupts in perf. The same effect could be achieved
by limiting the number of IRQs to the number of CPUs, but using a mask
instead will be useful for adding extended CPU hotplug support in the
future.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Once upon a time, OProfile and Perf fought hard over who could play with
the PMU. To stop all hell from breaking loose, pmu.c offered an internal
reserve/release API and took care of parsing PMU platform data passed in
from board support code.
Now that Perf has ingested OProfile, let's move the platform device
handling into the Perf driver and out of the PMU locking code.
Unfortunately, the lock has to remain to prevent Perf being bitten by
out-of-tree modules such as LTTng, which still claim a right to the PMU
when Perf isn't looking.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch removes const qualifiers from instances of struct arm_pmu,
and functions initialising them, in preparation for generalising
arm_pmu usage to system (AKA uncore) PMUs.
This will allow for dynamically modifiable structures (locks,
struct pmu) to be added as members of struct arm_pmu.
Acked-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: pm: avoid writing the auxillary control register for ARMv7
ARM: pm: some ARMv7 requires a dsb in resume to ensure correctness
ARM: pm: arm920/926: fix number of registers saved
ARM: pm: CPU specific code should not overwrite r1 (v:p offset)
ARM: 7066/1: proc-v7: disable SCTLR.TE when disabling MMU
ARM: 7065/1: kexec: ensure new kernel is entered in ARM state
ARM: 7003/1: vexpress: Add clock definition for the SP805.
ARM: 7051/1: cpuimx* boards: fix mach-types errors
ARM: 7019/1: Footbridge: select CLKEVT_I8253 for ARCH_NETWINDER
ARM: 7015/1: ARM errata: Possible cache data corruption with hit-under-miss enabled
ARM: 7014/1: cache-l2x0: Fix L2 Cache size calculation.
ARM: 6967/1: ep93xx: ts72xx: fix board model detection
ARM: 6965/1: ep93xx: add model detection for ts-7300 and ts-7400 boards
ARM: cache: detect VIPT aliasing I-cache on ARMv6
ARM: twd: register clockevents device before enabling PPI
ARM: realview: ensure visibility of writes during reset
ARM: perf: make name of arm_pmu_type consistent
ARM: perf: fix prototype of release_pmu
ARM: fix perf build with uclibc toolchains
Commit 540b5738 ("ARM: 6999/1: head, zImage: Always Enter the kernel in
ARM state") mandates that the kernel should be entered in ARM state.
If a Thumb-2 kernel kexecs a new kernel image, we need to ensure that
we change state when branching to the new code. This patch replaces a
mov pc, lr with a bx lr on Thumb-2 kernels so that we transition to ARM
state if need be.
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The nfsservctl system call is now gone, so we should remove all
linkage for it.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PGDIR_SHIFT and PMD_SHIFT for the classic 2-level page table format have
the same value (21). This patch converts the PGDIR_* uses in the kernel
to the PMD_* equivalent so that LPAE builds can reuse the same code.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that there is no more users, we can remove it from the kernel.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
The boot_params member of the mdesc structure is used to provide a
default physical address for the ATAG list. Since this value is fixed
at compile time and sometimes based on constants such as ARCH_PHYS_OFFSET,
it gets in the way of runtime PHYS_OFFSET and CONFIG_ARM_PATCH_PHYS_VIRT
usage.
Let's introduce atag_offset which should contains only the relative
offset from PHYS_OFFSET instead of an absolute value, in preparation
to move all instance of boot_params over to it.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Štetiar <ynezz@true.cz>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Remove ioaddr() usage from ecard.c, updating (and renaming) the
constants in RiscPC's hardware.h to contain the proper translation.
As this gets rid of the last ioaddr() usage, kill that too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This code can be removed now that MSM targets no longer need the 16-bit
offsets for P2V.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-arm-soc: (32 commits)
ARM: mmp: Change the way we use timer 0 as clockevent timer.
ARM: mmp: Switch to using timer 1 as clocksource timer.
ARM: mmp: Also start timer 1 on boot.
