The event channel number provided to evtchn_get can be provided by
userspace, so needs to be checked against the maximum number of event
channels prior to using it to index into evtchn_to_irq.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Event channels exposed to userspace by the evtchn module may be used by
other modules in an asynchronous manner, which requires that reference
counting be used to prevent the event channel from being closed before
the signals are delivered.
The reference count on new event channels defaults to -1 which indicates
the event channel is not referenced outside the kernel; evtchn_get fails
if called on such an event channel. The event channels made visible to
userspace by evtchn have a normal reference count.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Add IRQF_RESUME_EARLY and resume such IRQs earlier
genirq: Fix fatfinered fixup really
genirq: percpu: allow interrupt type to be set at enable time
genirq: Add support for per-cpu dev_id interrupts
genirq: Add IRQCHIP_SKIP_SET_WAKE flag
* 'stable/drivers-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xenbus: don't rely on xen_initial_domain to detect local xenstore
xenbus: Fix loopback event channel assuming domain 0
xen/pv-on-hvm:kexec: Fix implicit declaration of function 'xen_hvm_domain'
xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel
xen/pv-on-hvm kexec: update xs_wire.h:xsd_sockmsg_type from xen-unstable
xen/pv-on-hvm kexec+kdump: reset PV devices in kexec or crash kernel
xen/pv-on-hvm kexec: rebind virqs to existing eventchannel ports
xen/pv-on-hvm kexec: prevent crash in xenwatch_thread() when stale watch events arrive
* 'stable/drivers.bugfixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pciback: Check if the device is found instead of blindly assuming so.
xen/pciback: Do not dereference psdev during printk when it is NULL.
xen: remove XEN_PLATFORM_PCI config option
xen: XEN_PVHVM depends on PCI
xen/pciback: double lock typo
xen/pciback: use mutex rather than spinlock in vpci backend
xen/pciback: Use mutexes when working with Xenbus state transitions.
xen/pciback: miscellaneous adjustments
xen/pciback: use mutex rather than spinlock in passthrough backend
xen/pciback: use resource_size()
* 'stable/pci.fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pci: support multi-segment systems
xen-swiotlb: When doing coherent alloc/dealloc check before swizzling the MFNs.
xen/pci: make bus notifier handler return sane values
xen-swiotlb: fix printk and panic args
xen-swiotlb: Fix wrong panic.
xen-swiotlb: Retry up three times to allocate Xen-SWIOTLB
xen-pcifront: Update warning comment to use 'e820_host' option.
There are three different modes: PV, HVM, and initial domain 0. In all
the cases we would return -1 for failure instead of a proper error code.
Fix this by propagating the error code from the generic IRQ code.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The list operation checks whether the 'info' structure that is
retrieved from the list is NULL (otherwise it would not been able
to retrieve it). This check is not neccessary.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In case we can't allocate we are doomed. We should BUG_ON
instead of trying to dereference it later on.
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[v1: Use BUG_ON instead of BUG]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This adds a mechanism to resume selected IRQs during syscore_resume
instead of dpm_resume_noirq.
Under Xen we need to resume IRQs associated with IPIs early enough
that the resched IPI is unmasked and we can therefore schedule
ourselves out of the stop_machine where the suspend/resume takes
place.
This issue was introduced by 676dc3cf5b "xen: Use IRQF_FORCE_RESUME".
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1318713254.11016.52.camel@dagon.hellion.org.uk
Cc: stable@kernel.org (at least to 2.6.32.y)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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>
During a kexec boot some virqs such as timer and debugirq were already
registered by the old kernel. The hypervisor will return -EEXISTS from
the new EVTCHNOP_bind_virq request and the BUG in bind_virq_to_irq()
triggers. Catch the -EEXISTS error and loop through all possible ports to find
what port belongs to the virq/cpu combo.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
[v2:
- use NR_EVENT_CHANNELS instead of private MAX_EVTCHNS]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This is a patch to the events.c file that fixed up
whitespaces, tabs and braces errors found by the
checkpatch.pl tools.
Signed-off-by: Ruslan Pisarev <ruslan@rpisarev.org.ua>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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>
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>
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>
* '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()
* '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
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>
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>
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>
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>
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>
* '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()
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>
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>
* '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
* 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.
* '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().
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>
* '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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
(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>
Daniel De Graaf