Commit Graph

82 Commits

Author SHA1 Message Date
Russell King
73829af71f Merge branch 'vmalloc' of git://git.linaro.org/people/nico/linux into devel-stable 2011-12-05 23:27:59 +00:00
Nicolas Pitre
d0e6b2236a ARM: big removal of now unused vmalloc.h files
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-11-26 19:21:29 -05:00
Marc Zyngier
abd3ca51fb ARM: VExpress: convert to CONFIG_MULTI_IRQ_HANDLER
Convert the VExpress platform to be using the gic_handle_irq
function as its primary interrupt handler.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2011-11-15 18:14:00 +00:00
Linus Torvalds
6585dea1f9 Merge branch 'next/cross-platform' of git://git.linaro.org/people/arnd/arm-soc
* 'next/cross-platform' of git://git.linaro.org/people/arnd/arm-soc:
  arm/imx: use Kconfig choice for low-level debug UART selection
  ARM: realview: use Kconfig choice for debug UART selection
  ARM: plat-samsung: use Kconfig choice for debug UART selection
  ARM: versatile: convert logical CPU numbers to physical numbers
  ARM: ux500: convert logical CPU numbers to physical numbers
  ARM: shmobile: convert logical CPU numbers to physical numbers
  ARM: msm: convert logical CPU numbers to physical numbers
  ARM: exynos4: convert logical CPU numbers to physical numbers

Fix up trivial conflict (config DEBUG_S3C_UART move/split vs addition of
ARM_KPROBES_TEST option) in arch/arm/Kconfig.debug
2011-11-01 20:34:22 -07:00
Grant Likely
041af835b3 gpio: Fix ARM versatile-express build failure
A missing mach/gpio.h prevents building gpiolib on versatile express.

  CC      drivers/gpio/gpiolib.o
In file included from /.../linux/include/linux/gpio.h:18:0,
                 from /.../linux/drivers/gpio/gpiolib.c:10:
/.../linux/arch/arm/include/asm/gpio.h:5:23: fatal error: mach/gpio.h: No such file or directory
compilation terminated.
make[3]: *** [drivers/gpio/gpiolib.o] Error 1
make[2]: *** [drivers/gpio] Error 2
make[1]: *** [drivers] Error 2
make: *** [sub-make] Error 2

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-10-29 12:50:45 +02:00
Linus Torvalds
1fdb24e969 Merge branch 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits)
  ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET
  ARM: gic, local timers: use the request_percpu_irq() interface
  ARM: gic: consolidate PPI handling
  ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H
  ARM: mach-s5p64x0: remove mach/memory.h
  ARM: mach-s3c64xx: remove mach/memory.h
  ARM: plat-mxc: remove mach/memory.h
  ARM: mach-prima2: remove mach/memory.h
  ARM: mach-zynq: remove mach/memory.h
  ARM: mach-bcmring: remove mach/memory.h
  ARM: mach-davinci: remove mach/memory.h
  ARM: mach-pxa: remove mach/memory.h
  ARM: mach-ixp4xx: remove mach/memory.h
  ARM: mach-h720x: remove mach/memory.h
  ARM: mach-vt8500: remove mach/memory.h
  ARM: mach-s5pc100: remove mach/memory.h
  ARM: mach-tegra: remove mach/memory.h
  ARM: plat-tcc: remove mach/memory.h
  ARM: mach-mmp: remove mach/memory.h
  ARM: mach-cns3xxx: remove mach/memory.h
  ...

Fix up mostly pretty trivial conflicts in:
 - arch/arm/Kconfig
 - arch/arm/include/asm/localtimer.h
 - arch/arm/kernel/Makefile
 - arch/arm/mach-shmobile/board-ap4evb.c
 - arch/arm/mach-u300/core.c
 - arch/arm/mm/dma-mapping.c
 - arch/arm/mm/proc-v7.S
 - arch/arm/plat-omap/Kconfig
largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP ->
CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and
addition of NEED_MACH_MEMORY_H next to HAVE_IDE.
2011-10-28 12:02:27 -07:00
Russell King
bdf4e94823 Merge branch 'misc' into for-linus
Conflicts:
	arch/arm/mach-integrator/integrator_ap.c
2011-10-25 08:19:59 +01:00
Russell King
06afb1a087 Merge branches 'arnd-randcfg-fixes', 'debug', 'io' (early part), 'l2x0', 'p2v', 'pgt' (early part) and 'smp' into for-linus 2011-10-25 08:19:29 +01:00
Russell King
34471a9168 Merge branch 'ppi-irq-core-for-rmk' of git://github.com/mzyngier/arm-platforms into devel-stable 2011-10-23 14:42:30 +01:00
Russell King
a06f916b7a ARM: smp: fix clipping of number of CPUs
Rather than clipping the number of CPUs using the compile-time NR_CPUS
constant, use the runtime nr_cpu_ids value instead.  This allows the
nr_cpus command line option to work as expected.

