Even though the port is not used for anything real there yet, this
will change as tty buffers will be in tty_port in the near future. So
the port will be needed in all drivers.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the timer ticks while we are holding the spinlock, the system
deadlocks. It is due to synchronous del_timer.
So to fix that, use spinlocks that properly disable bottom halves.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Again, no need to do that from the pci probe function.
Hmm, I noticed this driver is marked as BROKEN. Won't touch it more,
it has to be converted to dynamic tty driver allocation first.
Perhaps it is time to move it to staging?
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
They are in .bss which is initialized to zeros when the module is
loaded/kernel booted.
What a strange way to do the initialization once in the pci probe
routine...
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* do not test if tty->index is in bounds. It is always.
* tty->index is not a minor! Fix that.
>From now on, let's assume that the parameter of the function is tty
index with base being zero. This makes also the code more readable.
Factually, there is no real change as tty_driver->minor_start is zero,
so the tests are equivalent. But it did not make sense. And if this
had changed eventually, it would have caused troubles.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Checking if tty->index is in bounds is not needed. The tty has the
index set in the initial open. This is done in get_tty_driver. And it
can be only in interval <0,driver->num).
So remove the tests which check exactly this interval. Some are
left untouched as they check against the current backing device count.
(Leaving apart that the check is racy in most of the cases.)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The macro is always defined now. This was there only for historical
reasons.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is needed because the tty buffer will become a tty_port member
later. That will help us to wipe out most of the races and checks for
the tty pointer in hot paths.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The test and the assignment were racy. Make it really a singleton.
This is achieved by one global variable initialized at the module
init.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It makes the code more readable. We move the setup to the allocation
location because we need to initialize timers only once.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Note that tty->ops->shutdown is called from whatever context the user
drops the last tty reference from. E.g. if one takes a reference in
an ISR, tty close happens on other CPU and the final tty put is from
the ISR, tty->ops->shutdown will be called from that hard irq context.
We would have a problem in vt if we start using tty refcounting from
other contexts than user there. It is because vt's shutdown uses
mutexes. This is yet to be fixed.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
By using ASYNC_SPD_MASK instead of the single speed bits.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is from tty_reopen:
struct tty_driver *driver = tty->driver;
...
tty->driver = driver;
and it doesn't make sense at all. The driver is intended to be set in
initialize_tty_struct from tty_init_dev (initial open). So this set in
tty_reopen is not needed.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the useless local variable and return the value itself.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.
pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It was added back in 2004 and never used for anything real. Remove the
only assignment in the tree as well.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Like the rest of the kernel, make a stub from alloc_tty_driver which
calls __alloc_tty_driver with proper owner. This will save us one more
assignment on the driver side.
Also this fixes some drivers which didn't set the owner. This allowed
user to remove the module from the system even though a tty from the
driver is still open.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TTY buffer head and tail are initialized in tty_buffer_init. No need
to do it once again in initialize_tty_struct where tty_buffer_init is
called.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a piece I missed the last time.
Do not copy the functionality all over the tree. Instead, use the
helper the tty layer provides us with.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We leave the existing paste mess alone and just fix up the vt side of
things.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of this ventures into selection which is still a complete lost cause. We
are not making it any worse. It's completely busted anyway.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At this point we have the tty_lock guarding a couple of oddities, plus the
translation and unimap still.
We also extend the console_lock in a couple of spots where coverage is wrong
and switch vcs_open to use the right lock !
[Fixed the locking issue Jiri reported]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The font methods are console_lock covered. Unfortunately they don't extend
the lock over all the needed tests.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
TIOCSERGETLSR should be saved in a uint so the cast here to unsigned
long is a bug.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following commit: be4b028195
(tty: serial: OMAP: block idle while the UART is transferring data in PIO mode),
is introducing an oops if OMAP is booted using device tree blob because
the pdata will not be initialized.
Check if pdata is set before de-referencing it.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Keyboard struct lifetime is easy, but the locking is not and is completely
ignored by the existing code. Tackle this one head on
- Make the kbd_table private so we can run down all direct users
- Hoick the relevant ioctl handlers into the keyboard layer
- Lock them with the keyboard lock so they don't change mid keypress
- Add helpers for things like console stop/start so we isolate the poking
around properly
- Tweak the braille console so it still builds
There are a couple of FIXME locking cases left for ioctls that are so hideous
they should be addressed in a later patch. After this patch the kbd_table is
private and all the keyboard jiggery pokery is in one place.
This update fixes speakup and also a memory leak in the original.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver is broken, as reported by Jiri, and to quote Ben:
Just remove the driver, I don't think anybody cares.
so I'm doing just that here.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
First step to debletcherising the vt console layer - pick a victim and fix
the locking
This is a nice simple object with its own rules so lets pick it out for
treatment. The user of the table already has a lock so we will also use the
same lock for updates.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a50f724a43.
