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* vfio: powerpc/spapr: Support Dynamic DMA windowsAlexey Kardashevskiy2015-06-114-5/+273
| | | | | | | | | | | | | | | | | | | | | | | | | | | This adds create/remove window ioctls to create and remove DMA windows. sPAPR defines a Dynamic DMA windows capability which allows para-virtualized guests to create additional DMA windows on a PCI bus. The existing linux kernels use this new window to map the entire guest memory and switch to the direct DMA operations saving time on map/unmap requests which would normally happen in a big amounts. This adds 2 ioctl handlers - VFIO_IOMMU_SPAPR_TCE_CREATE and VFIO_IOMMU_SPAPR_TCE_REMOVE - to create and remove windows. Up to 2 windows are supported now by the hardware and by this driver. This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional information such as a number of supported windows and maximum number levels of TCE tables. DDW is added as a capability, not as a SPAPR TCE IOMMU v2 unique feature as we still want to support v2 on platforms which cannot do DDW for the sake of TCE acceleration in KVM (coming soon). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Register memory and define IOMMU v2Alexey Kardashevskiy2015-06-114-83/+482
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The existing implementation accounts the whole DMA window in the locked_vm counter. This is going to be worse with multiple containers and huge DMA windows. Also, real-time accounting would requite additional tracking of accounted pages due to the page size difference - IOMMU uses 4K pages and system uses 4K or 64K pages. Another issue is that actual pages pinning/unpinning happens on every DMA map/unmap request. This does not affect the performance much now as we spend way too much time now on switching context between guest/userspace/host but this will start to matter when we add in-kernel DMA map/unmap acceleration. This introduces a new IOMMU type for SPAPR - VFIO_SPAPR_TCE_v2_IOMMU. New IOMMU deprecates VFIO_IOMMU_ENABLE/VFIO_IOMMU_DISABLE and introduces 2 new ioctls to register/unregister DMA memory - VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY - which receive user space address and size of a memory region which needs to be pinned/unpinned and counted in locked_vm. New IOMMU splits physical pages pinning and TCE table update into 2 different operations. It requires: 1) guest pages to be registered first 2) consequent map/unmap requests to work only with pre-registered memory. For the default single window case this means that the entire guest (instead of 2GB) needs to be pinned before using VFIO. When a huge DMA window is added, no additional pinning will be required, otherwise it would be guest RAM + 2GB. The new memory registration ioctls are not supported by VFIO_SPAPR_TCE_IOMMU. Dynamic DMA window and in-kernel acceleration will require memory to be preregistered in order to work. The accounting is done per the user process. This advertises v2 SPAPR TCE IOMMU and restricts what the userspace can do with v1 or v2 IOMMUs. In order to support memory pre-registration, we need a way to track the use of every registered memory region and only allow unregistration if a region is not in use anymore. So we need a way to tell from what region the just cleared TCE was from. This adds a userspace view of the TCE table into iommu_table struct. It contains userspace address, one per TCE entry. The table is only allocated when the ownership over an IOMMU group is taken which means it is only used from outside of the powernv code (such as VFIO). As v2 IOMMU supports IODA2 and pre-IODA2 IOMMUs (which do not support DDW API), this creates a default DMA window for IODA2 for consistency. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/mmu: Add userspace-to-physical addresses translation cacheAlexey Kardashevskiy2015-06-116-0/+347
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are adding support for DMA memory pre-registration to be used in conjunction with VFIO. The idea is that the userspace which is going to run a guest may want to pre-register a user space memory region so it all gets pinned once and never goes away. Having this done, a hypervisor will not have to pin/unpin pages on every DMA map/unmap request. This is going to help with multiple pinning of the same memory. Another use of it is in-kernel real mode (mmu off) acceleration of DMA requests where real time translation of guest physical to host physical addresses is non-trivial and may fail as linux ptes may be temporarily invalid. Also, having cached host physical addresses (compared to just pinning at the start and then walking the page table again on every H_PUT_TCE), we can be sure that the addresses which we put into TCE table are the ones we already pinned. This adds a list of memory regions to mm_context_t. Each region consists of a header and a list of physical addresses. This adds API to: 1. register/unregister memory regions; 2. do final cleanup (which puts all pre-registered pages); 3. do userspace to physical address