ARM: pxa168/gplugd: free correct GPIO
ARM: pxa168/gplugd: get rid of mfp-gplugd.h
ARM: pxa: fix logic error in PJ4 iWMMXt handling
mach-sa1100: fix PCI build problem
omap: timer: Set dmtimer used as clocksource in autoreload mode
OMAP3: am3517crane: remove NULL board_mux from board file
arm: mach-omap2: mux: use kstrdup()
arch:arm:plat-omap:iovmm: remove unused variable 'va'
Update Nook Color machine 3284 to common Encore name
am3505/3517: Various platform defines for UART4
OMAP: hwmod: fix build break on non-OMAP4 multi-OMAP2 builds
OMAP: Fix linking error in twl-common.c for OMAP2/3/4 only builds
iMX: Fix build for iMX53
ARM: mx5: board-cpuimx51.c fixup irq_to_gpio() usage
OMAP2+: PM: SmartReflex: use put_sync_suspend for IRQ-safe disabling
OMAP3: beagle: don't touch omap_device internals
OMAP1: enable GENERIC_IRQ_CHIP
...
The current cache detection code does not check for an aliasing
I-cache if the D-cache is found to be VIPT aliasing.
This patch fixes the problem by always checking for an aliasing
I-cache on v6 and later.
Signed-off-by: Will Deacon <will.deacon@arm.com>
The smp_twd clockevents driver currently enables the local timer PPI
before the clockevents device is registered. This can lead to a kernel
panic if a spurious timer interrupt is generated before registration
has completed since the kernel will treat it as an IPI timer.
This patch moves the clockevents device registration before the IRQ
unmasking so that we can always handle timer interrupts once they can
occur.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Commit f12482c9 ("ARM: 6974/1: pmu: refactor reservation") changed
{release,reserve}_pmu to take an enum arm_pmu_type as a parameter, but
inconsistently named the parameter `type' or `device'. It would be nice
if these were consistent.
This patch makes use of enum arm_pmu_type consistent, always using
`type'. Related printks are updated, explicitly mentioning `type' also.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: drop experimental status for ARM_PATCH_PHYS_VIRT
ARM: 7008/1: alignment: Make SIGBUS sent to userspace POSIXly correct
ARM: 7007/1: alignment: Prevent ignoring of faults with ARMv6 unaligned access model
ARM: 7010/1: mm: fix invalid loop for poison_init_mem
ARM: 7005/1: freshen up mm/proc-arm946.S
dmaengine: PL08x: Fix trivial build error
ARM: Fix build error for SMP=n builds
The generic library code already exports the generic function, this was
left-over from the ARM-specific version that just got removed.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a0bfa13738 mispells
cpuidle_idle_call() on ARM and SH code. Fix this to be consistent.
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: x86@kernel.org
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: David Brown <davidb@codeaurora.org>
[ Also done by Mark Brown - th ebug has been around forever, and was
noticed in -next, but the idle tree never picked it up. Bad bad bad ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
cpuidle: stop depending on pm_idle
x86 idle: move mwait_idle_with_hints() to where it is used
cpuidle: replace xen access to x86 pm_idle and default_idle
cpuidle: create bootparam "cpuidle.off=1"
mrst_pmu: driver for Intel Moorestown Power Management Unit
Unfortunately, the module fixups cause the kernel to fail to build
when SMP is not enabled. Fix this by removing the reference to
fixup_smp on non-SMP fixup kernels, but ensuring that if we do have
the SMP fixup section, we refuse to load the module.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
cpuidle users should call cpuidle_call_idle() directly
rather than via (pm_idle)() function pointer.
Architecture may choose to continue using (pm_idle)(),
but cpuidle need not depend on it:
my_arch_cpu_idle()
...
if(cpuidle_call_idle())
pm_idle();
cc: Kevin Hilman <khilman@deeprootsystems.com>
cc: Paul Mundt <lethal@linux-sh.org>
cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
PCI: remove printks about disabled bridge windows
PCI: fold pci_calc_resource_flags() into decode_bar()
PCI: treat mem BAR type "11" (reserved) as 32-bit, not 64-bit, BAR
PCI: correct pcie_set_readrq write size
PCI: pciehp: change wait time for valid configuration access
x86/PCI: Preserve existing pci=bfsort whitelist for Dell systems
PCI: ARI is a PCIe v2 feature
x86/PCI: quirks: Use pci_dev->revision
PCI: Make the struct pci_dev * argument of pci_fixup_irqs const.
