1262 Commits

Author SHA1 Message Date
Will Deacon
195bbcac2e ARM: 7500/1: io: avoid writeback addressing modes for __raw_ accessors
Data aborts taken to hyp mode do not provide a valid instruction
syndrome field in the HSR if the faulting instruction is a memory
access using a writeback addressing mode.

For hypervisors emulating MMIO accesses to virtual peripherals, taking
such an exception requires disassembling the faulting instruction in
order to determine the behaviour of the access. Since this requires
manually walking the two stages of translation, the world must be
stopped to prevent races against page aging in the guest, where the
first-stage translation is invalidated after the hypervisor has
translated to an IPA and the physical page is reused for something else.

This patch avoids taking this heavy performance penalty when running
Linux as a guest by ensuring that our I/O accessors do not make use of
writeback addressing modes.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:22:32 +01:00
Will Deacon
08928e7aea ARM: 7495/1: mutex: use generic atomic_dec-based implementation for ARMv6+
Commit a76d7bd96d65 ("ARM: 7467/1: mutex: use generic xchg-based
implementation for ARMv6+") removed the barrier-less, ARM-specific
mutex implementation in favour of the generic xchg-based code.

Since then, a bug was uncovered in the xchg code when running on SMP
platforms, due to interactions between the locking paths and the
MUTEX_SPIN_ON_OWNER code. This was fixed in 0bce9c46bf3b ("mutex: place
lock in contended state after fastpath_lock failure"), however, the
atomic_dec-based mutex algorithm is now marginally more efficient for
ARM (~0.5% improvement in hackbench scores on dual A15).

This patch moves ARMv6+ platforms to the atomic_dec-based mutex code.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:22:31 +01:00
Rob Herring
e780c452cf ARM: 7494/1: use generic termios.h
As pointed out by Arnd Bergmann, this fixes a couple of issues but will
increase code size:

The original macro user_termio_to_kernel_termios was not endian safe. It
used an unsigned short ptr to access the low bits in a 32-bit word.

Both user_termio_to_kernel_termios and kernel_termios_to_user_termio are
missing error checking on put_user/get_user and copy_to/from_user.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:22:31 +01:00
Rob Herring
d25c881aa3 ARM: 7493/1: use generic unaligned.h
This moves ARM over to the asm-generic/unaligned.h header. This has the
benefit of better code generated especially for ARMv7 on gcc 4.7+
compilers.

As Arnd Bergmann, points out: The asm-generic version uses the "struct"
version for native-endian unaligned access and the "byteshift" version
for the opposite endianess. The current ARM version however uses the
"byteshift" implementation for both.

Thanks to Nicolas Pitre for the excellent analysis:

Test case:

int foo (int *x) { return get_unaligned(x); }
long long bar (long long *x) { return get_unaligned(x); }

With the current ARM version:

foo:
	ldrb	r3, [r0, #2]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B]
	ldrb	r1, [r0, #1]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B]
	ldrb	r2, [r0, #0]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)]
	mov	r3, r3, asl #16	@ tmp154, MEM[(const u8 *)x_1(D) + 2B],
	ldrb	r0, [r0, #3]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B]
	orr	r3, r3, r1, asl #8	@, tmp155, tmp154, MEM[(const u8 *)x_1(D) + 1B],
	orr	r3, r3, r2	@ tmp157, tmp155, MEM[(const u8 *)x_1(D)]
	orr	r0, r3, r0, asl #24	@,, tmp157, MEM[(const u8 *)x_1(D) + 3B],
	bx	lr	@

bar:
	stmfd	sp!, {r4, r5, r6, r7}	@,
	mov	r2, #0	@ tmp184,
	ldrb	r5, [r0, #6]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 6B], MEM[(const u8 *)x_1(D) + 6B]
	ldrb	r4, [r0, #5]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 5B], MEM[(const u8 *)x_1(D) + 5B]
	ldrb	ip, [r0, #2]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 2B], MEM[(const u8 *)x_1(D) + 2B]
	ldrb	r1, [r0, #4]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 4B], MEM[(const u8 *)x_1(D) + 4B]
	mov	r5, r5, asl #16	@ tmp175, MEM[(const u8 *)x_1(D) + 6B],
	ldrb	r7, [r0, #1]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 1B], MEM[(const u8 *)x_1(D) + 1B]
	orr	r5, r5, r4, asl #8	@, tmp176, tmp175, MEM[(const u8 *)x_1(D) + 5B],
	ldrb	r6, [r0, #7]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 7B], MEM[(const u8 *)x_1(D) + 7B]
	orr	r5, r5, r1	@ tmp178, tmp176, MEM[(const u8 *)x_1(D) + 4B]
	ldrb	r4, [r0, #0]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D)], MEM[(const u8 *)x_1(D)]
	mov	ip, ip, asl #16	@ tmp188, MEM[(const u8 *)x_1(D) + 2B],
	ldrb	r1, [r0, #3]	@ zero_extendqisi2	@ MEM[(const u8 *)x_1(D) + 3B], MEM[(const u8 *)x_1(D) + 3B]
	orr	ip, ip, r7, asl #8	@, tmp189, tmp188, MEM[(const u8 *)x_1(D) + 1B],
	orr	r3, r5, r6, asl #24	@,, tmp178, MEM[(const u8 *)x_1(D) + 7B],
	orr	ip, ip, r4	@ tmp191, tmp189, MEM[(const u8 *)x_1(D)]
	orr	ip, ip, r1, asl #24	@, tmp194, tmp191, MEM[(const u8 *)x_1(D) + 3B],
	mov	r1, r3	@,
	orr	r0, r2, ip	@ tmp171, tmp184, tmp194
	ldmfd	sp!, {r4, r5, r6, r7}
	bx	lr

