This change adds a procfs connector event, which is emitted on every
successful process tracer attach or detach.
If some process connects to other one, kernelspace connector reports
process id and thread group id of both these involved processes. On
disconnection null process id is returned.
Such an event allows to create a simple automated userspace mechanism
to be aware about processes connecting to others, therefore predefined
process policies can be applied to them if needed.
Note, a detach signal is emitted only in case, if a tracer process
explicitly executes PTRACE_DETACH request. In other cases like tracee
or tracer exit detach event from proc connector is not reported.
Signed-off-by: Vladimir Zapolskiy <vzapolskiy@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (40 commits)
tg3: Fix tg3_skb_error_unmap()
net: tracepoint of net_dev_xmit sees freed skb and causes panic
drivers/net/can/flexcan.c: add missing clk_put
net: dm9000: Get the chip in a known good state before enabling interrupts
drivers/net/davinci_emac.c: add missing clk_put
af-packet: Add flag to distinguish VID 0 from no-vlan.
caif: Fix race when conditionally taking rtnl lock
usbnet/cdc_ncm: add missing .reset_resume hook
vlan: fix typo in vlan_dev_hard_start_xmit()
net/ipv4: Check for mistakenly passed in non-IPv4 address
iwl4965: correctly validate temperature value
bluetooth l2cap: fix locking in l2cap_global_chan_by_psm
ath9k: fix two more bugs in tx power
cfg80211: don't drop p2p probe responses
Revert "net: fix section mismatches"
drivers/net/usb/catc.c: Fix potential deadlock in catc_ctrl_run()
sctp: stop pending timers and purge queues when peer restart asoc
drivers/net: ks8842 Fix crash on received packet when in PIO mode.
ip_options_compile: properly handle unaligned pointer
iwlagn: fix incorrect PCI subsystem id for 6150 devices
...
* 'for-linus' of git://git.kernel.dk/linux-block:
block: Use hlist_entry() for io_context.cic_list.first
cfq-iosched: Remove bogus check in queue_fail path
xen/blkback: potential null dereference in error handling
xen/blkback: don't call vbd_size() if bd_disk is NULL
block: blkdev_get() should access ->bd_disk only after success
CFQ: Fix typo and remove unnecessary semicolon
block: remove unwanted semicolons
Revert "block: Remove extra discard_alignment from hd_struct."
nbd: adjust 'max_part' according to part_shift
nbd: limit module parameters to a sane value
nbd: pass MSG_* flags to kernel_recvmsg()
block: improve the bio_add_page() and bio_add_pc_page() descriptions
* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
dmaengine: shdma: fix a regression: initialise DMA channels for memcpy
dmaengine: shdma: Fix up fallout from runtime PM changes.
Revert "clocksource: sh_cmt: Runtime PM support"
Revert "clocksource: sh_tmu: Runtime PM support"
sh: Fix up asm-generic/ptrace.h fallout.
sh64: Move from P1SEG to CAC_ADDR for consistent sync.
sh64: asm/pgtable.h needs asm/mmu.h
sh: asm/tlb.h needs linux/swap.h
sh: mark DMA slave ID 0 as invalid
sh: Update shmin to reflect PIO dependency.
sh: arch/sh/kernel/process_32.c needs linux/prefetch.h.
sh: add MMCIF runtime PM support on ecovec
sh: switch ap325rxa to dynamically manage the platform camera
This reverts commit b1c43f82c5.
It was broken in so many ways, and results in random odd pty issues.
It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
cause endless work-loops (see commit a5660b41af: "tty: fix endless
work loop when the buffer fills up").
It also used an "unsigned int" return value fo the ->receive_buf()
function, but then made multiple functions return a negative error code,
and didn't actually check for the error in the caller.
And it didn't actually work at all. BenH bisected down odd tty behavior
to it:
"It looks like the patch is causing some major malfunctions of the X
server for me, possibly related to PTYs. For example, cat'ing a
large file in a gnome terminal hangs the kernel for -minutes- in a
loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
data in the quoted bits further down).
...
Some more data: It -looks- like what happens is that the
flush_to_ldisc work queue entry constantly re-queues itself (because
the PTY is full ?) and the workqueue thread will basically loop
forver calling it without ever scheduling, thus starving the consumer
process that could have emptied the PTY."
which is pretty much exactly the problem we fixed in a5660b41af.