translation; 4. manage usage counters; multiple registration of the same memory is allowed (once per container). This implements 2 counters per registered memory region: - @mapped: incremented on every DMA mapping; decremented on unmapping; initialized to 1 when a region is just registered; once it becomes zero, no more mappings allowe; - @used: incremented on every "register" ioctl; decremented on "unregister"; unregistration is allowed for DMA mapped regions unless it is the very last reference. For the very last reference this checks that the region is still mapped and returns -EBUSY so the userspace gets to know that memory is still pinned and unregistration needs to be retried; @used remains 1. Host physical addresses are stored in vmalloc'ed array. In order to access these in the real mode (mmu off), there is a real_vmalloc_addr() helper. In-kernel acceleration patchset will move it from KVM to MMU code. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: powerpc/powernv/ioda2: Use DMA windows API in ownership ↵Alexey Kardashevskiy2015-06-112-48/+141
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | control Before the IOMMU user (VFIO) would take control over the IOMMU table belonging to a specific IOMMU group. This approach did not allow sharing tables between IOMMU groups attached to the same container. This introduces a new IOMMU ownership flavour when the user can not just control the existing IOMMU table but remove/create tables on demand. If an IOMMU implements take/release_ownership() callbacks, this lets the user have full control over the IOMMU group. When the ownership is taken, the platform code removes all the windows so the caller must create them. Before returning the ownership back to the platform code, VFIO unprograms and removes all the tables it created. This changes IODA2's onwership handler to remove the existing table rather than manipulating with the existing one. From now on, iommu_take_ownership() and iommu_release_ownership() are only called from the vfio_iommu_spapr_tce driver. Old-style ownership is still supported allowing VFIO to run on older P5IOC2 and IODA IO controllers. No change in userspace-visible behaviour is expected. Since it recreates TCE tables on each ownership change, related kernel traces will appear more often. This adds a pnv_pci_ioda2_setup_default_config() which is called when PE is being configured at boot time and when the ownership is passed from VFIO to the platform code. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu/ioda2: Add get_table_size() to calculate the size of future tableAlexey Kardashevskiy2015-06-112-0/+39
| | | | | | | | | | | | | | | | | This adds a way for the IOMMU user to know how much a new table will use so it can be accounted in the locked_vm limit before allocation happens. This stores the allocated table size in pnv_pci_ioda2_get_table_size() so the locked_vm counter can be updated correctly when a table is being disposed. This defines an iommu_table_group_ops callback to let VFIO know how much memory will be locked if a table is created. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Use new helpers to do proper cleanup on PE releaseAlexey Kardashevskiy2015-06-111-19/+6
| | | | | | | | | | | | | The existing code programmed TVT#0 with some address and then immediately released that memory. This makes use of pnv_pci_ioda2_unset_window() and pnv_pci_ioda2_set_bypass() which do correct resource release and TVT update. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows APIAlexey Kardashevskiy2015-06-114-17/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This extends iommu_table_group_ops by a set of callbacks to support dynamic DMA windows management. create_table() creates a TCE table with specific parameters. it receives iommu_table_group to know nodeid in order to allocate TCE table memory closer to the PHB. The exact format of allocated multi-level table might be also specific to the PHB model (not the case now though). This callback calculated the DMA window offset on a PCI bus from @num and stores it in a just created table. set_window() sets the window at specified TVT index + @num on PHB. unset_window() unsets the window from specified TVT. This adds a free() callback to iommu_table_ops to free the memory (potentially a tree of tables) allocated for the TCE table. create_table() and free() are supposed to be called once per VFIO container and set_window()/unset_window() are supposed to be called for every group in a container. This adds IOMMU capabilities to iommu_table_group such as default 32bit window parameters and others. This makes use of new values in vfio_iommu_spapr_tce. IODA1/P5IOC2 do not support DDW so they do not advertise pagemasks to the userspace. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv: Implement multilevel TCE tablesAlexey Kardashevskiy2015-06-113-9/+111