In both cases the code is slightly suboptimal.  One may wonder why
wasting r2 with the constant 0 in the second case for example.  And all
the mov's could be folded in subsequent orr's, etc.

Now with the asm-generic version:

foo:
	ldr	r0, [r0, #0]	@ unaligned	@,* x
	bx	lr	@

bar:
	mov	r3, r0	@ x, x
	ldr	r0, [r0, #0]	@ unaligned	@,* x
	ldr	r1, [r3, #4]	@ unaligned	@,
	bx	lr	@

This is way better of course, but only because this was compiled for
ARMv7. In this case the compiler knows that the hardware can do
unaligned word access.  This isn't that obvious for foo(), but if we
remove the get_unaligned() from bar as follows:

long long bar (long long *x) {return *x; }

then the resulting code is:

bar:
	ldmia	r0, {r0, r1}	@ x,,
	bx	lr	@

So this proves that the presumed aligned vs unaligned cases does have
influence on the instructions the compiler may use and that the above
unaligned code results are not just an accident.

Still... this isn't fully conclusive without at least looking at the
resulting assembly fron a pre ARMv6 compilation.  Let's see with an
ARMv5 target:

foo:
	ldrb	r3, [r0, #0]	@ zero_extendqisi2	@ tmp139,* x
	ldrb	r1, [r0, #1]	@ zero_extendqisi2	@ tmp140,
	ldrb	r2, [r0, #2]	@ zero_extendqisi2	@ tmp143,
	ldrb	r0, [r0, #3]	@ zero_extendqisi2	@ tmp146,
	orr	r3, r3, r1, asl #8	@, tmp142, tmp139, tmp140,
	orr	r3, r3, r2, asl #16	@, tmp145, tmp142, tmp143,
	orr	r0, r3, r0, asl #24	@,, tmp145, tmp146,
	bx	lr	@

bar:
	stmfd	sp!, {r4, r5, r6, r7}	@,
	ldrb	r2, [r0, #0]	@ zero_extendqisi2	@ tmp139,* x
	ldrb	r7, [r0, #1]	@ zero_extendqisi2	@ tmp140,
	ldrb	r3, [r0, #4]	@ zero_extendqisi2	@ tmp149,
	ldrb	r6, [r0, #5]	@ zero_extendqisi2	@ tmp150,
	ldrb	r5, [r0, #2]	@ zero_extendqisi2	@ tmp143,
	ldrb	r4, [r0, #6]	@ zero_extendqisi2	@ tmp153,
	ldrb	r1, [r0, #7]	@ zero_extendqisi2	@ tmp156,
	ldrb	ip, [r0, #3]	@ zero_extendqisi2	@ tmp146,
	orr	r2, r2, r7, asl #8	@, tmp142, tmp139, tmp140,
	orr	r3, r3, r6, asl #8	@, tmp152, tmp149, tmp150,
	orr	r2, r2, r5, asl #16	@, tmp145, tmp142, tmp143,
	orr	r3, r3, r4, asl #16	@, tmp155, tmp152, tmp153,
	orr	r0, r2, ip, asl #24	@,, tmp145, tmp146,
	orr	r1, r3, r1, asl #24	@,, tmp155, tmp156,
	ldmfd	sp!, {r4, r5, r6, r7}
	bx	lr

Compared to the initial results, this is really nicely optimized and I
couldn't do much better if I were to hand code it myself.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:22:30 +01:00
Rob Herring
4a8052d844 ARM: 7491/1: use generic version of identical asm headers
Inspired by the AArgh64 claim that it should be separate from ARM and one
reason was being able to use more asm-generic headers. Doing a diff of
arch/arm/include/asm and include/asm-generic there are numerous asm
headers which are functionally identical to their asm-generic counterparts.
Delete the ARM version and use the generic ones.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:22:30 +01:00
Will Deacon
df547e08e8 ARM: 7503/1: mm: only flush both pmd entries for classic MMU
LPAE does not use two pmd entries for a pte, so the additional tlb
flushing is not required.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-25 09:15:57 +01:00
Sudeep KarkadaNagesha
051f1b1314 ARM: perf: move irq registration into pmu implementation
This patch moves the CPU-specific IRQ registration and parsing code into
the CPU PMU backend. This is required because a PMU may have more than
one interrupt, which in turn can be either PPI (per-cpu) or SPI
(requiring strict affinity setting at the interrupt distributor).

Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
[will: cosmetic edits and reworked interrupt dispatching]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-08-23 11:35:52 +01:00
Will Deacon
6dbc002970 ARM: perf: prepare for moving CPU PMU code into separate file
The CPU PMU code is tightly coupled with generic ARM PMU handling code.
This makes it cumbersome when trying to add support for other ARM PMUs
(e.g. interconnect, L2 cache controller, bus) as the generic parts of
the code are not readily reusable.

This patch cleans up perf_event.c so that reusable code is exposed via
header files to other potential PMU drivers. The CPU code is
consistently named to identify it as such and also to prepare for moving
it into a separate file.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-08-23 11:35:52 +01:00
Sudeep KarkadaNagesha
df3d17e068 ARM: pmu: remove arm_pmu_type enumeration
The arm_pmu_type enumeration was initially introduced to identify
different PMU types in the system, the usual one being that on the CPU
(ARM_PMU_DEVICE_CPU). With the removal of the PMU reservation code and
the introduction of devicetree bindings for the CPU PMU, the enumeration
is no longer required.

This patch removes the enumeration and updates the various CPU PMU
platform devices so that they no longer pass an .id field referring
to identify the PMU type.

Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Pawel Moll <pawel.moll@arm.com>
Acked-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
[will: cosmetic edits and actual removal of the enum type]
Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-08-23 11:35:51 +01:00
Will Deacon
f0d1bc4795 ARM: pmu: remove unused reservation mechanism
The PMU reservation mechanism was originally intended to allow OProfile
and perf-events to co-ordinate over access to the CPU PMU. Since then,
OProfile for ARM has moved to using perf as its backend, so the
reservation code is no longer used.

This patch removes the reservation code for the CPU PMU on ARM.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-08-23 11:35:51 +01:00
Jon Hunter
7be2958e97 ARM: PMU: Add runtime PM Support
Add runtime PM support to the ARM PMU driver so that devices such as OMAP
supporting dynamic PM can use the platform->runtime_* hooks to initialise
hardware at runtime. Without having these runtime PM hooks in place any
configuration of the PMU hardware would be lost when low power states are
entered and hence would prevent PMU from working.

This change also replaces the PMU platform functions enable_irq and disable_irq
added by Ming Lei with runtime_resume and runtime_suspend funtions. Ming had
added the enable_irq and disable_irq functions as a method to configure the
cross trigger interface on OMAP4 for routing the PMU interrupts. By adding
runtime PM support, we can move the code called by enable_irq and disable_irq
into the runtime PM callbacks runtime_resume and runtime_suspend.

Cc: Ming Lei <ming.lei@canonical.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-08-23 11:35:51 +01:00
Chao Xie
38f2e37724 ARM: cache: add extra feature enable for tauros2
The extra feature may be used by SOCs are prefetch, burst8,
write buffer coalesce

Signed-off-by: Chao Xie <xiechao.mail@gmail.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
2012-08-16 16:16:27 +08:00
Arnd Bergmann
19e4ab54e7 Merge branch 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds into next/drivers
From Bryan Wu <bryan.wu@canonical.com>:

Based on Linus Walleij's ARM LED consolidation work, this patchset introduce a
new generic led trigger for CPU not only for ARM but also for others.

For enabling CPU idle event, CPU arch code should call ledtrig_cpu() stub to
trigger idle start or idle end event.

These patches convert old style LED driver in arch/arm to gpio_led or new led
driver interface. Against 3.5 release and build successfully for all the machines.

Test ledtrig-cpu driver on OMAP4 Panda board.

v9 --> v10
 * fix compiling issue on versatile_defconfig reported by Russell King
 * rebase to 3.5 kernel and move patches to new git tree

v8 --> v9:
 * use mutex to replace rw_sema pointed out by Tim Gardner
 * add a new struct led_trigger_cpu
 * add lock_is_inited to record mutex lock initialization

v6 --> v7:
 * add a patch to unify the led-trigger name
 * fix some typo pointed
 * use BUG_ON to detect CPU numbers during building stage

v5 --> v6:
 * replace  __get_cpu_var() to per_cpu()
 * remove smp_processor_id() which is wrong with for_each_possible_cpu()
 * test on real OMAP4 Panda board
 * add comments about CPU hotplug in the CPU LED trigger driver

v4 --> v5:
 * rebase all the patches on top of latest linux-next
 * replace on_each_cpu() with for_each_possible_cpu()
 * add some description of ledtrig_cpu() API
 * remove old leds code from driver nwflash.c, which should use a new led trigger then
 * this trigger driver can be built as module now

v3 --> v4:
 * fix a typo pointed by Jochen Friedrich
 * fix some building errors
 * add Reviewed-by and Tested-by into patch log

v2 --> v3:
 * almost rewrote the whole ledtrig-cpu driver, which is more simple
 * every CPU will have a per-CPU trigger
 * cpu trigger can be assigned to any leds
 * fix a lockdep issue in led-trigger common code
 * other fix according to review

v1 --> v2:
 * remove select operations in Kconfig of every machines
 * add back supporting of led in core module of mach-integrator
 * solidate name scheme in ledtrig-cpu.c
 * add comments of CPU_LED_* cpu led events
 * fold patches of RealView and Versatile together
 * add machine_is_ check during assabet led driver init
 * add some Acked-by in patch logs
 * remove code for simpad machine in machine-sa11000, since Jochen Friedrich
   introduced gpiolib and gpio-led driver for simpad
 * on Assabet and Netwinder machine, LED operations is reversed like:
   setting bit means turn off leds
   clearing bit means turn on leds
 * add a new function to read CM_CTRL register for led driver

