Sometimes users need to be aware when a vfio_group attaches to a
KVM or detaches from it. KVM already calls get/put method from vfio to
manipulate the vfio_group reference, it can notify vfio_group in
a similar way.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Beyond vfio_iommu events, users might also be interested in
vfio_group events. For example, if a vfio_group is used along
with Qemu/KVM, whenever kvm pointer is set to/cleared from the
vfio_group, users could be notified.

Currently only VFIO_GROUP_NOTIFY_SET_KVM supported.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
[aw: remove use of new typedef]
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Currently vfio_register_notifier assumes that there is only one
notifier chain, which is in vfio_iommu. However, the user might
also be interested in events other than vfio_iommu, for example,
vfio_group. Refactor vfio_{un}register_notifier implementation
to make it feasible.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Reviewed-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NJike Song <jike.song@intel.com>
[aw: merge with commit 816ca69ea9c7 ("vfio: Fix handling of error returned by 'vfio_group_get_from_dev()'"), remove typedef]
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

'vfio_group_get_from_dev()' seems to return only NULL on error, not an
error pointer.

Fixes: 2169037d ("vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops")
Fixes: c086de81 ("vfio iommu: Add blocking notifier to notify DMA_UNMAP")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Capability header next field is an offset relative to the start of
the INFO buffer. tmp->next is assigned the proper value but iterations
implemented in vfio_info_cap_add and vfio_info_cap_shift use next
as an offset between the headers. When coping with multiple capabilities
this leads to an Oops.
Signed-off-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

As of commit d97ffe23 ("PCI: Fix return value from
pci_user_{read,write}_config_*()") it's unnecessary to call
pcibios_err_to_errno() to fixup the return value from these functions.

pcibios_err_to_errno() already does simple passthrough of -errno values,
therefore no functional change is expected.

[aw: changelog]
Signed-off-by: NCao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Adding myself as a maintainer of mediated device framework,
a sub module of VFIO.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

The Sample driver creates mdev device that simulates serial port over PCI
card.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Added details of sysfs ABI for mediated device framework
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Add file Documentation/vfio-mediated-device.txt that include details of
mediated device framework.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Defined device API strings. Vendor driver using mediated device
framework should use corresponding string for device_api attribute.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Updated vfio_platform_common.c file to use
vfio_set_irqs_validate_and_prepare()
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Updated vfio_pci.c file to use vfio_set_irqs_validate_and_prepare()
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Vendor driver using mediated device framework would use same mechnism to
validate and prepare IRQs. Introducing this function to reduce code
replication in multiple drivers.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Update msix_sparse_mmap_cap() to use vfio_info_add_capability()
Update region type capability to use vfio_info_add_capability()
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Vendor driver using mediated device framework should use
vfio_info_add_capability() to add capabilities.
Introduced this function to reduce code duplication in vendor drivers.

vfio_info_cap_shift() manipulated a data buffer to add an offset to each
element in a chain. This data buffer is documented in a uapi header.
Changing vfio_info_cap_shift symbol to be available to all drivers.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
about DMA_UNMAP.
Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
Notifier should be registered, if external user wants to use
vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages.
Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate
mappings.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
Mediated device only uses IOMMU APIs, the underlying hardware can be
managed by an IOMMU domain.

Aim of this change is:
- To use most of the code of TYPE1 IOMMU driver for mediated devices
- To support direct assigned device and mediated device in single module

This change adds pin and unpin support for mediated device to TYPE1 IOMMU
backend module. More details:
- Domain for external user is tracked separately in vfio_iommu structure.
  It is allocated when group for first mdev device is attached.
- Pages pinned for external domain are tracked in each vfio_dma structure
  for that iova range.
- Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of
  rb-tree is iova, but it actually aims to track pfns.
- On external pin request for an iova, page is pinned once, if iova is
  already pinned and tracked, ref_count is incremented.
- External unpin request unpins pages only when ref_count is 0.
- Pinned pages list is used to find pfn from iova and then unpin it.
  WARN_ON is added if there are entires in pfn_list while detaching the
  group and releasing the domain.
- Page accounting is updated to account in its address space where the
  pages are pinned/unpinned, i.e dma->task
-  Accouting for mdev device is only done if there is no iommu capable
  domain in the container. When there is a direct device assigned to the
  container and that domain is iommu capable, all pages are already pinned
  during DMA_MAP.
- Page accouting is updated on hot plug and unplug mdev device and pass
  through device.

