Commit graph

78 commits

Author SHA1 Message Date
Jeremy Fitzhardinge
e04195644e xen/events: use locked set|clear_bit() for cpu_evtchn_mask
The per-cpu event channel masks can be updated unlocked from multiple
CPUs, so use the locked variant.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-11-16 14:58:50 -08:00
Jan Beulich
1c6969ec8e xen/evtchn: clear secondary CPUs' cpu_evtchn_mask[] after restore
To bind all event channels to CPU#0, it is not sufficient to set all
of its cpu_evtchn_mask[] bits; all other CPUs also need to get their
bits cleared. Otherwise, evtchn_do_upcall() will start handling
interrupts on CPUs they're not intended to run on, which can be
particularly bad for per-CPU ones.

[ linux-2.6.18-xen.hg 7de7453dee36 ]

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-11-16 14:58:47 -08:00
Ian Campbell
6903591f31 xen: events: do not unmask event channels on resume
The IRQ core code will take care of disabling and reenabling
interrupts over suspend resume automatically, therefore we do not need
to do this in the Xen event channel code.

The only exception is those event channels marked IRQF_NO_SUSPEND
which the IRQ core ignores. We must unmask these ourselves, taking
care to obey the current IRQ_DISABLED status. Failure check for
IRQ_DISABLED leads to enabling polled only event channels, such as
that associated with the pv spinlocks, which must never be enabled:

[   21.970432] ------------[ cut here ]------------
[   21.970432] kernel BUG at arch/x86/xen/spinlock.c:343!
[   21.970432] invalid opcode: 0000 [#1] SMP
[   21.970432] last sysfs file: /sys/devices/virtual/net/lo/operstate
[   21.970432] Modules linked in:
[   21.970432]
[   21.970432] Pid: 0, comm: swapper Not tainted (2.6.32.24-x86_32p-xen-01034-g787c727 #34)
[   21.970432] EIP: 0061:[<c102e209>] EFLAGS: 00010046 CPU: 3
[   21.970432] EIP is at dummy_handler+0x3/0x7
[   21.970432] EAX: 0000021c EBX: dfc16880 ECX: 0000001a EDX: 00000000
[   21.970432] ESI: dfc02c00 EDI: 00000001 EBP: dfc47e10 ESP: dfc47e10
[   21.970432]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0069
[   21.970432] Process swapper (pid: 0, ti=dfc46000 task=dfc39440 task.ti=dfc46000)
[   21.970432] Stack:
[   21.970432]  dfc47e30 c10a39f0 0000021c 00000000 00000000 dfc16880 0000021c 00000001
[   21.970432] <0> dfc47e40 c10a4f08 0000021c 00000000 dfc47e78 c12240a7 c1839284 c1839284
[   21.970432] <0> 00000200 00000000 00000000 f5720000 c1f3d028 c1f3d02c 00000180 dfc47e90
[   21.970432] Call Trace:
[   21.970432]  [<c10a39f0>] ? handle_IRQ_event+0x5f/0x122
[   21.970432]  [<c10a4f08>] ? handle_percpu_irq+0x2f/0x55
[   21.970432]  [<c12240a7>] ? __xen_evtchn_do_upcall+0xdb/0x15f
[   21.970432]  [<c122481e>] ? xen_evtchn_do_upcall+0x20/0x30
[   21.970432]  [<c1030d47>] ? xen_do_upcall+0x7/0xc
[   21.970432]  [<c102007b>] ? apic_reg_read+0xd3/0x22d
[   21.970432]  [<c1002227>] ? hypercall_page+0x227/0x1005
[   21.970432]  [<c102d30b>] ? xen_force_evtchn_callback+0xf/0x14
[   21.970432]  [<c102da7c>] ? check_events+0x8/0xc
[   21.970432]  [<c102da3b>] ? xen_irq_enable_direct_end+0x0/0x1
[   21.970432]  [<c105e485>] ? finish_task_switch+0x62/0xba
[   21.970432]  [<c14e3f84>] ? schedule+0x808/0x89d
[   21.970432]  [<c1084dc5>] ? hrtimer_start_expires+0x1a/0x22
[   21.970432]  [<c1085154>] ? tick_nohz_restart_sched_tick+0x15a/0x162
[   21.970432]  [<c102f43a>] ? cpu_idle+0x6d/0x6f
[   21.970432]  [<c14db29e>] ? cpu_bringup_and_idle+0xd/0xf
[   21.970432] Code: 5d 0f 95 c0 0f b6 c0 c3 55 66 83 78 02 00 89 e5 5d 0f 95 \
c0 0f b6 c0 c3 55 b2 01 86 10 31 c0 84 d2 89 e5 0f 94 c0 5d c3 55 89 e5 <0f> 0b \
eb fe 55 80 3d 4c ce 84 c1 00 89 e5 57 56 89 c6 53 74 15
[   21.970432] EIP: [<c102e209>] dummy_handler+0x3/0x7 SS:ESP 0069:dfc47e10
[   21.970432] ---[ end trace c0b71f7e12cf3011 ]---