* 'for-arm-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
  ARM: use new LEDS CPU trigger stub to replace old one
  ARM: mach-sa1100: retire custom LED code
  ARM: mach-omap1: retire custom LED code
  ARM: mach-pnx4008: remove including old leds event API header file
  ARM: plat-samsung: remove including old leds event API header file
  ARM: mach-pxa: retire custom LED code
  char: nwflash: remove old led event code
  ARM: mach-footbridge: retire custom LED code
  ARM: mach-ebsa110: retire custom LED code
  ARM: mach-clps711x: retire custom LED code of P720T machine
  ARM: mach-integrator: retire custom LED code
  ARM: mach-integrator: move CM_CTRL to header file for accessing by other functions
  ARM: mach-orion5x: convert custom LED code to gpio_led and LED CPU trigger
  ARM: mach-shark: retire custom LED code
  ARM: mach-ks8695: remove leds driver, since nobody use it
  ARM: mach-realview and mach-versatile: retire custom LED code
  ARM: at91: convert old leds drivers to gpio_led and led_trigger drivers
  led-triggers: create a trigger for CPU activity

Conflicts:
	arch/arm/mach-clps711x/p720t.c
	arch/arm/mach-sa1100/leds-cerf.c
	arch/arm/mach-sa1100/leds-lart.c

Let's hope this is the last time we pull this and it doesn't cause
more trouble. I have verified that version 10 causes no build
warnings or errors any more, and the patches still look good.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2012-08-13 16:45:48 +02:00
Will Deacon
f5f2025ef3 ARM: 7488/1: mm: use 5 bits for swapfile type encoding
Page migration encodes the pfn in the offset field of a swp_entry_t.
For LPAE, we support physical addresses of up to 36 bits (due to
sparsemem limitations with the size of page flags), requiring 24 bits
to represent a pfn. A further 3 bits are used to encode a swp_entry into
a pte, leaving 5 bits for the type field. Furthermore, the core code
defines MAX_SWAPFILES_SHIFT as 5, so the additional type bit does not
get used.

This patch reduces the width of the type field to 5 bits, allowing us
to create up to 31 swapfiles of 64GB each.

Cc: <stable@vger.kernel.org>
Reviewed-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>
2012-08-11 09:15:59 +01:00
Will Deacon
47f1204329 ARM: 7487/1: mm: avoid setting nG bit for user mappings that aren't present
Swap entries are encoding in ptes such that !pte_present(pte) and
pte_file(pte). The remaining bits of the descriptor are used to identify
the swapfile and offset within it to the swap entry.

When writing such a pte for a user virtual address, set_pte_at
unconditionally sets the nG bit, which (in the case of LPAE) will
corrupt the swapfile offset and lead to a BUG:

[  140.494067] swap_free: Unused swap offset entry 000763b4
[  140.509989] BUG: Bad page map in process rs:main Q:Reg  pte:0ec76800 pmd:8f92e003

This patch fixes the problem by only setting the nG bit for user
mappings that are actually present.

Cc: <stable@vger.kernel.org>
Reviewed-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>
2012-08-11 09:15:59 +01:00
Colin Cross
237ec6f2e5 ARM: 7486/1: sched_clock: update epoch_cyc on resume
Many clocks that are used to provide sched_clock will reset during
suspend.  If read_sched_clock returns 0 after suspend, sched_clock will
appear to jump forward.  This patch resets cd.epoch_cyc to the current
value of read_sched_clock during resume, which causes sched_clock() just
after suspend to return the same value as sched_clock() just before
suspend.

In addition, during the window where epoch_ns has been updated before
suspend, but epoch_cyc has not been updated after suspend, it is unknown
whether the clock has reset or not, and sched_clock() could return a
bogus value.  Add a suspended flag, and return the pre-suspend epoch_ns
value during this period.

The new behavior is triggered by calling setup_sched_clock_needs_suspend
instead of setup_sched_clock.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-11 09:15:58 +01:00
Stefano Stabellini
ca98163376 xen/arm: compile netback
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-08 17:21:23 +00:00
Stefano Stabellini
0ec53ecf38 xen/arm: receive Xen events on ARM
Compile events.c on ARM.
Parse, map and enable the IRQ to get event notifications from the device
tree (node "/xen").