Tested by assigning below combinations of devices to a single VM:
- GPU pass through only
- vGPU device only
- One GPU pass through and one vGPU device
- Linux VM hot plug and unplug vGPU device while GPU pass through device
  exist
- Linux VM hot plug and unplug GPU pass through device while vGPU device
  exist
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Add task structure to vfio_dma structure. Task structure is used for:
- During DMA_UNMAP, same task who mapped it or other task who shares same
address space is allowed to unmap, otherwise unmap fails.
QEMU maps few iova ranges initially, then fork threads and from the child
thread calls DMA_UNMAP on previously mapped iova. Since child shares same
address space, DMA_UNMAP is successful.
- Avoid accessing struct mm while process is exiting by acquiring
reference of task's mm during page accounting.
- It is also used to get task mlock capability and rlimit for mlock.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Add find_iommu_group()
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NJike Song <jike.song@intel.com>
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Update arguments of vaddr_get_pfn() to take struct mm_struct *mm as input
argument.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Added task structure as input argument to vfio_lock_acct() function.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Added APIs for pining and unpining set of pages. These call back into
backend iommu module to actually pin and unpin pages.
Added two new callback functions to struct vfio_iommu_driver_ops. Backend
IOMMU module that supports pining and unpinning pages for mdev devices
should provide these functions.

Renamed static functions in vfio_type1_iommu.c to resolve conflicts
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

This change rearrange functions to have common function to increment
container_users
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NJike Song <jike.song@intel.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

This patch rearranges functions to get vfio_group from device
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NJike Song <jike.song@intel.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

vfio_mdev driver registers with mdev core driver.
mdev core driver creates mediated device and calls probe routine of
vfio_mdev driver for each device.
Probe routine of vfio_mdev driver adds mediated device to VFIO core module

This driver forms a shim layer that pass through VFIO devices operations
to vendor driver for mediated devices.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NJike Song <jike.song@intel.com>
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Design for Mediated Device Driver:
Main purpose of this driver is to provide a common interface for mediated
device management that can be used by different drivers of different
devices.

This module provides a generic interface to create the device, add it to
mediated bus, add device to IOMMU group and then add it to vfio group.

Below is the high Level block diagram, with Nvidia, Intel and IBM devices
as example, since these are the devices which are going to actively use
this module as of now.

 +---------------+
 |               |
 | +-----------+ |  mdev_register_driver() +--------------+
 | |           | +<------------------------+ __init()     |
 | |  mdev     | |                         |              |
 | |  bus      | +------------------------>+              |<-> VFIO user
 | |  driver   | |     probe()/remove()    | vfio_mdev.ko |    APIs
 | |           | |                         |              |
 | +-----------+ |                         +--------------+
 |               |
 |  MDEV CORE    |
 |   MODULE      |
 |   mdev.ko     |
 | +-----------+ |  mdev_register_device() +--------------+
 | |           | +<------------------------+              |
 | |           | |                         |  nvidia.ko   |<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | | Physical  | |
 | |  device   | |  mdev_register_device() +--------------+
 | | interface | |<------------------------+              |
 | |           | |                         |  i915.ko     |<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | |           | |
 | |           | |  mdev_register_device() +--------------+
 | |           | +<------------------------+              |
 | |           | |                         | ccw_device.ko|<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | +-----------+ |
 +---------------+

Core driver provides two types of registration interfaces:
1. Registration interface for mediated bus driver:

/**
  * struct mdev_driver - Mediated device's driver
  * @name: driver name
  * @probe: called when new device created
  * @remove:called when device removed
  * @driver:device driver structure
  *
  **/
struct mdev_driver {
         const char *name;
         int  (*probe)  (struct device *dev);
         void (*remove) (struct device *dev);
         struct device_driver    driver;
};

Mediated bus driver for mdev device should use this interface to register
and unregister with core driver respectively:

int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
void mdev_unregister_driver(struct mdev_driver *drv);

Mediated bus driver is responsible to add/delete mediated devices to/from
VFIO group when devices are bound and unbound to the driver.

