We allocate during interrupts so while our buffering is normally diced up
small anyway on some hardware at speed we can pressure the VM excessively
for page pairs. We don't really need big buffers to be linear so don't try
so hard.
In order to make this work well we will tidy up excess callers to request_room,
which cannot itself enforce this break up.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This was noticed by Matthias Urlichs and he proposed a fix. This patch
does the fixing a different way to avoid introducing several new race
conditions into the code.
The problem case is TTY_DRIVER_RESET_TERMIOS = 0. In that case while we
abort the ldisc change, the hangup processing has not cleaned up and restarted
the ldisc either.
We can't restart the ldisc stuff in the set_ldisc as we don't know what
the hangup did and may touch stuff we shouldn't as we are no longer
supposed to influence the tty at that point in case it has been re-opened
before we get rescheduled.
Instead do it the simple way. Always re-init the ldisc on the hangup, but
use TTY_DRIVER_RESET_TERMIOS to indicate that we should force N_TTY.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The original author didn't realise the kernel lock was a drop while sleep
lock so did clever (and wrong) things to work around the non need to avoid
deadlocks. Remove the cleverness and the comment (as we don't hold the BKL
now anyway in those paths)
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Nozomi tty handling is very broken on the open/close side (See
http://bugzilla.kernel.org/show_bug.cgi?id=13024 for one example). In
particular it marks the tty as closed on the first close() not on the last.
Most of the logic is pretty solid except for the open/close path so switch
to the tty_port helpers and let them do all the heavy lifting. This is also
fixes all the POSIX behaviour violations in the open/close paths.
Begin by adding the tty port usage
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stanse found a potential null dereference in mgsl_put_char and
mgsl_write. There is a check for tty being NULL, but it is
dereferenced earlier.
Actually, tty cannot be NULL in .write and .put_char, so remove
the tests.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stephen Rothwell found the following warning (x86_64 allmodconfig):
drivers/char/ip2/ip2main.c:511: warning: 'ip2_setup' defined but not used
This patch adds module parameter to fix the above warning.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On the kernel command line we can pass "module parameters". So #ifdef
MODULE is obsolute now. Remove it completely. When CONFIG_PCI=n and
building ip2main.c then we are hit by the following warning. So move
*pdev into #ifdef CONFIG_PCI.
drivers/char/ip2/ip2main.c: In function `ip2_loadmain':
drivers/char/ip2/ip2main.c:542: warning: unused variable `pdev'
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Acked-by: Michael H. Warfield <mhw@WittsEnd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We can pass "module parameters" on the kernel command line even when
!MODULE. So, #ifdef MODULE becomes obsolete. Also move the declaration
moxa_board_conf at the start of the function, since we were hit by the
following warning.
drivers/char/moxa.c: In function `moxa_init':
drivers/char/moxa.c:1040: warning: ISO C90 forbids mixed declarations and code
Signed-off-by: Rakib Mullick<rakib.mullick@gmail.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
vtermnos[] is unsigned, so this test was wrong.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Convert printks to pr_<level>
Convert some embedded function names to %s...__func__
Remove a period after exclamation points.
Remove #define pr_dbg which could be used by future kernel.h includes
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Stanse found unnecessary test in mxser_startup.
tty is dereferenced earlier, the test is superfluous. Remove it.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
With gcc 4.0.2:
drivers/char/cyclades.c: In function 'cyy_interrupt':
drivers/char/cyclades.c:581: warning: 'info' may be used uninitialized in this function
introduced by
: commit 3aeea5b922
: Author: Jiri Slaby <jirislaby@gmail.com>
: AuthorDate: Sat Sep 19 13:13:16 2009 -0700
: Commit: Live-CD User <linux@linux.site>
: CommitDate: Sat Sep 19 13:13:16 2009 -0700
:
: cyclades: introduce cyy_readb/writeb
In fact the true branch which uses uninitialized 'info' can never
happen because chip is always less than ->nchips and channel is
always less than 4 which we alloc.
So behave similar to rx handling and remove the test completely.
I wonder why gcc 4.4.1 doesn't spit a word.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix transmit bug that could drop send data if write() called close to
serial transmitter going idle after sending previous data. Bug is caused
by incorrect use of device information member tx_count.
Driver originally processed one data block (write call) at a time, waiting
for transmit idle before sending more. tx_count recorded how much data
was loaded in DMA buffers on write(), and was cleared on send completion.
tx_count use was overloaded to record accumulated data from put_char()
callback when transmitter was idle.