Milton Miller pointed out the 'unsigned int' issue.
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: Milton Miller <miltonm@bga.com>
Cc: Stefan Bigler <stefan.bigler@keymile.com>
Cc: Toby Gray <toby.gray@realvnc.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function attempts to free one fragment beyond the number of
fragments that were actually mapped. This patch brings back the limit
to the correct spot.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In certain circumstances, we can get an oops from a torn down device.
Most notably this is from CD roms trying to call scsi_ioctl. The root
cause of the problem is the fact that after scsi_remove_device() has
been called, the queue is fully torn down. This is actually wrong
since the queue can be used until the sdev release function is called.
Therefore, we add an extra reference to the queue which is released in
sdev->release, so the queue always exists.
Reported-by: Parag Warudkar <parag.lkml@gmail.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <jbottomley@parallels.com>
The failed_get label is used after the call to clk_get has succeeded, so it
should be moved up above the call to clk_put.
The failed_req labels doesn't do anything different than failed_get, so
delete it.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression e1,e2;
statement S;
@@
e1 = clk_get@p1(...);
... when != e1 = e2
when != clk_put(e1)
when any
if (...) { ... when != clk_put(e1)
when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
} else S
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
A recent patch has introduced a regression, where repeating a memcpy
DMA test with shdma module unloading between them skips the DMA channel
configuration. Fix this regression by always configuring the channel
during its allocation.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Currently the DM9000 driver requests the primary interrupt before it
resets the chip and puts it into a known good state. This means that if
the chip is asserting interrupt for some reason we can end up with a
screaming IRQ that the interrupt handler is unable to deal with. Avoid
this by only requesting the interrupt after we've reset the chip so we
know what state it's in.
This started manifesting itself on one of my boards in the past month or
so, I suspect as a result of some core infrastructure changes removing
some form of mitigation against bad behaviour here, even when things boot
it seems that the new code brings the interface up more quickly.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Go to existing error handling code at the end of the function that calls
clk_put.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression e1,e2;
statement S;
@@
e1 = clk_get@p1(...);
... when != e1 = e2
when != clk_put(e1)
when any
if (...) { ... when != clk_put(e1)
when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
} else S
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This avoids messages like this after suspend:
cdc_ncm 2-1.4:1.6: no reset_resume for driver cdc_ncm?
cdc_ncm 2-1.4:1.7: no reset_resume for driver cdc_ncm?
cdc_ncm 2-1.4:1.6: usb0: unregister 'cdc_ncm' usb-0000:00:1d.0-1.4, CDC NCM
This is important for the Ericsson F5521gw GSM/UMTS modem.
Otherwise modemmanager looses the fact that the cdc_ncm and cdc_acm devices
belong together.
The cdc_ether module does the same.
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.infradead.org/iommu-2.6:
intel-iommu: Fix off-by-one in RMRR setup
intel-iommu: Add domain check in domain_remove_one_dev_info
intel-iommu: Remove Host Bridge devices from identity mapping
intel-iommu: Use coherent DMA mask when requested
intel-iommu: Dont cache iova above 32bit
intel-iommu: Speed up processing of the identity_mapping function
intel-iommu: Check for identity mapping candidate using system dma mask
intel-iommu: Only unlink device domains from iommu
intel-iommu: Enable super page (2MiB, 1GiB, etc.) support
intel-iommu: Flush unmaps at domain_exit
intel-iommu: Remove obsolete comment from detect_intel_iommu
intel-iommu: fix VT-d PMR disable for TXT on S3 resume
Jens' back-merge commit 698567f3fa ("Merge commit 'v2.6.39' into
for-2.6.40/core") was incorrectly done, and re-introduced the
DISK_EVENT_MEDIA_CHANGE lines that had been removed earlier in commits
- 9fd097b149 ("block: unexport DISK_EVENT_MEDIA_CHANGE for
legacy/fringe drivers")
- 7eec77a181 ("ide: unexport DISK_EVENT_MEDIA_CHANGE for ide-gd
and ide-cd")
because of conflicts with the "g->flags" updates near-by by commit
d4dc210f69 ("block: don't block events on excl write for non-optical
devices")
As a result, we re-introduced the hanging behavior due to infinite disk
media change reports.