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-11-10 17:19:25 -08:00
Linus Torvalds
18cb657ca1 Merge branch 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
and branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm

* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: register xen pci notifier
  xen: initialize cpu masks for pv guests in xen_smp_init
  xen: add a missing #include to arch/x86/pci/xen.c
  xen: mask the MTRR feature from the cpuid
  xen: make hvc_xen console work for dom0.
  xen: add the direct mapping area for ISA bus access
  xen: Initialize xenbus for dom0.
  xen: use vcpu_ops to setup cpu masks
  xen: map a dummy page for local apic and ioapic in xen_set_fixmap
  xen: remap MSIs into pirqs when running as initial domain
  xen: remap GSIs as pirqs when running as initial domain
  xen: introduce XEN_DOM0 as a silent option
  xen: map MSIs into pirqs
  xen: support GSI -> pirq remapping in PV on HVM guests
  xen: add xen hvm acpi_register_gsi variant
  acpi: use indirect call to register gsi in different modes
  xen: implement xen_hvm_register_pirq
  xen: get the maximum number of pirqs from xen
  xen: support pirq != irq

* 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (27 commits)
  X86/PCI: Remove the dependency on isapnp_disable.
  xen: Update Makefile with CONFIG_BLOCK dependency for biomerge.c
  MAINTAINERS: Add myself to the Xen Hypervisor Interface and remove Chris Wright.
  x86: xen: Sanitse irq handling (part two)
  swiotlb-xen: On x86-32 builts, select SWIOTLB instead of depending on it.
  MAINTAINERS: Add myself for Xen PCI and Xen SWIOTLB maintainer.
  xen/pci: Request ACS when Xen-SWIOTLB is activated.
  xen-pcifront: Xen PCI frontend driver.
  xenbus: prevent warnings on unhandled enumeration values
  xenbus: Xen paravirtualised PCI hotplug support.
  xen/x86/PCI: Add support for the Xen PCI subsystem
  x86: Introduce x86_msi_ops
  msi: Introduce default_[teardown|setup]_msi_irqs with fallback.
  x86/PCI: Export pci_walk_bus function.
  x86/PCI: make sure _PAGE_IOMAP it set on pci mappings
  x86/PCI: Clean up pci_cache_line_size
  xen: fix shared irq device passthrough
  xen: Provide a variant of xen_poll_irq with timeout.
  xen: Find an unbound irq number in reverse order (high to low).
  xen: statically initialize cpu_evtchn_mask_p
  ...

Fix up trivial conflicts in drivers/pci/Makefile
2010-10-28 17:11:17 -07:00
Linus Torvalds
520045db94 Merge branches 'upstream/xenfs' and 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/xenfs' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen/privcmd: make privcmd visible in domU
  xen/privcmd: move remap_domain_mfn_range() to core xen code and export.
  privcmd: MMAPBATCH: Fix error handling/reporting
  xenbus: export xen_store_interface for xenfs
  xen/privcmd: make sure vma is ours before doing anything to it
  xen/privcmd: print SIGBUS faults
  xen/xenfs: set_page_dirty is supposed to return true if it dirties
  xen/privcmd: create address space to allow writable mmaps
  xen: add privcmd driver
  xen: add variable hypercall caller
  xen: add xen_set_domain_pte()
  xen: add /proc/xen/xsd_{kva,port} to xenfs

* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (29 commits)
  xen: include xen/xen.h for definition of xen_initial_domain()
  xen: use host E820 map for dom0
  xen: correctly rebuild mfn list list after migration.
  xen: improvements to VIRQ_DEBUG output
  xen: set up IRQ before binding virq to evtchn
  xen: ensure that all event channels start off bound to VCPU 0
  xen/hvc: only notify if we actually sent something
  xen: don't add extra_pages for RAM after mem_end
  xen: add support for PAT
  xen: make sure xen_max_p2m_pfn is up to date
  xen: limit extra memory to a certain ratio of base
  xen: add extra pages for E820 RAM regions, even if beyond mem_end
  xen: make sure xen_extra_mem_start is beyond all non-RAM e820
  xen: implement "extra" memory to reserve space for pages not present at boot
  xen: Use host-provided E820 map
  xen: don't map missing memory
  xen: defer building p2m mfn structures until kernel is mapped
  xen: add return value to set_phys_to_machine()
  xen: convert p2m to a 3 level tree
  xen: make install_p2mtop_page() static
  ...

Fix up trivial conflict in arch/x86/xen/mmu.c, and fix the use of
'reserve_early()' - in the new memblock world order it is now
'memblock_x86_reserve_range()' instead. Pointed out by Jeremy.
2010-10-26 18:20:19 -07:00
Jeremy Fitzhardinge
4fe7d5a708 xen: make hvc_xen console work for dom0.
Use the console hypercalls for dom0 console.

[ Impact: Add Xen dom0 console ]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:26:01 +01:00
Qing He
f731e3ef02 xen: remap MSIs into pirqs when running as initial domain
Implement xen_create_msi_irq to create an msi and remap it as pirq.
Use xen_create_msi_irq to implement an initial domain specific version
of setup_msi_irqs.

Signed-off-by: Qing He <qing.he@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:44 +01:00
Jeremy Fitzhardinge
38aa66fcb7 xen: remap GSIs as pirqs when running as initial domain
Implement xen_register_gsi to setup the correct triggering and polarity
properties of a gsi.
Implement xen_register_pirq to register a particular gsi as pirq and
receive interrupts as events.
Call xen_setup_pirqs to register all the legacy ISA irqs as pirqs.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:43 +01:00
Stefano Stabellini
809f9267bb xen: map MSIs into pirqs
Map MSIs into pirqs, writing 0 in the MSI vector data field and the pirq
number in the MSI destination id field.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:43 +01:00
Stefano Stabellini
3942b740e5 xen: support GSI -> pirq remapping in PV on HVM guests
Disable pcifront when running on HVM: it is meant to be used with pv
guests that don't have PCI bus.

Use acpi_register_gsi_xen_hvm to remap GSIs into pirqs.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:42 +01:00
Stefano Stabellini
42a1de56f3 xen: implement xen_hvm_register_pirq
xen_hvm_register_pirq allows the kernel to map a GSI into a Xen pirq and
receive the interrupt as an event channel from that point on.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:41 +01:00
Stefano Stabellini
01557baff6 xen: get the maximum number of pirqs from xen
Use PHYSDEVOP_get_nr_pirqs to get the maximum number of pirqs from xen.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:40 +01:00
Stefano Stabellini
7a043f119c xen: support pirq != irq
PHYSDEVOP_map_pirq might return a pirq different from what we asked if
we are running as an HVM guest, so we need to be able to support pirqs
that are different from linux irqs.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-22 21:25:40 +01:00
Ian Campbell
cb52e6d9ed xen: improvements to VIRQ_DEBUG output
* Fix bitmask formatting on 64 bit by specifying correct field widths.

* Output both global and local masked and pending information.