A bug was introduced when transmit code was reworked to allow multiple
blocks of data in the tx DMA buffers which keeps transmitter from going
idle between blocks. tx_count was set to size of last block loaded,
cleared when tx went idle, and monitored to know when to restart
transmitter without proper synchronization. tx_count could be cleared
when unsent data remained in DMA buffers and transmitter required
restarting, effectively dropping unsent data.
Solution:
1. tx_count now used only to track accumulated data from put_char
2. DMA buffer state tracked by direct inspection of descriptors
with spinlock synchronization
3. consolidate these tasks in tx_load() :
a. check for available buffer space
b. load buffers
c. restart DMA and or serial transmitter as needed
These steps were previously duplicated in multiple places,
sometimes incompletely.
4. fix use of tx_count as active transmit indicator,
instead using tx_active which is meant for that purpose
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (62 commits)
Input: atkbd - release previously reserved keycodes 248 - 254
Input: add KEY_WPS_BUTTON definition
Input: ads7846 - add regulator support
Input: winbond-cir - fix suspend/resume
Input: gamecon - use pr_err() and friends
Input: gamecon - constify some of the setup structures
Input: gamecon - simplify pad type handling
Input: gamecon - simplify coordinate calculation for PSX
Input: gamecon - fix some formatting issues
Input: gamecon - add rumble support for N64 pads
Input: wacom - add device type to device name string
Input: s3c24xx_ts - report touch only when stylus is down
Input: s3c24xx_ts - re-enable IRQ on resume
Input: wacom - constify product features data
Input: wacom - use per-device instance of wacom_features
Input: sh_keysc - enable building on SH-Mobile ARM
Input: wacom - get features from driver info
Input: rotary-encoder - set gpio direction for each requested gpio
Input: sh_keysc - update the driver with mode 6
Input: sh_keysc - switch to using bitmaps
...
* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Protect pid lookup in compat code with RCU
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Fix documentation of default chip disable()
* 'bkl-drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
nvram: Drop the BKL from nvram_open()
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, cacheinfo: Enable L3 CID only on AMD
x86, cacheinfo: Remove NUMA dependency, fix for AMD Fam10h rev D1
x86, cpu: Print AMD virtualization features in /proc/cpuinfo
x86, cacheinfo: Calculate L3 indices
x86, cacheinfo: Add cache index disable sysfs attrs only to L3 caches
x86, cacheinfo: Fix disabling of L3 cache indices
intel-agp: Switch to wbinvd_on_all_cpus
x86, lib: Add wbinvd smp helpers
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (88 commits)
powerpc: Fix lwsync feature fixup vs. modules on 64-bit
powerpc: Convert pmc_owner_lock to raw_spinlock
powerpc: Convert die.lock to raw_spinlock
powerpc: Convert tlbivax_lock to raw_spinlock
powerpc: Convert mpic locks to raw_spinlock
powerpc: Convert pmac_pic_lock to raw_spinlock
powerpc: Convert big_irq_lock to raw_spinlock
powerpc: Convert feature_lock to raw_spinlock
powerpc: Convert i8259_lock to raw_spinlock
powerpc: Convert beat_htab_lock to raw_spinlock
powerpc: Convert confirm_error_lock to raw_spinlock
powerpc: Convert ipic_lock to raw_spinlock
powerpc: Convert native_tlbie_lock to raw_spinlock
powerpc: Convert beatic_irq_mask_lock to raw_spinlock
powerpc: Convert nv_lock to raw_spinlock
powerpc: Convert context_lock to raw_spinlock
powerpc/85xx: Add NOR, LEDs and PIB support for MPC8568E-MDS boards
powerpc/86xx: Enable VME driver on the GE SBC610
powerpc/86xx: Enable VME driver on the GE PPC9A
powerpc/86xx: Add MSI section to GE PPC9A DTS
...
