summaryrefslogtreecommitdiffstats
path: root/drivers/xen
Commit message (Collapse)AuthorAgeFilesLines
* Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linusJames Bottomley2014-12-181-1/+1
|\
| * scsi: remove MSG_*_TAG definesChristoph Hellwig2014-12-041-1/+1
| | | | | | | | | | | | | | | | | | For SPI drivers use the message definitions from scsi.h, and for target drivers introduce a new TCM_*_TAG namespace. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com
* | Merge tag 'stable/for-linus-3.19-rc0-tag' of ↵Linus Torvalds2014-12-116-40/+130
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen features and fixes from David Vrabel: - Fully support non-coherent devices on ARM by introducing the mechanisms to request the hypervisor to perform the required cache maintainance operations. - A number of pciback bug fixes and cleanups. Notably a deadlock fix if a PCI device was manually uunbound and a fix for incorrectly restoring state after a function reset. - In x86 PVHVM guests, use the APIC for interrupts if this has been virtualized by the hardware. This reduces the number of interrupt- related VM exits on such hardware. * tag 'stable/for-linus-3.19-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (26 commits) Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single" xen/pci: Use APIC directly when APIC virtualization hardware is available xen/pci: Defer initialization of MSI ops on HVM guests xen-pciback: drop SR-IOV VFs when PF driver unloads xen/pciback: Restore configuration space when detaching from a guest. PCI: Expose pci_load_saved_state for public consumption. xen/pciback: Remove tons of dereferences xen/pciback: Print out the domain owning the device. xen/pciback: Include the domain id if removing the device whilst still in use driver core: Provide an wrapper around the mutex to do lockdep warnings xen/pciback: Don't deadlock when unbinding. swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single swiotlb-xen: call xen_dma_sync_single_for_device when appropriate swiotlb-xen: remove BUG_ON in xen_bus_to_phys swiotlb-xen: pass dev_addr to xen_dma_unmap_page and xen_dma_sync_single_for_cpu xen/arm: introduce GNTTABOP_cache_flush xen/arm/arm64: introduce xen_arch_need_swiotlb xen/arm/arm64: merge xen/mm32.c into xen/mm.c xen/arm: use hypercall to flush caches in map_page xen: add a dma_addr_t dev_addr argument to xen_dma_map_page ...
| * | Revert "swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_single"David Vrabel2014-12-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 2c3fc8d26dd09b9d7069687eead849ee81c78e46. This commit broke on x86 PV because entries in the generic SWIOTLB are indexed using (pseudo-)physical address not DMA address and these are not the same in a x86 PV guest. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
| * | xen-pciback: drop SR-IOV VFs when PF driver unloadsJan Beulich2014-12-041-0/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/pciback: Restore configuration space when detaching from a guest.Konrad Rzeszutek Wilk2014-12-041-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Remove tons of dereferencesKonrad Rzeszutek Wilk2014-12-041-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | xen/pciback: Print out the domain owning the device.Konrad Rzeszutek Wilk2014-12-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Include the domain id if removing the device whilst still in useKonrad Rzeszutek Wilk2014-12-041-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | driver core: Provide an wrapper around the mutex to do lockdep warningsKonrad Rzeszutek Wilk2014-12-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Don't deadlock when unbinding.Konrad Rzeszutek Wilk2014-12-045-16/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | swiotlb-xen: pass dev_addr to swiotlb_tbl_unmap_singleStefano Stabellini2014-12-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | swiotlb-xen: call xen_dma_sync_single_for_device when appropriateStefano Stabellini2014-12-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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: remove BUG_ON in xen_bus_to_physStefano Stabellini2014-12-041-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: pass dev_addr to xen_dma_unmap_page and xen_dma_sync_single_for_cpuStefano Stabellini2014-12-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | xen/arm/arm64: introduce xen_arch_need_swiotlbStefano Stabellini2014-12-041-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce an arch specific function to find out whether a particular dma mapping operation needs to bounce on the swiotlb buffer. On ARM and ARM64, if the page involved is a foreign page and the device is not coherent, we need to bounce because at unmap time we cannot execute any required cache maintenance operations (we don't know how to find the pfn from the mfn). No change of behaviour for x86. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * | xen: add a dma_addr_t dev_addr argument to xen_dma_map_pageStefano Stabellini2014-12-041-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dev_addr is the machine address of the page. The new parameter can be used by the ARM and ARM64 implementations of xen_dma_map_page to find out if the page is a local page (pfn == mfn) or a foreign page (pfn != mfn). dev_addr could be retrieved again from the physical address, using pfn_to_mfn, but it requires accessing an rbtree. Since we already have the dev_addr in our hands at the call site there is no need to get the mfn twice. 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>
* | | Merge tag 'arm64-upstream' of ↵Linus Torvalds2014-12-091-0/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Here's the usual mixed bag of arm64 updates, also including some related EFI changes (Acked by Matt) and the MMU gather range cleanup (Acked by you). Changes include: - support for alternative instruction patching from Andre - seccomp from Akashi - some AArch32 instruction emulation, required by the Android folks - optimisations for exception entry/exit code, cmpxchg, pcpu atomics - mmu_gather range calculations moved into core code - EFI updates from Ard, including long-awaited SMBIOS support - /proc/cpuinfo fixes to align with the format used by arch/arm/ - a few non-critical fixes across the architecture" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits) arm64: remove the unnecessary arm64_swiotlb_init() arm64: add module support for alternatives fixups arm64: perf: Prevent wraparound during overflow arm64/include/asm: Fixed a warning about 'struct pt_regs' arm64: Provide a namespace to NCAPS arm64: bpf: lift restriction on last instruction arm64: Implement support for read-mostly sections arm64: compat: align cacheflush syscall with arch/arm arm64: add seccomp support arm64: add SIGSYS siginfo for compat task arm64: add seccomp syscall for compat task asm-generic: add generic seccomp.h for secure computing mode 1 arm64: ptrace: allow tracer to skip a system call arm64: ptrace: add NT_ARM_SYSTEM_CALL regset arm64: Move some head.text functions to executable section arm64: jump labels: NOP out NOP -> NOP replacement arm64: add support to dump the kernel page tables arm64: Add FIX_HOLE to permanent fixed addresses arm64: alternatives: fix pr_fmt string for consistency arm64: vmlinux.lds.S: don't discard .exit.* sections at link-time ...
| * | efi: dmi: add support for SMBIOS 3.0 UEFI configuration tableArd Biesheuvel2014-11-051-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support to the UEFI side for detecting the presence of a SMBIOS 3.0 64-bit entry point. This allows the actual SMBIOS structure table to reside at a physical offset over 4 GB, which cannot be supported by the legacy SMBIOS 32-bit entry point. Since the firmware can legally provide both entry points, store the SMBIOS 3.0 entry point in a separate variable, and let the DMI decoding layer decide which one will be used. Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
* / scsi: use sdev as argument for sense code printingHannes Reinecke2014-11-121-4/+0
|/ | | | | | | | | | | We should be using the standard dev_printk() variants for sense code printing. [hch: remove __scsi_print_sense call in xen-scsiback, Acked by Juergen] [hch: folded bracing fix from Dan Carpenter] Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Robert Elliott <elliott@hp.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* xen/pci: Allocate memory for physdev_pci_device_add's optarrBoris Ostrovsky2014-10-231-11/+16