* Indicate in list of pending interrupts whether they are pending in
  the L2, masked globally and/or masked locally.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-22 12:57:35 -07:00
Jeremy Fitzhardinge
a52521f149 xen: set up IRQ before binding virq to evtchn
Make sure the irq is set up before binding a virq event channel to it.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-22 12:57:34 -07:00
Ian Campbell
b0097adeec xen: ensure that all event channels start off bound to VCPU 0
All event channels startbound to VCPU 0 so ensure that cpu_evtchn_mask
is initialised to reflect this. Otherwise there is a race after registering an
event channel but before the affinity is explicitly set where the event channel
can be delivered. If this happens then the event channel remains pending in the
L1 (evtchn_pending) array but is cleared in L2 (evtchn_pending_sel), this means
the event channel cannot be reraised until another event channel happens to
trigger the same L2 entry on that VCPU.

sizeof(cpu_evtchn_mask(0))==sizeof(unsigned long*) which is not correct, and
causes only the first 32 or 64 event channels (depending on architecture) to be
initially bound to VCPU0. Use sizeof(struct cpu_evtchn_s) instead.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: stable@kernel.org
2010-10-22 12:57:33 -07:00
Jeremy Fitzhardinge
3588fe2e3f xen/events: change to using fasteoi
Change event delivery to:
 - mask+clear event in the upcall function
 - use handle_fasteoi_irq as the handler
 - unmask in the eoi function (and handle migration)

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-22 12:57:21 -07:00
Konrad Rzeszutek Wilk
2c52f8d3f7 x86: xen: Sanitse irq handling (part two)
Thomas Gleixner cleaned up event handling to use the
sparse_irq handling, but the xen-pcifront patches utilized the
old mechanism. This fixes them to work with sparse_irq handling.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 17:12:38 -04:00
Alex Nixon
b5401a96b5 xen/x86/PCI: Add support for the Xen PCI subsystem
The frontend stub lives in arch/x86/pci/xen.c, alongside other
sub-arch PCI init code (e.g. olpc.c).

It provides a mechanism for Xen PCI frontend to setup/destroy
legacy interrupts, MSI/MSI-X, and PCI configuration operations.

[ Impact: add core of Xen PCI support ]
[ v2: Removed the IOMMU code and only focusing on PCI.]
[ v3: removed usage of pci_scan_all_fns as that does not exist]
[ v4: introduced pci_xen value to fix compile warnings]
[ v5: squished fixes+features in one patch, changed Reviewed-by to Ccs]
[ v7: added Acked-by]
Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Qing He <qing.he@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
2010-10-18 10:49:35 -04:00
Konrad Rzeszutek Wilk
15ebbb82ba xen: fix shared irq device passthrough
In driver/xen/events.c, whether bind_pirq is shareable or not is
determined by desc->action is NULL or not. But in __setup_irq,
startup(irq) is invoked before desc->action is assigned with
new action. So desc->action in startup_irq is always NULL, and
bind_pirq is always not shareable. This results in pt_irq_create_bind
failure when passthrough a device which shares irq to other devices.

This patch doesn't use probing_irq to determine if pirq is shareable
or not, instead set shareable flag in irq_info according to trigger
mode in xen_allocate_pirq. Set level triggered interrupts shareable.
Thus use this flag to set bind_pirq flag accordingly.

[v2: arch/x86/xen/pci.c no more, so file skipped]

Signed-off-by: Weidong Han <weidong.han@intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:49:29 -04:00
Konrad Rzeszutek Wilk
d9a8814f27 xen: Provide a variant of xen_poll_irq with timeout.
The 'xen_poll_irq_timeout' provides a method to pass in
the poll timeout for IRQs if requested. We also export
those two poll functions as Xen PCI fronted uses them.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-18 10:49:28 -04:00
Konrad Rzeszutek Wilk
3a69e9165a xen: Find an unbound irq number in reverse order (high to low).
In earlier Xen Linux kernels, the IRQ mapping was a straight 1:1 and the
find_unbound_irq started looking around 256 for open IRQs and up. IRQs
from 0 to 255 were reserved for PCI devices.  Previous to this patch,
the 'find_unbound_irq'  started looking at get_nr_hw_irqs() number.
For privileged  domain where the ACPI information is available that
returns the upper-bound of what the GSIs. For non-privileged PV domains,
where ACPI is no-existent the get_nr_hw_irqs() reports the IRQ_LEGACY (16).
With PCI passthrough enabled, and with PCI cards that have IRQs pinned
to a higher number than 16 we collide with previously allocated IRQs.
Specifically the PCI IRQs collide with the IPI's for Xen functions
(as they are allocated earlier).
For example:

00:00.11 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller (prog-if 10 [OHCI])
	...
	Interrupt: pin A routed to IRQ 18

[root@localhost ~]# cat /proc/interrupts | head
           CPU0       CPU1       CPU2
 16:      38186          0          0   xen-dyn-virq      timer0
 17:        149          0          0   xen-dyn-ipi       spinlock0
 18:        962          0          0   xen-dyn-ipi       resched0

and when the USB controller is loaded, the kernel reports:
IRQ handler type mismatch for IRQ 18
current handler: resched0

One way to fix this is to reverse the logic when looking for un-used
IRQ numbers and start with the highest available number. With that,
we would get:

           CPU0       CPU1       CPU2
... snip ..
292:         35          0          0   xen-dyn-ipi       callfunc0
293:       3992          0          0   xen-dyn-ipi       resched0
294:        224          0          0   xen-dyn-ipi       spinlock0
295:      57183          0          0   xen-dyn-virq      timer0
NMI:          0          0          0   Non-maskable interrupts
.. snip ..

And interrupts for PCI cards are now accessible.

This patch also includes the fix, found by Ian Campbell, titled
"xen: fix off-by-one error in find_unbound_irq."

[v2: Added an explanation in the code]
[v3: Rebased on top of tip/irq/core]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-10-18 10:49:10 -04:00
Jeremy Fitzhardinge
3b32f574a0 xen: statically initialize cpu_evtchn_mask_p
Sometimes cpu_evtchn_mask_p can get used early, before it has been
allocated.  Statically initialize it with an initdata version to catch
any early references.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:41:44 -04:00
Gerd Hoffmann
1a60d05f40 xen: set pirq name to something useful.
Impact: cleanup

Make pirq show useful information in /proc/interrupts

[v2: Removed the parts for arch/x86/xen/pci.c ]

Signed-off-by: Gerd Hoffmann <kraxel@xeni.home.kraxel.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:41:43 -04:00
Jeremy Fitzhardinge
b21ddbf503 xen: dynamically allocate irq & event structures
Dynamically allocate the irq_info and evtchn_to_irq arrays, so that
1) the irq_info array scales to the actual number of possible irqs,
and 2) we don't needlessly increase the static size of the kernel
when we aren't running under Xen.

Derived on patch from Mike Travis <travis@sgi.com>.

[Impact: reduce memory usage ]
[v2: Conflict in drivers/xen/events.c: Replaced alloc_bootmen with kcalloc ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:41:42 -04:00
Konrad Rzeszutek Wilk
0794bfc743 xen: identity map gsi->irqs
Impact: preserve compat with native

Reserve the lower irq range for use for hardware interrupts so we
can identity-map them.

[v2: Rebased on top tip/irq/core]
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:41:08 -04:00
Jeremy Fitzhardinge
d46a78b05c xen: implement pirq type event channels
A privileged PV Xen domain can get direct access to hardware.  In
order for this to be useful, it must be able to get hardware
interrupts.

Being a PV Xen domain, all interrupts are delivered as event channels.
PIRQ event channels are bound to a pirq number and an interrupt
vector.  When a IO APIC raises a hardware interrupt on that vector, it
is delivered as an event channel, which we can deliver to the
appropriate device driver(s).

This patch simply implements the infrastructure for dealing with pirq
event channels.

[ Impact: integrate hardware interrupts into Xen's event scheme ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:40:29 -04:00
Thomas Gleixner
77dff1c755 x86: xen: Sanitise sparse_irq handling
There seems to be more cleanups possible, but that's left to the xen
experts :)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
2010-10-12 16:53:44 +02:00
Jeremy Fitzhardinge
dffe2e1e1a xen: handle events as edge-triggered
Xen events are logically edge triggered, as Xen only calls the event
upcall when an event is newly set, but not continuously as it remains set.
As a result, use handle_edge_irq rather than handle_level_irq.

This has the important side-effect of fixing a long-standing bug of
events getting lost if:
 - an event's interrupt handler is running
 - the event is migrated to a different vcpu
 - the event is re-triggered

The most noticable symptom of these lost events is occasional lockups
of blkfront.