Cc: <stable@kernel.org>
Reported-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-20 22:06:57 +01:00
Russell King
cefd3e71ef Merge branch 'mach_memory_h' of git://git.linaro.org/people/nico/linux into devel-stable 2011-10-18 13:40:54 +01:00
Will Deacon
4a139b6470 ARM: versatile: convert logical CPU numbers to physical numbers
This patch uses the new cpu_logical_map() macro for converting logical
CPU numbers into physical numbers when dealing with the pen_release
variable in the SMP boot and CPU hotplug paths.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-10-17 10:01:11 +01:00
Nick Bowler
b3377d1865 ARM: 7064/1: vexpress: Use wfi macro in platform_do_lowpower.
Current Versatile Express CPU hotplug code includes a hardcoded WFI
instruction, in ARM encoding.  When the kernel is compiled in Thumb-2
mode, this is invalid and causes the machine to hang hard when a CPU
is offlined.

Using the wfi macro (which uses the appropriate assembler mnemonic)
causes the correct instruction to be emitted in either case.  As a
consequence of this change, an apparently vestigial "cc" clobber is
dropped from the asm (the macro uses "memory" only).

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Reviewed-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17 09:12:41 +01:00
Sascha Hauer
40c6d8aee4 ARM: 7022/1: allow to detect conflicting zreladdrs
Boards used to specify zreladdr in their Makefile.boot with
zreladdr-y := x, so conflicting zreladdrs were silently overwritten.
This patch changes this to zreladdr-y += x, so that we end
up with multiple words in zreladdr in such a case. We can
detect this later and complain if necessary.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17 09:12:40 +01:00
Nicolas Pitre
34561b557f ARM: mach-vexpress: remove mach/memory.h
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-10-13 12:49:29 -04:00
Nicolas Pitre
639da5ee37 ARM: add an extra temp register to the low level debugging addruart macro
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>
2011-09-26 10:11:25 -04:00
Russell King
4722cd7741 Merge branch 'for-rmk' of git://linux-arm.org/linux-2.6-wd into devel-stable
Conflicts:
	arch/arm/mach-imx/mach-cpuimx27.c
2011-09-16 21:45:16 +01:00
Nick Bowler
0ebb962e00 ARM: 7003/1: vexpress: Add clock definition for the SP805.
It seems that an entry for the SP805 watchdog in the table of clocks was
missing.  This results in the sp805_wdt driver rejecting the device with
the following errors:

  sp805-wdt mb:wdt: Clock not found
  sp805-wdt mb:wdt: Probe Failed!!!
  sp805-wdt: probe of mb:wdt failed with error -2

While not obviously stated in the hardware docs, the onboard SP810's
"REFCLK" is connected to a 32.768KHz crystal, and this drives the
watchdog.  Add a struct clk and corresponding lookup entry for it.

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-24 09:45:21 +01:00
Nicolas Pitre
e9ce8e5bd0 ARM: vexpress: convert boot_params to atag_offset
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2011-08-21 17:15:20 -04:00
Russell King
4b34f7d62e ARM: io: remove IO_SPACE_LIMIT from platforms without PCI/ISA
Nothing should be using PCI/ISA IO on these platforms, so their
IO_SPACE_LIMIT definitions are irrelevent.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-08-17 08:44:17 +01:00
Russell King
06f365acef Merge branches 'btc', 'dma', 'entry', 'fixes', 'linker-layout', 'misc', 'mmci', 'suspend' and 'vfp' into for-next 2011-07-22 23:08:48 +01:00
Stephen Boyd
7fa22bd546 ARM: 6993/1: platsmp: Allow secondary cpu hotplug with maxcpus=1
If an ARM system has multiple cpus in the same socket and the
kernel is booted with maxcpus=1, secondary cpus are possible but
not present due to how platform_smp_prepare_cpus() is called.
Since most typical ARM processors don't actually support physical
hotplug, initialize the present map to be equal to the possible
map in generic ARM SMP code. Also, always call
platform_smp_prepare_cpus() as long as max_cpus is non-zero (0
means no SMP) to allow platform code to do any SMP setup.