| | | | | | | | | | | | | | | | | | TCE tables might get too big in case of 4K IOMMU pages and DDW enabled on huge guests (hundreds of GB of RAM) so the kernel might be unable to allocate contiguous chunk of physical memory to store the TCE table. To address this, POWER8 CPU (actually, IODA2) supports multi-level TCE tables, up to 5 levels which splits the table into a tree of smaller subtables. This adds multi-level TCE tables support to pnv_pci_ioda2_table_alloc_pages() and pnv_pci_ioda2_table_free_pages() helpers. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Introduce pnv_pci_ioda2_set_windowAlexey Kardashevskiy2015-06-111-9/+38
| | | | | | | | | | | | | | | This is a part of moving DMA window programming to an iommu_ops callback. pnv_pci_ioda2_set_window() takes an iommu_table_group as a first parameter (not pnv_ioda_pe) as it is going to be used as a callback for VFIO DDW code. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Introduce helpers to allocate TCE pagesAlexey Kardashevskiy2015-06-111-20/+63
| | | | | | | | | | | | | | | | | | This is a part of moving TCE table allocation into an iommu_ops callback to support multiple IOMMU groups per one VFIO container. This moves the code which allocates the actual TCE tables to helpers: pnv_pci_ioda2_table_alloc_pages() and pnv_pci_ioda2_table_free_pages(). These do not allocate/free the iommu_table struct. This enforces window size to be a power of two. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Rework iommu_table creationAlexey Kardashevskiy2015-06-111-12/+12
| | | | | | | | | | | | | This moves iommu_table creation to the beginning to make following changes easier to review. This starts using table parameters from the iommu_table struct. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu/powernv: Release replaced TCEAlexey Kardashevskiy2015-06-117-69/+132
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment writing new TCE value to the IOMMU table fails with EBUSY if there is a valid entry already. However PAPR specification allows the guest to write new TCE value without clearing it first. Another problem this patch is addressing is the use of pool locks for external IOMMU users such as VFIO. The pool locks are to protect DMA page allocator rather than entries and since the host kernel does not control what pages are in use, there is no point in pool locks and exchange()+put_page(oldtce) is sufficient to avoid possible races. This adds an exchange() callback to iommu_table_ops which does the same thing as set() plus it returns replaced TCE and DMA direction so the caller can release the pages afterwards. The exchange() receives a physical address unlike set() which receives linear mapping address; and returns a physical address as the clear() does. This implements exchange() for P5IOC2/IODA/IODA2. This adds a requirement for a platform to have exchange() implemented in order to support VFIO. This replaces iommu_tce_build() and iommu_clear_tce() with a single iommu_tce_xchg(). This makes sure that TCE permission bits are not set in TCE passed to IOMMU API as those are to be calculated by platform code from DMA direction. This moves SetPageDirty() to the IOMMU code to make it work for both VFIO ioctl interface in in-kernel TCE acceleration (when it becomes available later). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv: Implement accessor to TCE entryAlexey Kardashevskiy2015-06-111-13/+21
| | | | | | | | | | | | | This replaces direct accesses to TCE table with a helper which returns an TCE entry address. This does not make difference now but will when multi-level TCE tables get introduces. No change in behavior is expected. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Add TCE invalidation for all attached groupsAlexey Kardashevskiy2015-06-111-12/+23
| | | | | | | | | | | | | | | The iommu_table struct keeps a list of IOMMU groups it is used for. At the moment there is just a single group attached but further patches will add TCE table sharing. When sharing is enabled, TCE cache in each PE needs to be invalidated so does the patch. This does not change pnv_pci_ioda1_tce_invalidate() as there is no plan to enable TCE table sharing on PHBs older than IODA2. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda2: Move TCE kill register address to PEAlexey Kardashevskiy2015-06-112-29/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | At the moment the DMA setup code looks for the "ibm,opal-tce-kill" property which contains the TCE kill register address. Writing to this register invalidates TCE cache on IODA/IODA2 hub. This moves the register address from iommu_table to pnv_pnb as this register belongs to PHB and invalidates TCE cache for all tables of all attached PEs. This moves the property reading/remapping code to a helper which is called when DMA is being configured for PE and which does DMA setup for both IODA1 and IODA2. This adds a new pnv_pci_ioda2_tce_invalidate_entire() helper which invalidates cache for the entire table. It should be called after every call to opal_pci_map_pe_dma_window(). It was not required before because there was just a single TCE table and 64bit DMA was handled via bypass window (which has no table so no cache was used) but this is going to change with Dynamic DMA windows (DDW). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu: Fix IOMMU ownership control functionsAlexey Kardashevskiy2015-06-111-5/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | This adds missing locks in iommu_take_ownership()/ iommu_release_ownership(). This marks all pages busy in iommu_table::it_map in order to catch errors if there is an attempt to use this table while ownership over it is taken. This only clears TCE content if there is no page marked busy in it_map. Clearing must be done outside of the table locks as iommu_clear_tce() called from iommu_clear_tces_and_put_pages() does this. In order to use bitmap_empty(), the existing code clears bit#0 which is set even in an empty table if it is bus-mapped at 0 as iommu_init_table() reserves page#0 to prevent buggy drivers from crashing when allocated page is bus-mapped at zero (which is correct). This restores the bit in the case of failure to bring the it_map to the state it was in when we called iommu_take_ownership(). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership controlAlexey Kardashevskiy2015-06-114-33/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds tce_iommu_take_ownership() and tce_iommu_release_ownership which call in a loop iommu_take_ownership()/iommu_release_ownership() for every table on the group. As there is just one now, no change in behaviour is expected. At the moment the iommu_table struct has a set_bypass() which enables/ disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code which calls this callback when external IOMMU users such as VFIO are about to get over a PHB. The set_bypass() callback is not really an iommu_table function but IOMMU/PE function. This introduces a iommu_table_group_ops struct and adds take_ownership()/release_ownership() callbacks to it which are called when an external user takes/releases control over the IOMMU. This replaces set_bypass() with ownership callbacks as it is not necessarily just bypass enabling, it can be something else/more so let's give it more generic name. The callbacks is implemented for IODA2 only. Other platforms (P5IOC2, IODA1) will use the old iommu_take_ownership/iommu_release_ownership API. The following patches will replace iommu_take_ownership/ iommu_release_ownership calls in IODA2 with full IOMMU table release/ create. As we here and touching bypass control, this removes pnv_pci_ioda2_setup_bypass_pe() as it does not do much more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base initialization to pnv_pci_ioda2_setup_dma_pe. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_groupAlexey Kardashevskiy2015-06-118-60/+241
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So far one TCE table could only be used by one IOMMU group. However IODA2 hardware allows programming the same TCE table address to multiple PE allowing sharing tables. This replaces a single pointer to a group in a iommu_table struct with a linked list of groups which provides the way of invalidating TCE cache for every PE when an actual TCE table is updated. This adds pnv_pci_link_table_and_group() and pnv_pci_unlink_table_and_group() helpers to manage the list. However without VFIO, it is still going to be a single IOMMU group per iommu_table. This changes iommu_add_device() to add a device to a first group from the group list of a table as it is only called from the platform init code or PCI bus notifier and at these moments there is only one group per table. This does not change TCE invalidation code to loop through all attached groups in order to simplify this patch and because it is not really needed in most cases. IODA2 is fixed in a later patch. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/spapr: vfio: Replace iommu_table with iommu_table_groupAlexey Kardashevskiy2015-06-118-92/+152
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modern IBM POWERPC systems support multiple (currently two) TCE tables per IOMMU group (a.k.a. PE). This adds a iommu_table_group container for TCE tables. Right now just one table is supported. This defines iommu_table_group struct which stores pointers to iommu_group and iommu_table(s). This replaces iommu_table with iommu_table_group where iommu_table was used to identify a group: - iommu_register_group(); - iommudata of generic iommu_group; This removes @data from iommu_table as it_table_group provides same access to pnv_ioda_pe. For IODA, instead of embedding iommu_table, the new iommu_table_group keeps pointers to those. The iommu_table structs are allocated dynamically. For P5IOC2, both iommu_table_group and iommu_table are embedded into PE struct. As there is no EEH and SRIOV support for P5IOC2, iommu_free_table() should not be called on iommu_table struct pointers so we can keep it embedded in pnv_phb::p5ioc2. For pSeries, this replaces multiple calls of kzalloc_node() with a new iommu_pseries_alloc_group() helper and stores the table group struct pointer into the pci_dn struct. For release, a iommu_table_free_group() helper is added. This moves iommu_table struct allocation from SR-IOV code to the generic DMA initialization code in pnv_pci_ioda_setup_dma_pe and pnv_pci_ioda2_setup_dma_pe as this is where DMA is actually initialized. This change is here because those lines had to be changed anyway. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda/ioda2: Rework TCE invalidation in tce_build()/tce_free()Alexey Kardashevskiy2015-06-112-37/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | The pnv_pci_ioda_tce_invalidate() helper invalidates TCE cache. It is supposed to be called on IODA1/2 and not called on p5ioc2. It receives start and end host addresses of TCE table. IODA2 actually needs PCI addresses to invalidate the cache. Those can be calculated from host addresses but since we are going to implement multi-level TCE tables, calculating PCI address from a host address might get either tricky or ugly as TCE table remains flat on PCI bus but not in RAM. This moves pnv_pci_ioda_tce_invalidate() from generic pnv_tce_build/ pnt_tce_free and defines IODA1/2-specific callbacks which call generic ones and do PHB-model-specific TCE cache invalidation. P5IOC2 keeps using generic callbacks as before. This changes pnv_pci_ioda2_tce_invalidate() to receives TCE index and number of pages which are PCI addresses shifted by IOMMU page shift. No change in behaviour is expected. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu: Move tce_xxx callbacks from ppc_md to iommu_tableAlexey Kardashevskiy2015-06-1112-111/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a iommu_table_ops struct and puts pointer to it into the iommu_table struct. This moves tce_build/tce_free/tce_get/tce_flush callbacks from ppc_md to the new struct where they really belong to. This adds the requirement for @it_ops to be initialized before calling iommu_init_table() to make sure that we do not leave any IOMMU table with iommu_table_ops uninitialized. This is not a parameter of iommu_init_table() though as there will be cases when iommu_init_table() will not be called on TCE tables, for example - VFIO. This does s/tce_build/set/, s/tce_free/clear/ and removes "tce_" redundant prefixes. This removes tce_xxx_rm handlers from ppc_md but does not add them to iommu_table_ops as this will be done later if we decide to support TCE hypercalls in real mode. This removes _vm callbacks as only virtual mode is supported by now so this also removes @rm parameter. For pSeries, this always uses tce_buildmulti_pSeriesLP/ tce_buildmulti_pSeriesLP. This changes multi callback to fall back to tce_build_pSeriesLP/tce_free_pSeriesLP if FW_FEATURE_MULTITCE is not present. The reason for this is we still have to support "multitce=off" boot parameter in disable_multitce() and we do not want to walk through all IOMMU tables in the system and replace "multi" callbacks with single ones. For powernv, this defines _ops per PHB type which are P5IOC2/IODA1/IODA2. This makes the callbacks for them public. Later patches will extend callbacks for IODA1/2. No change in behaviour is expected. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv: Do not set "read" flag if direction==DMA_NONEAlexey Kardashevskiy2015-06-113-6/+17
| | | | | | | | | | | | | | | | Normally a bitmap from the iommu_table is used to track what TCE entry is in use. Since we are going to use iommu_table without its locks and do xchg() instead, it becomes essential not to put bits which are not implied in the direction flag as the old TCE value (more precisely - the permission bits) will be used to decide whether to put the page or not. This adds iommu_direction_to_tce_perm() (its counterpart is there already) and uses it for powernv's pnv_tce_build(). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Rework groups attachingAlexey Kardashevskiy2015-06-111-16/+24
| | | | | | | | | | | | | | This is to make extended ownership and multiple groups support patches simpler for review. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Moving pinning/unpinning to helpersAlexey Kardashevskiy2015-06-111-20/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a pretty mechanical patch to make next patches simpler. New tce_iommu_unuse_page() helper does put_page() now but it might skip that after the memory registering patch applied. As we are here, this removes unnecessary checks for a value returned by pfn_to_page() as it cannot possibly return NULL. This moves tce_iommu_disable() later to let tce_iommu_clear() know if the container has been enabled because if it has not been, then put_page() must not be called on TCEs from the TCE table. This situation is not yet possible but it will after KVM acceleration patchset is applied. This changes code to work with physical addresses rather than linear mapping addresses for better code readability. Following patches will add an xchg() callback for an IOMMU table which will accept/return physical addresses (unlike current tce_build()) which will eliminate redundant conversions. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Disable DMA mappings on disabled containerAlexey Kardashevskiy2015-06-111-0/+6
