Commit Graph

152 Commits

Author SHA1 Message Date
Konrad Rzeszutek Wilk
7736594836 xen/irq: Alter the locking to use a mutex instead of a spinlock.
When we allocate/change the IRQ informations, we do not
need to use spinlocks. We can use a mutex (which is
what the generic IRQ code does for allocations/changes).
Fixes a slew of:

BUG: sleeping function called from invalid context at /linux/kernel/mutex.c:271
in_atomic(): 1, irqs_disabled(): 0, pid: 3216, name: xenstored
2 locks held by xenstored/3216:
 #0:  (&u->bind_mutex){......}, at: [<ffffffffa02e0920>] evtchn_ioctl+0x30/0x3a0 [xen_evtchn]
 #1:  (irq_mapping_update_lock){......}, at: [<ffffffff8138b274>] bind_evtchn_to_irq+0x24/0x90
Pid: 3216, comm: xenstored Not tainted 3.1.0-rc6-00021-g437a3d1 #2
Call Trace:
 [<ffffffff81088d10>] __might_sleep+0x100/0x130
 [<ffffffff81645c2f>] mutex_lock_nested+0x2f/0x50
 [<ffffffff81627529>] __irq_alloc_descs+0x49/0x200
 [<ffffffffa02e0920>] ? evtchn_ioctl+0x30/0x3a0 [xen_evtchn]
 [<ffffffff8138b214>] xen_allocate_irq_dynamic+0x34/0x70
 [<ffffffff8138b2ad>] bind_evtchn_to_irq+0x5d/0x90
 [<ffffffffa02e03c0>] ? evtchn_bind_to_user+0x60/0x60 [xen_evtchn]
 [<ffffffff8138c282>] bind_evtchn_to_irqhandler+0x32/0x80
 [<ffffffffa02e03a9>] evtchn_bind_to_user+0x49/0x60 [xen_evtchn]
 [<ffffffffa02e0a34>] evtchn_ioctl+0x144/0x3a0 [xen_evtchn]
 [<ffffffff811b4070>] ? vfsmount_lock_local_unlock+0x50/0x80
 [<ffffffff811a6a1a>] do_vfs_ioctl+0x9a/0x5e0
 [<ffffffff811b476f>] ? mntput+0x1f/0x30
 [<ffffffff81196259>] ? fput+0x199/0x240
 [<ffffffff811a7001>] sys_ioctl+0xa1/0xb0
 [<ffffffff8164ea82>] system_call_fastpath+0x16/0x1b

Reported-by: Jim Burns <jim_burn@bellsouth.net>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-15 04:32:02 -04:00
Konrad Rzeszutek Wilk
78316ada22 xen/pci: Remove 'xen_allocate_pirq_gsi'.
In the past (2.6.38) the 'xen_allocate_pirq_gsi' would allocate
an entry in a Linux IRQ -> {XEN_IRQ, type, event, ..} array. All
of that has been removed in 2.6.39 and the Xen IRQ subsystem uses
an linked list that is populated when the call to
'xen_allocate_irq_gsi' (universally done from any of the xen_bind_*
calls) is done. The 'xen_allocate_pirq_gsi' is a NOP and there is
no need for it anymore so lets remove it.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-11 13:19:33 -04:00
Konrad Rzeszutek Wilk
a0ee056709 xen/pci: Squash pci_xen_initial_domain and xen_setup_pirqs together.
Since they are only called once and the rest of the pci_xen_*
functions follow the same pattern of setup.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-07-11 13:19:30 -04:00
Konrad Rzeszutek Wilk
b5328cd145 xen: Fix compile warning when CONFIG_SMP is not defined.
.. which is quite benign.

drivers/xen/events.c:398: warning: unused variable ‘desc’

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-06-15 14:25:01 -04:00
Stefano Stabellini
e5ac0bda96 xen: use the trigger info we already have to choose the irq handler
Do not use pirq_needs_eoi to decide which irq handler to use because Xen
always returns true if the guest does not support pirq_eoi_map.
Use the trigger information we already have from MP-tables and ACPI.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reported-by: Thomas Goetz <tom.goetz@virtualcomputer.com>
Tested-by: Thomas Goetz <tom.goetz@virtualcomputer.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-31 11:44:03 -04:00
Linus Torvalds
e33ab8f275 Merge branches 'stable/irq', 'stable/p2m.bugfixes', 'stable/e820.bugfixes' and 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/irq' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: do not clear and mask evtchns in __xen_evtchn_do_upcall

* 'stable/p2m.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/p2m: Create entries in the P2M_MFN trees's to track 1-1 mappings

* 'stable/e820.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/setup: Fix for incorrect xen_extra_mem_start initialization under 32-bit
  xen/setup: Ignore E820_UNUSABLE when setting 1-1 mappings.

