Commit Graph

91767 Commits

Author SHA1 Message Date
e6816f34e4 [ARM] 4944/2: magician: enable i2c bus
Since recent PXA changes the (non-power-)I2C bus has to be explicitly
enabled from board initialisation code.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
103a175489 [ARM] 4943/2: magician: fix magician.h GPIO header includes
PXA GPIO definitions were split from pxa-regs.h into pxa2xx-gpio.h.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
df56eacdd5 [ARM] 4942/1: magician: fix the backlight driver name
corgi_bl was renamed to generic_bl.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
4fa575b237 [ARM] 4941/1: Add initial defconfig for HTC Magician PDA phones
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
b86a5da8f7 [ARM] 4946/1: pxa3xx: Print an error if we refuse to suspend
The PXA3xx will not suspend if there are no wakeup sources configured.
Print a diagnostic message to make it easier for the user to see what's
happening.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
835e7f1c9a [ARM] 4901/3: mainstone: Register primary I2C bus
Mainstone has the primary I2C bus exposed for use on plugin modules.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
90b8fc3496 [ARM] 4867/1: Adds flash, udc, mci support for gumstix F boards
This patch implements support for Gumstix-F flash, udc and mci. Fixes since the last time are:
- Steve Sakoman as maintainer
- cleanup for udc and mci setup

Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
4354e18812 [ARM] pxa: remove keypad register definitions from pxa-regs.h
Keypad registers are now fully defined within pxa27x-keypad.c, no
need to keep those definitions in pxa-regs.h

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
5fa41510f0 [ARM] pxa: add keypad support for littleton
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:06 +01:00
468e086f78 [ARM] pxa: add keypad support for zylonite
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
55c26e4011 [ARM] pxa: add partial keypad support for mainstone
This is partial because mainstone's keypad is really special, some of
the keys like '1', '2', ... are actually connected to two row/column
juntions, thus pressing '1' is equivalent to pressing 'A' & 'H'.

This is really brain damanged since it makes distinguishing between
pressing '1' and multiple keys pressing of 'A' & 'H' difficult.

So these special keys are not supported for the time being.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
3732098041 [ARM] pxa: add pxa27x_keypad device and pxa_set_keypad_info()
also update the clk definitions in pxa27x and pxa3xx.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
450d28749c [ARM] pxa: use gpio_keys.c to support mainstone's wakeup switch of GPIO1
NOTE: currently don't know if the key code of KEY_SUSPEND is fit for
such usage.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
c0a596d6a1 [ARM] pxa: allow dynamic enable/disable of GPIO wakeup for pxa{25x,27x}
Changes include:

1. rename MFP_LPM_WAKEUP_ENABLE into MFP_LPM_CAN_WAKEUP to indicate
   the board capability of this pin to wakeup the system

2. add gpio_set_wake() and keypad_set_wake() to allow dynamically
   enable/disable wakeup from GPIOs and keypad GPIO

   * these functions are currently kept in mfp-pxa2xx.c due to their
     dependency to the MFP configuration

3. pxa2xx_mfp_config() only gives early warning if MFP_LPM_CAN_WAKEUP
   is set on incorrect pins

So that the GPIO's wakeup capability is now decided by the following:

   a) processor's capability: (only those GPIOs which have dedicated
      bits within PWER/PRER/PFER can wakeup the system), this is
      initialized by pxa{25x,27x}_init_mfp()

   b) board design decides:
      - whether the pin is designed to wakeup the system (some of
        the GPIOs are configured as other functions, which is not
        intended to be a wakeup source), by OR'ing the pin config
        with MFP_LPM_CAN_WAKEUP

      - which edge the pin is designed to wakeup the system, this
        may depends on external peripherals/connections, which is
        totally board specific; this is indicated by MFP_LPM_EDGE_*

   c) the corresponding device's (most likely the gpio_keys.c) wakeup
      attribute:

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
9b02b2df00 [ARM] pxa: use new pin configuration mechanism for lubbock
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
fef06d274f [ARM] pxa: use new pin configuration mechanism for mainstone
1. the following code to configure PGSRx is no way portable and
   intuitive:

-	PGSR0 = 0x00008800;
-       PGSR1 = 0x00000002;
-       PGSR2 = 0x0001FC00;
-       PGSR3 = 0x00001F81;

   this is removed as low power state has already been encoded in
   the pin configuration definitions.

   Note: there is no specific reason for some of the GPIOs to drive
   high in low power mode as indicated by the above setting, those
   bits are ignored, and the result is validated to work.

