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>
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>
Allow one shot timer mode to be used with the TWD. This allows
NOHZ mode to be used on SMP systems using the TWD localtimer.
Tested on Versatile Express and U8500.
Tested-by: Linus Walleij <linus.walleij@stericsson.com>
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>
When we soft-CPU hotplug a CPU, we reset the stack pointer and
jump back to start_secondary(). This allows us to restart as if
the CPU was actually reset.
However, we weren't resetting the frame pointer, which could cause
problems with backtracing. Reset the frame pointer to zero (which
means no parent frame) just like the early assembly code also does.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
smp.c is becoming too large, so split out the TLB maintainence
broadcasting into a separate smp_tlb.c file.
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>
The original scheme for reporting spurious wakeups was broken - it
tried to use printk() from a context which wasn't coherent with the
other CPUs, which risks corrupting the printk() data.
Fix this by noting the number spurious wakeups, and only report them
when we are properly woken - when we will be coherent with the rest
of the system.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We used to print a bland error message which gave no clue as to the
failure when we failed to bring up a secondary CPU. Resolve this by
separating the two failure cases.
If boot_secondary() fails, we print a message indicating the returned
error code from boot_secondary():
"CPU%u: failed to boot: %d\n", cpu, ret.
However, if boot_secondary() succeeded, but the CPU did not appear to
mark itself online within the timeout, indicate that it failed to come
online:
"CPU%u: failed to come online\n", cpu
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can not guarantee that VFP will be enabled when CPU hotplug brings
a CPU back online from a reset state. Add a hotplug CPU notifier to
ensure that the VFP coprocessor access is enabled whenever a CPU comes
back online.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is a subtle race in the CPU hotplug code, where a CPU which has
been offlined can online itself before being requested, which results
in things going astray on the next online/offline cycle.
What happens in the normal online/offline/online cycle is:
CPU0 CPU3
requests boot of CPU3
pen_release = 3
flush cache line
checks pen_release, reads 3
starts boot
pen_release = -1
... requests CPU3 offline ...
... dies ...
checks pen_release, reads -1
requests boot of CPU3
pen_release = 3
flush cache line
checks pen_release, reads 3
starts boot
pen_release = -1
However, as the write of -1 of pen_release is not fully flushed back to
memory, and the checking of pen_release is done with caches disabled,
this allows CPU3 the opportunity to read the old value of pen_release:
CPU0 CPU3
requests boot of CPU3
pen_release = 3
flush cache line
checks pen_release, reads 3
starts boot
pen_release = -1
... requests CPU3 offline ...
... dies ...
checks pen_release, reads 3
starts boot
pen_release = -1
requests boot of CPU3
pen_release = 3
flush cache line
Fix this by grouping the write of pen_release along with its cache line
flushing code to ensure that any update to pen_release is always pushed
out to physical memory.
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>
Don't call idle_task_exit() with interrupts disabled, and ensure
that we have a memory barrier after interrupts are disabled but
before signalling that this CPU has shut down.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
platform_cpu_die() is entered from the CPU's own idle thread, which
can not be migrated to other CPUs. Moreover, the 'cpu' argument
comes from the thread info, which will always be the 'current'
CPU. So remove this useless bug check.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We always need to wait for the dying CPU to reach a safe state before
taking it down, irrespective of the requirements of the platform.
Move the completion code into the ARM SMP hotplug code rather than
having each platform re-implement this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
All platforms call trace_hardirqs_off() in their secondary startup code,
so move this into the core SMP code - it doesn't need to be in the
per-platform code.
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>
Milo is an old boot loader, which is no longer relevant for these
platforms. References to it are misleading. Move the code out
of poke_milo(), and remove references to milo in comments.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
scu_get_core_count() never returns zero cores, so we don't need to
check and correct if ncores is zero.
Tegra was missing the check against NR_CPUS, leading to a potential
bitfield overflow if this becomes the case.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure that the number of CPUs is sanity checked before setting
the number of possible CPUs. This avoids any chance of overflowing
the cpu_possible bitmap.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Wait for CPUs to indicate that they've stopped, after sending the
stop IPI, rather than blindly continuing on and hoping that they've
stopped in time. Print a warning if we fail to stop the other CPUs.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use r0,r3-r6 rather than r0,r3,r4,r6,r7, which makes it easier to
understand which registers can be modified. Also document which
registers hold values which must be preserved.
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>
send_ipi_message() does nothing except call smp_cross_call(). As
this is a static function, nothing external to this file calls it,
so we can easily clean up this now unnecessary indirection.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It is kernel-wide policy that options depending on EXPERIMENTAL should
also have '(EXPERIMENTAL)' in their option text, and options with
'(EXPERIMENTAL)' depend on EXPERIMENTAL.
Ensure that all ARM options comply with this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As our SMP implementation uses MESI protocols. Grouping together data
which is mostly only read together means that we avoid unnecessary
cache line bouncing when this code shares a cache line with other data.
In other words, cache lines associated with read-mostly data are
expected to spend most of their time in shared state.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Today more boards with arm cpu have selectable pci bus.
This patch makes this more scalable and remove line continuations in
Kconfig
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As we've now removed the spinlock and bitmask, we have nothing left
which requires interrupts to be disabled when sending an IPI. All
current IPI-sending implementations use the GIC, which also does not
require interrupts disabled when calling gic_raise_softirq().
Remove the now unnecessary IRQ disable.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid using bitmasks and locks in the percpu area for IPIs, and instead
use individual software generated interrupts to identify the reason for
the IPI. This avoids the problems of having spinlocks in the percpu
area.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows us to use smp_cross_call() to trigger a number of different
software generated interrupts, rather than combining them all on one
SGI. Recover the SGI number via do_IPI.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
smp_cross_call_done() was removed long ago (see 78d236c - remove useless
smp_cross_call_done()). Remove those which have been subsequently
merged.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for_linus' of git://github.com/at91linux/linux-2.6-at91:
at91/board-yl-9200: fix typo in video support
atmel_spi: fix warning In function 'atmel_spi_dma_map_xfer'
at91/picotux200: remove commenting usb device and dataflash support
at91: rename rm9200ek and rm9200dk board file name
at91rm9200ek: fix warning: 'ek_mmc_data' defined but not used
at91rm9200dk: fix warning: 'dk_mmc_data' defined but not used
at91: Convert remaining boards to new-style UART initialization
at91: merge all at91rm9200 defconfig in one single file
Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.
compat_copy_strings() plays with bprm->vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.
Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.
Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