Tssk, tssk, people! Don't do back-merges at all, and *definitely* don't
do them to hide merge conflicts from me - especially as I'm likely
better at merging them than you are, since I do so many merges.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some cases we can read wrong temperature value. If after that
temperature value will not be updated to good one, we badly configure
tx power parameters and device is unable to send a data.
Resolves:
https://bugzilla.kernel.org/show_bug.cgi?id=35932
Cc: stable@kernel.org # 2.6.39+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This is the same fix as
commit 841051602e
Author: Matteo Croce <technoboy85@gmail.com>
Date: Fri Dec 3 02:25:08 2010 +0100
The ath9k driver subtracts 3 dBm to the txpower as with two radios the
signal power is doubled.
The resulting value is assigned in an u16 which overflows and makes
the card work at full power.
in two more places. I grepped the ath tree and didn't find any others.
Cc: stable@kernel.org
Signed-off-by: Daniel Halperin <dhalperi@cs.washington.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
blkbk->pending_pages can be NULL here so I added a check for it.
Signed-off-by: Dan Carpenter <error27@gmail.com>
[v1: Redid the loop a bit]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
We were mapping an extra byte (and hence usually an extra page):
iommu_prepare_identity_map() expects to be given an 'end' argument which
is the last byte to be mapped; not the first byte *not* to be mapped.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The comment in domain_remove_one_dev_info() states "No need to compare
PCI domain; it has to be the same". But for the si_domain that isn't
going to be true, as it consists of all the PCI devices that are
identity mapped thus multiple PCI domains can be in si_domain. The
code needs to validate the PCI domain too.
Signed-off-by: Mike Habeck <habeck@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When using the 1:1 (identity) PCI DMA remapping, PCI Host Bridge devices
that do not use the IOMMU causes a kernel panic. Fix that by not
inserting those devices into the si_domain.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The __intel_map_single function is not honoring the passed in DMA mask.
This results in not using the coherent DMA mask when called from
intel_alloc_coherent().
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Reviewed-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Mike Travis and Mike Habeck reported an issue where iova allocation
would return a range that was larger than a device's dma mask.
https://lkml.org/lkml/2011/3/29/423
The dmar initialization code will reserve all PCI MMIO regions and copy
those reservations into a domain specific iova tree. It is possible for
one of those regions to be above the dma mask of a device. It is typical
to allocate iovas with a 32bit mask (despite device's dma mask possibly
being larger) and cache the result until it exhausts the lower 32bit
address space. Freeing the iova range that is >= the last iova in the
lower 32bit range when there is still an iova above the 32bit range will
corrupt the cached iova by pointing it to a region that is above 32bit.
If that region is also larger than the device's dma mask, a subsequent
allocation will return an unusable iova and cause dma failure.
Simply don't cache an iova that is above the 32bit caching boundary.
Reported-by: Mike Travis <travis@sgi.com>
Reported-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Acked-by: Mike Travis <travis@sgi.com>
Tested-by: Mike Habeck <habeck@sgi.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When there are a large count of PCI devices, and the pass through
option for iommu is set, much time is spent in the identity_mapping
function hunting though the iommu domains to check if a specific
device is "identity mapped".
Speed up the function by checking the cached info to see if
it's mapped to the static identity domain.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The identity mapping code appears to make the assumption that if the
devices dma_mask is greater than 32bits the device can use identity
mapping. But that is not true: take the case where we have a 40bit
device in a 44bit architecture. The device can potentially receive a
physical address that it will truncate and cause incorrect addresses
to be used.
Instead check to see if the device's dma_mask is large enough
to address the system's dma_mask.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Mike Habeck <habeck@sgi.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Commit a97590e5 added unlinking domains from iommus to reciprocate the
iommu from domains unlinking that was already done. We actually want
to only do this for device domains and never for the static
identity map domain or VM domains. The SI domain is special and
never freed, while VM domain->id lives in their own special address
space, separate from iommu->domain_ids.
In the current code, a VM can get domain->id zero, then mark that
domain unused when unbound from pci-stub. This leads to DMAR
write faults when the device is re-bound to the host driver.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
There are no externally-visible changes with this. In the loop in the
internal __domain_mapping() function, we simply detect if we are mapping:
- size >= 2MiB, and
- virtual address aligned to 2MiB, and
- physical address aligned to 2MiB, and
- on hardware that supports superpages.