* 'stable/mmu.bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen mmu: fix a race window causing leave_mm BUG()
2011-05-19 16:14:58 -07:00
Linus Torvalds
5318991645 Merge branches 'stable/backend.base.v3' and 'stable/gntalloc.v7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/backend.base.v3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/pci: Fix compiler error when CONFIG_XEN_PRIVILEGED_GUEST is not set.
  xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions.
  xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override.
  xen/irq: The Xen hypervisor cleans up the PIRQs if the other domain forgot.
  xen/irq: Export 'xen_pirq_from_irq' function.
  xen/irq: Add support to check if IRQ line is shared with other domains.
  xen/irq: Check if the PCI device is owned by a domain different than DOMID_SELF.
  xen/pci: Add xen_[find|register|unregister]_device_domain_owner functions.

* 'stable/gntalloc.v7' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/gntdev,gntalloc: Remove unneeded VM flags
2011-05-19 16:14:25 -07:00
Stefano Stabellini
7e186bdd00 xen: do not clear and mask evtchns in __xen_evtchn_do_upcall
Change the irq handler of evtchns and pirqs that don't need EOI (pirqs
that correspond to physical edge interrupts) to handle_edge_irq.

Use handle_fasteoi_irq for pirqs that need eoi (they generally
correspond to level triggered irqs), no risk in loosing interrupts
because we have to EOI the irq anyway.

This change has the following benefits:

- it uses the very same handlers that Linux would use on native for the
same irqs (handle_edge_irq for edge irqs and msis, and
handle_fasteoi_irq for everything else);

- it uses these handlers in the same way native code would use them: it
let Linux mask\unmask and ack the irq when Linux want to mask\unmask
and ack the irq;

- it fixes a problem occurring when a driver calls disable_irq() in its
handler: the old code was unconditionally unmasking the evtchn even if
the irq is disabled when irq_eoi was called.

See Documentation/DocBook/genericirq.tmpl for more informations.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[v1: Fixed space/tab issues]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-05-10 12:47:40 -04:00
Konrad Rzeszutek Wilk
1eff1ad028 xen/irq: The Xen hypervisor cleans up the PIRQs if the other domain forgot.
And if the other domain forgot to clean up its PIRQs we don't need
to fail the operation. Just take a note of it and continue on.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-14 11:17:56 -04:00
Konrad Rzeszutek Wilk
e6197acc72 xen/irq: Export 'xen_pirq_from_irq' function.
We need this to find the real Xen PIRQ value for a device
that requests an MSI or MSI-X. In the past we used
'xen_gsi_from_irq' since that function would return
an Xen PIRQ or GSI depending on the provided IRQ. Now that
we have seperated that we need to use the correct
function.

[v2: Deal with rebase on stable/irq.cleanup]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-14 11:17:55 -04:00
Konrad Rzeszutek Wilk
c7c2c3a286 xen/irq: Add support to check if IRQ line is shared with other domains.
We do this via the PHYSDEVOP_irq_status_query support hypervisor call.
We will get a positive value if another domain has binded its
PIRQ to the specified GSI (IRQ line).

[v2: Deal with v2.6.37-rc1 rebase fallout]
[v3: Deal with stable/irq.cleanup fallout]
[v4: xen_ignore_irq->xen_test_irq_shared]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-04-14 11:17:54 -04:00
Konrad Rzeszutek Wilk
beafbdc1df xen/irq: Check if the PCI device is owned by a domain different than DOMID_SELF.
We check if there is a domain owner for the PCI device. In case of failure
(meaning no domain has registered for this device) we make DOMID_SELF the owner.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: deal with rebasing on v2.6.37-1]
[v3: deal with rebasing on stable/irq.cleanup]
[v4: deal with rebasing on stable/irq.ween_of_nr_irqs]
[v5: deal with rebasing on v2.6.39-rc3]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Xiantao Zhang <xiantao.zhang@intel.com>
2011-04-14 11:17:36 -04:00
Linus Torvalds
16ad56972c Merge branch 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug-fixes-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Allow PV-OPS kernel to detect whether XSAVE is supported
  xen: just completely disable XSAVE
  xen/debug: Don't be so verbose with WARN on 1-1 mapping errors.
  xen: events: fix error checks in bind_*_to_irqhandler()
2011-04-11 20:01:04 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Nicolas Kaiser
361ae8cb57 xen: events: fix error checks in bind_*_to_irqhandler()
Checking 'irq < 0' doesn't work when 'irq' is unsigned.