After applying this patch it's possible to boot an ARM system
with maxcpus=1 on the command line and then hotplug in secondary
cpus via sysfs. This is more in line with how x86 does things.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-07 14:45:07 +01:00
Rob Herring
2fdf99934c ARM: 6946/1: vexpress: move v2m clock init to init_early
Commit 7ff550de99 breaks vexpress booting. The
v2m clock table needs to be setup in init_early before the timer
initialization occurs.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-06 10:56:09 +01:00
Russell King
4b60e5f90d Merge branches 'consolidate-clksrc', 'consolidate-flash', 'consolidate-generic', 'consolidate-smp', 'consolidate-stmp' and 'consolidate-zones' into consolidate 2011-05-23 18:05:10 +01:00
Russell King
23828a7a97 clockevents: ARM sp804: obtain sp804 timer rate via clks
This allows platforms to specify the rate of the SP804 clockevent via
the clk subsystem.  While ARM boards clock these at 1MHz, BCMRing also
has SP804 timers but are clocked at different rates.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23 18:04:53 +01:00
Russell King
57cc4f7de2 clockevents: ARM sp804: allow clockevent name to be specified
This allows platforms to specify the clcokevent name upon registration.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23 18:04:53 +01:00
Russell King
7ff550de99 clocksource: ARM sp804: obtain sp804 timer rate via clks
This allows platforms to specify the rate of the SP804 clocksource via
the clk subsystem.  While ARM boards clock these at 1MHz, BCMRing also
has SP804 timers but are clocked at different rates.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23 18:04:53 +01:00
Russell King
fb593cf38f clocksource: ARM sp804: allow clocksource name to be specified
This allows platforms to specify the clocksource name upon
registration, which is necessary should they wish to register more
than one sp804 clocksource.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23 18:04:53 +01:00
Russell King
0f7b332f97 ARM: consolidate SMP cross call implementation
Rather than having each platform class provide a mach/smp.h header for
smp_cross_call(), arrange for them to register the function with the
core ARM SMP code instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-23 16:53:17 +01:00
Marc Zyngier
667f390bee ARM: 6910/1: MTD: physmap: let set_vpp() pass a platform_device instead of a map_info
The set_vpp() method provided by physmap passes a map_info back to
the platform code, which has little relevance as far as the platform
is concerned (this parameter is completely unused).

Instead, pass the platform_device, which can be used in the pismo
driver to retrieve some important information in a nicer way, instead
of the hack that was in place.

The empty set_vpp function in board-at572d940hf_ek.c is left untouched,
as the board/SoC is scheduled for removal.

Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-20 22:27:34 +01:00
Marc Zyngier
0f71fd492d ARM: 6909/1: VExpress: Use physmap driver instead of integrator-flash
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-20 22:27:08 +01:00
Will Deacon
80b5efbd43 ARM: 6771/1: vexpress: add support for multiple core tiles
The current Versatile Express BSP defines the MACHINE_START macro
in the core tile code.

This patch moves this into the generic board code and introduces a
method for determining the current tile at runtime, allowing the
Kernel to have support for multiple tiles compiled in. Tile-specific
functions are executed via a descriptor struct containing the correct
implementations for the current tile.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-20 09:32:21 +00:00
Russell King
196f020fbb Merge branches 'fixes', 'pgt-next' and 'versatile' into devel 2011-03-20 09:32:12 +00:00
Will Deacon
3de4ade3d6 ARM: 6751/1: vexpress: select applicable errata workarounds in Kconfig
The Cortex-A9 tile on the Versatile Express suffers from a number of
engineering errata.

This patch selects workarounds in the ARCH_VEXPRESS_CA9X4 Kconfig entry
so that users don't need to worry about which ones to apply.