| | | | | | | | | | physdev_pci_device_add's optarr[] is a zero-sized array and therefore reference to add.optarr[0] is accessing memory that does not belong to the 'add' variable. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* xen/balloon: Don't continue ballooning when BP_ECANCELED is encounteredBoris Ostrovsky2014-10-231-0/+3
| | | | | | | | | | | | | | | | Commit 3dcf63677d4e ("xen/balloon: cancel ballooning if adding new memory failed") makes reserve_additional_memory() return BP_ECANCELED when an error is encountered. This error, however, is ignored by the caller (balloon_process()) since it is overwritten by subsequent call to update_schedule(). This results in continuous attempts to add more memory, all of which are likely to fail again. We should stop trying to schedule next iteration of ballooning when the current one has failed. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* Merge tag 'stable/for-linus-3.18-rc0-tag' of ↵Linus Torvalds2014-10-1112-19/+2167
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen updates from David Vrabel: "Features and fixes: - Add pvscsi frontend and backend drivers. - Remove _PAGE_IOMAP PTE flag, freeing it for alternate uses. - Try and keep memory contiguous during PV memory setup (reduces SWIOTLB usage). - Allow front/back drivers to use threaded irqs. - Support large initrds in PV guests. - Fix PVH guests in preparation for Xen 4.5" * tag 'stable/for-linus-3.18-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (22 commits) xen: remove DEFINE_XENBUS_DRIVER() macro xen/xenbus: Remove BUG_ON() when error string trucated xen/xenbus: Correct the comments for xenbus_grant_ring() x86/xen: Set EFER.NX and EFER.SCE in PVH guests xen: eliminate scalability issues from initrd handling xen: sync some headers with xen tree xen: make pvscsi frontend dependant on xenbus frontend arm{,64}/xen: Remove "EXPERIMENTAL" in the description of the Xen options xen-scsifront: don't deadlock if the ring becomes full x86: remove the Xen-specific _PAGE_IOMAP PTE flag x86/xen: do not use _PAGE_IOMAP PTE flag for I/O mappings x86: skip check for spurious faults for non-present faults xen/efi: Directly include needed headers xen-scsiback: clean up a type issue in scsiback_make_tpg() xen-scsifront: use GFP_ATOMIC under spin_lock MAINTAINERS: Add xen pvscsi maintainer xen-scsiback: Add Xen PV SCSI backend driver xen-scsifront: Add Xen PV SCSI frontend driver xen: Add Xen pvSCSI protocol description xen/events: support threaded irqs for interdomain event channels ...
| * xen: remove DEFINE_XENBUS_DRIVER() macroDavid Vrabel2014-10-066-12/+25
| | | | | | | | | | | | | | | | | | | | The DEFINE_XENBUS_DRIVER() macro looks a bit weird and causes sparse errors. Replace the uses with standard structure definitions instead. This is similar to pci and usb device registration. Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/xenbus: Remove BUG_ON() when error string trucatedChen Gang2014-10-061-4/+1
| | | | | | | | | | | | | | | | | | xenbus_va_dev_error() is for printing error, so when error string is too long to be truncated, need not BUG_ON(), still return truncation string is OK. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/xenbus: Correct the comments for xenbus_grant_ring()Chen Gang2014-10-061-2/+2
| | | | | | | | | | | | | | | | A grant reference (which is a positive number) can indicate success, so the original comments need be improved. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/efi: Directly include needed headersDaniel Kiper2014-09-231-0/+2
| | | | | | | | | | | | | | | | | | | | I discovered that some needed stuff is defined/declared in headers which are not included directly. Currently it works but if somebody remove required headers from currently included headers then build will break. So, just in case directly include all needed headers. Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen-scsiback: clean up a type issue in scsiback_make_tpg()Dan Carpenter2014-09-231-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | This code was confusing because we had an unsigned long and then we compared it to UINT_MAX and then we stored it in a u16. How many bytes is this supposed to have: 2, 4 or 16??? I've made it a u16 throughout. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen-scsiback: Add Xen PV SCSI backend driverJuergen Gross2014-09-233-0/+2134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduces the Xen pvSCSI backend. With pvSCSI it is possible for a Xen domU to issue SCSI commands to a SCSI LUN assigned to that domU. The SCSI commands are passed to the pvSCSI backend in a driver domain (usually Dom0) which is owner of the physical device. This allows e.g. to use SCSI tape drives in a Xen domU. The code is taken from the pvSCSI implementation in Xen done by Fujitsu based on Linux kernel 2.6.18. Changes from the original version are: - port to upstream kernel - put all code in just one source file - adapt to Linux style guide - use target core infrastructure instead doing pure pass-through - enable module unloading - support SG-list in grant page(s) - support task abort - remove redundant struct backend - allocate resources dynamically - correct minor error in scsiback_fast_flush_area - free allocated resources in case of error during I/O preparation - remove CDB emulation, now handled by target core infrastructure Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/events: support threaded irqs for interdomain event channelsJuergen Gross2014-09-231-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Export bind_interdomain_evtchn_to_irq() so drivers can use threaded interrupt handlers with: irq = bind_interdomain_evtchn_to_irq(remote_dom, remote_port); if (irq < 0) /* error */ ret = request_threaded_irq(...); Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/grant-table: refactor error cleanup in grow_gnttab_list()Chen Gang2014-09-231-1/+1
| | | | | | | | | | | | | | | | | | The cleanup loop in grow_gnttab_list() is safe from the underflow of the unsigned 'i' since nr_glist_frames is >= 1, but refactor it anyway. Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
* | Merge tag 'pci-v3.18-changes' of ↵Linus Torvalds2014-10-091-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "The interesting things here are: - Turn on Config Request Retry Status Software Visibility. This caused hangs last time, but we included a fix this time. - Rework PCI device configuration to use _HPP/_HPX more aggressively - Allow PCI devices to be put into D3cold during system suspend - Add arm64 PCI support - Add APM X-Gene host bridge driver - Add TI Keystone host bridge driver - Add Xilinx AXI host bridge driver More detailed summary: Enumeration - Check Vendor ID only for Config Request Retry Status (Rajat Jain) - Enable Config Request Retry Status when supported (Rajat Jain) - Add generic domain handling (Catalin Marinas) - Generate uppercase hex for modalias interface class (Ricardo Ribalda Delgado) Resource management - Add missing MEM_64 mask in pci_assign_unassigned_bridge_resources() (Yinghai Lu) - Increase IBM ipr SAS Crocodile BARs to at least system page size (Douglas Lehr) PCI device hotplug - Prevent NULL dereference during pciehp probe (Andreas Noever) - Move _HPP & _HPX handling into core (Bjorn Helgaas) - Apply _HPP to PCIe devices as well as PCI (Bjorn Helgaas) - Apply _HPP/_HPX to display devices (Bjorn Helgaas) - Preserve SERR & PARITY settings when applying _HPP/_HPX (Bjorn Helgaas) - Preserve MPS and MRRS settings when applying _HPP/_HPX (Bjorn Helgaas) - Apply _HPP/_HPX to all devices, not just hot-added ones (Bjorn Helgaas) - Fix wait time in pciehp timeout message (Yinghai Lu) - Add more pciehp Slot Control debug output (Yinghai Lu) - Stop disabling pciehp notifications during init (Yinghai Lu) MSI - Remove arch_msi_check_device() (Alexander Gordeev) - Rename pci_msi_check_device() to pci_msi_supported() (Alexander Gordeev) - Move D0 check into pci_msi_check_device() (Alexander Gordeev) - Remove unused kobject from struct msi_desc (Yijing Wang) - Remove "pos" from the struct msi_desc msi_attrib (Yijing Wang) - Add "msi_bus" sysfs MSI/MSI-X control for endpoints (Yijing Wang) - Use __get_cached_msi_msg() instead of get_cached_msi_msg() (Yijing Wang) - Use __read_msi_msg() instead of read_msi_msg() (Yijing Wang) - Use __write_msi_msg() instead of write_msi_msg() (Yijing Wang) Power management - Drop unused runtime PM support code for PCIe ports (Rafael J. Wysocki) - Allow PCI devices to be put into D3cold during system