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-14 13:37:32 +00:00
Stefano Stabellini
256f631f1f xen/arm: Introduce xen_ulong_t for unsigned long
All the original Xen headers have xen_ulong_t as unsigned long type, however
when they have been imported in Linux, xen_ulong_t has been replaced with
unsigned long. That might work for x86 and ia64 but it does not for arm.
Bring back xen_ulong_t and let each architecture define xen_ulong_t as they
see fit.

Also explicitly size pointers (__DEFINE_GUEST_HANDLE) to 64 bit.


Changes in v3:

- remove the incorrect changes to multicall_entry;
- remove the change to apic_physbase.


Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-14 13:34:43 +00:00
Stefano Stabellini
e54d2f6152 xen/arm: sync_bitops
sync_bitops functions are equivalent to the SMP implementation of the
original functions, independently from CONFIG_SMP being defined.

We need them because _set_bit etc are not SMP safe if !CONFIG_SMP. But
under Xen you might be communicating with a completely external entity
who might be on another CPU (e.g. two uniprocessor guests communicating
via event channels and grant tables). So we need a variant of the bit
ops which are SMP safe even on a UP kernel.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-08 16:34:01 +00:00
Stefano Stabellini
36a67abce2 xen/arm: page.h definitions
ARM Xen guests always use paging in hardware, like PV on HVM guests in
the X86 world.

Changes in v3:

- improve comments.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-08-08 16:33:46 +00:00
Stefano Stabellini
aa2466d21b xen/arm: hypercalls
Use r12 to pass the hypercall number to the hypervisor.

We need a register to pass the hypercall number because we might not
know it at compile time and HVC only takes an immediate argument.

Among the available registers r12 seems to be the best choice because it
is defined as "intra-procedure call scratch register".

Use the ISS to pass an hypervisor specific tag.


Changes in v2:
- define an HYPERCALL macro for 5 arguments hypercall wrappers, even if
at the moment is unused;
- use ldm instead of pop;
- fix up comments.


Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-14 13:33:21 +00:00
Stefano Stabellini
4c071ee526 arm: initial Xen support
- Basic hypervisor.h and interface.h definitions.
- Skeleton enlighten.c, set xen_start_info to an empty struct.
- Make xen_initial_domain dependent on the SIF_PRIVILIGED_BIT.

The new code only compiles when CONFIG_XEN is set, that is going to be
added to arch/arm/Kconfig in patch #11 "xen/arm: introduce CONFIG_XEN on
ARM".

Changes in v3:

- improve comments.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-09-14 13:53:39 +00:00
Linus Torvalds
9a2533c3eb Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM fixes from Russell King:
 "This fixes various issues found during July"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT caches
  ARM: Fix undefined instruction exception handling
  ARM: 7480/1: only call smp_send_stop() on SMP
  ARM: 7478/1: errata: extend workaround for erratum #720789
  ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP
  ARM: 7476/1: vfp: only clear vfp state for current cpu in vfp_pm_suspend
  ARM: 7468/1: ftrace: Trace function entry before updating index
  ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+
  ARM: 7466/1: disable interrupt before spinning endlessly
  ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option
2012-08-01 16:30:45 -07:00
Bryan Wu
fa8bbb13ab ARM: use new LEDS CPU trigger stub to replace old one
Cc:  Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-08-01 11:22:14 +08:00
Will Deacon
b74253f784 ARM: 7479/1: mm: avoid NULL dereference when flushing gate_vma with VIVT caches
The vivt_flush_cache_{range,page} functions check that the mm_struct
of the VMA being flushed has been active on the current CPU before
performing the cache maintenance.

The gate_vma has a NULL mm_struct pointer and, as such, will cause a
kernel fault if we try to flush it with the above operations. This
happens during ELF core dumps, which include the gate_vma as it may be
useful for debugging purposes.

This patch adds checks to the VIVT cache flushing functions so that VMAs
with a NULL mm_struct are flushed unconditionally (the vectors page may
be dirty if we use it to store the current TLS pointer).

Cc: <stable@vger.kernel.org> # 3.4+
Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Tested-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 12:04:47 +01:00
Will Deacon
a76d7bd96d ARM: 7467/1: mutex: use generic xchg-based implementation for ARMv6+
The open-coded mutex implementation for ARMv6+ cores suffers from a
severe lack of barriers, so in the uncontended case we don't actually
protect any accesses performed during the critical section.

Furthermore, the code is largely a duplication of the ARMv6+ atomic_dec
code but optimised to remove a branch instruction, as the mutex fastpath
was previously inlined. Now that this is executed out-of-line, we can
reuse the atomic access code for the locking (in fact, we use the xchg
code as this produces shorter critical sections).

This patch uses the generic xchg based implementation for mutexes on
ARMv6+, which introduces barriers to the lock/unlock operations and also
has the benefit of removing a fair amount of inline assembly code.

Cc: <stable@vger.kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nico@linaro.org>
Reported-by: Shan Kang <kangshan0910@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:41 +01:00
Linus Torvalds
27c1ee3f92 Merge branch 'akpm' (Andrew's patch-bomb)
Merge Andrew's first set of patches:
 "Non-MM patches:

   - lots of misc bits

   - tree-wide have_clk() cleanups

   - quite a lot of printk tweaks.  I draw your attention to "printk:
     convert the format for KERN_<LEVEL> to a 2 byte pattern" which
     looks a bit scary.  But afaict it's solid.

