On revisions of the Cortex-A9 prior to r2p0, the Store Buffer does not
have any automatic draining mechanism and therefore a livelock may occur
if an external agent continuously polls a memory location waiting to
observe an update.
This workaround defines cpu_relax() as smp_mb(), preventing correctly
written polling loops from denying visibility of updates to memory.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There's no need to noMMU to put tlb_flush() in asm/tlbflush.h - it's
part of the tlb shootdown interface. Move it to asm/tlb.h instead, as
per x86.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to delay freeing any mapped page on SMP and ARMv7 systems to
ensure that the data is not accessed by other CPUs, or is used for
speculative prefetch with ARMv7. This includes not only mapped pages
but also pages used for the page tables themselves.
This avoids races with the MMU/other CPUs accessing pages after they've
been freed but before we've invalidated the TLB.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In sysctl_soft_reset(), switch to slow mode before resetting the system
via the system controller. This is required.
Reviewed-by: Stanley Miao <stanley.miao@windriver.com>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The effect of cache sync operation is to drain the store buffer and
wait for all internal buffers to be empty. In normal conditions, store
buffer is able to merge the normal memory writes within its 32-byte
data buffers. Due to this erratum present in r3p0, the effect of cache
sync operation on the store buffer still remains when the operation
completes. This means that the store buffer is always asked to drain
and this prevents it from merging any further writes.
This can severely affect performance on the write traffic esp. on
Normal memory NC one.
The proposed workaround is to replace the normal offset of cache sync
operation(0x730) by another offset targeting an unmapped PL310
register 0x740.
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure that the ISA/PCI IO space accessors are properly ordered on
ARMv6+ architectures. These should always be ordered with respect to
all other accesses.
This also fixes __iormb() and __iowmb() not being visible to ioread/
iowrite if a platform defines its own MMIO accessors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Changing the virt_to_phys() argument to "const volatile void *" avoids
compiler warnings in some situations where this function is used.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Timers on Versatile Express mainboard are used as system clock/event
sources. Driver assumes that they are clocked with 1MHz signal.
Old V2M firmware apparently configured it by default, but on newer
boards one can observe that "sleep 1" command takes over 30 seconds
to finish, as the timers are fed with 32kHz instead...
This patch performs required magic and also removes code clearing
timer's control registers, as exactly the same operations are
performed by the timer driver few jiffies later.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: fix missing branch in __error_a
ARM: fix /proc/$PID/stack on SMP
ARM: Fix build regression on SA11x0, PXA, and H720x targets
ARM: 6625/1: use memblock memory regions for "System RAM" I/O resources
ARM: fix wrongly patched constants
ARM: 6624/1: fix dependency for CONFIG_SMP_ON_UP
ARM: 6623/1: Thumb-2: Fix out-of-range offset for Thumb-2 in proc-v7.S
ARM: 6622/1: fix dma_unmap_sg() documentation
ARM: 6621/1: bitops: remove condition code clobber for CLZ
ARM: 6620/1: Change misleading warning when CONFIG_CMDLINE_FORCE is used
ARM: 6619/1: nommu: avoid mapping vectors page when !CONFIG_MMU
ARM: sched_clock: make minsec argument to clocks_calc_mult_shift() zero
ARM: sched_clock: allow init_sched_clock() to be called early
ARM: integrator: fix compile warning in cpu.c
ARM: 6616/1: Fix ep93xx-fb init/exit annotations
ARM: twd: fix display of twd frequency
ARM: udelay: prevent math rounding resulting in short udelays
The CLZ instruction does not alter the condition flags, so remove the
"cc" clobber from the inline asm for fls().
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sched_clock is supposed to be initialized early - in the recently added
init_early platform hook. However, in doing so we end up calling
mod_timer() before the timer lists are initialized, resulting in an
oops.
Split the initialization in two - the part which the platform calls
early which starts things off. The addition of the timer can be
delayed until after we have more of the kernel initialized - when the
normal time sources are initialized.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (243 commits)
omap2: Make OMAP2PLUS select OMAP_DM_TIMER
OMAP4: hwmod data: Fix alignment and end of line in structurefields
OMAP4: hwmod data: Move the DMA structures
OMAP4: hwmod data: Move the smartreflex structures
OMAP4: hwmod data: Fix missing SIDLE_SMART_WKUP in smartreflexsysc
arm: omap: tusb6010: add name for MUSB IRQ
arm: omap: craneboard: Add USB EHCI support
omap2+: Initialize serial port for dynamic remuxing for n8x0
omap2+: Add struct omap_board_data and use it for platform level serial init
omap2+: Allow hwmod state changes to mux pads based on the state changes
omap2+: Add support for hwmod specific muxing of devices
omap2+: Add omap_mux_get_by_name
OMAP2: PM: fix compile error when !CONFIG_SUSPEND
MAINTAINERS: OMAP: hwmod: update hwmod code, data maintainership
OMAP4: Smartreflex framework extensions
OMAP4: hwmod: Add inital data for smartreflex modules.