PCI hotplug: cpqphp: use pci_dev->vendor
PCI hotplug: cpqphp: use pci_dev->subsystem_{vendor|device}
x86/PCI: config space accessor functions should not ignore the segment argument
PCI: Assign values to 'pci_obff_signal_type' enumeration constants
x86/PCI: reduce severity of host bridge window conflict warnings
PCI: enumerate the PCI device only removed out PCI hieratchy of OS when re-scanning PCI
PCI: PCIe AER: add aer_recover_queue
x86/PCI: select direct access mode for mmconfig option
PCI hotplug: Rename is_ejectable which also exists in dock.c
This patch adds irq_domain infrastructure for translating from
hardware irq numbers to linux irqs. This is particularly important
for architectures adding device tree support because the current
implementation (excluding PowerPC and SPARC) cannot handle
translation for more than a single interrupt controller. irq_domain
supports device tree translation for any number of interrupt
controllers.
This patch converts x86, Microblaze, ARM and MIPS to use irq_domain
for device tree irq translation. x86 is untested beyond compiling it,
irq_domain is enabled for MIPS and Microblaze, but the old behaviour is
preserved until the core code is modified to actually register an
irq_domain yet. On ARM it works and is required for much of the new
ARM device tree board support.
PowerPC has /not/ been converted to use this new infrastructure. It
is still missing some features before it can replace the virq
infrastructure already in powerpc (see documentation on
irq_domain_map/unmap for details). Followup patches will add the
missing pieces and migrate PowerPC to use irq_domain.
SPARC has its own method of managing interrupts from the device tree
and is unaffected by this change.
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (237 commits)
ARM: 7004/1: fix traps.h compile warnings
ARM: 6998/2: kernel: use proper memory barriers for bitops
ARM: 6997/1: ep93xx: increase NR_BANKS to 16 for support of 128MB RAM
ARM: Fix build errors caused by adding generic macros
ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU
ARM: CPU hotplug: pass in proper affinity mask on IRQ migration
ARM: GIC: avoid routing interrupts to offline CPUs
ARM: CPU hotplug: fix abuse of irqdesc->node
ARM: 6981/2: mmci: adjust calculation of f_min
ARM: 7000/1: LPAE: Use long long printk format for displaying the pud
ARM: 6999/1: head, zImage: Always Enter the kernel in ARM state
ARM: btc: avoid invalidating the branch target cache on kernel TLB maintanence
ARM: ARM_DMA_ZONE_SIZE is no more
ARM: mach-shark: move ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-sa1100: move ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-realview: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-pxa: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-ixp4xx: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-h720x: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
ARM: mach-davinci: move from ARM_DMA_ZONE_SIZE to mdesc->dma_zone_size
...
This patch removes all the module loader hook implementations in the
architecture specific code where the functionality is the same as that
now provided by the recently added default hooks.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
perf: Remove the nmi parameter from the oprofile_perf backend
x86, perf: Make copy_from_user_nmi() a library function
perf: Remove perf_event_attr::type check
x86, perf: P4 PMU - Fix typos in comments and style cleanup
perf tools: Make test use the preset debugfs path
perf tools: Add automated tests for events parsing
perf tools: De-opt the parse_events function
perf script: Fix display of IP address for non-callchain path
perf tools: Fix endian conversion reading event attr from file header
perf tools: Add missing 'node' alias to the hw_cache[] array
perf probe: Support adding probes on offline kernel modules
perf probe: Add probed module in front of function
perf probe: Introduce debuginfo to encapsulate dwarf information
perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
perf probe: Remove redundant dwarf functions
perf probe: Move strtailcmp to string.c
perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
tracing/kprobe: Update symbol reference when loading module
tracing/kprobes: Support module init function probing
kprobes: Return -ENOENT if probe point doesn't exist
...
Aside of the usual motivation for constification, this function has a
history of being abused a hook for interrupt and other fixups so I turned
this function const ages ago in the MIPS code but it should be done
treewide.
