The new XIVE interrupt controller on POWER9 can direct external
interrupts to the hypervisor or the guest.  The interrupts directed to
the hypervisor are controlled by an LPCR bit called LPCR_HVICE, and
come in as a "hypervisor virtualization interrupt".  This sets the
LPCR bit so that hypervisor virtualization interrupts can occur while
we are in the guest.  We then also need to cope with exiting the guest
because of a hypervisor virtualization interrupt.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

POWER9 replaces the various power-saving mode instructions on POWER8
(doze, nap, sleep and rvwinkle) with a single "stop" instruction, plus
a register, PSSCR, which controls the depth of the power-saving mode.
This replaces the use of the nap instruction when threads are idle
during guest execution with the stop instruction, and adds code to
set PSSCR to a value which will allow an SMT mode switch while the
thread is idle (given that the core as a whole won't be idle in these
cases).
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

POWER9 includes a new interrupt controller, called XIVE, which is
quite different from the XICS interrupt controller on POWER7 and
POWER8 machines.  KVM-HV accesses the XICS directly in several places
in order to send and clear IPIs and handle interrupts from PCI
devices being passed through to the guest.

In order to make the transition to XIVE easier, OPAL firmware will
include an emulation of XICS on top of XIVE.  Access to the emulated
XICS is via OPAL calls.  The one complication is that the EOI
(end-of-interrupt) function can now return a value indicating that
another interrupt is pending; in this case, the XIVE will not signal
an interrupt in hardware to the CPU, and software is supposed to
acknowledge the new interrupt without waiting for another interrupt
to be delivered in hardware.

This adapts KVM-HV to use the OPAL calls on machines where there is
no XICS hardware.  When there is no XICS, we look for a device-tree
node with "ibm,opal-intc" in its compatible property, which is how
OPAL indicates that it provides XICS emulation.

In order to handle the EOI return value, kvmppc_read_intr() has
become kvmppc_read_one_intr(), with a boolean variable passed by
reference which can be set by the EOI functions to indicate that
another interrupt is pending.  The new kvmppc_read_intr() keeps
calling kvmppc_read_one_intr() until there are no more interrupts
to process.  The return value from kvmppc_read_intr() is the
largest non-zero value of the returns from kvmppc_read_one_intr().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

On POWER9, the msgsnd instruction is able to send interrupts to
other cores, as well as other threads on the local core.  Since
msgsnd is generally simpler and faster than sending an IPI via the
XICS, we use msgsnd for all IPIs sent by KVM on POWER9.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

POWER9 adds new capabilities to the tlbie (TLB invalidate entry)
and tlbiel (local tlbie) instructions.  Both instructions get a
set of new parameters (RIC, PRS and R) which appear as bits in the
instruction word.  The tlbiel instruction now has a second register
operand, which contains a PID and/or LPID value if needed, and
should otherwise contain 0.

This adapts KVM-HV's usage of tlbie and tlbiel to work on POWER9
as well as older processors.  Since we only handle HPT guests so
far, we need RIC=0 PRS=0 R=0, which ends up with the same instruction
word as on previous processors, so we don't need to conditionally
execute different instructions depending on the processor.

The local flush on first entry to a guest in book3s_hv_rmhandlers.S
is a loop which depends on the number of TLB sets.  Rather than
using feature sections to set the number of iterations based on
which CPU we're on, we now work out this number at VM creation time
and store it in the kvm_arch struct.  That will make it possible to
get the number from the device tree in future, which will help with
compatibility with future processors.

Since mmu_partition_table_set_entry() does a global flush of the
whole LPID, we don't need to do the TLB flush on first entry to the
guest on each processor.  Therefore we don't set all bits in the
tlb_need_flush bitmap on VM startup on POWER9.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

This adds code to handle two new guest-accessible special-purpose
registers on POWER9: TIDR (thread ID register) and PSSCR (processor
stop status and control register).  They are context-switched
between host and guest, and the guest values can be read and set
via the one_reg interface.