OMAP4: PM: Program correct init voltages for scalable VDDs
OMAP4: Adding voltage driver support
OMAP4: Register voltage PMIC parameters with the voltage layer
OMAP3: PM: Program correct init voltages for VDD1 and VDD2
...
Fix up trivial conflict in arch/arm/plat-omap/Kconfig
Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The commit 6ac6b817f3 (ARM: pxa: encode
IRQ number into .nr_irqs) removed definition of ITE_LAST_IRQ which
caused the following build error:
CC arch/arm/common/it8152.o
arch/arm/common/it8152.c: In function 'it8152_init_irq':
arch/arm/common/it8152.c:86: error: 'IT8152_LAST_IRQ' undeclared (first use in this function)
arch/arm/common/it8152.c:86: error: (Each undeclared identifier is reported only once
arch/arm/common/it8152.c:86: error: for each function it appears in.)
make[2]: *** [arch/arm/common/it8152.o] Error 1
Defining the IT8152_LAST_IRQ in the arch/arm/include/hardware/it8152.c
fixes the build.
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Replace the page_to_dma() and dma_to_page() macros with their PFN
equivalents. This allows us to map parts of memory which do not have
a struct page allocated to them to bus addresses. This will be used
internally by dma_alloc_coherent()/dma_alloc_writecombine().
Build tested on Versatile, OMAP1, IOP13xx and KS8695.
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes below build error by adding the missing asm/memory.h,
which is needed for arch_is_coherent().
$ make pxa3xx_defconfig; make
CC init/do_mounts_rd.o
In file included from include/linux/list_bl.h:5,
from include/linux/rculist_bl.h:7,
from include/linux/dcache.h:7,
from include/linux/fs.h:381,
from init/do_mounts_rd.c:3:
include/linux/bit_spinlock.h: In function 'bit_spin_unlock':
include/linux/bit_spinlock.h:61: error: implicit declaration of function 'arch_is_coherent'
make[1]: *** [init/do_mounts_rd.o] Error 1
make: *** [init] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sev is used to send wakeup event to other cores in ARMv6K and above.
This has been moved from platform specific part to standard common
ARM header file (asm/system.h). Also introduced wfi() and wfe().
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows platforms to hook into the initialization early to setup
things like scheduler clocks, etc.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than storing each machine init hook separately, store a
pointer to the machine description record and dereference this
instead. This pointer is only available while the init sections
are present, which is not a problem as we only use it from init
code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Per subarch interrupt handler macros V3.
This patch breaks out code from the irq_handler macro
into arch_irq_handler and arch_irq_handler_default.
The macros are put in the header file "entry-macro-multi.S"
The arch_irq_handler_default macro is designed to be
used by irq_handler in entry-armv.S while arch_irq_handler
is suitable for per-subarch use.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Normally different ARM platform has different way to decode the IRQ
hardware status and demultiplex to the corresponding IRQ handler.
This is highly optimized by macro irq_handler in entry-armv.S, and
each machine defines their own macro to decode the IRQ number.
However, this prevents multiple machine classes to be built into a
single kernel.
By allowing each machine to specify thier own handler, and making
function pointer 'handle_arch_irq' to point to it at run time, this
can be solved. And introduce CONFIG_MULTI_IRQ_HANDLER to allow both
solutions to work.
Comparing with the highly optimized macro of irq_handler, the new
function must be written with care not to lose too much performance.
And the IPI stuff on SMP is expected to move to the provided arch
IRQ handler as well.
The assembly code to invoke handle_arch_irq is optimized by Russell
King.
Signed-off-by: Eric Miao <eric.miao@canonical.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
... and also remove misleading comment stating that this header is
auto-generated.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Uwe Kleine-Knig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide common sched_clock() infrastructure for platforms to use to
create a 64-bit ns based sched_clock() implementation from a counter
running at a non-variable clock rate.
This implementation is based upon maintaining an epoch for the counter
and an epoch for the nanosecond time. When we desire a sched_clock()
time, we calculate the number of counter ticks since the last epoch
update, convert this to nanoseconds and add to the epoch nanoseconds.
We regularly refresh these epochs within the counter wrap interval.
We perform a similar calculation as above, and store the new epochs.
We read and write the epochs in such a way that sched_clock() can easily
(and locklessly) detect when an update is in progress, and repeat the
loading of these constants when they're known not to be stable. The
one caveat is that sched_clock() is not called in the middle of an
update. We achieve that by disabling IRQs.
