xen/arm: introduce GNTTABOP_cache_flush

Introduce support for new hypercall GNTTABOP_cache_flush.
Use it to perform cache flashing on pages used for dma when necessary.

If GNTTABOP_cache_flush is supported by the hypervisor, we don't need to
bounce dma map operations that involve foreign grants and non-coherent
devices.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
swiotlb-xen: pass dev_addr to xen_dma_unmap_page and xen_dma_sync_single_for_cpu

xen_dma_unmap_page and xen_dma_sync_single_for_cpu take a dma_addr_t
handle as argument, not a physical address.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
swiotlb-xen: remove BUG_ON in xen_bus_to_phys

On x86 truncation cannot occur because config XEN depends on X86_64 ||
(X86_32 && X86_PAE).

On ARM truncation can occur without CONFIG_ARM_LPAE, when the dma
operation involves foreign grants. However in that case the physical
address returned by xen_bus_to_phys is actually invalid (there is no mfn
to pfn tracking for foreign grants on ARM) and it is not used.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
swiotlb-xen: call xen_dma_sync_single_for_device when appropriate

In xen_swiotlb_sync_single we always call xen_dma_sync_single_for_cpu,
even when we should call xen_dma_sync_single_for_device. Fix that.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single

Need to pass the pointer within the swiotlb internal buffer to the
swiotlb library, that in the case of xen_unmap_single is dev_addr, not
paddr.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
CC: stable@vger.kernel.org
xen/pciback: Don't deadlock when unbinding.

As commit 0a9fd0152929db372ff61b0d6c280fdd34ae8bdb
'xen/pciback: Document the entry points for 'pcistub_put_pci_dev''
explained there are four entry points in this function.
Two of them are when the user fiddles in the SysFS to
unbind a device which might be in use by a guest or not.

Both 'unbind' states will cause a deadlock as the the PCI lock has
already been taken, which then pci_device_reset tries to take.

We can simplify this by requiring that all callers of
pcistub_put_pci_dev MUST hold the device lock. And then
we can just call the lockless version of pci_device_reset.

To make it even simpler we will modify xen_pcibk_release_pci_dev
to quality whether it should take a lock or not - as it ends
up calling xen_pcibk_release_pci_dev and needs to hold the lock.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
driver core: Provide an wrapper around the mutex to do lockdep warnings

Instead of open-coding it in drivers that want to double check
that their functions are indeed holding the device lock.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Suggested-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pciback: Include the domain id if removing the device whilst still in use

Cleanup the function a bit - also include the id of the
domain that is using the device.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pciback: Print out the domain owning the device.

We had been printing it only if the device was built with
debug enabled. But this information is useful in the field
to troubleshoot.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pciback: Remove tons of dereferences

A little cleanup. No functional difference.

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
PCI: Expose pci_load_saved_state for public consumption.

We have the pci_load_and_free_saved_state, and pci_store_saved_state
but are missing the functionality to just load the state
multiple times in the PCI device without having to free/save
the state.

This patch makes it possible to use this function.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pciback: Restore configuration space when detaching from a guest.

The commit "xen/pciback: Don't deadlock when unbinding." was using
the version of pci_reset_function which would lock the device lock.
That is no good as we can dead-lock. As such we swapped to using
the lock-less version and requiring that the callers
of 'pcistub_put_pci_dev' take the device lock. And as such
this bug got exposed.

Using the lock-less version is  OK, except that we tried to
use 'pci_restore_state' after the lock-less version of
__pci_reset_function_locked - which won't work as 'state_saved'
is set to false. Said 'state_saved' is a toggle boolean that
is to be used by the sequence of a) pci_save_state/pci_restore_state
or b) pci_load_and_free_saved_state/pci_restore_state. We don't
want to use a) as the guest might have messed up the PCI
configuration space and we want it to revert to the state
when the PCI device was binded to us. Therefore we pick
b) to restore the configuration space.

We restore from our 'golden' version of PCI configuration space, when an:
 - Device is unbinded from pciback
 - Device is detached from a guest.

Reported-by:  Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen-pciback: drop SR-IOV VFs when PF driver unloads

When a PF driver unloads, it may find it necessary to leave the VFs
around simply because of pciback having marked them as assigned to a
guest. Utilize a suitable notification to let go of the VFs, thus
allowing the PF to go back into the state it was before its driver
loaded (which in particular allows the driver to be loaded again with
it being able to create the VFs anew, but which also allows to then
pass through the PF instead of the VFs).

Don't do this however for any VFs currently in active use by a guest.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
[v2: Removed the switch statement, moved it about]
[v3: Redid it a bit differently]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pci: Defer initialization of MSI ops on HVM guests

If the hardware supports APIC virtualization we may decide not to use
pirqs and instead use APIC/x2APIC directly, meaning that we don't want
to set x86_msi.setup_msi_irqs and x86_msi.teardown_msi_irq to
Xen-specific routines.  However, x2APIC is not set up by the time
pci_xen_hvm_init() is called so we need to postpone setting these ops
until later, when we know which APIC mode is used.

(Note that currently x2APIC is never initialized on HVM guests. This
may change in the future)

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen/pci: Use APIC directly when APIC virtualization hardware is available

When hardware supports APIC/x2APIC virtualization we don't need to use
pirqs for MSI handling and instead use APIC since most APIC accesses
(MMIO or MSR) will now be processed without VMEXITs.

As an example, netperf on the original code produces this profile
(collected wih 'xentrace -e 0x0008ffff -T 5'):

    342 cpu_change
    260 CPUID
  34638 HLT
  64067 INJ_VIRQ
  28374 INTR
  82733 INTR_WINDOW
     10 NPF
  24337 TRAP
 370610 vlapic_accept_pic_intr
 307528 VMENTRY
 307527 VMEXIT
 140998 VMMCALL
    127 wrap_buffer

After applying this patch the same test shows

    230 cpu_change
    260 CPUID
  36542 HLT
    174 INJ_VIRQ
  27250 INTR
    222 INTR_WINDOW
     20 NPF
  24999 TRAP
 381812 vlapic_accept_pic_intr
 166480 VMENTRY
 166479 VMEXIT
  77208 VMMCALL
     81 wrap_buffer

ApacheBench results (ab -n 10000 -c 200) improve by about 10%

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
video: fbdev: vt8623fb: suppress build warning

this patch fixes following build warning:
drivers/video/fbdev/vt8623fb.c: In function ‘vt8623_pci_probe’:
drivers/video/fbdev/vt8623fb.c:734:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  par->state.vgabase = (void __iomem *) vga_res.start;
                       ^
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
video: fbdev: s3fb: suppress build warning

this patch fixes following build warning:
drivers/video/fbdev/s3fb.c: In function ‘s3_pci_probe’:
drivers/video/fbdev/s3fb.c:1185:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  par->state.vgabase = (void __iomem *) vga_res.start;
                       ^
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
video: fbdev: arkfb: suppress build warning

this patch fixes following build warning:

drivers/video/fbdev/arkfb.c: In function ‘ark_pci_probe’:
drivers/video/fbdev/arkfb.c:1019:23: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
  par->state.vgabase = (void __iomem *) vga_res.start;
                       ^
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
video: fbdev-LCDC: Deletion of an unnecessary check before the function call "vfree"

The vfree() function performs also input parameter validation.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
video: uvesafb: Deletion of an unnecessary check before the function call "uvesafb_free"

The uvesafb_free() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>