This is preparation for userspace handling MMIO and ioport accesses.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We use the ptrace API struct, and we currently don't let them set
anything but the normal registers (we'd have to filter the others).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Theoretical debates aside, now it boots.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Strictly, it's only needed when we have features (size or multiport).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Since PCI is little endian, 8-bit access might work, but the spec section
is very clear on this:

  4.1.3.1 Driver Requirements: PCI Device Layout

  The driver MUST access each field using the “natural” access method,
  i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit
  fields and 8-bit accesses for 8-bit fields.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

The VIRTIO_F_ANY_LAYOUT and VIRTIO_F_NOTIFY_ON_EMPTY features are pre-1.0
only.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

This allows modern implementations to ensure they don't use legacy
feature bits or SCSI commands (which are not used in v1.0 non-legacy).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

This provides backdoor access to the device MMIOs, and every device should
have one.  From the virtio 1.0 spec (CS03):

  4.1.4.7.1 Device Requirements: PCI configuration access capability

  The device MUST present at least one VIRTIO_PCI_CAP_PCI_CFG capability.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

The virtqueue_add() calls START_USE() upon entry. The virtqueue_kick() is
called if vq->num_added == (1 << 16) - 1 before calling END_USE().
The virtqueue_kick_prepare() called via virtqueue_kick() calls START_USE()
upon entry, and will call panic() if DEBUG is enabled.
Move this virtqueue_kick() call to after END_USE() call.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

This patch add a support for second version of the virtio-mmio device,
which follows OASIS "Virtual I/O Device (VIRTIO) Version 1.0"
specification.

Main changes:

1. The control register symbolic names use the new device/driver
   nomenclature rather than the old guest/host one.

2. The driver detect the device version (version 1 is the pre-OASIS
   spec, version 2 is compatible with fist revision of the OASIS spec)
   and drives the device accordingly.

3. New version uses direct addressing (64 bit address split into two
   low/high register) instead of the guest page size based one,
   and addresses each part of the queue (descriptors, available, used)
   separately.

4. The device activity is now explicitly triggered by writing to the
   "queue ready" register.

5. Whole 64 bit features are properly handled now (both ways).
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

release function in modern driver is unused:
it's a left-over from when each driver had
to have its own release.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

If set, try legacy interface first, modern one if that fails.  Useful to
work around device/driver bugs, and for compatibility testing.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Useful for testing device virtio 1 compatibility.
Based on patch by Rusty - couldn't resist putting
that flying car joke in there!
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

The ABI *is* stable, and has been for a while now.
Drop Kconfig warning saying that it's not guaranteed
to work.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

This drivers -> this driver.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

makes code look a bit prettier.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Most of our code has
struct foo {
}

Fix one instances where ring is inconsistent.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Most of our code has
struct foo {
}

Fix two instances where blk is inconsistent.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Most of our code has
struct foo {
}

Fix two instances where balloon is inconsistent.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Virtio 1.0 spec lists device config as optional.
Set get/set callbacks to NULL. Drivers can check that
and fail gracefully.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

We don't know the # of VQs that drivers are going to use so it's hard to
predict how much memory we'll need to map. However, the relevant
capability does give us an upper limit.
If that's below a page, we can reduce the number of required
mappings by mapping it all once ahead of the time.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

QEMU wants it, so why not?  Trust, but verify.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Lightly tested against qemu.

One thing *not* implemented here is separate mappings
for descriptor/avail/used rings. That's nice to have,
will be done later after we have core support.

This also exposes the PCI layout to userspace, and
adds macros for PCI layout offsets:

QEMU wants it, so why not?  Trust, but verify.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Based on patches by Michael S. Tsirkin <mst@redhat.com>, but I found it
hard to follow so changed to use structures which are more
self-documenting.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Most of initialization is device-independent.
Let's move it to common.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Device VQs were getting freed twice: once in every device's removal
functions, and then again in virtio_pci_legacy_remove().  The ones in
devices are called first, so drop the useless second call.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Virtio drivers should map the part of the range they need, not
necessarily all of it.
To this end, support mapping ranges within BAR on s390.
Since multiple ranges can now be mapped within a BAR, we keep track of
the number of mappings created, and only clear out the mapping for a BAR
when this number reaches 0.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Virtio drivers should map the part of the BAR they need, not necessarily
all of it.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

pci-iomap.c was (apparently, mistakenly) reintroduced as part of
commit 83c2dc15
    MN10300: Handle cacheable PCI regions in pci_iomap()
probably as side-effect of forward-porting the patch
from an old kernel.

It's not really needed: the generic pci_iomap does the right thing here.

The new file isn't compiled so it's safe to drop.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Cc: trivial@kernel.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/balloon needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/scsi needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/net needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/console needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/blk needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/9p needs config space access so make it
fail gracefully if not there.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio_pci does not depend on virtio_config:
let's not include it, users can pull it in as necessary.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Pull libata fixes from Tejun Heo:

 - Bartlomiej will be co-maintaining PATA portion of libata.  git
   workflow will stay the same.

 - sata_sil24 wasn't happy with tag ordered submission.  An option to
   restore the old tag allocation behavior is implemented for sil24.

 - a very old race condition in PIO host state machine which can trigger
   BUG fixed.

