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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
chown/chmod,etc... don't call permission in the same way that the normal
"open for write" calls do. They still write to the filesystem, so bump the
write count during these operations.
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is the first really tricky patch in the series. It elevates the writer
count on a mount each time a non-special file is opened for write.
We used to do this in may_open(), but Miklos pointed out that __dentry_open()
is used as well to create filps. This will cover even those cases, while a
call in may_open() would not have.
There is also an elevated count around the vfs_create() call in open_namei().
See the comments for more details, but we need this to fix a 'create, remount,
fail r/w open()' race.
Some filesystems forego the use of normal vfs calls to create
struct files. Make sure that these users elevate the mnt
writer count because they will get __fput(), and we need
to make sure they're balanced.
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This basically audits the callers of xattr_permission(), which calls
permission() and can perform writes to the filesystem.
[AV: add missing parts - removexattr() and nfsd posix acls, plug for a leak
spotted by Miklos]
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This takes care of all of the direct callers of vfs_mknod().
Since a few of these cases also handle normal file creation
as well, this also covers some calls to vfs_create().
So that we don't have to make three mnt_want/drop_write()
calls inside of the switch statement, we move some of its
logic outside of the switch and into a helper function
suggested by Christoph.
This also encapsulates a fix for mknod(S_IFREG) that Miklos
found.
[AV: merged mkdir handling, added missing nfsd pieces]
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>
