mtd: fix oops in dataflash driver

I'm seeing an oops in mtd_dataflash.c with Linux 3.3. What appears to
be happening is that otp_select_filemode calls mtd_read_fact_prot_reg
with -1 for offset and length and a NULL buffer to test if OTP
operations are supported. This finds its way down to otp_read in
mtd_dataflash.c and causes an oops when memcpying the returned data
into the NULL buf.

None of the checks in otp_read catches the negative length and offset.
Changing the length of the dummy read to 0 prevents the oops.

Cc: stable@kernel.org [3.3+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
jffs2: Fix lock acquisition order bug in gc path

The locking policy is such that the erase_complete_block spinlock is
nested within the alloc_sem mutex.  This fixes a case in which the
acquisition order was erroneously reversed.  This issue was caught by
the following lockdep splat:

   =======================================================
   [ INFO: possible circular locking dependency detected ]
   3.0.5 #1
   -------------------------------------------------------
   jffs2_gcd_mtd6/299 is trying to acquire lock:
    (&c->alloc_sem){+.+.+.}, at: [<c01f7714>] jffs2_garbage_collect_pass+0x314/0x890

   but task is already holding lock:
    (&(&c->erase_completion_lock)->rlock){+.+...}, at: [<c01f7708>] jffs2_garbage_collect_pass+0x308/0x890

   which lock already depends on the new lock.

   the existing dependency chain (in reverse order) is:

   -> #1 (&(&c->erase_completion_lock)->rlock){+.+...}:
          [<c008bec4>] validate_chain+0xe6c/0x10bc
          [<c008c660>] __lock_acquire+0x54c/0xba4
          [<c008d240>] lock_acquire+0xa4/0x114
          [<c046780c>] _raw_spin_lock+0x3c/0x4c
          [<c01f744c>] jffs2_garbage_collect_pass+0x4c/0x890
          [<c01f937c>] jffs2_garbage_collect_thread+0x1b4/0x1cc
          [<c0071a68>] kthread+0x98/0xa0
          [<c000f264>] kernel_thread_exit+0x0/0x8

   -> #0 (&c->alloc_sem){+.+.+.}:
          [<c008ad2c>] print_circular_bug+0x70/0x2c4
          [<c008c08c>] validate_chain+0x1034/0x10bc
          [<c008c660>] __lock_acquire+0x54c/0xba4
          [<c008d240>] lock_acquire+0xa4/0x114
          [<c0466628>] mutex_lock_nested+0x74/0x33c
          [<c01f7714>] jffs2_garbage_collect_pass+0x314/0x890
          [<c01f937c>] jffs2_garbage_collect_thread+0x1b4/0x1cc
          [<c0071a68>] kthread+0x98/0xa0
          [<c000f264>] kernel_thread_exit+0x0/0x8

   other info that might help us debug this:

    Possible unsafe locking scenario:

          CPU0                    CPU1
          ----                    ----
     lock(&(&c->erase_completion_lock)->rlock);
                                  lock(&c->alloc_sem);
                                  lock(&(&c->erase_completion_lock)->rlock);
     lock(&c->alloc_sem);

    *** DEADLOCK ***

   1 lock held by jffs2_gcd_mtd6/299:
    #0:  (&(&c->erase_completion_lock)->rlock){+.+...}, at: [<c01f7708>] jffs2_garbage_collect_pass+0x308/0x890