2. the following code to configure GPIO wakeup is removed as this
   is now totally handled by pxa2xx_mfp_config():

-       PWER  = 0xC0000002;
-       PRER  = 0x00000002;
-       PFER  = 0x00000002;

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:05 +01:00
3d3934c357 [ARM] pxa: move ARRAY_AND_SIZE definition to generic.h
for use by other platforms

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
7facc2f937 [ARM] pxa: add MFP-alike pin configuration support for pxa{25x, 27x}
Pin configuration on pxa{25x,27x} has now separated from generic GPIO
into dedicated mfp-pxa2xx.c by this patch. The name "mfp" is borrowed
from pxa3xx and is used here to alert the difference between the two
concepts: pin configuration and generic GPIOs.  A GPIO can be called
a "GPIO" _only_ when the corresponding pin is configured so.

A pin configuration on pxa{25x,27x} is composed of:

    - alternate function selection (or pin mux as commonly called)
    - low power state or sleep state
    - wakeup enabling from low power mode

The following MFP_xxx bit definitions in mfp.h are re-used:

    - MFP_PIN(x)
    - MFP_AFx
    - MFP_LPM_DRIVE_{LOW, HIGH}
    - MFP_LPM_EDGE_*

Selecting alternate function on pxa{25x, 27x} involves configuration
of GPIO direction register GPDRx, so a new bit and MFP_DIR_{IN, OUT}
are introduced. And pin configurations are defined by the following
two macros:

    - MFP_CFG_IN  : for input alternate functions
    - MFP_CFG_OUT : for output alternate functions

Every configuration should provide a low power state if it configured
as output using MFP_CFG_OUT().  As a general guideline, the low power
state should be decided to minimize the overall power dissipation. As
an example, it is better to drive the pin as high level in low power
mode if the GPIO is configured as an active low chip select.

Pins configured as GPIO are defined by MFP_CFG_IN(). This is to avoid
side effects when it is firstly configured as output.  The actual
direction of the GPIO is configured by gpio_direction_{input, output}

Wakeup enabling on pxa{25x, 27x} is actually GPIO based wakeup, thus
the device based enable_irq_wake() mechanism is not applicable here.

E.g.  invoking enable_irq_wake() with a GPIO IRQ as in the following
code to enable OTG wakeup is by no means portable and intuitive, and
it is valid _only_ when GPIO35 is configured as USB_P2_1:

    enable_irq_wake( gpio_to_irq(35) );

To make things worse, not every GPIO is able to wakeup the system.
Only a small number of them can, on either rising or falling edge,
or when level is high (for keypad GPIOs).

Thus, another new bit is introduced to indicate that the GPIO will
wakeup the system:

    - MFP_LPM_WAKEUP_ENABLE

The following macros can be used in platform code, and be OR'ed to
the GPIO configuration to enable its wakeup:

    - WAKEUP_ON_EDGE_{RISE, FALL, BOTH}
    - WAKEUP_ON_LEVEL_HIGH

The WAKEUP_ON_LEVEL_HIGH is used for keypad GPIOs _only_, there is
no edge settings for those GPIOs.

These WAKEUP_ON_* flags OR'ed on wrong GPIOs will be ignored in case
that platform code author is careless enough.

The tradeoff here is that the wakeup source is fully determined by
the platform configuration, instead of enable_irq_wake().

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
a683b14df8 [ARM] pxa: separate GPIOs and their mode definitions to pxa2xx-gpio.h
two reasons:
1. GPIO namings and their mode definitions are conceptually not part
   of the PXA register definitions

2. this is actually a temporary move in the transition of PXA2xx to
   use MFP-alike APIs (as what PXA3xx is now doing), so that legacy
   code will still work and new code can be added in step by step

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
4be35e236c [ARM] pxa: move mfp sysdev registeration out for suspend/resume order
MFP configurations after resume should be done before the GPIO registers
are restored.  Move the mfp sysdev registeration to the same place where
GPIO and IRQ sysdev(s) are registered to better control the order.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
06b2666e89 [ARM] pxa: rename mfp.c to mfp-pxa3xx.c to indicate it's pxa3xx specific
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
689c04a390 [ARM] pxa: make pxa_gpio_irq_type() processor generic
The main issue here is that pxa3xx does not have GAFRx registers,
access directly to these registers should be avoided for pxa3xx:

1. introduce __gpio_is_occupied() to indicate the GAFRx and GPDRx
   registers are already configured on pxa{25x,27x} while returns
   0 always on pxa3xx

2. pxa_gpio_mode(gpio | GPIO_IN) is replaced directly with assign-
   ment of GPDRx, the side effect of this change is that the pin
   _must_ be configured before use, pxa_gpio_irq_type() will not
   change the pin to GPIO, as this restriction is sane, esp. with
   the new MFP framework