   - backlight updates

   - lib/ feature work (notably the addition and use of memweight())

   - checkpatch updates

   - rtc updates

   - nilfs updates

   - fatfs updates (partial, still waiting for acks)

   - kdump, proc, fork, IPC, sysctl, taskstats, pps, etc

   - new fault-injection feature work"

* Merge emailed patches from Andrew Morton <akpm@linux-foundation.org>: (128 commits)
  drivers/misc/lkdtm.c: fix missing allocation failure check
  lib/scatterlist: do not re-write gfp_flags in __sg_alloc_table()
  fault-injection: add tool to run command with failslab or fail_page_alloc
  fault-injection: add selftests for cpu and memory hotplug
  powerpc: pSeries reconfig notifier error injection module
  memory: memory notifier error injection module
  PM: PM notifier error injection module
  cpu: rewrite cpu-notifier-error-inject module
  fault-injection: notifier error injection
  c/r: fcntl: add F_GETOWNER_UIDS option
  resource: make sure requested range is included in the root range
  include/linux/aio.h: cpp->C conversions
  fs: cachefiles: add support for large files in filesystem caching
  pps: return PTR_ERR on error in device_create
  taskstats: check nla_reserve() return
  sysctl: suppress kmemleak messages
  ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION
  ipc: compat: use signed size_t types for msgsnd and msgrcv
  ipc: allow compat IPC version field parsing if !ARCH_WANT_OLD_COMPAT_IPC
  ipc: add COMPAT_SHMLBA support
  ...
2012-07-30 17:25:34 -07:00
Will Deacon
c1d7e01d78 ipc: use Kconfig options for __ARCH_WANT_[COMPAT_]IPC_PARSE_VERSION
Rather than #define the options manually in the architecture code, add
Kconfig options for them and select them there instead.  This also allows
us to select the compat IPC version parsing automatically for platforms
using the old compat IPC interface.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-30 17:25:21 -07:00
Linus Torvalds
6f51f51582 Merge branch 'for-linus-for-3.6-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping
Pull DMA-mapping updates from Marek Szyprowski:
 "Those patches are continuation of my earlier work.

  They contains extensions to DMA-mapping framework to remove limitation
  of the current ARM implementation (like limited total size of DMA
  coherent/write combine buffers), improve performance of buffer sharing
  between devices (attributes to skip cpu cache operations or creation
  of additional kernel mapping for some specific use cases) as well as
  some unification of the common code for dma_mmap_attrs() and
  dma_mmap_coherent() functions.  All extensions have been implemented
  and tested for ARM architecture."

* 'for-linus-for-3.6-rc1' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma-mapping: add support for DMA_ATTR_SKIP_CPU_SYNC attribute
  common: DMA-mapping: add DMA_ATTR_SKIP_CPU_SYNC attribute
  ARM: dma-mapping: add support for dma_get_sgtable()
  common: dma-mapping: introduce dma_get_sgtable() function
  ARM: dma-mapping: add support for DMA_ATTR_NO_KERNEL_MAPPING attribute
  common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute
  common: dma-mapping: add support for generic dma_mmap_* calls
  ARM: dma-mapping: fix error path for memory allocation failure
  ARM: dma-mapping: add more sanity checks in arm_dma_mmap()
  ARM: dma-mapping: remove custom consistent dma region
  mm: vmalloc: use const void * for caller argument
  scatterlist: add sg_alloc_table_from_pages function
2012-07-30 10:11:31 -07:00
Marek Szyprowski
dc2832e1e7 ARM: dma-mapping: add support for dma_get_sgtable()
This patch adds support for dma_get_sgtable() function which is required
to let drivers to share the buffers allocated by DMA-mapping subsystem.

Generic implementation based on virt_to_page() is not suitable for ARM
dma-mapping subsystem.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
2012-07-30 12:25:47 +02:00
Marek Szyprowski
64ccc9c033 common: dma-mapping: add support for generic dma_mmap_* calls
Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a
generic method for implementing mmap user call to dma_map_ops structure.

This patch converts ARM and PowerPC architectures (the only providers of
dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic
dma_map_ops based call and adds a generic cross architecture
definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine
functions.

The generic mmap virt_to_page-based fallback implementation is provided for
architectures which don't provide their own implementation for mmap method.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
2012-07-30 12:25:46 +02:00
Marek Szyprowski
e9da6e9905 ARM: dma-mapping: remove custom consistent dma region
This patch changes dma-mapping subsystem to use generic vmalloc areas
for all consistent dma allocations. This increases the total size limit
of the consistent allocations and removes platform hacks and a lot of
duplicated code.