Due to function pointer passing in varous places a few other functions
had to be constified as well.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
To: Anton Vorontsov <avorontsov@mvista.com>
To: Chris Metcalf <cmetcalf@tilera.com>
To: Colin Cross <ccross@android.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
To: Eric Miao <eric.y.miao@gmail.com>
To: Erik Gilling <konkers@android.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
To: "H. Peter Anvin" <hpa@zytor.com>
To: Imre Kaloz <kaloz@openwrt.org>
To: Ingo Molnar <mingo@redhat.com>
To: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
To: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Krzysztof Halasa <khc@pm.waw.pl>
To: Lennert Buytenhek <kernel@wantstofly.org>
To: Matt Turner <mattst88@gmail.com>
To: Nicolas Pitre <nico@fluxnic.net>
To: Olof Johansson <olof@lixom.net>
Acked-by: Paul Mundt <lethal@linux-sh.org>
To: Richard Henderson <rth@twiddle.net>
To: Russell King <linux@arm.linux.org.uk>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-pci@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Our selection of interrupts to consider for IRQ migration is sub-
standard. We were potentially including per-CPU interrupts in our
migration strategy, but omitting chained interrupts. This caused
some interrupts to remain on a downed CPU.
We were also trying to migrate interrupts which were not migratable,
resulting in an OOPS.
Instead, iterate over all interrupts, skipping per-CPU interrupts
or interrupts whose affinity does not include the downed CPU, and
attempt to set the affinity for every one else if their chip
implements irq_set_affinity().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that the GIC takes care of selecting a target interrupt from the
affinity mask, we don't need all this complexity in the core code
anymore. Just detect when we need to break affinity.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
irqdesc's node member is supposed to mark the numa node number for the
interrupt. Our use of it is non-standard. Remove this, replacing the
functionality with a test of the affinity mask.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently, the documented kernel entry requirements are not
explicit about whether the kernel should be entered in ARM or
Thumb, leading to an ambiguitity about how to enter Thumb-2
kernels. As a result, the kernel is reliant on the zImage
decompressor to enter the kernel proper in the correct instruction
set state.
This patch changes the boot entry protocol for head.S and Image to
be the same as for zImage: in all cases, the kernel is now entered
in ARM.
Documentation/arm/Booting is updated to reflect this new policy.
A different rule will be needed for Cortex-M class CPUs as and when
support for those lands in mainline, since these CPUs don't support
the ARM instruction set at all: a note is added to the effect that
the kernel must be entered in Thumb on such systems.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These occur extremely rarely in the kernel and writing test cases for
them is difficult.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These use the register calling conventions required by the new decoding
table framework for calling simulated instructions.
We rename the old versions of these functions to *_old for now.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM multiply long instructions. It replaces use of
prep_emulate_rdhi16rdlo12rs8rm0_wflags().
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM bit-field manipulation instructions.
Various other instruction forms can also make use of this and it is used
to replace use of prep_emulate_rd12{rm0}{_modify}
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM multiply-accumulate instructions. These don't allow use of PC so we
don't have to add special cases for this.
This function is used to replace use of prep_emulate_rd16rs8rm0_wflags
and prep_emulate_rd16rn12rs8rm0_wflags.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM media instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is an emulation function for the LDRD and STRD instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM data-processing instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is for use by inline assembler which will be added to kprobes-arm.c
It saves memory when used on newer ARM architectures and also provides
correct interworking should ARM probes be required on Thumb kernels in
the future.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This writes a new value to PC which was obtained as the result of an ARM
ALU instruction. For ARMv7 and later this performs interworking.
On ARM kernels we shouldn't encounter any ALU instructions trying to
switch to Thumb mode so support for this isn't strictly necessary.
However, the approach taken in all other instruction decoding is for us
to avoid unpredictable modification of the PC for security reasons. This
is usually achieved by rejecting insertion of probes on problematic
instruction, but for ALU instructions we can't do this as it depends on
the contents of the CPU registers at the time the probe is hit. So, as
we require some form of run-time checking to trap undesirable PC
modification, we may as well simulate the instructions correctly, i.e.
in the way they would behave in the absence of a probe.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We will reject probing of unprivileged load and store instructions.