   stack backtrace:
   [<c00155dc>] (unwind_backtrace+0x0/0x100) from [<c0463dc0>] (dump_stack+0x20/0x24)
   [<c0463dc0>] (dump_stack+0x20/0x24) from [<c008ae84>] (print_circular_bug+0x1c8/0x2c4)
   [<c008ae84>] (print_circular_bug+0x1c8/0x2c4) from [<c008c08c>] (validate_chain+0x1034/0x10bc)
   [<c008c08c>] (validate_chain+0x1034/0x10bc) from [<c008c660>] (__lock_acquire+0x54c/0xba4)
   [<c008c660>] (__lock_acquire+0x54c/0xba4) from [<c008d240>] (lock_acquire+0xa4/0x114)
   [<c008d240>] (lock_acquire+0xa4/0x114) from [<c0466628>] (mutex_lock_nested+0x74/0x33c)
   [<c0466628>] (mutex_lock_nested+0x74/0x33c) from [<c01f7714>] (jffs2_garbage_collect_pass+0x314/0x890)
   [<c01f7714>] (jffs2_garbage_collect_pass+0x314/0x890) from [<c01f937c>] (jffs2_garbage_collect_thread+0x1b4/0x1cc)
   [<c01f937c>] (jffs2_garbage_collect_thread+0x1b4/0x1cc) from [<c0071a68>] (kthread+0x98/0xa0)
   [<c0071a68>] (kthread+0x98/0xa0) from [<c000f264>] (kernel_thread_exit+0x0/0x8)

This was introduce in '81cfc9f jffs2: Fix serious write stall due to erase'.

Cc: stable@kernel.org [2.6.37+]
Signed-off-by: Josh Cartwright <joshc@linux.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
mtd: ams-delta: fix request_mem_region() failure

A call to request_mem_region() has been introduced in the omap-gpio
driver recently (commit 96751fcbe5438e95514b025e9cee7a6d38038f40,
"gpio/omap: Use devm_ API and add request_mem_region"). This change
prevented the Amstrad Delta NAND driver, which was doing the same in
order to take control over OMAP MPU I/O lines that the NAND device hangs
off, from loading successfully.

The I/O lines and corresponding registers used by the NAND driver are a
subset of those used for the GPIO function. Then, to avoid run time
collisions, all MPUIO GPIO lines should be marked as requested while
initializing the NAND driver, and vice versa, a single MPUIO GPIO line
already requested before the NAND driver initialization is attempted
should prevent the NAND device from being started successfully.

There is another driver, omap-keypad, which also manipulates MPUIO
registers, but has never been calling request_mem_region() on startup,
so it's not affected by the change in the gpio-omap and works correctly.
It uses the depreciated omap_read/write functions for accessing MPUIO
registers. Unlike the NAND driver, these I/O lines and registers are
separate from those used by the GPIO driver. However, both register sets
are non-contiguous and overlapping, so it would be impractical to
request the two sets separately, one from the gpio-omap, the other form
the omap-keypad driver.

In order to solve all these issues correctly, a solution first suggested
by Artem Bityutskiy, then closer specified by Tony Lindgren while they
commented the initial version of this fix, should be implemented. The
gpio-omap driver should export a few functions which would allow the
other two drivers to access MPUIO registers in a safe manner instead of
trying to manage them in parallel to the GPIO driver.  However, such a
big change, affecting 3 drivers all together, is not suitable for the rc
cycle, and should be prepared for the merge window.  Then, an
alternative solution is proposed as a regression fix.

For the ams-delta NAND driver to initialize correctly in coexistence
with the changed GPIO driver, drop the request_mem_region() call from
the former, especially as this call is going to be removed while the
long-term solution is implemented.

Tested on Amstrad Delta.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
gpio: pch9: Use proper flow type handlers

Jean-Francois Dagenais reported:

 Configuring a gpio pin with the gpio-pch driver with
 "IRQF_TRIGGER_LOW | IRQF_ONESHOT" generates an interrupt storm for
 threaded ISR until the ISR thread actually gets to physically clear
 the interrupt on the triggering chip!! The immediate observable
 symptom is the high CPU usage for my ISR thread task and the
 interrupt count in /proc/interrupts incrementing radically.

The driver is wrong in several ways:

1) Using handle_simple_irq() does not provide proper flow control
   handling. In the case of oneshot threaded handlers for the
   demultiplexed interrupts this results in an interrupt storm because
   the simple handler does not deal with masking/unmasking.  Even
   without threaded oneshot handlers an interrupt storm for level type
   interrupts can easily be triggered when the interrupt is disabled
   and the interrupt line is activated from the device.