Many thanks to Tom Kopec and Daniel Stodden in tracking this down.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Tom Kopec <tek@acm.org>
Cc: Daniel Stodden <daniel.stodden@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
2010-08-24 11:14:12 -07:00
Jeremy Fitzhardinge
aaca49642b xen: use percpu interrupts for IPIs and VIRQs
IPIs and VIRQs are inherently per-cpu event types, so treat them as such:
 - use a specific percpu irq_chip implementation, and
 - handle them with handle_percpu_irq

This makes the path for delivering these interrupts more efficient
(no masking/unmasking, no locks), and it avoid problems with attempts
to migrate them.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
2010-08-24 11:13:28 -07:00
Linus Torvalds
1787985782 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:
  xen: Do not suspend IPI IRQs.
  powerpc: Use IRQF_NO_SUSPEND not IRQF_TIMER for non-timer interrupts
  ixp4xx-beeper: Use IRQF_NO_SUSPEND not IRQF_TIMER for non-timer interrupt
  irq: Add new IRQ flag IRQF_NO_SUSPEND
2010-08-06 13:25:43 -07:00
Stefano Stabellini
ca65f9fc0c Introduce CONFIG_XEN_PVHVM compile option
This patch introduce a CONFIG_XEN_PVHVM compile time option to
enable/disable Xen PV on HVM support.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2010-07-29 11:11:33 -07:00
Ian Campbell
4877c73728 xen: Do not suspend IPI IRQs.
In general the semantics of IPIs are that they are are expected to
continue functioning after dpm_suspend_noirq().

Specifically I have seen a deadlock between the callfunc IPI and the
stop machine used by xen's do_suspend() routine. If one CPU has already
called dpm_suspend_noirq() then there is a window where it can be sent
a callfunc IPI before all the other CPUs have entered stop_cpu().

If this happens then the first CPU ends up spinning in stop_cpu()
waiting for the other to rendezvous in state STOPMACHINE_PREPARE while
the other is spinning in csd_lock_wait().

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-29 13:24:58 +02:00
Stefano Stabellini
99ad198c49 xen: Fix find_unbound_irq in presence of ioapic irqs.
Don't break the assumption that the first 16 irqs are ISA irqs;
make sure that the irq is actually free before using it.

Use dynamic_irq_init_keep_chip_data instead of
dynamic_irq_init so that chip_data is not NULL (a NULL chip_data breaks
setup_vector_irq).

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:46:30 -07:00
Stefano Stabellini
183d03cc4f xen: Xen PCI platform device driver.
Add the xen pci platform device driver that is responsible
for initializing the grant table and xenbus in PV on HVM mode.
Few changes to xenbus and grant table are necessary to allow the delayed
initialization in HVM mode.
Grant table needs few additional modifications to work in HVM mode.

The Xen PCI platform device raises an irq every time an event has been
delivered to us. However these interrupts are only delivered to vcpu 0.
The Xen PCI platform interrupt handler calls xen_hvm_evtchn_do_upcall
that is a little wrapper around __xen_evtchn_do_upcall, the traditional
Xen upcall handler, the very same used with traditional PV guests.

When running on HVM the event channel upcall is never called while in
progress because it is a normal Linux irq handler (and we cannot switch
the irq chip wholesale to the Xen PV ones as we are running QEMU and
might have passed in PCI devices), therefore we cannot be sure that
evtchn_upcall_pending is 0 when returning.
For this reason if evtchn_upcall_pending is set by Xen we need to loop
again on the event channels set pending otherwise we might loose some
event channel deliveries.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:46:09 -07:00
Sheng Yang
38e20b07ef x86/xen: event channels delivery on HVM.
Set the callback to receive evtchns from Xen, using the
callback vector delivery mechanism.

