Commit Graph

138 Commits

Author SHA1 Message Date
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
Ian Campbell
bb5d079aef xen: events: drop XEN_ALLOC_IRQ flag to xen_allocate_pirq_msi
All callers pass this flag so it is pointless.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:35 -05:00
Ian Campbell
ae1635b05f xen: events: do not leak IRQ from xen_allocate_pirq_msi when no pirq available.
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-10 14:44:34 -05:00
Konrad Rzeszutek Wilk
1aa0b51a03 xen/irq: Cleanup up the pirq_to_irq for DomU PV PCI passthrough guests as well.
We only did this for PV guests that are xen_initial_domain() but
there is not reason not to do this for other cases. The other
case is only exercised when you pass in a PCI device to a PV guest
_and_ the device in question.

Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:02:22 -05:00
Thomas Gleixner
676dc3cf5b xen: Use IRQF_FORCE_RESUME
Mark the IRQF_NO_SUSPEND interrupts IRQF_FORCE_RESUME and remove the extra
walk through the interrupt descriptors.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:02:21 -05:00
Ian Campbell
aa673c1cb3 xen: Fix compile error introduced by "switch to new irq_chip functions"
drivers/xen/events.c: In function 'ack_pirq':
drivers/xen/events.c:568: error: implicit declaration of function 'irq_move_irq'

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:00:30 -05:00
Thomas Gleixner
c9e265e030 xen: Switch to new irq_chip functions
Convert Xen to the new irq_chip functions. Brings us closer to enable
CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:00:29 -05:00
Thomas Gleixner
149f256f8c xen: Remove stale irq_chip.end
irq_chip.end got obsolete with the removal of __do_IRQ()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:00:28 -05:00
Ian Campbell
7214610475 xen: events: do not free legacy IRQs
c514d00c8057 "xen: events: add xen_allocate_irq_{dynamic, gsi} and
xen_free_irq" correctly avoids reallocating legacy IRQs (which are
managed by the arch core) but erroneously did not prevent them being
freed.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-03-03 12:00:27 -05:00
Ian Campbell
89911501f3 xen: events: allocate GSIs and dynamic IRQs from separate IRQ ranges.
There are three cases which we need to care about, PV guest, PV domain
0 and HVM guest.

The PV guest case is simple since it has no access to ACPI or real
APICs and therefore has no GSIs therefore we simply dynamically
allocate all IRQs. The potentially interesting case here is PIRQ type
event channels associated with passed through PCI devices. However
even in this case the guest has no direct interaction with the
physical GSI since that happens in the PCI backend.

The PV domain 0 and HVM guest cases are actually the same. In domain 0
case the kernel sees the host ACPI and GSIs (although it only sees the
APIC indirectly via the hypervisor) and in the HVM guest case it sees
the virtualised ACPI and emulated APICs. In these cases we start
allocating dynamic IRQs at nr_irqs_gsi so that they cannot clash with
any GSI.

Currently xen_allocate_irq_dynamic starts at nr_irqs and works
backwards looking for a free IRQ in order to (try and) avoid clashing
with GSIs used in domain 0 and in HVM guests. This change avoids that
although we retain the behaviour of allowing dynamic IRQs to encroach
on the GSI range if no suitable IRQs are available since a future IRQ
clash is deemed preferable to failure right now.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
2011-03-03 12:00:21 -05:00
Ian Campbell
c9df1ce585 xen: events: add xen_allocate_irq_{dynamic, gsi} and xen_free_irq
This is neater than open-coded calls to irq_alloc_desc_at and
irq_free_desc.

No intended behavioural change.

Note that we previously were not checking the return value of
irq_alloc_desc_at which would be failing for GSI<NR_IRQS_LEGACY
because the core architecture code has already allocated those for
us. Hence the additional check against NR_IRQS_LEGACY in
xen_allocate_irq_gsi.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
2011-03-03 11:56:59 -05:00
Ian Campbell
cbf6aa89fc xen:events: move find_unbound_irq inside CONFIG_PCI_MSI
The only caller is xen_allocate_pirq_msi which is also under this
ifdef so this fixes:
    drivers/xen/events.c:377: warning: 'find_unbound_pirq' defined but not used
when CONFIG_PCI_MSI=n

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
2011-03-03 11:56:58 -05:00
Ian Campbell
2e820f58f7 xen/irq: implement bind_interdomain_evtchn_to_irqhandler for backend drivers
Impact: new Xen-internal API

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-28 09:39:37 -05:00
Ian Campbell
b052181a98 xen: events: mark cpu_evtchn_mask_p as __refdata
This variable starts out pointing at init_evtchn_mask which is marked
__initdata but is set to point to a non-init data region in xen_init_IRQ
which is itself an __init function so this is safe.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Tested-and-acked-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-02-11 14:46:25 -05:00
Linus Torvalds
9f99a2f0e4 Merge branch 'stable/bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/bug-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/event: validate irq before get evtchn by irq
  xen/fb: fix potential memory leak
  xen/fb: fix xenfb suspend/resume race.
  xen: disable ACPI NUMA for PV guests
  xen/irq: Cleanup the find_unbound_irq
2011-01-10 08:48:46 -08:00