The assigned bind_evtchn_to_irq() and bind_virq_to_irq()
return int, so using int appears appropriate.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-30 15:37:04 -04:00
Thomas Gleixner
a3b975c49e xen: Use new irq_move functions
These functions take irq_data as an argument and avoid a redundant
lookup in the sparse irq case.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-29 14:48:15 +02:00
Thomas Gleixner
c442b8068f xen: Cleanup genirq namespace
Converted with coccinelle.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-29 14:48:15 +02:00
Linus Torvalds
5a39837f76 Merge branches 'stable/irq.fairness' and 'stable/irq.ween_of_nr_irqs' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/irq.fairness' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: events: Remove redundant clear of l2i at end of round-robin loop
  xen: events: Make round-robin scan fairer by snapshotting each l2 word once only
  xen: events: Clean up round-robin evtchn scan.
  xen: events: Make last processed event channel a per-cpu variable.
  xen: events: Process event channels notifications in round-robin order.

* 'stable/irq.ween_of_nr_irqs' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: events: Fix compile error if CONFIG_SMP is not defined.
  xen: events: correct locking in xen_irq_from_pirq
  xen: events: propagate irq allocation failure instead of panicking
  xen: events: do not workaround too-small nr_irqs
  xen: events: remove use of nr_irqs as upper bound on number of pirqs
  xen: events: dynamically allocate irq info structures
  xen: events: maintain a list of Xen interrupts
  xen: events: push setup of irq<->{evtchn,ipi,virq,pirq} maps into irq_info init functions
  xen: events: turn irq_info constructors into initialiser functions
  xen: events: use per-cpu variable for cpu_evtchn_mask
  xen: events: refactor GSI pirq bindings functions
  xen: events: rename restore_cpu_pirqs -> restore_pirqs
  xen: events: remove unused public functions
  xen: events: fix xen_map_pirq_gsi error return
  xen: events: simplify comment
  xen: events: separate two unrelated halves of if condition

Fix up trivial conflicts in drivers/xen/events.c
2011-03-17 18:27:49 -07:00
Linus Torvalds
7a6362800c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits)
  bonding: enable netpoll without checking link status
  xfrm: Refcount destination entry on xfrm_lookup
  net: introduce rx_handler results and logic around that
  bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag
  bonding: wrap slave state work
  net: get rid of multiple bond-related netdevice->priv_flags
  bonding: register slave pointer for rx_handler
  be2net: Bump up the version number
  be2net: Copyright notice change. Update to Emulex instead of ServerEngines
  e1000e: fix kconfig for crc32 dependency
  netfilter ebtables: fix xt_AUDIT to work with ebtables
  xen network backend driver
  bonding: Improve syslog message at device creation time
  bonding: Call netif_carrier_off after register_netdevice
  bonding: Incorrect TX queue offset
  net_sched: fix ip_tos2prio
  xfrm: fix __xfrm_route_forward()
  be2net: Fix UDP packet detected status in RX compl
  Phonet: fix aligned-mode pipe socket buffer header reserve
  netxen: support for GbE port settings
  ...

Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c
with the staging updates.
2011-03-16 16:29:25 -07:00
Linus Torvalds
5f6fb45466 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (116 commits)
  x86: Enable forced interrupt threading support
  x86: Mark low level interrupts IRQF_NO_THREAD
  x86: Use generic show_interrupts
  x86: ioapic: Avoid redundant lookup of irq_cfg
  x86: ioapic: Use new move_irq functions
  x86: Use the proper accessors in fixup_irqs()
  x86: ioapic: Use irq_data->state
  x86: ioapic: Simplify irq chip and handler setup
  x86: Cleanup the genirq name space
  genirq: Add chip flag to force mask on suspend
  genirq: Add desc->irq_data accessor
  genirq: Add comments to Kconfig switches
  genirq: Fixup fasteoi handler for oneshot mode
  genirq: Provide forced interrupt threading
  sched: Switch wait_task_inactive to schedule_hrtimeout()
  genirq: Add IRQF_NO_THREAD
  genirq: Allow shared oneshot interrupts
  genirq: Prepare the handling of shared oneshot interrupts
  genirq: Make warning in handle_percpu_event useful
  x86: ioapic: Move trigger defines to io_apic.h
  ...