2. Physical device driver interface
This interface provides vendor driver the set APIs to manage physical
device related work in its driver. APIs are :

* dev_attr_groups: attributes of the parent device.
* mdev_attr_groups: attributes of the mediated device.
* supported_type_groups: attributes to define supported type. This is
			 mandatory field.
* create: to allocate basic resources in vendor driver for a mediated
         device. This is mandatory to be provided by vendor driver.
* remove: to free resources in vendor driver when mediated device is
         destroyed. This is mandatory to be provided by vendor driver.
* open: open callback of mediated device
* release: release callback of mediated device
* read : read emulation callback.
* write: write emulation callback.
* ioctl: ioctl callback.
* mmap: mmap emulation callback.

Drivers should use these interfaces to register and unregister device to
mdev core driver respectively:

extern int  mdev_register_device(struct device *dev,
                                 const struct parent_ops *ops);
extern void mdev_unregister_device(struct device *dev);

There are no locks to serialize above callbacks in mdev driver and
vfio_mdev driver. If required, vendor driver can have locks to serialize
above APIs in their driver.
Signed-off-by: NKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: NNeo Jia <cjia@nvidia.com>
Reviewed-by: NJike Song <jike.song@intel.com>
Reviewed-by: NDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>

Pull KVM fixes from Paolo Bonzini:
 "ARM fixes.  There are a couple pending x86 patches but they'll have to
  wait for next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm/arm64: vgic: Kick VCPUs when queueing already pending IRQs
  KVM: arm/arm64: vgic: Prevent access to invalid SPIs
  arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a single CPU

Merge media fixes from Mauro Carvalho Chehab:
 "This contains two patches fixing problems with my patch series meant
  to make USB drivers to work again after the DMA on stack changes.

  The last patch on this series is actually not related to DMA on stack.
  It solves a longstanding bug affecting module unload, causing
  module_put() to be called twice. It was reported by the user who
  reported and tested the issues with the gp8psk driver with the DMA
  fixup patches. As we're late at -rc cycle, maybe you prefer to not
  apply it right now. If this is the case, I'll add to the pile of
  patches for 4.10.

  Exceptionally this time, I'm sending the patches via e-mail, because
  I'm on another trip, and won't be able to use the usual procedure
  until Monday. Also, it is only three patches, and you followed already
  the discussions about the first one"

* emailed patches from Mauro Carvalho Chehab <mchehab@osg.samsung.com>:
  gp8psk: Fix DVB frontend attach
  gp8psk: fix gp8psk_usb_in_op() logic
  dvb-usb: move data_mutex to struct dvb_usb_device

Pull char/misc fixes from Greg KH:
 "Here are three small driver fixes for some reported issues for
  4.9-rc5.

  One for the hyper-v subsystem, fixing up a naming issue that showed up
  in 4.9-rc1, one mei driver fix, and one fix for parallel ports,
  resolving a reported regression.

  All have been in linux-next with no reported issues"

* tag 'char-misc-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  ppdev: fix double-free of pp->pdev->name
  vmbus: make sysfs names consistent with PCI
  mei: bus: fix received data size check in NFC fixup

Pull driver core fixes from Greg KH:
 "Here are two driver core fixes for 4.9-rc5.

  The first resolves an issue with some drivers not liking to be unbound
  and bound again (if CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled), which
  solves some reported problems with graphics and storage drivers. The
  other resolves a smatch error with the 4.9-rc1 driver core changes
  around this feature.

  Both have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: fix smatch warning on dev->bus check
  driver core: skip removal test for non-removable drivers

Pull staging/IIO fixes from Grek KH:
 "Here are a few small staging and iio driver fixes for reported issues.

  The last one was cherry-picked from my -next branch to resolve a build
  warning that Arnd fixed, in his quest to be able to turn
  -Wmaybe-uninitialized back on again. That patch, and all of the
  others, have been in linux-next for a while with no reported issues"

* tag 'staging-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: maxim_thermocouple: detect invalid storage size in read()
  staging: nvec: remove managed resource from PS2 driver
  Revert "staging: nvec: ps2: change serio type to passthrough"
  drivers: staging: nvec: remove bogus reset command for PS/2 interface
  staging: greybus: arche-platform: fix device reference leak
  staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value
  staging: sm750fb: Fix bugs introduced by early commits
  iio: hid-sensors: Increase the precision of scale to fix wrong reading interpretation.
  iio: orientation: hid-sensor-rotation: Add PM function (fix non working driver)
  iio: st_sensors: fix scale configuration for h3lis331dl
  staging: iio: ad5933: avoid uninitialized variable in error case

Pull USB / PHY fixes from Greg KH:
 "Here are a number of small USB and PHY driver fixes for 4.9-rc5