suspend (Rafael J. Wysocki) AER - Add additional AER error strings (Gong Chen) - Make <linux/aer.h> standalone includable (Thierry Reding) Virtualization - Add ACS quirk for Solarflare SFC9120 & SFC9140 (Alex Williamson) - Add ACS quirk for Intel 10G NICs (Alex Williamson) - Add ACS quirk for AMD A88X southbridge (Marti Raudsepp) - Remove unused pci_find_upstream_pcie_bridge(), pci_get_dma_source() (Alex Williamson) - Add device flag helpers (Ethan Zhao) - Assume all Mellanox devices have broken INTx masking (Gavin Shan) Generic host bridge driver - Fix ioport_map() for !CONFIG_GENERIC_IOMAP (Liviu Dudau) - Add pci_register_io_range() and pci_pio_to_address() (Liviu Dudau) - Define PCI_IOBASE as the base of virtual PCI IO space (Liviu Dudau) - Fix the conversion of IO ranges into IO resources (Liviu Dudau) - Add pci_get_new_domain_nr() and of_get_pci_domain_nr() (Liviu Dudau) - Add support for parsing PCI host bridge resources from DT (Liviu Dudau) - Add pci_remap_iospace() to map bus I/O resources (Liviu Dudau) - Add arm64 architectural support for PCI (Liviu Dudau) APM X-Gene - Add APM X-Gene PCIe driver (Tanmay Inamdar) - Add arm64 DT APM X-Gene PCIe device tree nodes (Tanmay Inamdar) Freescale i.MX6 - Probe in module_init(), not fs_initcall() (Lucas Stach) - Delay enabling reference clock for SS until it stabilizes (Tim Harvey) Marvell MVEBU - Fix uninitialized variable in mvebu_get_tgt_attr() (Thomas Petazzoni) NVIDIA Tegra - Make sure the PCIe PLL is really reset (Eric Yuen) - Add error path tegra_msi_teardown_irq() cleanup (Jisheng Zhang) - Fix extended configuration space mapping (Peter Daifuku) - Implement resource hierarchy (Thierry Reding) - Clear CLKREQ# enable on port disable (Thierry Reding) - Add Tegra124 support (Thierry Reding) ST Microelectronics SPEAr13xx - Pass config resource through reg property (Pratyush Anand) Synopsys DesignWare - Use NULL instead of false (Fabio Estevam) - Parse bus-range property from devicetree (Lucas Stach) - Use pci_create_root_bus() instead of pci_scan_root_bus() (Lucas Stach) - Remove pci_assign_unassigned_resources() (Lucas Stach) - Check private_data validity in single place (Lucas Stach) - Setup and clear exactly one MSI at a time (Lucas Stach) - Remove open-coded bitmap operations (Lucas Stach) - Fix configuration base address when using 'reg' (Minghuan Lian) - Fix IO resource end address calculation (Minghuan Lian) - Rename get_msi_data() to get_msi_addr() (Minghuan Lian) - Add get_msi_data() to pcie_host_ops (Minghuan Lian) - Add support for v3.65 hardware (Murali Karicheri) - Fold struct pcie_port_info into struct pcie_port (Pratyush Anand) TI Keystone - Add TI Keystone PCIe driver (Murali Karicheri) - Limit MRSS for all downstream devices (Murali Karicheri) - Assume controller is already in RC mode (Murali Karicheri) - Set device ID based on SoC to support multiple ports (Murali Karicheri) Xilinx AXI - Add Xilinx AXI PCIe driver (Srikanth Thokala) - Fix xilinx_pcie_assign_msi() return value test (Dan Carpenter) Miscellaneous - Clean up whitespace (Quentin Lambert) - Remove assignments from "if" conditions (Quentin Lambert) - Move PCI_VENDOR_ID_VMWARE to pci_ids.h (Francesco Ruggeri) - x86: Mark DMI tables as initialization data (Mathias Krause) - x86: Move __init annotation to the correct place (Mathias Krause) - x86: Mark constants of pci_mmcfg_nvidia_mcp55() as __initconst (Mathias Krause) - x86: Constify pci_mmcfg_probes[] array (Mathias Krause) - x86: Mark PCI BIOS initialization code as such (Mathias Krause) - Parenthesize PCI_DEVID and PCI_VPD_LRDT_ID parameters (Megan Kamiya) - Remove unnecessary variable in pci_add_dynid() (Tobias Klauser)" * tag 'pci-v3.18-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (109 commits) arm64: dts: Add APM X-Gene PCIe device tree nodes PCI: Add ACS quirk for AMD A88X southbridge devices PCI: xgene: Add APM X-Gene PCIe driver PCI: designware: Remove open-coded bitmap operations PCI/MSI: Remove unnecessary temporary variable PCI/MSI: Use __write_msi_msg() instead of write_msi_msg() MSI/powerpc: Use __read_msi_msg() instead of read_msi_msg() PCI/MSI: Use __get_cached_msi_msg() instead of get_cached_msi_msg() PCI/MSI: Add "msi_bus" sysfs MSI/MSI-X control for endpoints PCI/MSI: Remove "pos" from the struct msi_desc msi_attrib PCI/MSI: Remove unused kobject from struct msi_desc PCI/MSI: Rename pci_msi_check_device() to pci_msi_supported() PCI/MSI: Move D0 check into pci_msi_check_device() PCI/MSI: Remove arch_msi_check_device() irqchip: armada-370-xp: Remove arch_msi_check_device() PCI/MSI/PPC: Remove arch_msi_check_device() arm64: Add architectural support for PCI PCI: Add pci_remap_iospace() to map bus I/O resources of/pci: Add support for parsing PCI host bridge resources from DT of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr() ... Conflicts: arch/arm64/boot/dts/apm-storm.dtsi