Reported-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-27 12:08:48 +00:00
Russell King
0462b4477e ARM: realview/vexpress: consolidate SMP bringup code
Realview and Versatile Express share the same SMP bringup code, so
consolidate the two implementations.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19 11:11:41 +00:00
Russell King
cdab142a80 ARM: realview/vexpress: consolidate localtimer support
Realview and Versatile Express local timer support is identical, so
consolidate the implementations.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19 11:11:36 +00:00
Russell King
493a451bb5 ARM: vexpress: use new init_early for clock tree and sched_clock init
Initialize the clock tree and our sched_clock() early.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19 11:11:10 +00:00
Russell King
0fb44b910f ARM: vexpress: switch Versatile Express to use consolidated CLCD
This switches Versatile Express to use the conslidated CLCD panel
support, including the display capabilities.  As Versatile Express uses
a PL111, it can support the full range of pixel formats - 444, 5551,
565 in both RGB and BGR mode.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-19 11:09:31 +00:00
Russell King
b75c178afa ARM: P2V: avoid initializers and assembly using PHYS_OFFSET
As PHYS_OFFSET will be becoming a variable, we can't have it used in
initializers nor assembly code.  Replace those in generic code with
a run-time initialization.  Replace those in platform code using the
individual platform specific PLAT_PHYS_OFFSET.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: David Brown <davidb@codeaurora.org>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-17 23:27:30 +00:00
Russell King
f4117ac9e2 ARM: P2V: separate PHYS_OFFSET from platform definitions
This uncouple PHYS_OFFSET from the platform definitions, thereby
facilitating run-time computation of the physical memory offset.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-17 23:26:55 +00:00
Nick Bowler
95c34f831f ARM: 6633/1: vexpress: register platform PATA device.
The compactflash device on this platform is not usable simply because it
is never registered with the kernel.  Fix that up.

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-25 16:19:12 +00:00
Pawel Moll
baaece2245 ARM: 6635/2: Configure reference clock for Versatile Express timers
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>
2011-01-25 16:18:33 +00:00
Russell King
ec15038f2b ARM: realview,vexpress: fix section mismatch warning for pen_release
Fix two section mismatch warnings in the platform SMP bringup code for
Realview and Versatile Express:

WARNING: arch/arm/mach-realview/built-in.o(.text+0x8ac): Section mismatch in reference from the function write_pen_release() to the variable .cpuinit.data:pen_release
The function write_pen_release() references
the variable __cpuinitdata pen_release.
This is often because write_pen_release lacks a __cpuinitdata
annotation or the annotation of pen_release is wrong.

WARNING: arch/arm/mach-vexpress/built-in.o(.text+0x7b4): Section mismatch in reference from the function write_pen_release() to the variable .cpuinit.data:pen_release
The function write_pen_release() references
the variable __cpuinitdata pen_release.
This is often because write_pen_release lacks a __cpuinitdata
annotation or the annotation of pen_release is wrong.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-25 15:08:01 +00:00
Russell King
4073723acb Merge branch 'misc' into devel
Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c
2011-01-06 22:32:52 +00:00
Russell King
4ec3eb1363 Merge branch 'smp' into misc
Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/mm/ioremap.c
2011-01-06 22:32:03 +00:00
Russell King
58daf18cdc Merge branch 'clksrc' into devel
Conflicts:
	arch/arm/mach-vexpress/v2m.c
	arch/arm/plat-omap/counter_32k.c
	arch/arm/plat-versatile/Makefile
2011-01-05 18:09:03 +00:00
Russell King
31edf274f9 Merge branches 'ftrace', 'gic', 'io', 'kexec', 'mod', 'sa11x0', 'sh' and 'versatile' into devel 2011-01-05 18:08:10 +00:00
Russell King
0af85dda39 ARM: vexpress: add sched_clock() for Versatile Express
Add a sched_clock() implementation to Versatile Express using the new
sched_clock() infrastructure for extending 32bit counters to full
64-bit nanoseconds.

Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-01-05 11:16:00 +00:00
Russell King
e9882777d9 ARM: CPU hotplug: add Versatile Express hotplug CPU support
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-20 15:09:15 +00:00
Russell King
3705ff6da5 ARM: Fix subtle race in CPU pen_release hotplug code
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>
2010-12-20 15:09:13 +00:00