  Nothing major, just small fixes for reported issues, all of these have
  been in linux-next for a while with no reported issues"

* tag 'usb-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix TIOCMIWAIT
  cdc-acm: fix uninitialized variable
  drivers/usb: Skip auto handoff for TI and RENESAS usb controllers
  usb: musb: remove duplicated actions
  usb: musb: da8xx: Don't print phy error on -EPROBE_DEFER
  phy: sun4i: check PMU presence when poking unknown bit of pmu
  phy-rockchip-pcie: remove deassert of phy_rst from exit callback
  phy: da8xx-usb: rename the ohci device to ohci-da8xx
  phy: Add reset callback for not generic phy
  uwb: fix device reference leaks
  usb: gadget: u_ether: remove interrupt throttling
  usb: dwc3: st: add missing <linux/pinctrl/consumer.h> include
  usb: dwc3: Fix error handling for core init

Pull more block fixes from Jens Axboe:
 "Since I mistakenly left out the lightnvm regression fix yesterday and
  the aoeblk seems adequately tested at this point, might as well send
  out another pull to make -rc5"

* 'for-linus' of git://git.kernel.dk/linux-block:
  aoe: fix crash in page count manipulation
  lightnvm: invalid offset calculation for lba_shift

Pull SCSI fixes from James Bottomley:
 "The megaraid_sas patch in here fixes a major regression in the last
  fix set that made all megaraid_sas cards unusable. It turns out no-one
  had actually tested such an "obvious" fix, sigh. The fix for the fix
  has been tested ...

  The next most serious is the vmw_pvscsi abort problem which basically
  means that aborts don't work on the vmware paravirt devices and error
  handling always escalates to reset.

  The rest are an assortment of missed reference counting in certain
  paths and corner case bugs that show up on some architectures"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: megaraid_sas: fix macro MEGASAS_IS_LOGICAL to avoid regression
  scsi: qla2xxx: fix invalid DMA access after command aborts in PCI device remove
  scsi: qla2xxx: do not queue commands when unloading
  scsi: libcxgbi: fix incorrect DDP resource cleanup
  scsi: qla2xxx: Fix scsi scan hang triggered if adapter fails during init
  scsi: scsi_dh_alua: Fix a reference counting bug
  scsi: vmw_pvscsi: return SUCCESS for successful command aborts
  scsi: mpt3sas: Fix for block device of raid exists even after deleting raid disk
  scsi: scsi_dh_alua: fix missing kref_put() in alua_rtpg_work()

Pull clk fixes from Stephen Boyd:
 "The typical collection of minor bug fixes in clk drivers. We don't
  have anything in the core framework here, just driver fixes.

  There's a boot fix for Samsung devices and a safety measure for qoriq
  to prevent CPUs from running too fast. There's also a fix for i.MX6Q
  to properly handle audio clock rates. We also have some "that's
  obviously wrong" fixes like bad NULL pointer checks in the MPP driver
  and a poor usage of __pa in the xgene clk driver that are fixed here"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: mmp: pxa910: fix return value check in pxa910_clk_init()
  clk: mmp: pxa168: fix return value check in pxa168_clk_init()
  clk: mmp: mmp2: fix return value check in mmp2_clk_init()
  clk: qoriq: Don't allow CPU clocks higher than starting value
  clk: imx: fix integer overflow in AV PLL round rate
  clk: xgene: Don't call __pa on ioremaped address
  clk/samsung: Use CLK_OF_DECLARE_DRIVER initialization method for CLKOUT
  clk: rockchip: don't return NULL when failing to register ddrclk branch

The DVB binding schema at the DVB core assumes that the frontend is a
separate driver.  Faling to do that causes OOPS when the module is
removed, as it tries to do a symbol_put_addr on an internal symbol,
causing craches like:

    WARNING: CPU: 1 PID: 28102 at kernel/module.c:1108 module_put+0x57/0x70
    Modules linked in: dvb_usb_gp8psk(-) dvb_usb dvb_core nvidia_drm(PO) nvidia_modeset(PO) snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd soundcore nvidia(PO) [last unloaded: rc_core]
    CPU: 1 PID: 28102 Comm: rmmod Tainted: P        WC O 4.8.4-build.1 #1
    Hardware name: MSI MS-7309/MS-7309, BIOS V1.12 02/23/2009
    Call Trace:
       dump_stack+0x44/0x64
       __warn+0xfa/0x120
       module_put+0x57/0x70
       module_put+0x57/0x70
       warn_slowpath_null+0x23/0x30
       module_put+0x57/0x70
       gp8psk_fe_set_frontend+0x460/0x460 [dvb_usb_gp8psk]
       symbol_put_addr+0x27/0x50
       dvb_usb_adapter_frontend_exit+0x3a/0x70 [dvb_usb]