2) Acknowlegding the demultiplexed interrupt before calling the
   handler is wrong for level type interrupts.

3) The set_type function unconditionally enables the interrupt. It's
   supposed to set the type and nothing else. The unmasking is done by
   the core code.

Move the acknowledge code into a separate function and add it to the
demux irqchip callbacks.

Remove the unconditional enabling from the set_type() callback and set
the proper flow handlers depending on the selected type (level/edge).

Reported-and-tested-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
gpio/exynos: Fix compiler warnings when non-exynos machines are selected

Fixes the following compiler warnings:

drivers/gpio/gpio-samsung.c: In function ‘samsung_gpiolib_init’:
drivers/gpio/gpio-samsung.c:2980:1: warning: label ‘err_ioremap1’ defined but not used [-Wunused-label]
drivers/gpio/gpio-samsung.c:2978:1: warning: label ‘err_ioremap2’ defined but not used [-Wunused-label]
drivers/gpio/gpio-samsung.c:2976:1: warning: label ‘err_ioremap3’ defined but not used [-Wunused-label]
drivers/gpio/gpio-samsung.c:2974:1: warning: label ‘err_ioremap4’ defined but not used [-Wunused-label]
drivers/gpio/gpio-samsung.c:2722:55: warning: unused variable ‘gpio_base4’ [-Wunused-variable]

drivers/gpio/gpio-samsung.c:455:32: warning: ‘exynos_gpio_cfg’ defined but not used [-Wunused-variable]
drivers/gpio/gpio-samsung.c:2126:33: warning: ‘exynos4_gpios_1’ defined but not used [-Wunused-variable]
drivers/gpio/gpio-samsung.c:2228:33: warning: ‘exynos4_gpios_2’ defined but not used [-Wunused-variable]
drivers/gpio/gpio-samsung.c:2373:33: warning: ‘exynos4_gpios_3’ defined but not used [-Wunused-variable]

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
ARM: mach-shmobile: convert mackerel to use the generic MMC GPIO hotplug helper

This also fixes the following modular mmc build failure:

arch/arm/mach-shmobile/built-in.o: In function `ag5evm_sdhi0_gpio_cd':
pfc-sh73a0.c:(.text+0x7c0): undefined reference to `mmc_detect_change'

on this platform by eliminating the use of an inline function, which
calls into the mmc core.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ARM: mach-shmobile: convert ag5evm to use the generic MMC GPIO hotplug helper

This also fixes the following modular mmc build failure:

arch/arm/mach-shmobile/built-in.o: In function `mackerel_sdhi0_gpio_cd':
pfc-sh7372.c:(.text+0x1138): undefined reference to `mmc_detect_change'

on this platform by eliminating the use of an inline function, which
calls into the mmc core.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ARM / mach-shmobile: r8a7779 SMP TWD boot regression fix

Fix SMP TWD boot regression on r8a7779 based platforms caused by:

4200b16 ARM: shmobile: convert to twd_local_timer_register() interface

After the merge of the above commit it has been impossible to boot
r8a7779 based SoCs with SMP enabled and CONFIG_HAVE_ARM_TWD=y. The
kernel crashes at smp_init_cpus() timing which is before the console
has been initialized, so to the user this looks like a kernel lock up
without any particular error message.

This patch fixes the regression on r8a7779 by moving the TWD
registration code from smp_init_cpus() to sys_timer->init() time.

Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ARM / mach-shmobile: sh73a0 SMP TWD boot regression fix

Fix SMP TWD boot regression on sh73a0 based platforms caused by:

4200b16 ARM: shmobile: convert to twd_local_timer_register() interface

After the merge of the above commit it has been impossible to boot
sh73a0 based SoCs with SMP enabled and CONFIG_HAVE_ARM_TWD=y. The
kernel crashes at smp_init_cpus() timing which is before the console
has been initialized, so to the user this looks like a kernel lock up
without any particular error message.

This patch fixes the regression on sh73a0 by moving the TWD
registration code from smp_init_cpus() to sys_timer->init() time.

