Mathieu Desnoyers pointed out that the ARM barriers were lacking:

- cmpxchg, xchg and atomic add return need memory barriers on
  architectures which can reorder the relative order in which memory
  read/writes can be seen between CPUs, which seems to include recent
  ARM architectures. Those barriers are currently missing on ARM.

- test_and_xxx_bit were missing SMP barriers.

So put these barriers in.  Provide separate atomic_add/atomic_sub
operations which do not require barriers.

Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This is needed to allow or stop the unwinding at certain points in the
kernel like exception entries.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Aaro says:
> With spinlock debugs enabled I get might_sleep() warnings when using
> ptrace.

tracked down to a missing enable_irq before calling do_undefinstr().

Reported-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This declaration specifies the "function" type and size for various
assembly functions, mainly needed for generating the correct branch
instructions in Thumb-2.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This just leaves include/asm-arm/plat-* to deal with.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Luc Van Oostenryck reported:

  The code removed by this patch tested the irq_cpustat_t members
  __local_irq_count and __local_bh_count but these fields have
  been removed some time ago:

  http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commitdiff;h=3ab146c93e039dec99fec8d441a8dd046fe510cc

Fix this oversight.

Acked-by:  Bill Gatliff <bgat@billgatliff.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

This patch implements Thumb-2 application support in Linux. Original
implementation by Paul Brook with fixes for VFP and Neon by Catalin
Marinas.

Signed-off-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch adds a prefetch abort handler similar to the data abort one
and renames the latter for consistency. Initial implementation by Paul
Brook with some renaming by Catalin Marinas.

Signed-off-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

* at91: (24 commits)
  [ARM] 4615/4: sam926[13]ek buttons updated
  [ARM] 4765/1: [AT91] AT91CAP9A-DK board support
  [ARM] 4764/1: [AT91] AT91CAP9 core support
  [ARM] 4738/1: at91sam9261: Remove udc pullup enabling in board initialisation
  [ARM] 4761/1: [AT91] Board-support for NEW_LEDs
  [ARM] 4760/1: [AT91] SPI CS0 errata on AT91RM9200
  [ARM] 4759/1: [AT91] Buttons on CSB300
  [ARM] 4758/1: [AT91] LEDs
  [ARM] 4757/1: [AT91] UART initialization
  [ARM] 4756/1: [AT91] Makefile cleanup
  [ARM] 4755/1: [AT91] NAND update
  [ARM] 4754/1: [AT91] SSC library support
  [ARM] 4753/1: [AT91] Use DMA_BIT_MASK
  [ARM] 4752/1: [AT91] RTT, RTC and WDT peripherals on SAM9
  [ARM] 4751/1: [AT91] ISI peripheral on SAM9263
  [ARM] 4750/1: [AT91] STN LCD displays on SAM9261
  [ARM] 4734/1: at91sam9263ek: include IRQ for Ethernet PHY
  [ARM] 4646/1: AT91: configurable HZ, default to 128
  [ARM] 4688/1: at91: speed-up irq processing
  [ARM] 4657/1: AT91: Header definition update
  ...

* ep93xx:
  [ARM] 4671/1: ep93xx: remove obsolete gpio_line_* operations
  [ARM] 4670/1: ep93xx: implement IRQT_BOTHEDGE gpio irq sense type
  [ARM] 4669/1: ep93xx: simplify GPIO code and cleanups
  [ARM] 4668/1: ep93xx: implement new GPIO API

* iop:
  [ARM] 4770/1: GLAN Tank: correct physmap_flash_data width field
  [ARM] 4732/1: GLAN Tank: register rtc-rs5c372 i2c device
  [ARM] 4708/1: iop: update defconfigs for 2.6.24

* kprobes:
  ARM kprobes: let's enable it
  ARM kprobes: special hook for the kprobes breakpoint handler
  ARM kprobes: prevent some functions involved with kprobes from being probed
  ARM kprobes: don't let a single-stepped stmdb corrupt the exception stack
  ARM kprobes: add the kprobes hook to the page fault handler
  ARM kprobes: core code
  ARM kprobes: instruction single-stepping support

* ks8695:
  [ARM] 4603/1: KS8695: debugfs interface to view pin state
  [ARM] 4601/1: KS8695: PCI support

* misc:
  [ARM] remove duplicate includes
  [ARM] CONFIG_DEBUG_STACK_USAGE
  [ARM] 4689/1: small comment wrap fix
  [ARM] 4687/1: Trivial arch/arm/kernel/entry-common.S comment fix
  [ARM] 4666/1: ixp4xx: fix sparse warnings in include/asm-arm/arch-ixp4xx/io.h
  [ARM] remove reference to non-existent MTD_OBSOLETE_CHIPS
  [SERIAL] 21285: Report baud rate back via termios
  [ARM] Remove pointless casts from void pointers,
  [ARM] Misc minor interrupt handler cleanups
  [ARM] Remove at91_lcdc.h
  [ARM] ARRAY_SIZE() cleanup
  [ARM] Update mach-types

* msm:
  [ARM] msm: dma support for MSM7X00A
  [ARM] msm: board file for MACH_HALIBUT (QCT MSM7200A)
  [ARM] msm: irq and timer support for ARCH_MSM7X00A
  [ARM] msm: core platform support for ARCH_MSM7X00A

* s3c2410: (33 commits)
  [ARM] 4795/1: S3C244X: Add armclk and setparent call
  [ARM] 4794/1: S3C24XX: Comonise S3C2440 and S3C2442 clock code
  [ARM] 4793/1: S3C24XX: Add IRQ->GPIO pin mapping function
  [ARM] 4792/1: S3C24XX: Remove warnings from debug-macro.S
  [ARM] 4791/1: S3C2412: Make fclk a parent of msysclk
  [ARM] 4790/1: S3C2412: Fix parent selection for msysclk.
  [ARM] 4789/1: S3C2412: Add missing CLKDIVN register values
  [ARM] 4788/1: S3C24XX: Fix paramet to s3c2410_dma_ctrl if S3C2410_DMAF_AUTOSTART used.
  [ARM] 4787/1: S3C24XX: s3c2410_dma_request() should return the allocated channel number
  [ARM] 4786/1: S3C2412: Add SPI FIFO controll constants
  [ARM] 4785/1: S3C24XX: Add _SHIFT definitions for S3C2410_BANKCON registers
  [ARM] 4784/1: S3C24XX: Fix GPIO restore glitches
  [ARM] 4783/1: S3C24XX: Add s3c2410_gpio_getpull()
  [ARM] 4782/1: S3C24XX: Define FIQ_START for any FIQ users
  [ARM] 4781/1: S3C24XX: DMA suspend and resume support
  [ARM] 4780/1: S3C2412: Allow for seperate DMA channels for TX and RX
  [ARM] 4779/1: S3C2412: Add s3c2412_gpio_set_sleepcfg() call
  [ARM] 4778/1: S3C2412: Add armclk and init from DVS state
  [ARM] 4777/1: S3C24XX: Ensure clk_set_rate() checks the set_rate method for the clk
  [ARM] 4775/1: s3c2410: fix compilation error if only s3c2442 cpu is selected
  ...

* sa1100:
  [ARM] sa1100: add clock source support

* vfp:
  [ARM] 4584/2: ARMv7: Add Advanced SIMD (NEON) extension support
  [ARM] 4583/1: ARMv7: Add VFPv3 support
  [ARM] 4582/2: Add support for the common VFP subarchitecture