(and likewise for larger superpages).
We automatically use a superpage for such mappings. We never have to
worry about *breaking* superpages, since we trust that we will always
*unmap* the same range that was mapped. So all we need to do is ensure
that dma_pte_clear_range() will also cope with superpages.
Adjust pfn_to_dma_pte() to take a superpage 'level' as an argument, so
it can return a PTE at the appropriate level rather than always
extending the page tables all the way down to level 1. Again, this is
simplified by the fact that we should never encounter existing small
pages when we're creating a mapping; any old mapping that used the same
virtual range will have been entirely removed and its obsolete page
tables freed.
Provide an 'intel_iommu=sp_off' argument on the command line as a
chicken bit. Not that it should ever be required.
==
The original commit seen in the iommu-2.6.git was Youquan's
implementation (and completion) of my own half-baked code which I'd
typed into an email. Followed by half a dozen subsequent 'fixes'.
I've taken the unusual step of rewriting history and collapsing the
original commits in order to keep the main history simpler, and make
life easier for the people who are going to have to backport this to
older kernels. And also so I can give it a more coherent commit comment
which (hopefully) gives a better explanation of what's going on.
The original sequence of commits leading to identical code was:
Youquan Song (3):
intel-iommu: super page support
intel-iommu: Fix superpage alignment calculation error
intel-iommu: Fix superpage level calculation error in dma_pfn_level_pte()
David Woodhouse (4):
intel-iommu: Precalculate superpage support for dmar_domain
intel-iommu: Fix hardware_largepage_caps()
intel-iommu: Fix inappropriate use of superpages in __domain_mapping()
intel-iommu: Fix phys_pfn in __domain_mapping for sglist pages
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
The new instruction_pointer_set helper is defined for people who have
converted to asm-generic/ptrace.h, so don't use it generally unless
the arch needs it (in which case it has been converted). This should
fix building of kgdb tests for arches not yet converted.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit e5cb966c08.
It causes new build regressions with gcc-4.2 which is
pretty common on non-x86 platforms.
Reported-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
catc_ctrl_run() calls usb_submit_urb() with GFP_KERNEL, while it is called from
catc_ctrl_async() and catc_ctrl_done() with catc->ctrl_lock spinlock held.
The patch replaces GFP_KERNEL with GFP_ATOMIC.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes a driver crash during packet reception due to not enough
bytes allocated in the skb. Since the loop reads out 4 bytes at a time, we
need to allow for up to 3 bytes of slack space.
Signed-off-by: Dennis Aberilla <denzzzhome@yahoo.com>
Signed-off-by: David S. Miller <davem@zippy.davemloft.net>
For 6150 devices, modify the supported PCI subsystem ID.
Cc: stable@kernel.org
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
zd1211 devices register 'EP 4 OUT' endpoint as Interrupt type on USB 2.0:
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
However on USB 1.1 endpoint becomes Bulk:
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Commit 37939810b9 assumed that endpoint is
always interrupt type and changed usb_bulk_msg() calls to usb_interrupt_msg().
Problem here is that usb_bulk_msg() on interrupt endpoint selfcorrects the
call and changes requested pipe to interrupt type (see usb_bulk_msg).
However with usb_interrupt_msg() on bulk endpoint does not correct the
pipe type to bulk, but instead URB is submitted with interrupt type pipe.
So pre-2.6.39 used usb_bulk_msg() and therefore worked with both endpoint
types, however in 2.6.39 usb_interrupt_msg() with bulk endpoint causes
ohci_hcd to fail submitted URB instantly with -ENOSPC and preventing zd1211rw
from working with OHCI.
Fix this by detecting endpoint type and using correct endpoint/pipe types
for URB. Also fix asynchronous zd_usb_iowrite16v_async() to use right
URB type on 'EP 4 OUT'.
Cc: stable@kernel.org
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fix kernel oops when trying to use passive scheduled scans. The
reason was that in passive scans there are no SSIDs, so there was a
NULL pointer dereference.