| * xen/pciback: Use PCI device flag helper functionsEthan Zhao2014-09-161-2/+2
| | | | | | | | | | | | | | | | | | Use PCI device flag helper functions when assigning or releasing device. No functional change. Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: David Vrabel <david.vrabel@citrix.com>
* | Merge tag 'stable/for-linus-3.17-b-rc4-tag' of ↵Linus Torvalds2014-09-113-18/+9
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen bug fixes from David Vrabel: - fix for PVHVM suspend/resume and migration - don't pointlessly retry certain ballooning ops - fix gntalloc when grefs have run out. - fix PV boot if KSALR is enable or very large modules are used. * tag 'stable/for-linus-3.17-b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: don't copy bogus duplicate entries into kernel page tables xen/gntalloc: safely delete grefs in add_grefs() undo path xen/gntalloc: fix oops after runnning out of grant refs xen/balloon: cancel ballooning if adding new memory failed xen/manage: Always freeze/thaw processes when suspend/resuming
| * xen/gntalloc: safely delete grefs in add_grefs() undo pathDavid Vrabel2014-09-041-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a gref could not be added (perhaps because the limit has been reached or there are no more grant references available), the undo path may crash because __del_gref() frees the gref while it is being used for a list iteration. A comment suggests that using list_for_each_entry() is safe since the gref isn't removed from the list being iterated over, but it is freed and thus list_for_each_entry_safe() must be used. Also, explicitly delete the gref from the local per-file list, even though this is not strictly necessary. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen/gntalloc: fix oops after runnning out of grant refsDavid Vrabel2014-09-041-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | Only set gref->gref_id if foreign access was successfully granted and the grant ref is valid. If gref->gref_id == -ENOSPC the test in __del_gref() would incorrectly attempt to end foreign access (because grant_ref_t is unsigned). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Dave Scott <dave.scott@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen/balloon: cancel ballooning if adding new memory failedDavid Vrabel2014-09-021-2/+2
| | | | | | | | | | | | | | | | | | If the balloon driver is adding additional memory regions to the balloon and add_memory() fails it will likely continuously fail so cancel the balloon operation. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
| * xen/manage: Always freeze/thaw processes when suspend/resumingRoss Lagerwall2014-09-021-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always freeze processes when suspending and thaw processes when resuming to prevent a race noticeable with HVM guests. This prevents a deadlock where the khubd kthread (which is designed to be freezable) acquires a usb device lock and then tries to allocate memory which requires the disk which hasn't been resumed yet. Meanwhile, the xenwatch thread deadlocks waiting for the usb device lock. Freezing processes fixes this because the khubd thread is only thawed after the xenwatch thread finishes resuming all the devices. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: stable@vger.kernel.org