The PSSCR contains some fields which are guest-accessible and some
which are only accessible in hypervisor mode.  We only allow the
guest-accessible fields to be read or set by userspace.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Some special-purpose registers that were present and accessible
by guests on POWER8 no longer exist on POWER9, so this adds
feature sections to ensure that we don't try to context-switch
them when going into or out of a guest on POWER9.  These are
all relatively obscure, rarely-used registers, but we had to
context-switch them on POWER8 to avoid creating a covert channel.
They are: SPMC1, SPMC2, MMCRS, CSIGR, TACR, TCSCR, and ACOP.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

On POWER9, the SDR1 register (hashed page table base address) is no
longer used, and instead the hardware reads the HPT base address
and size from the partition table.  The partition table entry also
contains the bits that specify the page size for the VRMA mapping,
which were previously in the LPCR.  The VPM0 bit of the LPCR is
now reserved; the processor now always uses the VRMA (virtual
real-mode area) mechanism for guest real-mode accesses in HPT mode,
and the RMO (real-mode offset) mechanism has been dropped.

When entering or exiting the guest, we now only have to set the
LPIDR (logical partition ID register), not the SDR1 register.
There is also no requirement now to transition via a reserved
LPID value.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

This adapts the KVM-HV hashed page table (HPT) code to read and write
HPT entries in the new format defined in Power ISA v3.00 on POWER9
machines.  The new format moves the B (segment size) field from the
first doubleword to the second, and trims some bits from the AVA
(abbreviated virtual address) and ARPN (abbreviated real page number)
fields.  As far as possible, the conversion is done when reading or
writing the HPT entries, and the rest of the code continues to use
the old format.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

This merges in the ppc-kvm topic branch to get changes to
arch/powerpc code that are necessary for adding POWER9 KVM support.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Define and set the POWER9 HFSCR doorbell bit so that guests can use
msgsndp.

ISA 3.0 calls this MSGP, so name it accordingly in the code.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

ISA 3.0 defines a new PECE (Power-saving mode Exit Cause Enable) field
in the LPCR (Logical Partitioning Control Register), called
LPCR_PECE_HVEE (Hypervisor Virtualization Exit Enable).

KVM code will need to know about this bit, so add a definition for it.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

ISA 3.00 adds the logical PVR value 0x0f000005, so add a definition for
this.

Define PCR_ARCH_207 to reflect ISA 2.07 compatibility mode in the processor
compatibility register (PCR).

[paulus@ozlabs.org - moved dummy PCR_ARCH_300 value into next patch]
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

This defines real-mode versions of opal_int_get_xirr(), opal_int_eoi()
and opal_int_set_mfrr(), for use by KVM real-mode code.

It also exports opal_int_set_mfrr() so that the modular part of KVM
can use it to send IPIs.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

POWER9 requires the host to set up a partition table, which is a
table in memory indexed by logical partition ID (LPID) which
contains the pointers to page tables and process tables for the
host and each guest.

This factors out the initialization of the partition table into
a single function.  This code was previously duplicated between
hash_utils_64.c and pgtable-radix.c.

This provides a function for setting a partition table entry,
which is used in early MMU initialization, and will be used by
KVM whenever a guest is created.  This function includes a tlbie
instruction which will flush all TLB entries for the LPID and
all caches of the partition table entry for the LPID, across the
system.

This also moves a call to memblock_set_current_limit(), which was
in radix_init_partition_table(), but has nothing to do with the
partition table.  By analogy with the similar code for hash, the
call gets moved to near the end of radix__early_init_mmu().  It
now gets called when running as a guest, whereas previously it
would only be called if the kernel is running as the host.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

These definitions will be needed by KVM.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Drop duplicate header asm/iommu.h from book3s_64_vio_hv.c.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

The hashed page table MMU in POWER processors can update the R
(reference) and C (change) bits in a HPTE at any time until the
HPTE has been invalidated and the TLB invalidation sequence has
completed.  In kvmppc_h_protect, which implements the H_PROTECT
hypercall, we read the HPTE, modify the second doubleword,
invalidate the HPTE in memory, do the TLB invalidation sequence,
and then write the modified value of the second doubleword back
to memory.  In doing so we could overwrite an R/C bit update done
by hardware between when we read the HPTE and when the TLB
invalidation completed.  To fix this we re-read the second
doubleword after the TLB invalidation and OR in the (possibly)
new values of R and C.  We can use an OR since hardware only ever
sets R and C, never clears them.

This race was found by code inspection.  In principle this bug could
cause occasional guest memory corruption under host memory pressure.

Fixes: a8606e20 ("KVM: PPC: Handle some PAPR hcalls in the kernel", 2011-06-29)
Cc: stable@vger.kernel.org # v3.19+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

When switching from/to a guest that has a transaction in progress,
we need to save/restore the checkpointed register state.  Although
XER is part of the CPU state that gets checkpointed, the code that
does this saving and restoring doesn't save/restore XER.