This patch removed shmobile_twd_init() which is no longer needed

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
ARM / mach-shmobile: Invalidate caches when booting secondary cores

Make sure L1 caches are invalidated when booting secondary
cores. Needed to boot all mach-shmobile SMP systems that
are using Cortex-A9 including sh73a0, r8a7779 and EMEV2.

Thanks to imx and tegra guys for actual code.

Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/renesas into fixes

By Guennadi Liakhovetski (2) and others via Rafael J. Wysocki:
"[...] urgent fixes for Renesas ARM-based platforms.  Four of these
commits are fixes of regressions new in 3.4-rc and the last one is
necessary for SMP to work on those systems in general."

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/renesas:
  ARM / mach-shmobile: Invalidate caches when booting secondary cores
  ARM / mach-shmobile: sh73a0 SMP TWD boot regression fix
  ARM / mach-shmobile: r8a7779 SMP TWD boot regression fix
  ARM: mach-shmobile: convert ag5evm to use the generic MMC GPIO hotplug helper
  ARM: mach-shmobile: convert mackerel to use the generic MMC GPIO hotplug helper
ARM: EXYNOS: use s5p-timer for UniversalC210 board

Commit 069d4e743 ("ARM: EXYNOS4: Remove clock event timers using
ARM private timers") removed support for local timers and forced
to use MCT as event source. However MCT is not operating properly
on early revision of EXYNOS4 SoCs. All UniversalC210 boards are
based on it, so that commit broke support for it. This patch
provides a workaround that enables UniversalC210 boards to boot
again. s5p-timer is used as an event source, it works only for
non-SMP builds.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
ARM: EXYNOS: fix ctrlbit for exynos5_clk_pdma1

It should be (1 << 2) for ctrlbit of exynos5_clk_pdma1.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Merge branch 'v3.4-samsung-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes

* 'v3.4-samsung-fixes-5' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: EXYNOS: fix ctrlbit for exynos5_clk_pdma1
  ARM: EXYNOS: use s5p-timer for UniversalC210 board
Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull a few more GPIO bug fixes from Grant Likely:
 "Oops, missed a couple.  Here's an updated pull req for GPIO"

A set of PCH bug fixes, and one patch to fix up compile warnings

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  gpio/exynos: Fix compiler warnings when non-exynos machines are selected
  gpio: pch9: Use proper flow type handlers
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM: SoC fixes from Olof Johansson:
 "I was hoping to be done with fixes for 3.4 but we got two branches
  from subarch maintainers the last couple of days.  So here is one
  last(?) pull request for arm-soc containing 7 patches:

   - Five of them are for shmobile dealing with SMP setup and compile
     failures
   - The remaining two are for regressions on the Samsung platforms"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: EXYNOS: fix ctrlbit for exynos5_clk_pdma1
  ARM: EXYNOS: use s5p-timer for UniversalC210 board
  ARM / mach-shmobile: Invalidate caches when booting secondary cores
  ARM / mach-shmobile: sh73a0 SMP TWD boot regression fix
  ARM / mach-shmobile: r8a7779 SMP TWD boot regression fix
  ARM: mach-shmobile: convert ag5evm to use the generic MMC GPIO hotplug helper
  ARM: mach-shmobile: convert mackerel to use the generic MMC GPIO hotplug helper
Linux 3.4-rc7

.. and this should hopefully be the last -rc before final 3.4 release.
Merge tag 'for-linus-3.4-20120513' of git://git.infradead.org/linux-mtd

Pull three MTD fixes from David Woodhouse:
 - Fix a lock ordering deadlock in JFFS2
 - Fix an oops in the dataflash driver, triggered by a dummy call to test
   whether it has OTP functionality.
 - Fix request_mem_region() failure on amsdelta NAND driver.

* tag 'for-linus-3.4-20120513' of git://git.infradead.org/linux-mtd:
  mtd: ams-delta: fix request_mem_region() failure
  jffs2: Fix lock acquisition order bug in gc path
  mtd: fix oops in dataflash driver