Trivial patch which adds the __init macro to the module_init
function and all of its helper functions of drivers/char/vme_scc.c
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6: (41 commits)
of: remove undefined request_OF_resource & release_OF_resource
of/sparc: Remove sparc-local declaration of allnodes and devtree_lock
of: move definition of of_chosen into common code.
of: remove unused extern reference to devtree_lock
of: put default string compare and #a/s-cell values into common header
of/flattree: Don't assume HAVE_LMB
of: protect linux/of.h with CONFIG_OF
proc_devtree: fix THIS_MODULE without module.h
of: Remove old and misplaced function declarations
of/flattree: Make the kernel accept ePAPR style phandle information
of/flattree: endian-convert members of boot_param_header
of: assume big-endian properties, adding conversions where necessary
of: use __be32 for cell value accessors
of/flattree: use OF_ROOT_NODE_{SIZE,ADDR}_CELLS DEFAULT for fdt parsing
of/flattree: use callback to setup initrd from /chosen
proc_devtree: include linux/of.h
of: make set_node_proc_entry private to proc_devtree.c
of: include linux/proc_fs.h
of/flattree: merge early_init_dt_scan_memory() common code
of: add 'of_' prefix to machine_is_compatible()
...
Instead of allocating just one buffer for a port's in_vq, fill
the entire in_vq with buffers so the host need not stall while
an application consumes the data and makes the buffer available
again for the host.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With MULTIPORT support, the control queue is an integral part of the
functioning of the device. If we can't get any buffers allocated, the
host won't be able to relay important information and the device may not
function as intended.
Ensure 'probe' doesn't succeed until the control queue has at least one
buffer allocated for its ivq.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add the ability to remove the virtio_console module.
This aids debugging.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If unused data exists in in_vq, ensure we flush that first and then
detach unused buffers, which will ensure all buffers from the in_vq are
removed.
Also ensure we free the buffers after detaching them.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove port data; deregister from the hvc core if it's a console port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the 'nr_ports' variable in the config space is updated to a higher
value, that means new ports have been hotplugged.
Introduce a new workqueue to handle such updates and create new ports.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove any data that we might have in a port's inbuf when closing a port
or when any data is received when a port is closed.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The host can set a name for ports so that they're easily discoverable
instead of going by the /dev/vportNpn naming. This attribute will be
placed in /sys/class/virtio-ports/vportNpn/name. udev scripts can then
create symlinks to the port using the name.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a guest_connected field that ensures only one process
can have a port open at a time.
This also ensures we don't have a race when we later add support for
dropping buffers when closing the char dev and buffer caching is turned
off for the particular port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allow guest userspace applications to open, read from, write to, poll
the ports via the char dev interface.
When a port gets opened, a notification is sent to the host via a
control message indicating a connection has been established. Similarly,
on closing of the port, a notification is sent indicating disconnection.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The char device will be used as an interface by applications on the
guest to communicate with apps on the host.
The devices created are placed in /dev/vportNpn where N is the
virtio-console device number and n is the port number for that device.
One dynamic major device number is allocated for each device and minor
numbers are allocated for the ports contained within that device.
The file operation for the char devs will be added in the following
commits.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When ports get advertised as char devices, the buffers will come from
userspace. Equip the fill_readbuf function with the ability to write
to userspace buffers.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit adds a new feature, MULTIPORT. If the host supports this
feature as well, the config space has the number of ports defined for
that device. New ports are spawned according to this information.
The config space also has the maximum number of ports that can be
spawned for a particular device. This is useful in initializing the
appropriate number of virtqueues in advance, as ports might be
hot-plugged in later.
Using this feature, generic ports can be created which are not tied to
hvc consoles.
We also open up a private channel between the host and the guest via
which some "control" messages are exchanged for the ports, like whether
the port being spawned is a console port, resizing the console window,
etc.
Next commits will add support for hotplugging and presenting char
devices in /dev/ for bi-directional guest-host communication.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Adding support for generic ports that will write to userspace will need
some code changes.
Consolidate the write routine into send_buf() and put_chars() now just
calls into the new function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In preparation for serving data to userspace (generic ports) as well as
in-kernel users (hvc consoles), separate out the functionality common to
both in a 'fill_readbuf()' function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With support for multiple ports, each port will have its own input and
output vqs. Prepare the probe function for this change.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Console ports could be hot-added. Also, with the new multiport support,
a port is identified as a console port only if the host sends a control
message.
Move the console port init into a separate function so it can be invoked
from other places.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Move out console-specific stuff into a separate struct from 'struct
port' as we need to maintain two lists: one for all the ports (which
includes consoles) and one only for consoles since the hvc callbacks
only give us the vtermno.
This makes console handling cleaner.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When multiple console support is added, ensure each port's size gets
updated when a new one is opened via hvc.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rather than assume a single port, add a 'struct ports_device' which
stores data related to all the ports for that device.
Currently, there's only one port and is hooked up with hvc, but that
will change.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now we can use an allocation function to remove our global console variable.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