To solve the problem, we now check the number of SSIDs provided in the
sched_scan request and only access the list if there's one or more
(ie. passive scan is not forced). We also force all the channels to
be passive by adding the IEEE80211_CHAN_PASSIVE_SCAN flag locally
before the checks in the wl1271_scan_get_sched_scan_channels()
function.
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Use a different value for DFS dwell time when performing a scheduled
scan. Previously we were using the same value as for normal passive
scans. This adds some flexibility between these two different types
of passive scan.
For now we use 150 TUs for DFS channel dwell time. This may need to
be fine-tuned in the future.
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
DFS channels were never getting included in the scheduled scans,
because they always contain the passive flag as well and the call was
asking for DFS and active channels.
Fix this by ignoring the passive flag when collecting DFS channels.
Also, move the DFS channels in the channel list before the 5GHz active
channels (this was implemented in the FW differently than specified).
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
We were comparing bitwise AND results with a boolean, so when the
boolean was set to true, it was not matching as it should.
Fix this by booleanizing the bitwise AND results with !!.
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Before this patch, the command sequence number is being set before
lbs_queue_cmd() adds the command to the queue. However, lbs_queue_cmd()
sometimes forces commands to queue-jump (e.g. CMD_802_11_WAKEUP_CONFIRM).
It currently does this without considering that sequence numbers might need
adjusting to keep things running in order.
Fix this by setting the sequence number at a later stage, just before
we're actually submitting the command to the hardware. Also fixes a
possible race where seqnum was being modified outside of the driver
lock.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This reverts commit 1b842e91fe.
There is a fundamental ordering race between the early and late probe
paths and the runtime PM tie-in that results in __pm_runtime_resume()
attempting to take a lock that hasn't been initialized yet (which by
proxy also suggests that pm_runtime_init() hasn't yet been run on the
device either, making the entire thing unsafe) -- resulting in instant
death on SMP or on UP with spinlock debugging enabled:
sh_tmu.0: used for clock events
sh_tmu.0: used for periodic clock events
BUG: spinlock trylock failure on UP on CPU#0, swapper/0
lock: 804db198, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
...
Revert it for now until the ordering issues can be resolved, or we can get
some more help from the runtime PM framework to make this possible.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Ask for delayed callbacks on TX ring full, to give the
other side more of a chance to make progress.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add an API that tells the other side that callbacks
should be delayed until a lot of work has been done.
Implement using the new event_idx feature.
Note: it might seem advantageous to let the drivers
ask for a callback after a specific capacity has
been reached. However, as a single head can
free many entries in the descriptor table,
we don't really have a clue about capacity
until get_buf is called. The API is the simplest
to implement at the moment, we'll see what kind of
hints drivers can pass when there's more than one
user of the feature.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Support the new event index feature. When acked,
utilize it to reduce the # of interrupts sent to the guest.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Support for the new event idx feature:
1. When enabling interrupts, publish the current avail index
value to the host to get interrupts on the next update.
2. Use the new avail_event feature to reduce the number
of exits from the guest.
Simple test with the simulator:
[virtio]# time ./virtio_test
spurious wakeus: 0x7
real 0m0.169s
user 0m0.140s
sys 0m0.019s
[virtio]# time ./virtio_test --no-event-idx
spurious wakeus: 0x11
real 0m0.649s
user 0m0.295s
sys 0m0.335s
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST
feature bit. Whenever the bit is set, the guest kernel must
always tell the host before we free pages back to the allocator.
Without this feature, we might free a page (and have another
user touch it) while the hypervisor is unprepared for it.
But, if the bit is _not_ set, we are under no obligation to
reverse the order; we're under no obligation to do _anything_.
As of now, qemu-kvm defines the bit, but doesn't set it.
This patch makes the "tell host first" logic the only case. This
should make everybody happy, and reduce the amount of untested or
untestable code in the kernel.
This _also_ means that we don't have to preserve a pfn list
after the pages are freed, which should let us get rid of some
temporary storage (vb->pfns) eventually.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
That's already been done by the virtio infrastructure before the probe
function is called.
Reported-by: alexey.kardashevskiy@au1.ibm.com
Acked-by: Amit Shah <amit.shah@redhat.com>
Tested-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It is easier to figure out the context by reading SCSI_SENSE_BUFFERSIZE
instead of plain '96'.
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