Atomic allocations are served from special pool preallocated on boot,
because vmalloc areas cannot be reliably created in atomic context.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
2012-07-30 12:25:45 +02:00
Peter Maydell
a5d5f7daa7 ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option
The memory regions which are passed to arm_add_memory() from
device tree blobs via early_init_dt_add_memory_arch() can
have sizes which are larger than will fit in a 32 bit integer,
so switch to using a phys_addr_t to hold them, to avoid
silently dropping the top 32 bits of the size. Similarly, use
phys_addr_t in early_mem() so that mem=size@start command line
options specifying more than 4GB behave sensibly.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-29 22:19:14 +01:00
Linus Torvalds
cea8f46c36 Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
 "First ARM push of this merge window, post me coming back from holiday.
  This is what has been in linux-next for the last few weeks.  Not much
  to say which isn't described by the commit summaries."

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (32 commits)
  ARM: 7463/1: topology: Update cpu_power according to DT information
  ARM: 7462/1: topology: factorize the update of sibling masks
  ARM: 7461/1: topology: Add arch_scale_freq_power function
  ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit}
  ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handling
  ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_fork path
  ARM: 7453/1: audit: only allow syscall auditing for pure EABI userspace
  ARM: 7452/1: delay: allow timer-based delay implementation to be selected
  ARM: 7451/1: arch timer: implement read_current_timer and get_cycles
  ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs
  ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
  ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration
  ARM: 7447/1: rwlocks: remove unused branch labels from trylock routines
  ARM: 7446/1: spinlock: use ticket algorithm for ARMv6+ locking implementation
  ARM: 7445/1: mm: update CONTEXTIDR register to contain PID of current process
  ARM: 7444/1: kernel: add arch-timer C3STOP feature
  ARM: 7460/1: remove asm/locks.h
  ARM: 7439/1: head.S: simplify initial page table mapping
  ARM: 7437/1: zImage: Allow DTB command line concatenation with ATAG_CMDLINE
  ARM: 7436/1: Do not map the vectors page as write-through on UP systems
  ...
2012-07-27 15:14:26 -07:00
Russell King
91b006def3 Merge branches 'audit', 'delay', 'fixes', 'misc' and 'sta2x11' into for-linus 2012-07-27 23:06:32 +01:00
Linus Torvalds
84eda28060 Merge branch 'kmap_atomic' of git://github.com/congwang/linux
Pull final kmap_atomic cleanups from Cong Wang:
 "This should be the final round of cleanup, as the definitions of enum
  km_type finally get removed from the whole tree.  The patches have
  been in linux-next for a long time."

* 'kmap_atomic' of git://github.com/congwang/linux:
  pipe: remove KM_USER0 from comments
  vmalloc: remove KM_USER0 from comments
  feature-removal-schedule.txt: remove kmap_atomic(page, km_type)
  tile: remove km_type definitions
  um: remove km_type definitions
  asm-generic: remove km_type definitions
  avr32: remove km_type definitions
  frv: remove km_type definitions
  powerpc: remove km_type definitions
  arm: remove km_type definitions
  highmem: remove the deprecated form of kmap_atomic
  tile: remove usage of enum km_type
  frv: remove the second parameter of kmap_atomic_primary()
  jbd2: remove the second argument of kmap_atomic
2012-07-27 11:26:48 -07:00
Rob Herring
dd9bf78040 ARM: iop3xx: use fixed PCI i/o mapping
Move iop33x and iop32x PCI to fixed i/o mapping and remove io.h. This
changes the PCI bus addresses from the cpu address to 0 based. It appears
that there is translation h/w for this, but its untested.

Not sure what to do with io_offset. I think it should always be 0.
AFAICT, PCI setup is skipped if the ATU is already setup.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2012-07-26 09:10:04 -05:00
Rob Herring
3c5d169988 ARM: move PCI i/o resource setup into common code
With consolidation of the PCI i/o mappings, the i/o space is being
set to start at a PCI bus addr of 0x0 and fixed to 64K per bus. In
this case the core ARM PCI setup code can setup the i/o resource.

Currently, the resource is only setup if the platform did not setup
an i/o resource.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2012-07-26 09:09:17 -05:00
Rob Herring
c279443709 ARM: Add fixed PCI i/o mapping
This adds a fixed virtual mapping for PCI i/o addresses. The mapping is
located at the last 2MB of vmalloc region (0xfee00000-0xff000000). 2MB
is used to align with PMD size, but IO_SPACE_LIMIT is 1MB. The space
is reserved after .map_io and can be mapped at any time later with
pci_ioremap_io. Platforms which need early i/o mapping (e.g. for vga
console) can call pci_map_io_early in their .map_io function.

This has changed completely from the 1st implementation which only
supported creating the static mapping at .map_io.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Nicolas Pitre <nico@linaro.org>
2012-07-25 09:26:42 -05:00
Cong Wang
4b7a7d8890 arm: remove km_type definitions
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-07-24 15:27:28 +08:00
Linus Torvalds
3645f0cd96 arm-soc: sparse IRQ conversion
The I.MX platform is getting converted to use sparse IRQs. We are doing
 this for all platforms over time, because this is one of the
 requirements for building a multiplatform kernel, and generally a good
 idea.
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Merge tag 'irq' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull arm-soc sparse IRQ conversion from Arnd Bergmann:
 "The I.MX platform is getting converted to use sparse IRQs.  We are
  doing this for all platforms over time, because this is one of the
  requirements for building a multiplatform kernel, and generally a good
  idea."