The traditional way for receiving event channel notifications from Xen
is via the interrupts from the platform PCI device.
The callback vector is a newer alternative that allow us to receive
notifications on any vcpu and doesn't need any PCI support: we allocate
a vector exclusively to receive events, in the vector handler we don't
need to interact with the vlapic, therefore we avoid a VMEXIT.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2010-07-22 16:45:59 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Eric W. Biederman
ca4dbc6684 xen: Remove unnecessary arch specific xen irq functions.
Right now xen's use of the x86 and ia64 handle_irq is just bizarre and very
fragile as it is very non-obvious the function exists and is is used by
code out in drivers/....  Luckily using handle_irq is completely unnecessary,
and we can just use the generic irq apis instead.

This still leaves drivers/xen/events.c as a problematic user of the generic
irq apis it has "static struct irq_info irq_info[NR_IRQS]" but that can be
fixed some other time.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <4B7CAAD2.10803@kernel.org>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-18 17:17:58 -08:00
Ian Campbell
fed5ea87e0 xen: don't leak IRQs over suspend/resume.
On resume irq_info[*].evtchn is reset to 0 since event channel mappings
are not preserved over suspend/resume. The other contents of irq_info
is preserved to allow rebind_evtchn_irq() to function.

However when a device resumes it will try to unbind from the
previous IRQ (e.g.  blkfront goes blkfront_resume() -> blkif_free() ->
unbind_from_irqhandler() -> unbind_from_irq()). This will fail due to the
check for VALID_EVTCHN in unbind_from_irq() and the IRQ is leaked. The
device will then continue to resume and allocate a new IRQ, eventually
leading to find_unbound_irq() panic()ing.

Fix this by changing unbind_from_irq() to handle teardown of interrupts
which have type!=IRQT_UNBOUND but are not currently bound to a specific
event channel.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>
2009-12-03 11:14:55 -08:00
Tejun Heo
384be2b18a Merge branch 'percpu-for-linus' into percpu-for-next
Conflicts:
	arch/sparc/kernel/smp_64.c
	arch/x86/kernel/cpu/perf_counter.c
	arch/x86/kernel/setup_percpu.c
	drivers/cpufreq/cpufreq_ondemand.c
	mm/percpu.c

Conflicts in core and arch percpu codes are mostly from commit
ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many
num_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all
the first chunk allocators into mm/percpu.c, the changes are moved
from arch code to mm/percpu.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-08-14 14:45:31 +09:00
Pekka Enberg
a70c352a37 xen: Use kcalloc() in xen_init_IRQ()
The init_IRQ() function is now called with slab allocator initialized.
Therefore, we must not use the bootmem allocator in xen_init_IRQ().

Fixes the following boot-time warning:

  ------------[ cut here ]------------
  WARNING: at mm/bootmem.c:535 alloc_arch_preferred_bootmem+0x27/0x45()
  Modules linked in:
  Pid: 0, comm: swapper Not tainted 2.6.30 #1
  Call Trace:
   [<ffffffff8102d6e3>] ? warn_slowpath_common+0x73/0xb0
   [<ffffffff810210d9>] ? pvclock_clocksource_read+0x49/0x90
   [<ffffffff812e522f>] ? alloc_arch_preferred_bootmem+0x27/0x45
   [<ffffffff812e5761>] ? ___alloc_bootmem_nopanic+0x39/0xc9
   [<ffffffff812e57fa>] ? ___alloc_bootmem+0x9/0x2f
   [<ffffffff812e9e21>] ? xen_init_IRQ+0x25/0x61
   [<ffffffff812d69ee>] ? start_kernel+0x1b5/0x29e
  ---[ end trace 4eaa2a86a8e2da22 ]---

Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: lists@nerdbynature.de
Cc: jeremy.fitzhardinge@citrix.com
LKML-Reference: <1246438278.22417.28.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-01 11:19:47 +02:00
Tejun Heo
245b2e70ea percpu: clean up percpu variable definitions
Percpu variable definition is about to be updated such that all percpu
symbols including the static ones must be unique.  Update percpu
variable definitions accordingly.