* | PCI: Remove DEFINE_PCI_DEVICE_TABLE macro useBenoit Taine2014-08-121-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | We should prefer `struct pci_device_id` over `DEFINE_PCI_DEVICE_TABLE` to meet kernel coding style guidelines. This issue was reported by checkpatch. A simplified version of the semantic patch that makes this change is as follows (http://coccinelle.lip6.fr/): // <smpl> @@ identifier i; declarer name DEFINE_PCI_DEVICE_TABLE; initializer z; @@ - DEFINE_PCI_DEVICE_TABLE(i) + const struct pci_device_id i[] = z; // </smpl> [bhelgaas: add semantic patch] Signed-off-by: Benoit Taine <benoit.taine@lip6.fr> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* Merge tag 'stable/for-linus-3.17-rc0-tag' of ↵Linus Torvalds2014-08-074-328/+39
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen updates from David Vrabel: - remove unused V2 grant table support - note that Konrad is xen-blkkback/front maintainer - add 'xen_nopv' option to disable PV extentions for x86 HVM guests - misc minor cleanups * tag 'stable/for-linus-3.17-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-pciback: Document the 'quirks' sysfs file xen/pciback: Fix error return code in xen_pcibk_attach() xen/events: drop negativity check of unsigned parameter xen/setup: Remove Identity Map Debug Message xen/events/fifo: remove a unecessary use of BM() xen/events/fifo: ensure all bitops are properly aligned even on x86 xen/events/fifo: reset control block and local HEADs on resume xen/arm: use BUG_ON xen/grant-table: remove support for V2 tables x86/xen: safely map and unmap grant frames when in atomic context MAINTAINERS: Make me the Xen block subsystem (front and back) maintainer xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests.
| * xen/pciback: Fix error return code in xen_pcibk_attach()Wei Yongjun2014-08-011-0/+1
| | | | | | | | | | | | | | | | | | Fix to return -EFAULT from the error handling case instead of 0 when version mismatch with pcifront. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Reviewed-by Jan Beulich <jbeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/events: drop negativity check of unsigned parameterAndrey Utkin2014-08-011-1/+1
| | | | | | | | | | | | | | Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=80531 Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
| * xen/events/fifo: remove a unecessary use of BM()Frediano Ziglio2014-07-311-1/+1
| | | | | | | | | | | | | | | | | | | | Since 05a812ac474d0d6aef6d54b66bb08b81abde79c6 (xen/events/fifo: correctly align bitops), ready is an unsigned long instead of uint32_t and the BM() macro is no longer required. Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| * xen/events/fifo: ensure all bitops are properly aligned even on x86David Vrabel2014-07-311-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using the FIFO-based ABI on x86_64, if the last port is at the end of an event array page then sync_test_bit() on this port's event word will read beyond the end of the page and in certain circumstances this may fault. The fault requires the following page in the kernel's direct mapping to be not present, which would mean: a) the array page is the last page of RAM; or b) the following page is ballooned out /and/ it has been used for a foreign mapping by a kernel driver (such as netback or blkback) /and/ the grant has been unmapped. Use the infrastructure added for arm64 to ensure that all bitops operating on event words are unsigned long aligned. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org
| * xen/events/fifo: reset control block and local HEADs on resumeDavid Vrabel2014-07-311-20/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | When using the FIFO-based event channel ABI, if the control block or the local HEADs are not reset after resuming the guest may see stale HEAD values and will fail to traverse the FIFO correctly. This may prevent one or more VCPUs from receiving any events following a resume. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org
| * xen/grant-table: remove support for V2 tablesDavid Vrabel2014-07-141-303/+6