Sasha reported that this causes problems, so revert it.
Cc: Alan Cox <alan@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit d3bda5298a.
Sasha reported that this causes problems, so revert it.
Cc: Sasha Levin <levinsasha928@gmail.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In DMA-operated uart, I found that rx data can be taken by the UART
interrupts during the DMA irq handler. pl011_int is occurred just
before it goes inside spin_lock_irq. When it returns to the callback,
DMA buffer already has been flushed. Then, pl011_dma_rx_chars gets
invalid data. So I add check for the residue as the patch bellow.
Signed-off-by: Chanho Min <chanho.min@lge.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without that fix machines having a s3c2442 CPU have something
like that in dmesg:
samsung-uart s3c2440-uart.0: could not find driver data
samsung-uart s3c2440-uart.1: could not find driver data
samsung-uart s3c2440-uart.2: could not find driver data
And serial is never initialized.
The previous log was obtained trough early printk on the gta02
machine.
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/mux.c included 'linux/tty.h' twice, remove
the duplicate.
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are multiple users of this file from different source
paths now, and rather than have ../ paths in include statements,
just move the file to the linux header dir.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Just a few new device ids, omap serial driver regression fixes, and a
build fix for the 8250 driver movement.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Serial/TTY fixes for the 3.3-rc3 tree
Just a few new device ids, omap serial driver regression fixes, and a
build fix for the 8250 driver movement.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'tty-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: serial: omap-serial: wakeup latency constraint is in microseconds, not milliseconds
tty: serial: OMAP: block idle while the UART is transferring data in PIO mode
tty: serial: OMAP: use a 1-byte RX FIFO threshold in PIO mode
m32r: relocate drivers back out of 8250 dir
tty: fix a build failure on sparc
serial: samsung: Add support for EXYNOS5250
serial: samsung: Add support for EXYNOS4212 and EXYNOS4412
drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer
Big things here is the deletion of the Android pmem driver, as it's
obsolete and no one uses it, the gma500 driver as it's already in the
drm portion of the kernel tree, and the pohmelfs filesystem as it's
obsolete and a rewritten version is being proposed for the fs/ section
of the kernel.
Other than that, a smattering of different bugfixes and regressions, and
some omap drm api merge fixups that were needed due to api changes in
the main portion of the drm tree, allowing this code to build properly
again.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Staging tree patches for 3.3-rc3
Big things here is the deletion of the Android pmem driver, as it's
obsolete and no one uses it, the gma500 driver as it's already in the
drm portion of the kernel tree, and the pohmelfs filesystem as it's
obsolete and a rewritten version is being proposed for the fs/ section
of the kernel.
Other than that, a smattering of different bugfixes and regressions, and
some omap drm api merge fixups that were needed due to api changes in
the main portion of the drm tree, allowing this code to build properly
again.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'staging-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (28 commits)
staging: pohmelfs: remove drivers/staging/pohmelfs
staging: android/ram_console: Don't build on arches w/o ioremap
staging: r8712u: Use asynchronous firmware loading
staging: usbip: fix to prevent potentially using uninitialized spinlock
staging: r8712u: Fix problem when CONFIG_R8712_AP is set
staging: tidspbridge: fix incorrect free to drv_datap
staging: tidspbridge: fix bridge_open memory leaks
staging: android: lowmemorykiller: Don't wait more than one second for a process to die
MAINTAINERS: staging: iio: add iio information
staging: zcache: fix serialization bug in zv stats
staging: fix go7007-usb license
Staging: android: binder: Fix crashes when sharing a binder file between processes
Staging: android: Remove pmem driver
Staging: asus_oled: fix NULL-ptr crash on unloading
Staging: asus_oled: fix image processing
Staging: android: binder: Don't call dump_stack in binder_vma_open
staging: r8712u: Add new Sitecom UsB ID
zcache: Set SWIZ_BITS to 8 to reduce tmem bucket lock contention.
zcache: fix deadlock condition
staging: drm/omap: fix locking issue
...
A few fixes for kobject warnings that have popped up in the cpu hotplug path,
and a regression fix for the speed of the hotplug memory code.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Driver core fixes for the 3.3-rc3 tree.
A few fixes for kobject warnings that have popped up in the cpu hotplug path,
and a regression fix for the speed of the hotplug memory code.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'driver-core-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver-core: cpu: fix kobject warning when hotplugging a cpu
ACPI: remove duplicated lines of merging problems with acpi_processor_add
docbook: fix fatal errors in device-drivers docbook and add DMA Management section
drivers/base/memory.c: fix memory_dev_init() long delay
driver core: cpu: remove kernel warning when removing a cpu
Nothing big here, some Kconfig fixes for the MISC_DEVICES config option
that was being used incorrectly, and some other minor bug fixes.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Minor char-misc fixes for 3.3-rc3
Nothing big here, some Kconfig fixes for the MISC_DEVICES config option
that was being used incorrectly, and some other minor bug fixes.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'char-misc-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mmc: cb710 core: Add missing spin_lock_init for irq_lock of struct cb710_chip
cs5535-mfgpt: don't call __init function from __devinit
vmw_balloon: fix for a -Wuninitialized warning
drivers: misc: Remove MISC_DEVICES config option
c2port: fix build error for duramar2150 due to missing header.