Finally, if the clock rate is known at compile time, the counter to ns
conversion factors can be specified, allowing sched_clock() to be tightly
optimized. We ensure that these factors are correct by providing an
initialization function which performs a run-time check.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The hardware page tables use an XN bit 'execute never'. Historically,
we've had a Linux 'execute allow' bit, in the positive sense. Get rid
of this artifact as future hardware will continue to have the XN sense.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
FIRST_USER_PGD_NR is now unnecessary, as this has been replaced by
FIRST_USER_ADDRESS except in the architecture code. Fix up the last
usage of FIRST_USER_PGD_NR, and remove the definition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We have two places where we create identity mappings - one when we bring
secondary CPUs online, and one where we setup some mappings for soft-
reboot. Combine these two into a single implementation. Also collect
the identity mapping deletion function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This switches the ordering of the Linux vs hardware page tables in
each page, thereby eliminating some of the arithmetic in the page
table walks. As we now place the Linux page table at the beginning
of the page, we can deal with the offset in the pgt by simply masking
it away, along with the other control bits.
This also makes the arithmetic all be positive, rather than a mixture.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When a CPU is hot unplugged, the generic tick code cleans up the
clock event device, but fails to call down to the device's set_mode
function to actually shut the device down.
To work around this, we've historically had a local_timer_stop()
callback out of the hotplug code. However, this adds needless
complexity when we have the clock event device itself available.
Explicitly call the clock event device's set_mode function with
CLOCK_EVT_MODE_UNUSED, so that the hardware can be cleanly shutdown
without any special external callbacks. When/if the generic code
is fixed, percpu_timer_stop() can be killed off.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* __fixup_smp_on_up has been modified with support for the
THUMB2_KERNEL case. For THUMB2_KERNEL only, fixups are split
into halfwords in case of misalignment, since we can't rely on
unaligned accesses working before turning the MMU on.
No attempt is made to optimise the aligned case, since the
number of fixups is typically small, and it seems best to keep
the code as simple as possible.
* Add a rotate in the fixup_smp code in order to support
CPU_BIG_ENDIAN, as suggested by Nicolas Pitre.
* Add an assembly-time sanity-check to ALT_UP() to ensure that
the content really is the right size (4 bytes).
(No check is done for ALT_SMP(). Possibly, this could be fixed
by splitting the two uses ot ALT_SMP() (ALT_SMP...SMP_UP versus
ALT_SMP...SMP_UP_B) into two macros. In the first case,
ALT_SMP needs to expand to >= 4 bytes, not == 4.)
* smp_mpidr.h (which implements ALT_SMP()/ALT_UP() manually due
to macro limitations) has not been modified: the affected
instruction (mov) has no 16-bit encoding, so the correct
instruction size is satisfied in this case.
* A "mode" parameter has been added to smp_dmb:
smp_dmb arm @ assumes 4-byte instructions (for ARM code, e.g. kuser)
smp_dmb @ uses W() to ensure 4-byte instructions for ALT_SMP()
This avoids assembly failures due to use of W() inside smp_dmb,
when assembling pure-ARM code in the vectors page.
There might be a better way to achieve this.
* Kconfig: make SMP_ON_UP depend on
(!THUMB2_KERNEL || !BIG_ENDIAN) i.e., THUMB2_KERNEL is now
supported, but only if !BIG_ENDIAN (The fixup code for Thumb-2
currently assumes little-endian order.)
Tested using a single generic realview kernel on:
ARM RealView PB-A8 (CONFIG_THUMB2_KERNEL={n,y})
ARM RealView PBX-A9 (SMP)
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>
With "ARM: CPU hotplug: remove bug checks in platform_cpu_die()", we
now do not use hard_smp_processor_id(), we no longer need to read the
hardware processor ID. Remove the include providing this function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is a certain amount of smp_prepare_cpus() which doesn't belong
in the platform support code - that is, code which is invariant to the
SMP implementation. Move this code into arch/arm/kernel/smp.c, and
add a platform_ prefix to the original function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The IPI and local timer interrupts weren't being properly accounted
for in /proc/stat. Collect them from the irq_stat structure, and
return their sum.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This separates out the individual IPI interrupt counts from the
total IPI count, which allows better visibility of what IPIs are
being used for.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As per x86, align the initial column according to how many IRQs we
have. Also, provide an english explaination for the 'LOC:' and
'IPI:' lines.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move the ipi_count into irq_stat, which allows the ipi_data structure
to be entirely removed.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide __inc_irq_stat() and __get_irq_stat() to increment and
read the irq stat counters.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is no longer
necessary to carry an ad hoc version of kmap_atomic() added in commit
7e5a69e83b "ARM: 6007/1: fix highmem with VIPT cache and DMA" to cope
with reentrancy.
In fact, it is now actively wrong to rely on fixed kmap type indices
(namely KM_L1_CACHE) as kmap_atomic() totally ignores them now and a
concurrent instance of it may reuse any slot for any purpose.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch adds the PL310 Auxiliary Control Register bitfields
so that SOC's can use these bit fields to construct the AUXCTRL
value to be passed/programmed instead of hardcoding it.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Avoid adding nasty genirq-specific code to local timers to enable PPI
interrupts. Instead, provide a gic function to do this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
