Under load the following bug message appeared while using sysrq-t:

BUG: scheduling while atomic: bash/3662/0x00000004
0000000000105b74 000000003ba17740 0000000000000002 0000000000000000
       000000003ba177e0 000000003ba17758 000000003ba17758 0000000000105bfe
       0000000000817ba8 000000003f2a5350 0000000000000000 0000000000000000
       000000003ba17740 000000000000000c 000000003ba17740 000000003ba177b0
       0000000000568630 0000000000105bfe 000000003ba17740 000000003ba17790
Call Trace:
([<0000000000105b74>] show_trace+0x13c/0x158)
 [<0000000000105c58>] show_stack+0xc8/0xfc
 [<0000000000105cbc>] dump_stack+0x30/0x40
 [<000000000012a0c8>] __schedule_bug+0x84/0x94
 [<000000000056234e>] schedule+0x5ea/0x970
 [<0000000000477cd2>] __sclp_vt220_write+0x1f6/0x3ec
 [<0000000000477f00>] sclp_vt220_con_write+0x38/0x48
 [<0000000000130b4a>] __call_console_drivers+0xbe/0xd8
 [<0000000000130bf0>] _call_console_drivers+0x8c/0xd0
 [<0000000000130eea>] release_console_sem+0x1a6/0x2fc
 [<0000000000131786>] vprintk+0x262/0x480
 [<00000000001319fa>] printk+0x56/0x68
 [<0000000000125aaa>] print_cfs_rq+0x45e/0x4a4
 [<000000000012614e>] sched_debug_show+0x65e/0xee8
 [<000000000012a8fc>] show_state_filter+0x1cc/0x1f0
 [<000000000044d39c>] sysrq_handle_showstate+0x2c/0x3c
 [<000000000044d1fe>] __handle_sysrq+0xae/0x18c
 [<00000000002001f2>] write_sysrq_trigger+0x8a/0x90
 [<00000000001f7862>] proc_reg_write+0x9a/0xc4
 [<00000000001a83d4>] vfs_write+0xb8/0x174
 [<00000000001a8b88>] sys_write+0x58/0x8c
 [<0000000000112e7c>] sysc_noemu+0x10/0x16
 [<0000020000116f68>] 0x20000116f68

The problem seems to be, that with a full console buffer, release_console_sem
disables interrupts with spin_lock_irqsave and then calls the console function
without enabling interrupts. __sclp_vt220_write checks for in_interrupt, to
decide if it can schedule. It should check for in_atomic instead.

The same is true for sclp_tty.c.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When an alias device is set offline while it is in use this may
result in a panic in the cleanup part of the dasd_block_tasklet.
The problem here is that there may exist some ccw requests that were
originally created for the alias device and transferred to the base
device when the alias was set offline. When these request are
cleaned up later, the discipline pointer in the alias device may not
be valid anymore. To fix this use the base device discipline to find
the cleanup function.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Adding interface control check (ifcc) handling in error recovery.
First retry up to 255 times and if all retries fail try an alternate
path if possible.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This intendeds to make proper shutdown of qeth devices easier.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This provides unified return codes for common response codes and
also makes the debug feature messages more similar and informational.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In some cases the current sense id procedure trips over incomplete
hardware responses. In these cases, checking against the preset value
of 0xFFFF is not enough. More critically, the VM DIAG call will always be
considered to have provided data after such an incident, even if it was not
successful at all.

The solution is to always initialize the control unit data before doing a
sense id call. Check the condition code before considering the control unit
data. And initialize again, before evaluating the VM data.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Drivers that register a ->fault handler, but do not range-check the
offset argument, must set VM_DONTEXPAND in the vm_flags in order to
prevent an expanding mremap from overflowing the resource.