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
663707c1a9 [ARM] pxa: move GPIO sysdev outside of generic.c into gpio.c
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
b9e25aced3 [ARM] pxa: merge assignment of set_wake into pxa_init_{irq,gpio}()
To further clean up the GPIO and IRQ structure:

1. pxa_init_irq_gpio() and pxa_init_gpio() combines into a single
   function pxa_init_gpio()

2. assignment of set_wake merged into pxa_init_{irq,gpio}() as
   an argument

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
f6fb7af476 [ARM] pxa: integrate low IRQ chip (ICIP) and high IRQ chip (ICIP2) into one
This makes the code better organized and simplified a bit.  The change
will lose a bit of performance when performing IRQ ack/mask/unmask,but
that's not too much after checking the result binary.

This patch also removes the ugly #ifdef CONFIG_PXA27x .. #endif by
carefully not to access those pxa{27x,3xx} specific registers, this
is done by keeping an internal IRQ number variable.  The pxa-regs.h
is also modified so registers for IRQ > PXA_IRQ(31) are made public
even if CONFIG_PXA{27x,3xx} isn't defined (for pxa25x's sake)

The incorrect assumption in the original code that internal irq starts
from 0 is also corrected by comparing with PXA_IRQ(0).

"struct sys_device" for the IRQ are reduced into one single device on
pxa{27x,3xx}.

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:04 +01:00
e3630db1fa [ARM] pxa: move GPIO IRQ specific code out of irq.c into gpio.c
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
0e037bbb4a [ARM] pxa: introduce GPIO_CHIP() macro to clean up the definitions
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
dfa1067996 [ARM] pxa: cleanup the coding style of pxa_gpio_set_type()
by

1. wrapping long lines and making comments tidy

2. using IRQ_TYPE_* instead of migration macros __IRQT_*

3. introduce a pr_debug() for the commented printk(KERN_DEBUG ...)
   stuff

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
a7bf4dbaba [ARM] pxa: make GPIO IRQ code less dependent on the internal IRQs
by:

1. introduce dedicated pxa_{mask,unmask}_low_gpio()

2. remove set_irq_chip(IRQ_GPIO_2_x, ...) which has already been
   initialized in pxa_init_irq()

3. introduce dedicated pxa_init_gpio_set_wake()

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
7a26d3a33f [ARM] pxa: generalize the muxed gpio IRQ handling code with loop and ffs()
1. As David Brownell suggests, using ffs() is going to make the loop
   a bit faster (by avoiding unnecessary shift and iteration)

2. Russell suggested find_{first,next}_bit() being used with the
   gedr[] array

Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
d72b1370b0 [ARM] 4868/1: Enhance pxa270 GPIO definitions
Enhanced GPIO alternate functions descriptions,
taken from Intel PXA270 Developers Manual.

Signed-off-by: Robert Jarzmik <rjarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
942de47bfe [ARM] 4834/3: Convert ASoC pxa2xx-ac97 driver to use the clock API
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
93873fbfd8 [ARM] 4833/3: Convert non-SoC PXA2xx AC97 driver to clock API
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
60bfe7fa3d [ARM] 4832/2: Support AC97CLK on PXA3xx via the clock API
The AC97 clock rate on PXA3xx is generated with a configurable divider
from sys_pll.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:03 +01:00
27b98a671f [ARM] 4831/2: Add PXA2xx AC97 clocks to clock API
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:02 +01:00
dcc88a170c [ARM] 4830/1: Add support for the CLK_POUT pin on PXA3xx CPUs
Expose control of the PXA3xx 13MHz CLK_POUT pin via the clock API

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:29:02 +01:00
c48b2e90ae [ARM] remove redundant display of free swap space in show_mem()
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:28:10 +01:00
28fab1a2fd [ARM] Fix kernel mode preemption
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>
2008-04-19 11:28:09 +01:00
84081bd220 [ARM] 4881/1: print unrecognised processor ID as part of failure message
If we fail to boot due to an unsupported processor ID, print the
processor ID as part of the failure message.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:28:08 +01:00
0f9801463b [ARM] 4854/1: fix the load address of uImage for CONFIG_ZBOOT_ROM=y
U-Boot puts an image at the load address specified in the uImage
header before jumping to the entry point.

In the CONFIG_ZBOOT_ROM case ZBOOT_ROM_TEXT is the right load
address.

Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:28:07 +01:00
cbfc0f0406 [ARM] 4852/1: Add timerfd_create, timerfd_settime and timerfd_gettime syscall entries
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:28:06 +01:00
184dd48102 [ARM] Update mach-types
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 11:28:05 +01:00
15f7d677cc [ARM] Remove leds-tosa.c
See f99ee0b99214cf5329e711859e3f5fd02c820a24

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-04-19 10:14:31 +01:00
ad775f5a8f [PATCH] r/o bind mounts: debugging for missed calls
There have been a few oopses caused by 'struct file's with NULL f_vfsmnts.
There was also a set of potentially missed mnt_want_write()s from
dentry_open() calls.

This patch provides a very simple debugging framework to catch these kinds of
bugs.  It will WARN_ON() them, but should stop us from having any oopses or
mnt_writer count imbalances.

I'm quite convinced that this is a good thing because it found bugs in the
stuff I was working on as soon as I wrote it.

[hch: made it conditional on a debug option.
      But it's still a little bit too ugly]

[hch: merged forced remount r/o fix from Dave and akpm's fix for the fix]

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:28 -04:00
2e4b7fcd92 [PATCH] r/o bind mounts: honor mount writer counts at remount
Originally from: Herbert Poetzl <herbert@13thfloor.at>

This is the core of the read-only bind mount patch set.

Note that this does _not_ add a "ro" option directly to the bind mount
operation.  If you require such a mount, you must first do the bind, then
follow it up with a 'mount -o remount,ro' operation:

If you wish to have a r/o bind mount of /foo on bar:

	mount --bind /foo /bar
	mount -o remount,ro /bar

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:27 -04:00
3d733633a6 [PATCH] r/o bind mounts: track numbers of writers to mounts
This is the real meat of the entire series.  It actually
implements the tracking of the number of writers to a mount.
However, it causes scalability problems because there can be
hundreds of cpus doing open()/close() on files on the same mnt at
the same time.  Even an atomic_t in the mnt has massive scalaing
problems because the cacheline gets so terribly contended.

This uses a statically-allocated percpu variable.  All want/drop
operations are local to a cpu as long that cpu operates on the same
mount, and there are no writer count imbalances.  Writer count
imbalances happen when a write is taken on one cpu, and released
on another, like when an open/close pair is performed on two

Upon a remount,ro request, all of the data from the percpu
variables is collected (expensive, but very rare) and we determine
if there are any outstanding writers to the mount.

I've written a little benchmark to sit in a loop for a couple of
seconds in several cpus in parallel doing open/write/close loops.

http://sr71.net/~dave/linux/openbench.c

The code in here is a a worst-possible case for this patch.  It
does opens on a _pair_ of files in two different mounts in parallel.
This should cause my code to lose its "operate on the same mount"
optimization completely.  This worst-case scenario causes a 3%
degredation in the benchmark.

I could probably get rid of even this 3%, but it would be more
complex than what I have here, and I think this is getting into
acceptable territory.  In practice, I expect writing more than 3
bytes to a file, as well as disk I/O to mask any effects that this
has.

(To get rid of that 3%, we could have an #defined number of mounts
in the percpu variable.  So, instead of a CPU getting operate only
on percpu data when it accesses only one mount, it could stay on
percpu data when it only accesses N or fewer mounts.)

[AV] merged fix for __clear_mnt_mount() stepping on freed vfsmount

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:27 -04:00
2c463e9548 [PATCH] r/o bind mounts: check mnt instead of superblock directly
If we depend on the inodes for writeability, we will not catch the r/o mounts
when implemented.

This patches uses __mnt_want_write().  It does not guarantee that the mount
will stay writeable after the check.  But, this is OK for one of the checks
because it is just for a printk().

The other two are probably unnecessary and duplicate existing checks in the
VFS.  This won't make them better checks than before, but it will make them
detect r/o mounts.

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:27 -04:00
ec82687f29 [PATCH] r/o bind mounts: elevate count for xfs timestamp updates
Elevate the write count during the xfs m/ctime updates.

XFS has to do it's own timestamp updates due to an unfortunate VFS
design limitation, so it will have to track writers by itself aswell.

[hch: split out from the touch_atime patch as it's not related to it at all]

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:26 -04:00
2f676cbc0d [PATCH] r/o bind mounts: make access() use new r/o helper
It is OK to let access() go without using a mnt_want/drop_write() pair because
it doesn't actually do writes to the filesystem, and it is inherently racy
anyway.  This is a rare case when it is OK to use __mnt_is_readonly()
directly.

Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:26 -04:00
9ac9b8474c [PATCH] r/o bind mounts: write counts for truncate()
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19 00:29:25 -04:00