* tag 'irq' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: imx: select USE_OF
  ARM: imx: Fix build error due to missing irqs.h include
  ARM: imx: enable SPARSE_IRQ for imx platform
  ARM: fiq: change FIQ_START to a variable
  tty: serial: imx: remove the use of MXC_INTERNAL_IRQS
  ARM: imx: remove unneeded mach/irq.h inclusion
  i2c: imx: remove unneeded mach/irqs.h inclusion
  ARM: imx: add a legacy irqdomain for mx31ads
  ARM: imx: add a legacy irqdomain for 3ds_debugboard
  ARM: imx: pass gpio than irq number into mxc_expio_init
  ARM: imx: leave irq_base of wm8350_platform_data uninitialized
  dma: ipu: remove the use of ipu_platform_data
  ARM: imx: move irq_domain_add_legacy call into avic driver
  ARM: imx: move irq_domain_add_legacy call into tzic driver
  gpio/mxc: move irq_domain_add_legacy call into gpio driver
  ARM: imx: eliminate macro IRQ_GPIOx()
  ARM: imx: eliminate macro IOMUX_TO_IRQ()
  ARM: imx: eliminate macro IMX_GPIO_TO_IRQ()
2012-07-23 17:36:02 -07:00
Will Deacon
d0a533b182 ARM: 7452/1: delay: allow timer-based delay implementation to be selected
This patch allows a timer-based delay implementation to be selected by
switching the delay routines over to use get_cycles, which is
implemented in terms of read_current_timer. This further allows us to
skip the loop calibration and have a consistent delay function in the
face of core frequency scaling.

To avoid the pain of dealing with memory-mapped counters, this
implementation uses the co-processor interface to the architected timers
when they are available. The previous loop-based implementation is
kept around for CPUs without the architected timers and we retain both
the maximum delay (2ms) and the corresponding conversion factors for
determining the number of loops required for a given interval. Since the
indirection of the timer routines will only work when called from C,
the sa1100 sleep routines are modified to branch to the loop-based delay
functions directly.

Tested-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:42:23 +01:00
Will Deacon
923df96b9f ARM: 7451/1: arch timer: implement read_current_timer and get_cycles
This patch implements read_current_timer using the architected timers
when they are selected via CONFIG_ARM_ARCH_TIMER. If they are detected
not to be usable at runtime, we return -ENXIO to the caller.

Furthermore, if read_current_timer is exported then we can implement
get_cycles in terms of it for use as both an entropy source and for
implementing __udelay and friends.

Tested-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:42:23 +01:00
Will Deacon
b9a50f7490 ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs
DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad for ARM CPUs
with native support for unaligned memory accesses (v6+) when running
little-endian.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:41:11 +01:00
Will Deacon
8c56cc8be5 ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions
This patch implements the word-at-a-time interface for ARM using the
same algorithm as x86. We use the fls macro from ARMv5 onwards, where
we have a clz instruction available which saves us a mov instruction
when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001
constant. Big-endian configurations make use of the implementation from
asm-generic.

With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:41:11 +01:00
Will Deacon
4295b898f5 ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration
In order to provide PMU name strings compatible with the OProfile
user ABI, an enumeration of all PMUs is currently used by perf to
identify each PMU uniquely. Unfortunately, this does not scale well
in the presence of multiple PMUs and creates a single, global namespace
across all PMUs in the system.

This patch removes the enumeration and instead uses the name string
for the PMU to map onto the OProfile variant. perf_pmu_name is
implemented for CPU PMUs, which is all that OProfile cares about anyway.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:41:10 +01:00
Will Deacon
881ccccb6b ARM: 7447/1: rwlocks: remove unused branch labels from trylock routines
The ARM arch_{read,write}_trylock implementations include unused
backwards branch labels, since we don't retry the locking operation
if the exclusive store fails.

This patch removes the labels.

Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:41:10 +01:00
Will Deacon
546c2896a4 ARM: 7446/1: spinlock: use ticket algorithm for ARMv6+ locking implementation
Ticket spinlocks ensure locking fairness by introducing a FIFO-like
nature to the granting of lock acquisitions and also reducing the
thundering herd effect when spinning on a lock by allowing the cacheline
to remain in a shared state amongst the waiting CPUs. This is especially
important on systems where memory-access times are not necessarily
uniform when accessing the lock structure (for example, on a
multi-cluster platform where the lock is allocated into L1 when a CPU
releases it).

This patch implements the ticket spinlock algorithm for ARM, replacing
the simpler implementation for ARMv6+ processors.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:41:10 +01:00
Paul Bolle
a5203c4ce6 ARM: 7460/1: remove asm/locks.h
Commit 64ac24e738823161693bf791f87adc802cf529ff ("Generic semaphore
implementation") removed the last include of this header. Apparently it
was just an oversight to keep this header. It can safely be removed now.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-09 17:39:59 +01:00