Here are a few minor USB fixes and a bunch of device id updates for the
USB drivers.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
USB fixes for 3.3-rc3
Here are a few minor USB fixes and a bunch of device id updates for the
USB drivers.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'usb-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: usbserial: add new PID number (0xa951) to the ftdi driver
usb: ch9.h: usb_endpoint_maxp() uses __le16_to_cpu()
usb: musb: fix a build error on mips
uwb & wusb & usb wireless controllers: fix kconfig error & build errors
usb: Skip PCI USB quirk handling for Netlogic XLP
powerpc/usb: fix issue of CPU halt when missing USB PHY clock
usb: otg: mv_otg: Add dependence
usb: host: Distinguish Kconfig text for Freescale controllers
USB: add new zte 3g-dongle's pid to option.c
usb: ch9.h: usb_endpoint_maxp() uses __le16_to_cpu()
USB: qcserial: don't enable autosuspend
USB: qcserial: add several new serial devices
usb: otg: mv_otg: Add dependence
usb: gadget: zero: fix bug in loopback autoresume handling
The receive FIFO wakeup latency estimate in the omap-serial driver is
three orders of magnitude too small. This effectively prevents the
MPU from going to a low-power state when CONFIG_CPU_IDLE=y. This is a
major power management regression and masks some other FIFO-related
bugs in the driver.
Fix by correcting the most egregious problem in the RX wakeup latency
estimate. There are several other flaws in the estimator; these will
be fixed by a separate patch series intended for 3.4.
The difference in low-power states with this patch can be observed via
debugfs in pm_debug/count.
This estimate does not have any effect when CONFIG_CPU_IDLE=n.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent OMAP UARTs from going idle while they are still transferring
data in PIO mode. This works around an oversight in the OMAP UART
hardware present in OMAP34xx and earlier: an idle UART won't send a
wakeup when the TX FIFO threshold is reached. This causes long delays
during data transmission when the MPU powerdomain enters a low-power
mode. The MPU interrupt controller is not able to respond to
interrupts when it's in a low-power state, so the TX buffer is not
refilled until another wakeup event occurs.
This fix changes the erratum i291 DMA idle workaround. Rather than
toggling between force-idle and no-idle, it will toggle between
smart-idle and no-idle. The important part of the workaround is the
no-idle part, so this shouldn't result in any change in behavior.
This fix should work on all OMAP UARTs. Future patches intended for
the 3.4 merge window will make this workaround conditional on a
"feature" flag, and will use the OMAP36xx+ TX event wakeup support.
Thanks to Kevin Hilman <khilman@ti.com> for mentioning the erratum i291
workaround, which led to the development of this approach.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the (default) PIO mode, use a one-byte RX FIFO threshold. The OMAP
UART IP blocks do not appear to be capable of waking the system under
an RX timeout condition. Since the previous RX FIFO threshold was 16
bytes, this meant that omap-serial.c did not become aware of any
received data until all those bytes arrived or until another UART
interrupt occurred. This made the serial console and presumably other
serial applications (GPS, serial Bluetooth) unusable or extremely
slow. A 1-byte RX FIFO threshold also allows the MPU to enter a
low-power consumption state while waiting for the FIFO to fill.
This can be verified using the serial console by comparing the
behavior when "0123456789abcde" is pasted in from another window, with
the behavior when "0123456789abcdef" is pasted in. Since the former
string is less than sixteen bytes long, the string is not echoed for
some time, while the latter string is echoed immediately.
DMA operation is unaffected by this patch.
Thanks to Russell King - ARM Linux <linux@arm.linux.org.uk> for some
additional information on the standard behavior of the RX timeout
event, which was used to improve this commit description.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
_parse_integer() does one or two division instructions (which are slow)
per digit parsed to perform the overflow check.
Furthermore, these are particularly expensive examples of division
instruction as the number of clock cycles required to complete them may
go up with the position of the most significant set bit in the dividend:
if (*res > div_u64(ULLONG_MAX - val, base))
which is as maximal as possible.
Worse, on 32-bit arches, more than one of these division instructions
may be required per digit.
So, assuming we don't support a base of more than 16, skip the check if the
top nibble of the result is not set at this point.
Signed-off-by: David Howells <dhowells@redhat.com>
[ Changed it to not dereference the pointer all the time - even if the
compiler can and does optimize it away, the code just looks cleaner.
And edited the top nybble test slightly to make the code generated on
x86-64 better in the loop - test against a hoisted constant instead of
shifting and testing the result ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jiri Slaby