These rarely occur and writing test cases for them is difficult.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We'll treat the preload instructions as nops as they are just
performance hints.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The kernel doesn't currently support VFP or Neon code, and probing of
code with CP15 operations is fraught with bad consequences. So we will
just reject probing these instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We reject probing of load/store exclusive instructions because any
emulation routine could never succeed in gaining exclusive access as the
exception framework clears the exclusivity monitor when a probes
breakpoint is hit.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch improves the performance of LDM and STM instruction
emulation. This is desirable because.
- jprobes and kretprobes probe the first instruction in a function and,
when the frame pointer is omitted, this instruction is often a STM
used to push registers onto the stack.
- The STM and LDM instructions are common in the body and tail of
functions.
- At the same time as being a common instruction form, they also have
one of the slowest and most complicated simulation routines.
The approach taken to optimisation is to use emulation rather than
simulation, that is, a modified form of the instruction is run with
an appropriate register context.
Benchmarking on an OMAP3530 shows the optimised emulation is between 2
and 3 times faster than the simulation routines. On a Kirkwood based
device the relative performance was very significantly better than this.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The encoding of these instructions is substantially the same for both
ARM and Thumb, so we can have common decoding and simulation functions.
This patch moves the simulation functions from kprobes-arm.c to
kprobes-common.c. It also adds a new simulation function
(simulate_ldm1_pc) for the case where we load into PC because this may
need to interwork.
The instruction decoding is done by a custom function
(kprobe_decode_ldmstm) rather than just relying on decoding table
entries because we will later be adding optimisation code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This writes a value to PC which was obtained as the result of a
LDR or LDM instruction. For ARMv5T and later this must perform
interworking.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
For hints which may have observable effects, like SEV (send event), we
use kprobe_emulate_none which emulates the hint by executing the
original instruction.
For NOP we simulate the instruction using kprobe_simulate_nop, which
does nothing. As probes execute with interrupts disabled this is also
used for hints which may block for an indefinite time, like WFE (wait
for event).
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These are very rare and/or problematic to emulate so we will take the
easy option and disallow probing them (as does the existing ARM
implementation).
Rejecting these instructions doesn't actually require any entries in the
decoding table as it is the default case for instructions which aren't
found.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
We previously changed the behaviour of probes so that conditional
instructions don't fire when the condition isn't met. For ARM branches,
and Thumb branches in IT blocks, this means they don't fire if the
branch isn't taken.
For consistency, we implement the same for Thumb conditional branch
instructions. This involves setting up insn_check_cc to point to the
relevant condition checking function. As the emulation routine is only
called when this condition passes, it doesn't need to check again and
can unconditionally update PC.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
SVC (SWI) instructions shouldn't occur in kernel code so we don't
need to be able to probe them.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The normal Thumb singlestepping routine updates the IT state after
calling the instruction handler. We don't what this to happen after the
IT instruction simulation sets the IT state, therefore we need to
provide a custom singlestep routine.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These instructions are equivalent to
stmdb sp!,{r0-r7,lr}
ldmdb sp!,{r0-r7,pc}
and we emulate them by transforming them into the 32-bit Thumb
instructions
stmdb r9!,{r0-r7,r8}
ldmdb r9!,{r0-r7,r8}
This is simpler, and almost certainly executes faster, than writing
simulation functions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Most of these instructions only operate on the low registers R0-R7
so they can make use of t16_emulate_loregs_rwflags.
The instructions which use SP or PC for addressing have their own
simulation functions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These data-processing instructions operate on the full range of CPU
registers, so to simulate them we have to modify the registers used
by the instruction. We can't make use of the decoding table framework to
do this because the registers aren't encoded cleanly in separate
nibbles, therefore we need a custom decode function.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This writes a value to PC, with interworking. I.e. switches to Thumb or
ARM mode depending on the state of the least significant bit.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These instructions only operate on the low registers R0-R7, therefore
it is possible to emulate them by executing the original instruction
unaltered if we restore and save these registers. This is what
t16_emulate_loregs does.
Some of these instructions don't update the PSR when they execute in an
IT block, so there are two flavours of emulation functions:
t16_emulate_loregs_{noit}rwflags
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
For hints which may have observable effects, like SEV (send event), we
use kprobe_emulate_none which emulates the hint by executing the
original instruction.