I've audited the tree and attempted to fix these problems (usually by
adding VM_DONTEXPAND where it is not obvious).
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit c9f6d3d5 ("[POWERPC] adb: Replace
sleep notifier with platform driver suspend/resume hooks") introduced
compile errors on m68k because <linux/platform_device.h> is not
explicitly included.  On powerpc, it's pulled in through <asm/prom.h>.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently early kernel messages, i.e., those from uncompression, go to the
debugging UART. And if it is enabled in the platform configuration, but
not initialized by the bootloader, the machine hangs, waiting for UART
status change. Besides, having those messages on another UART - typically
the console UART - may be preferrable. This patch allows selecting the
UART in kernel configuration.
Signed-off-by: NGuennadi Liakhovetski <lg@denx.de>
Acked-by: NAndrew Victor <linux@maxim.org.za>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Warning message :
WARNING: vmlinux.o(.text+0x9afc): Section mismatch: reference to .init.text:sa1110_mb_enable (between 'sa1111_probe' and 'sa1111_remove')
WARNING: vmlinux.o(.text+0x13b1ac): Section mismatch: reference to .init.text:pcmcia_jornada720_init (between 'pcmcia_probe' and 'pcmcia_remove')

* fixes the 'section mismatch' building warnings for target sa1100. Solution is __init -> __devinit. Thanks to Randy Dunlap for pointing out the solution.
Signed-off-by: NKristoffer Ericson <kristoffer.ericson@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/serial/21285.c: In function 'serial21285_set_termios':
drivers/serial/21285.c:280: error: 'tty' undeclared (first use in this function)
drivers/serial/21285.c:280: error: (Each undeclared identifier is reported only once
drivers/serial/21285.c:280: error: for each function it appears in.)
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

After discussions with Anthony Liguori, it seems that the virtio
balloon can be made even simpler.  Here's my attempt.

The device configuration tells the driver how much memory it should
take from the guest (ie. balloon size).  The guest feeds the page
numbers it has taken via one virtqueue.

A second virtqueue feeds the page numbers the driver wants back: if
the device has the VIRTIO_BALLOON_F_MUST_TELL_HOST bit, then this
queue is compulsory, otherwise it's advisory (and the guest can simply
fault the pages back in).

This driver can be enhanced later to deflate the balloon via a
shrinker, oom callback or we could even go for a complete set of
in-guest regulators.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

As Avi pointed out, as we continue to massage the virtio PCI ABI, we can make
things a little more friendly to users by utilizing the PCI revision field to
indicate which version of the ABI we're using.  This is a hard ABI version
and incrementing it will cause the guest driver to break.

This is the necessary changes to virtio_pci to support this.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This is a PCI device that implements a transport for virtio.  It allows virtio
devices to be used by QEMU based VMMs like KVM or Xen.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Am Freitag, 1. Februar 2008 schrieb Christian Borntraeger:
> Right. I will fix that with an additional patch.

This patch goes on top of the minor number patch. Please let me know if
you want a merged patch:

Currently virtio_blk creates the disk name combinging "vd"  with 'a'++.
This will give strange names after vdz. I have implemented names up to
vdzzz - inspired by the sd.c code. That should be sufficient for now.

There is one driver in the kernel (driver/s390/block/dasd_genhd.c) that
implements names from dasda-dasdzzzz allowing even more disks. Maybe
a janitor can come up with a common implementation usable for all kind
of block device drivers.

I have tested this patch with 100 disks - seems to work.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Rusty,

currently virtio_blk uses one major number per device. While this works
quite well on most systems it is wasteful and will exhaust major numbers
on larger installations.

This patch allocates a major number on init and will use 16 minor numbers
for each disk. That will allow ~64k virtio_blk disks.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Rusty,

I currently try to make my guest boot from an virtio root device
without having an external kernel. Some of the tools that I tried
expect HDIO_GETGEO to work. The most interesting value is likely
the geo.start value to get the offset of a partition. This value
is filled by block/ioctl.c if fops->getgeo is set. This patch also
fills in some standard values for heads, sectors and cylinders.

Makes sense?
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It is done in order to improve performance.
Signed-off-by: NDor Laor <dor.laor@qumranet.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This fixes a potential dangling xmit problem.