From Derek's tests:
    "Attach bug is fixed, tuning works, module unloads without
     crashing. Everything seems ok!"
Reported-by: NDerek <user.vdr@gmail.com>
Tested-by: NDerek <user.vdr@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit bc29131ecb10 ("[media] gp8psk: don't do DMA on stack") fixed the
usage of DMA on stack, but the memcpy was wrong for gp8psk_usb_in_op().
Fix it.

From Derek's email:
    "Fix confirmed using 2 different Skywalker models with
     HD mpeg4, SD mpeg2."
Suggested-by: NJohannes Stezenbach <js@linuxtv.org>
Fixes: bc29131ecb10 ("[media] gp8psk: don't do DMA on stack")
Tested-by: NDerek <user.vdr@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The data_mutex is initialized too late, as it is needed for
each device driver's power control, causing an OOPS:

    dvb-usb: found a 'TerraTec/qanu USB2.0 Highspeed DVB-T Receiver' in warm state.
    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100 PGD 0
    Oops: 0002 [#1] SMP
    Modules linked in: dvb_usb_cinergyT2(+) dvb_usb
    CPU: 0 PID: 2029 Comm: modprobe Not tainted 4.9.0-rc4-dvbmod #24
    Hardware name: FUJITSU LIFEBOOK A544/FJNBB35 , BIOS Version 1.17 05/09/2014
    task: ffff88020e943840 task.stack: ffff8801f36ec000
    RIP: 0010:[<ffffffff846617af>]  [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100
    RSP: 0018:ffff8801f36efb10  EFLAGS: 00010282
    RAX: 0000000000000000 RBX: ffff88021509bdc8 RCX: 00000000c0000100
    RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88021509bdcc
    RBP: ffff8801f36efb58 R08: ffff88021f216320 R09: 0000000000100000
    R10: ffff88021f216320 R11: 00000023fee6c5a1 R12: ffff88020e943840
    R13: ffff88021509bdcc R14: 00000000ffffffff R15: ffff88021509bdd0
    FS:  00007f21adb86740(0000) GS:ffff88021f200000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 0000000215bce000 CR4: 00000000001406f0
    Call Trace:
       mutex_lock+0x16/0x25
       cinergyt2_power_ctrl+0x1f/0x60 [dvb_usb_cinergyT2]
       dvb_usb_device_init+0x21e/0x5d0 [dvb_usb]
       cinergyt2_usb_probe+0x21/0x50 [dvb_usb_cinergyT2]
       usb_probe_interface+0xf3/0x2a0
       driver_probe_device+0x208/0x2b0
       __driver_attach+0x87/0x90
       driver_probe_device+0x2b0/0x2b0
       bus_for_each_dev+0x52/0x80
       bus_add_driver+0x1a3/0x220
       driver_register+0x56/0xd0
       usb_register_driver+0x77/0x130
       do_one_initcall+0x46/0x180
       free_vmap_area_noflush+0x38/0x70
       kmem_cache_alloc+0x84/0xc0
       do_init_module+0x50/0x1be
       load_module+0x1d8b/0x2100
       find_symbol_in_section+0xa0/0xa0
       SyS_finit_module+0x89/0x90
       entry_SYSCALL_64_fastpath+0x13/0x94
    Code: e8 a7 1d 00 00 8b 03 83 f8 01 0f 84 97 00 00 00 48 8b 43 10 4c 8d 7b 08 48 89 63 10 4c 89 3c 24 41 be ff ff ff ff 48 89 44 24 08 <48> 89 20 4c 89 64 24 10 eb 1a 49 c7 44 24 08 02 00 00 00 c6 43 RIP  [<ffffffff846617af>] __mutex_lock_slowpath+0x6f/0x100 RSP <ffff8801f36efb10>
    CR2: 0000000000000000

So, move it to the struct dvb_usb_device and initialize it
before calling the driver's callbacks.
Reported-by: NJörg Otte <jrg.otte@gmail.com>
Tested-by: NJörg Otte <jrg.otte@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>