Fix up trivial(?) conflicts in arch/x86/pci/xen.c due to genirq name
space changes clashing with the Xen cleanups.  The set_irq_msi() had
moved to xen_bind_pirq_msi_to_irq().
2011-03-15 19:23:40 -07:00
Konrad Rzeszutek Wilk
44626e4a3b xen: events: Fix compile error if CONFIG_SMP is not defined.
drivers/xen/events.c:396: error: 'struct irq_data' has no member named 'affinity'

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-15 16:40:33 -04:00
Linus Torvalds
27d2a8b97e Merge branches 'stable/ia64', 'stable/blkfront-cleanup' and 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/ia64' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: ia64 build broken due to "xen: switch to new schedop hypercall by default."

* 'stable/blkfront-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Union the blkif_request request specific fields

* 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: annotate functions which only call into __init at start of day
  xen p2m: annotate variable which appears unused
  xen: events: mark cpu_evtchn_mask_p as __refdata
2011-03-15 10:49:16 -07:00
Ian Campbell
a7b807ce8c xen: events: correct locking in xen_irq_from_pirq
One of those spin_lock() calls should be an unlock...

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-14 10:53:02 -04:00
Ian Campbell
7bee976822 xen: events: propagate irq allocation failure instead of panicking
Running out of IRQs need not be fatal to the machine as a whole.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:45 -05:00
Ian Campbell
6cb9bf3aaf xen: events: do not workaround too-small nr_irqs
With the introduction of e7bcecb7b1 "genirq: Make nr_irqs runtime expandable"
nr_irqs can grow as necessary to accommodate our allocation requests.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:44 -05:00
Ian Campbell
69c358ce37 xen: events: remove use of nr_irqs as upper bound on number of pirqs
There isn't really much relationship between the two, other than
nr_irqs often being the larger of the two.

Allows us to remove a nr_irqs sized array, the only users of this
array are MSI setup and restore, neither of which are particularly
performance critical.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:43 -05:00
Ian Campbell
ca62ce8cde xen: events: dynamically allocate irq info structures
Removes nr_irq sized array allocation at start of day.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:42 -05:00
Ian Campbell
6cb6537d34 xen: events: maintain a list of Xen interrupts
In a PVHVM kernel not all interrupts are Xen interrupts (APIC interrupts can also be present).

Currently we get away with walking over all interrupts because the
lookup in the irq_info array simply returns IRQT_UNBOUND and we ignore
it. However this array will be going away in a future patch so we need
to manually track which interrupts have been allocated by the Xen
events infrastructure.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:41 -05:00
Ian Campbell
3d4cfa3736 xen: events: push setup of irq<->{evtchn,ipi,virq,pirq} maps into irq_info init functions
Encapsulate setup of XXX_to_irq array in the relevant
xen_irq_info_*_init function.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:40 -05:00
Ian Campbell
9158c3588a xen: events: turn irq_info constructors into initialiser functions
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:39 -05:00
Ian Campbell
cb60d11427 xen: events: use per-cpu variable for cpu_evtchn_mask
I can't see any reason why it isn't already.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:38 -05:00
Ian Campbell
f4d0635bf8 xen: events: refactor GSI pirq bindings functions
Following the example set by xen_allocate_pirq_msi and
xen_bind_pirq_msi_to_irq:

xen_allocate_pirq becomes xen_allocate_pirq_gsi and now only allocates
a pirq number and does not bind it.

xen_map_pirq_gsi becomes xen_bind_pirq_gsi_to_irq and binds an
existing pirq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:37 -05:00
Ian Campbell
0a85226ff2 xen: events: rename restore_cpu_pirqs -> restore_pirqs
There is nothing per-cpu about this function.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:36 -05:00
Ian Campbell
76465b2daf xen: events: remove unused public functions
I was unable to find any user of these functions in either the
functionality pending for 2.6.39 or the xen/next-2.6.32 branch of
xen.git

An exception to this was xen_gsi_from_irq which did appear to be used
in xen/next-2.6.32's pciback. However in the 2.6.39 version of pciback
xen_pirq_from_irq is, correctly AFAICT, used instead.