We also suppress refill interrupts until we need them.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Fix bug found by Christian Borntraeger: if the other side fills all
the registered network buffers before we enable NAPI, we will never
get an interrupt.  The simplest fix is to process the input queue once
on open.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Hello Rusty,

virtnet_probe already calls alloc_etherdev, which calls ether_setup.
There is no need to do that again.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This is needed for the virtio PCI device to be compiled as a module.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Simple cleanup.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This patch moves virtio under the virtualization menu and changes virtio
devices to not claim to only be for lguest.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Anthony Liguori found double interrupt suppression in the virtio_net
driver, triggered by two skb_recv_done's in a row.  This is because
virtio_ring's interrupt suppression is a best-effort optimization: it
contains no synchronization so the host can miss it and still send
interrupts.

But it's certainly nicer for virtio users if calling disable_cb
actually disables callbacks, so we check for the race in the interrupt
routine.

Note: SMP guests might require syncronization here, but since
disable_cb is actually called from interrupt context, there has to be
some form of synchronization before the next same interrupt handler is
called (Linux guarantees that the same device's irq handler will never
run simultanously on multiple CPUs).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

A reset function solves three problems:

1) It allows us to renegotiate features, eg. if we want to upgrade a
   guest driver without rebooting the guest.

2) It gives us a clean way of shutting down virtqueues: after a reset,
   we know that the buffers won't be used by the host, and

3) It helps the guest recover from messed-up drivers.

So we remove the ->shutdown hook, and the only way we now remove
feature bits is via reset.

We leave it to the driver to do the reset before it deletes queues:
the balloon driver, for example, needs to chat to the host in its
remove function.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Since we want to reset the device to remove them, this is simpler
(device is reset for us on driver remove).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

1) Turn GSO on virtio net into an all-or-nothing (keep checksumming
   separate).  Having multiple bits is a pain: if you can't support something
   you should handle it in software, which is still a performance win.

2) Make VIRTIO_NET_HDR_GSO_ECN a flag in the header, so it can apply to
   IPv6 or v4.

3) Rename VIRTIO_NET_F_NO_CSUM to VIRTIO_NET_F_CSUM (ie. means we do
   checksumming).

4) Add csum and gso params to virtio_net to allow more testing.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It's far easier to deal with packets if we don't have to parse the
packet to figure out the header length to know how much to pull into
the skb data.  Add the field to the virtio_net_hdr struct (and fix the
spaces that somehow crept in there).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

The other side (host) can set the NO_NOTIFY flag as an optimization,
to say "no need to kick me when you add things".  Make it clear that
this is advisory only; especially that we should always notify when
the ring is full.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

It seems that virtio_net wants to disable callbacks (interrupts) before
calling netif_rx_schedule(), so we can't use the return value to do so.

Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback
now returns void, rather than a boolean.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Previously we used a type/len pair within the config space, but this
seems overkill.  We now simply define a structure which represents the
layout in the config space: the config space can now only be extended
at the end.

The main driver-visible changes:
1) We indicate what fields are present with an explicit feature bit.
2) Virtqueues are explicitly numbered, and not in the config space.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Use it in virtio_net (replacing buggy version there), it's also going
to be used by TAP for partial csum support.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>

Building the aic7xxx driver includes the copy
of an .h file from a _shipped file.

In a highly parallel build Ingo saw that the
build sometimes failed (included distcc usage).
It was tracked down to a missing dependency from the .c
source file to the generated .h file.
We started to build the .c file before the
copy (cat) operation of the .h file completed
and we then only got half of the definitions
from the copied .h file.

Add an explicit dependency from the .c files to the
generated .h files so make knows all dependencies and
finsih the build of the .h files before it starts
building the .o files.

Ingo tested this fix and reported:
good news: hundreds of successful kernel builds and no failures
overnight.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NAndrew Vasquez <andrew.vasquez@qlogic.com>
Acked-by: NJames Smart <james.smart@emulex.com>
Acked-by: NDarrick J. Wong <djwong@us.ibm.com>
Acked-by: NDavid Somayajulu <david.somayajulu@qlogic.com>
Acked-by: NMark Salyzyn <mark_salyzyn@adaptec.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>