* as,cfq: rename ioc_count uniquely

* cpufreq: rename cpu_dbs_info uniquely

* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it

* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and
  rename it

* ipv4,6: rename cookie_scratch uniquely

* x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to
  pmc_irq_entry and nmi_entry to pmc_nmi_entry

* perf_counter: rename disable_count to perf_disable_count

* ftrace: rename test_event_disable to ftrace_test_event_disable

* kmemleak: rename test_pointer to kmemleak_test_pointer

* mce: rename next_interval to mce_next_interval

[ Impact: percpu usage cleanups, no duplicate static percpu var names ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm <linux-mm@kvack.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
2009-06-24 15:13:48 +09:00
Tejun Heo
204fba4aa3 percpu: cleanup percpu array definitions
Currently, the following three different ways to define percpu arrays
are in use.

1. DEFINE_PER_CPU(elem_type[array_len], array_name);
2. DEFINE_PER_CPU(elem_type, array_name[array_len]);
3. DEFINE_PER_CPU(elem_type, array_name)[array_len];

Unify to #1 which correctly separates the roles of the two parameters
and thus allows more flexibility in the way percpu variables are
defined.

[ Impact: cleanup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-mm@kvack.org
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
2009-06-24 15:13:45 +09:00
Linus Torvalds
be15f9d63b Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits)
  xen: cache cr0 value to avoid trap'n'emulate for read_cr0
  xen/x86-64: clean up warnings about IST-using traps
  xen/x86-64: fix breakpoints and hardware watchpoints
  xen: reserve Xen start_info rather than e820 reserving
  xen: add FIX_TEXT_POKE to fixmap
  lguest: update lazy mmu changes to match lguest's use of kvm hypercalls
  xen: honour VCPU availability on boot
  xen: add "capabilities" file
  xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
  xen/sys/hypervisor: change writable_pt to features
  xen: add /sys/hypervisor support
  xen/xenbus: export xenbus_dev_changed
  xen: use device model for suspending xenbus devices
  xen: remove suspend_cancel hook
  xen/dev-evtchn: clean up locking in evtchn
  xen: export ioctl headers to userspace
  xen: add /dev/xen/evtchn driver
  xen: add irq_from_evtchn
  xen: clean up gate trap/interrupt constants
  xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
  ...
2009-06-10 16:16:27 -07:00
Yinghai Lu
85ac16d033 x86/irq: change irq_desc_alloc() to take node instead of cpu
This simplifies the node awareness of the code. All our allocators
only deal with a NUMA node ID locality not with CPU ids anyway - so
there's no need to maintain (and transform) a CPU id all across the
IRq layer.

v2: keep move_irq_desc related

[ Impact: cleanup, prepare IRQ code to be NUMA-aware ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
LKML-Reference: <49F65536.2020300@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 12:21:17 +02:00
Yinghai Lu
d5dedd4507 irq: change ->set_affinity() to return status
according to Ingo, change set_affinity() in irq_chip should return int,
because that way we can handle failure cases in a much cleaner way, in
the genirq layer.

v2: fix two typos

[ Impact: extend API ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: linux-arch@vger.kernel.org
LKML-Reference: <49F654E9.4070809@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-28 12:21:16 +02:00
Ian Campbell
d4c045364d xen: add irq_from_evtchn
Given an evtchn, return the corresponding irq.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-03-30 09:26:49 -07:00
Ian Campbell
90af9514ac xen: explicitly initialise the cpu field of irq_info
I was seeing a very odd crash on 64 bit in bind_evtchn_to_cpu because
cpu_from_irq(irq) was coming out as -1. I found this was coming direct
from the mk_ipi_info call.

It's not clear to me that this isn't a compiler bug (implicit
initialisation to zero of unsigned shorts in a struct not handled
correctly?).

On the other hand is it true that all event channels start of bound to
CPU 0? If not then -1 might be correct and the various other functions
should cope with this.

Signed-off-by: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 12:18:22 +01:00
Jeremy Fitzhardinge
3445a8fd7c xen: make sure that softirqs get handled at the end of event processing
Make sure that irq_enter()/irq_exit() wrap the entire event processing
loop, rather than each individual event invokation.  This makes sure
that softirq processing is deferred until the end of event processing,
rather than in the middle with interrupts disabled.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 12:18:09 +01:00
Jeremy Fitzhardinge
d77bbd4db4 xen: remove irq bindcount
There should be no need for us to maintain our own bind count for
irqs, since the surrounding irq system should keep track of shared
irqs for us.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-09 12:18:00 +01:00