Only a minority of functions in events.h use "extern" so drop it from
those places for consistency.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:35 -05:00
Ian Campbell
a0e181167e xen: events: fix xen_map_pirq_gsi error return
Fix initial value of irq so that first goto out (if pirq or gsi
arguments are too large) actually returns an error.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:34 -05:00
Ian Campbell
653378acdd xen: events: simplify comment
It is never valid assume any particular relationship between a Xen
PIRQ number and and Linux IRQ number so there is no need to hedge when
saying so.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:33 -05:00
Ian Campbell
be49472f04 xen: events: separate two unrelated halves of if condition
Clarifies which bit the comment applies to.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:48:32 -05:00
Keir Fraser
3b7bcdf282 xen: events: Remove redundant clear of l2i at end of round-robin loop
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 991:9ba6d9f3fbc0]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:47:59 -05:00
Keir Fraser
24b51c2f2d xen: events: Make round-robin scan fairer by snapshotting each l2 word once only
(except for starting l2 word, which we scan in two parts).

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 990:427276ac595d]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:47:58 -05:00
Keir Fraser
ada6814c87 xen: events: Clean up round-robin evtchn scan.
Also fixes a couple of boundary cases.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 988:c88a02a22a05]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:47:57 -05:00
Ian Campbell
f1f4a323d4 xen: events: Make last processed event channel a per-cpu variable.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 325:b2768401db94]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:47:56 -05:00
Scott Rixner
ab7f863e41 xen: events: Process event channels notifications in round-robin order.
Avoids fairness issue resulting from domain 0 processing lowest
numbered event channel first.

Fixes bug #1115 "Event channel port scanning unfair".

Bugzilla: http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1115
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 324:7fe1c6d02a2b
 various variables have different names in this tree:
  l1  -> pending_words
  l2  -> pending_bits
  l1i -> word_idx
  l2i -> bit_idx]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:47:55 -05:00
Ian Campbell
71eef7d1e3 xen: events: remove dom0 specific xen_create_msi_irq
The function name does not distinguish it from xen_allocate_pirq_msi
(which operates on domU and pvhvm domains rather than dom0).

Hoist domain 0 specific functionality up into the only caller leaving
functionality common to all guest types in xen_bind_pirq_msi_to_irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:45 -05:00
Ian Campbell
ca1d8fe952 xen: events: use xen_bind_pirq_msi_to_irq from xen_create_msi_irq
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:44 -05:00
Ian Campbell
f420e010ed xen: events: push set_irq_msi down into xen_create_msi_irq
Makes the tail end of this function look even more like
xen_bind_pirq_msi_to_irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:43 -05:00
Ian Campbell
2e55288f63 xen: events: update pirq_to_irq in xen_create_msi_irq
I don't think this was a deliberate ommision.

Makes the tail end of this function look even more like
xen_bind_pirq_msi_to_irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:42 -05:00
Ian Campbell
8135591e90 xen: events: refactor xen_create_msi_irq slightly
Calling PHYSDEVOP_map_pirq earlier simplifies error handling and
starts to make the tail end of this function look like
xen_bind_pirq_msi_to_irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:41 -05:00
Ian Campbell
bf480d952b xen: events: separate MSI PIRQ allocation from PIRQ binding to IRQ
Split the binding aspect of xen_allocate_pirq_msi out into a new
xen_bind_pirq_to_irq function.

In xen_hvm_setup_msi_irq when allocating a pirq write the MSI message
to signal the PIRQ as soon as the pirq is obtained. There is no way to
free the pirq back so if the subsequent binding to an IRQ fails we
want to ensure that we will reuse the PIRQ next time rather than leak
it.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:40 -05:00
Ian Campbell
5cad61a6ba xen: events: assume PHYSDEVOP_get_free_pirq exists
The find_unbound_pirq is called only from xen_allocate_pirq_msi and
only if alloc_pirq is true. The only caller which does this is
xen_hvm_setup_msi_irqs. The use of this function is gated, in
pci_xen_hvm_init, on XENFEAT_hvm_pirqs.

The PHYSDEVOP_get_free_pirq interfaces was added to the hypervisor in
22410:be96f6058c05 while XENFEAT_hvm_pirqs was added a couple of
minutes prior in 22409:6663214f06ac. Therefore we do not need to
concern ourselves with hypervisors which support XENFEAT_hvm_pirqs but
not PHYSDEVOP_get_free_pirq.

This eliminates the fallback path in find_unbound_pirq which walks to
pirq_to_irq array looking for a free pirq. Unlike the
PHYSDEVOP_get_free_pirq interface this fallback only looks up a free
pirq but does not reserve it. Removing this fallback will simplify
locking in the future.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:39 -05:00
Ian Campbell
4b41df7f6e xen: events: return irq from xen_allocate_pirq_msi
consistent with other similar functions.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:37 -05:00