Signed-off-by: NKeir Fraser <keir.fraser@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 991:9ba6d9f3fbc0]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

(except for starting l2 word, which we scan in two parts).
Signed-off-by: NKeir Fraser <keir.fraser@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 990:427276ac595d]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Also fixes a couple of boundary cases.
Signed-off-by: NKeir Fraser <keir.fraser@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 988:c88a02a22a05]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[ijc: forward ported from linux-2.6.18-xen.hg 325:b2768401db94]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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=1115Signed-off-by: NIan 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: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Makes the tail end of this function look even more like
xen_bind_pirq_msi_to_irq.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

consistent with other similar functions.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

All callers pass this flag so it is pointless.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Mark the IRQF_NO_SUSPEND interrupts IRQF_FORCE_RESUME and remove the extra
walk through the interrupt descriptors.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/events.c: In function 'ack_pirq':
drivers/xen/events.c:568: error: implicit declaration of function 'irq_move_irq'
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Convert Xen to the new irq_chip functions. Brings us closer to enable
CONFIG_GENERIC_HARDIRQS_NO_DEPRECATED
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

irq_chip.end got obsolete with the removal of __do_IRQ()
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

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: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>

Otherwise we fail to properly suspend/resume all of the emulated devices.

Something between 2.6.38-rc2 and rc3 appears to have exposed this
issue, but it's always been wrong not to do this.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: NJeremy Fitzhardinge <jeremy@goop.org>

drivers/xen/platform-pci.c:127: error: implicit declaration of function
          'pci_request_region'
drivers/xen/platform-pci.c:165: error: implicit declaration of function
          'pci_release_region'
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

platform-pci is rather generic for a modular distro style kernel.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This is the correct interface to use and something has broken the use
of the previous incorrect interface (which fails because the request
conflicts with the resources assigned for the PCI device itself
instead of nesting like the PCI interfaces do).
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@kernel.org # 2.6.37 only

When adding a page to m2p_override we change the p2m of the page so we
need to also clear the old pte of the kernel linear mapping because it
doesn't correspond anymore.

When we remove the page from m2p_override we restore the original p2m of
the page and we also restore the old pte of the kernel linear mapping.

Before changing the p2m mappings in m2p_add_override and
m2p_remove_override, check that the page passed as argument is valid and
return an error if it is not.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Use gnttab_map_refs and gnttab_unmap_refs to map and unmap the grant
ref, so that we can have a corresponding struct page.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

gnttab_map_refs maps some grant refs and uses the new m2p override to
set a proper m2p mapping for the granted pages.

gnttab_unmap_refs unmaps the granted refs and removes th mappings from
the m2p override.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

apply_to_page_range will acquire PTE lock while priv->lock is held,
and mn_invl_range_start tries to acquire priv->lock with PTE already
held.  Fix by not holding priv->lock during the entire map operation.
This is safe because map->vma is set nonzero while the lock is held,
which will cause subsequent maps to fail and will cause the unmap
ioctl (and other users of gntdev_del_map) to return -EBUSY until the
area is unmapped. It is similarly impossible for gntdev_vma_close to
be called while the vma is still being created.
Signed-off-by: NDaniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

It's the struct page of the L1 pte page.  But we can get its mfn
by simply doing an arbitrary_virt_to_machine() on it anyway (which is
the safe conservative choice; since we no longer allow HIGHPTE pages,
we would never expect to be operating on a mapped pte page).
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This flag controls the meaning of gnttab_map_grant_ref.host_addr and
specifies that the field contains a reference to the pte entry to be
used to perform the mapping. Therefore move the use of this flag to
the point at which we actually use a reference to the pte instead of
something else, splitting up the usage of the flag in this way is
confusing and potentially error prone.

The other flags are all properties of the mapping itself as opposed to
properties of the hypercall arguments and therefore it make sense to
continue to pass them round in map->flags.
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Cc: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
Cc: Derek G. Murray <Derek.Murray@cl.cam.ac.uk>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

These pages are from other domains, so don't have any local PFN.
VM_PFNMAP is the closest concept Linux has to this.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The gntdev driver allows usermode to map granted pages from other
domains.  This is typically used to implement a Xen backend driver
in user mode.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NStefano Stabellini <Stefano.Stabellini@eu.citrix.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

When retrieving the event channel number from irq, the irq
number may not be valid under some conditions.

So far that can be when we suspend/resume and irq ends with -1.
Validate and return sanitized irq and provide diagnostics information.

[v3: added unlikely on the WARN path]
[v2: reworded the commit message]
Signed-off-by: NJoe Jin <joe.jin@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: NGurudas Pai <gurudas.pai@oracle.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andrew Morton <akpm@linux-foundation.org>

Impact: build fix

Making the xenbus backend support a separate module is needlessly complex
and causes build failures.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[corresponds to 616ff7a06a3f in git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>