| | | | | | | | | | | | | | | | Since 11c7ff17c9b6dbf3a4e4f36be30ad531a6cf0ec9 (xen/grant-table: Force to use v1 of grants.) the code for V2 grant tables is not used. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * x86/xen: safely map and unmap grant frames when in atomic contextDavid Vrabel2014-07-141-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch_gnttab_map_frames() and arch_gnttab_unmap_frames() are called in atomic context but were calling alloc_vm_area() which might sleep. Also, if a driver attempts to allocate a grant ref from an interrupt and the table needs expanding, then the CPU may already by in lazy MMU mode and apply_to_page_range() will BUG when it tries to re-enable lazy MMU mode. These two functions are only used in PV guests. Introduce arch_gnttab_init() to allocates the virtual address space in advance. Avoid the use of apply_to_page_range() by using saving and using the array of PTE addresses from the alloc_vm_area() call. N.B. 'alloc_vm_area' pre-allocates the pagetable so there is no need to worry about having to do a PGD/PUD/PMD walk (like apply_to_page_range does) and we can instead do set_pte. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> ---- [v2: Add comment about alloc_vm_area] [v3: Fix compile error found by 0-day bot]
* | Merge branch 'x86-efi-for-linus' of ↵Linus Torvalds2014-08-043-0/+375
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI changes from Ingo Molnar: "Main changes in this cycle are: - arm64 efi stub fixes, preservation of FP/SIMD registers across firmware calls, and conversion of the EFI stub code into a static library - Ard Biesheuvel - Xen EFI support - Daniel Kiper - Support for autoloading the efivars driver - Lee, Chun-Yi - Use the PE/COFF headers in the x86 EFI boot stub to request that the stub be loaded with CONFIG_PHYSICAL_ALIGN alignment - Michael Brown - Consolidate all the x86 EFI quirks into one file - Saurabh Tangri - Additional error logging in x86 EFI boot stub - Ulf Winkelvos - Support loading initrd above 4G in EFI boot stub - Yinghai Lu - EFI reboot patches for ACPI hardware reduced platforms" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) efi/arm64: Handle missing virtual mapping for UEFI System Table arch/x86/xen: Silence compiler warnings xen: Silence compiler warnings x86/efi: Request desired alignment via the PE/COFF headers x86/efi: Add better error logging to EFI boot stub efi: Autoload efivars efi: Update stale locking comment for struct efivars arch/x86: Remove efi_set_rtc_mmss() arch/x86: Replace plain strings with constants xen: Put EFI machinery in place xen: Define EFI related stuff arch/x86: Remove redundant set_bit(EFI_MEMMAP) call arch/x86: Remove redundant set_bit(EFI_SYSTEM_TABLES) call efi: Introduce EFI_PARAVIRT flag arch/x86: Do not access EFI memory map if it is not available efi: Use early_mem*() instead of early_io*() arch/ia64: Define early_memunmap() x86/reboot: Add EFI reboot quirk for ACPI Hardware Reduced flag efi/reboot: Allow powering off machines using EFI efi/reboot: Add generic wrapper around EfiResetSystem() ...
| * | xen: Put EFI machinery in placeDaniel Kiper2014-07-183-0/+375
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables EFI usage under Xen dom0. Standard EFI Linux Kernel infrastructure cannot be used because it requires direct access to EFI data and code. However, in dom0 case it is not possible because above mentioned EFI stuff is fully owned and controlled by Xen hypervisor. In this case all calls from dom0 to EFI must be requested via special hypercall which in turn executes relevant EFI code in behalf of dom0. When dom0 kernel boots it checks for EFI availability on a machine. If it is detected then artificial EFI system table is filled. Native EFI callas are replaced by functions which mimics them by calling relevant hypercall. Later pointer to EFI system table is passed to standard EFI machinery and it continues EFI subsystem initialization taking into account that there is no direct access to EFI boot services, runtime, tables, structures, etc. After that system runs as usual. This patch is based on Jan Beulich and Tang Liang work. Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Tang Liang <liang.tang@oracle.com> Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com Signed-off-by: Matt Fleming <matt.fleming@intel.com>
* | | Merge tag 'stable/for-linus-3.16-rc7-tag' of ↵Linus Torvalds2014-07-301-1/+8
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen fix from David Vrabel: "Fix BUG when trying to expand the grant table. This seems to occur often during boot with Ubuntu 14.04 PV guests" * tag 'stable/for-linus-3.16-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: safely map and unmap grant frames when in atomic context