This fixes it by saving and restoring the XER.  To allow userspace
to read/write the checkpointed XER value, we also add a new ONE_REG
specifier.

The visible effect of this bug is that the guest may see its XER
value being corrupted when it uses transactions.

Fixes: e4e38121 ("KVM: PPC: Book3S HV: Add transactional memory support")
Fixes: 0a8eccef ("KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit")
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

This keeps a per vcpu cache for recently page faulted MMIO entries.
On a page fault, if the entry exists in the cache, we can avoid some
time-consuming paths, for example, looking up HPT, locking HPTE twice
and searching mmio gfn from memslots, then directly call
kvmppc_hv_emulate_mmio().

In current implenment, we limit the size of cache to four. We think
it's enough to cover the high-frequency MMIO HPTEs in most case.
For example, considering the case of using virtio device, for virtio
legacy devices, one HPTE could handle notifications from up to
1024 (64K page / 64 byte Port IO register) devices, so one cache entry
is enough; for virtio modern devices, we always need one HPTE to handle
notification for each device because modern device would use a 8M MMIO
register to notify host instead of Port IO register, typically the
system's configuration should not exceed four virtio devices per
vcpu, four cache entry is also enough in this case. Of course, if needed,
we could also modify the macro to a module parameter in the future.
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Currently we mark a HPTE for emulated MMIO with HPTE_V_ABSENT bit
set as well as key 0x1f. However, those HPTEs may be conflicted with
the HPTE for real guest RAM page HPTE with key 0x1f when the page
get paged out.

This patch clears the key field of HPTE when the page is paged out,
then recover it when HPTE is re-established.
Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Using list_move_tail() instead of list_del() + list_add_tail().
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

A bunch of KVM functions are only called from assembler.
Give them prototypes in asm-prototypes.h
This reduces sparse warnings.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Squash a couple of sparse warnings by making things static.

Build tested.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Merge branch 'x86/cpufeature' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into kvm/next

Topic branch for AVX512_4VNNIW and AVX512_4FMAPS support in KVM.

Sparse populated CPUID leafs are collected in a software provided leaf to
avoid bloat of the x86_capability array, but there is no way to rebuild the
real leafs (e.g. for KVM CPUID enumeration) other than rereading the CPUID
leaf from the CPU. While this is possible it is problematic as it does not
take software disabled features into account. If a feature is disabled on
the host it should not be exposed to a guest either.

Add get_scattered_cpuid_leaf() which rebuilds the leaf from the scattered
cpuid table information and the active CPU features.

[ tglx: Rewrote changelog ]
Signed-off-by: He Chen <he.chen@linux.intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Luwei Kang <luwei.kang@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Piotr Luc <Piotr.Luc@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/1478856336-9388-3-git-send-email-he.chen@linux.intel.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

cpuid_regs is defined multiple times as structure and enum. Rename the enum
and move all of it to processor.h so we don't end up with more instances.

Rename the misnomed register enumeration from CR_* to the obvious CPUID_*.

[ tglx: Rewrote changelog ]
Signed-off-by: He Chen <he.chen@linux.intel.com>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Luwei Kang <luwei.kang@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Piotr Luc <Piotr.Luc@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/1478856336-9388-2-git-send-email-he.chen@linux.intel.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

This changes the way that we support the new ISA v3.00 HPTE format.
Instead of adapting everything that uses HPTE values to handle either
the old format or the new format, depending on which CPU we are on,
we now convert explicitly between old and new formats if necessary
in the low-level routines that actually access HPTEs in memory.
This limits the amount of code that needs to know about the new
format and makes the conversions explicit.  This is OK because the
old format contains all the information that is in the new format.

This also fixes operation under a hypervisor, because the H_ENTER
hypercall (and other hypercalls that deal with HPTEs) will continue
to require the HPTE value to be supplied in the old format.  At
present the kernel will not boot in HPT mode on POWER9 under a
hypervisor.

This fixes and partially reverts commit 50de596d
("powerpc/mm/hash: Add support for Power9 Hash", 2016-04-29).

Fixes: 50de596d ("powerpc/mm/hash: Add support for Power9 Hash")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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: Derek <user.vdr@gmail.com>
Tested-by: Derek <user.vdr@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Linus 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: Johannes Stezenbach <js@linuxtv.org>
Fixes: bc29131ecb10 ("[media] gp8psk: don't do DMA on stack")
Tested-by: Derek <user.vdr@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>