For NOP we simulate the instruction using kprobe_simulate_nop, which
does nothing. As probes execute with interrupts disabled this is also
used for hints which may block for an indefinite time, like WFE (wait
for event).
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The existing ARM instruction decoding functions are a mass of if/else
code. Rather than follow this pattern for Thumb instruction decoding
this patch implements an infrastructure for a new table driven scheme.
This has several advantages:
- Reduces the kernel size by approx 2kB. (The ARM instruction decoding
will eventually have -3.1kB code, +1.3kB data; with similar or better
estimated savings for Thumb decoding.)
- Allows programmatic checking of decoding consistency and test case
coverage.
- Provides more uniform source code and is therefore, arguably, clearer.
For a detailed explanation of how decoding tables work see the in-source
documentation in kprobes.h, and also for kprobe_decode_insn().
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
When we come to emulating Thumb instructions then, to interwork
correctly, the code on in the instruction slot must be invoked with a
function pointer which has the least significant bit set. Rather that
set this by hand in every Thumb emulation function we will add a new
field for this purpose to arch_specific_insn, called insn_fn.
This also enables us to seamlessly share emulation functions between ARM
and Thumb code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
When a probe fires we must single-step the instruction which was
replaced by a breakpoint. As the steps to do this vary between ARM and
Thumb instructions we need a way to customise single-stepping.
This is done by adding a new hook called insn_singlestep to
arch_specific_insn which is initialised by the instruction decoding
functions.
These single-step hooks must update PC and call the instruction handler.
For Thumb instructions an additional step of updating ITSTATE is needed.
We do this after calling the handler because some handlers will need to
test if they are running in an IT block.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Now we no longer trigger probes on conditional instructions when the
condition is false, we can make use of conditional instructions as
breakpoints in ARM code to avoid taking unnecessary exceptions.
Note, we can't rely on not getting an exception when the condition check
fails, as that is Implementation Defined on newer ARM architectures. We
therefore still need to perform manual condition checks as well.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch changes the behavior of kprobes on ARM so that:
Kprobes on conditional instructions don't trigger when the
condition is false. For conditional branches, this means that
they don't trigger in the branch not taken case.
Rationale:
When probes are placed onto conditionally executed instructions in a
Thumb IT block, they may not fire if the condition is not met. This
is because we use invalid instructions for breakpoints and "it is
IMPLEMENTATION DEFINED whether the instruction executes as a NOP or
causes an Undefined Instruction exception". Therefore, for consistency,
we will ignore all probes on any conditional instructions when the
condition is false. Alternative solutions seem to be too complex to
implement or inconsistent.
This issue was discussed on linux.arm.kernel in the thread titled
"[RFC] kprobes with thumb2 conditional code" See
http://comments.gmane.org/gmane.linux.linaro.devel/2985
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This advances the ITSTATE bits in CPSR to their values for the next
instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Extend the breakpoint insertion and catching functions to support Thumb
code.
As breakpoints are no longer of a fixed size, the flush_insns macro
is modified to take a size argument instead of an instruction count.
Note, we need both 16- and 32-bit Thumb breakpoints, because if we
were to use a 16-bit breakpoint to replace a 32-bit instruction which
was in an IT block, and the condition check failed, then the breakpoint
may not fire (it's unpredictable behaviour) and the CPU could then try
and execute the second half of the 32-bit Thumb instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Extend arch_prepare_kprobe to support probing of Thumb code. For
the actual decoding of Thumb instructions, stub functions are
added which currently just reject the probe.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Fix up kprobes framework so that it builds and correctly interworks on
Thumb-2 kernels.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The str_pc_offset value is architecturally defined on ARMv7 onwards so
we can make it a compile time constant. This means on Thumb kernels the
runtime checking code isn't needed, which saves us from having to fix it
to work for Thumb.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Move str_pc_offset into kprobes-common.c as it will be needed by common
code later.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This file will contain the instruction decoding and emulation code
which is common to both ARM and Thumb instruction sets.
For now, we will just move over condition_checks from kprobes-arm.c
This table is also renamed to kprobe_condition_checks to avoid polluting
the public namespace with a too generic name.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