 - other driver-specific changes

* 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata: prevent HSM state change race between ISR and PIO
  libata: allow sata_sil24 to opt-out of tag ordered submission
  ata: pata_at91: depend on !ARCH_MULTIPLATFORM
  ahci: Remove Device ID for Intel Sunrise Point PCH
  ahci: Use dev_info() to inform about the lack of Device Sleep support
  libata: Whitelist SSDs that are known to properly return zeroes after TRIM
  sata_dwc_460ex: fix resource leak on error path
  ata: add MAINTAINERS entry for libata PATA drivers
  libata: clean up MAINTAINERS entries
  libata: export ata_get_cmd_descript()
  ahci_xgene: Fix the DMA state machine lockup for the ATA_CMD_PACKET PIO mode command.
  ahci_xgene: Fix the endianess issue in APM X-Gene SoC AHCI SATA controller driver.

Pull workqueue fix from Tejun Heo:
 "The xfs folks have been running into weird and very rare lockups for
  some time now.  I didn't think this could have been from workqueue
  side because no one else was reporting it.  This time, Eric had a
  kdump which we looked into and it turned out this actually was a
  workqueue bug and the bug has been there since the beginning of
  concurrency managed workqueue.

  A worker pool ensures forward progress of the workqueues associated
  with it by always having at least one worker reserved from executing
  work items.  When the pool is under contention, the idle one tries to
  create more workers for the pool and if that doesn't succeed quickly
  enough, it calls the rescuers to the pool.

  This logic had a subtle race condition in an early exit path.  When a
  worker invokes this manager function, the function may return %false
  indicating that the caller may proceed to executing work items either
  because another worker is already performing the role or conditions
  have changed and the pool is no longer under contention.

  The latter part depended on the assumption that whether more workers
  are necessary or not remains stable while the pool is locked; however,
  pool->nr_running (concurrency count) may change asynchronously and it
  getting bumped from zero asynchronously could send off the last idle
  worker to execute work items.

  The race window is fairly narrow, and, even when it gets triggered,
  the pool deadlocks iff if all work items get blocked on pending work
  items of the pool, which is highly unlikely but can be triggered by
  xfs.

  The patch removes the race window by removing the early exit path,
  which doesn't server any purpose anymore anyway"

* 'for-3.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix subtle pool management issue which can stall whole worker_pool

Pull pin control fixes from Linus Walleij:
 "Here is a (hopefully final) slew of pin control fixes for the v3.19
  series.  The deadlock fix is kind of serious and tagged for stable,
  the rest is business as usual.

   - Fix two deadlocks around the pin control mutexes, a long-standing
     issue that manifest itself in plug/unplug of pin controllers.
     (Tagged for stable.)

   - Handle an error path with zero functions in the Qualcomm pin
     controller.

   - Drop a bogus second GPIO chip added in the Lantiq driver.

   - Fix sudden IRQ loss on Rockchip pin controllers.

   - Register the GIT tree in MAINTAINERS"

* tag 'pinctrl-v3.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: MAINTAINERS: add git tree reference
  pinctrl: qcom: Don't iterate past end of function array
  pinctrl: lantiq: remove bogus of_gpio_chip_add
  pinctrl: Fix two deadlocks
  pinctrl: rockchip: Avoid losing interrupts when supporting both edges

Pull networking fixes from David Miller:

 1) Socket addresses returned in the error queue need to be fully
    initialized before being passed on to userspace, fix from Willem de
    Bruijn.

 2) Interrupt handling fixes to davinci_emac driver from Tony Lindgren.

 3) Fix races between receive packet steering and cpu hotplug, from Eric
    Dumazet.

 4) Allowing netlink sockets to subscribe to unknown multicast groups
    leads to crashes, don't allow it.  From Johannes Berg.

 5) One to many socket races in SCTP fixed by Daniel Borkmann.

 6) Put in a guard against the mis-use of ipv6 atomic fragments, from
    Hagen Paul Pfeifer.

 7) Fix promisc mode and ethtool crashes in sh_eth driver, from Ben
    Hutchings.

 8) NULL deref and double kfree fix in sxgbe driver from Girish K.S and
    Byungho An.

 9) cfg80211 deadlock fix from Arik Nemtsov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (36 commits)
  s2io: use snprintf() as a safety feature
  r8152: remove sram_read
  r8152: remove generic_ocp_read before writing
  bgmac: activate irqs only if there is nothing to poll
  bgmac: register napi before the device
  sh_eth: Fix ethtool operation crash when net device is down
  sh_eth: Fix promiscuous mode on chips without TSU
  ipv6: stop sending PTB packets for MTU < 1280
  net: sctp: fix race for one-to-many sockets in sendmsg's auto associate
  genetlink: synchronize socket closing and family removal
  genetlink: disallow subscribing to unknown mcast groups
  genetlink: document parallel_ops
  net: rps: fix cpu unplug
  net: davinci_emac: Add support for emac on dm816x
  net: davinci_emac: Fix ioremap for devices with MDIO within the EMAC address space
  net: davinci_emac: Fix incomplete code for getting the phy from device tree
  net: davinci_emac: Free clock after checking the frequency
  net: davinci_emac: Fix runtime pm calls for davinci_emac
  net: davinci_emac: Fix hangs with interrupts
  ip: zero sockaddr returned on error queue
  ...