| | | | | | | | | | | | | | | | At the moment DMA map/unmap requests are handled irrespective to the container's state. This allows the user space to pin memory which it might not be allowed to pin. This adds checks to MAP/UNMAP that the container is enabled, otherwise -EPERM is returned. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Move locked_vm accounting to helpersAlexey Kardashevskiy2015-06-111-19/+63
| | | | | | | | | | | | | | | | | | | | | | | | | There moves locked pages accounting to helpers. Later they will be reused for Dynamic DMA windows (DDW). This reworks debug messages to show the current value and the limit. This stores the locked pages number in the container so when unlocking the iommu table pointer won't be needed. This does not have an effect now but it will with the multiple tables per container as then we will allow attaching/detaching groups on fly and we may end up having a container with no group attached but with the counter incremented. While we are here, update the comment explaining why RLIMIT_MEMLOCK might be required to be bigger than the guest RAM. This also prints pid of the current process in pr_warn/pr_debug. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Use it_page_sizeAlexey Kardashevskiy2015-06-111-13/+13
| | | | | | | | | | | | | | | | This makes use of the it_page_size from the iommu_table struct as page size can differ. This replaces missing IOMMU_PAGE_SHIFT macro in commented debug code as recently introduced IOMMU_PAGE_XXX macros do not include IOMMU_PAGE_SHIFT. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Check that IOMMU page is fully contained by system pageAlexey Kardashevskiy2015-06-111-0/+16
| | | | | | | | | | | | | | | | | | This checks that the TCE table page size is not bigger that the size of a page we just pinned and going to put its physical address to the table. Otherwise the hardware gets unwanted access to physical memory between the end of the actual page and the end of the aligned up TCE page. Since compound_order() and compound_head() work correctly on non-huge pages, there is no need for additional check whether the page is huge. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* vfio: powerpc/spapr: Move page pinning from arch code to VFIO IOMMU driverAlexey Kardashevskiy2015-06-113-72/+67
| | | | | | | | | | | | | | | | | | | | | | This moves page pinning (get_user_pages_fast()/put_page()) code out of the platform IOMMU code and puts it to VFIO IOMMU driver where it belongs to as the platform code does not deal with page pinning. This makes iommu_take_ownership()/iommu_release_ownership() deal with the IOMMU table bitmap only. This removes page unpinning from iommu_take_ownership() as the actual TCE table might contain garbage and doing put_page() on it is undefined behaviour. Besides the last part, the rest of the patch is mechanical. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> [aw: for the vfio related changes] Acked-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu: Always release iommu_table in iommu_free_table()Alexey Kardashevskiy2015-06-111-3/+5
| | | | | | | | | | | | | | | At the moment iommu_free_table() only releases memory if the table was initialized for the platform code use, i.e. it had it_map initialized (which purpose is to track DMA memory space use). With dynamic DMA windows, we will need to be able to release iommu_table even if it was used for VFIO in which case it_map is NULL so does the patch. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu: Put IOMMU group explicitlyAlexey Kardashevskiy2015-06-113-8/+20
| | | | | | | | | | | | | | | | | | | | So far an iommu_table lifetime was the same as PE. Dynamic DMA windows will change this and iommu_free_table() will not always require the group to be released. This moves iommu_group_put() out of iommu_free_table(). This adds a iommu_pseries_free_table() helper which does iommu_group_put() and iommu_free_table(). Later it will be changed to receive a table_group and we will have to change less lines then. This should cause no behavioural change. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv/ioda: Clean up IOMMU group registrationAlexey Kardashevskiy2015-06-111-20/+8
| | | | | | | | | | | | | The existing code has 3 calls to iommu_register_group() and all 3 branches actually cover all possible cases. This replaces 3 calls with one and moves the registration earlier; the latter will make more sense when we add TCE table sharing. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/iommu/powernv: Get rid of set_iommu_table_base_and_groupAlexey Kardashevskiy2015-06-114-19/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The set_iommu_table_base_and_group() name suggests that the function sets table base and add a device to an IOMMU group. The actual purpose for table base setting is to put some reference into a device so later iommu_add_device() can get the IOMMU group reference and the device to the group. At the moment a group cannot be explicitly passed to iommu_add_device() as we want it to work from the bus notifier, we can fix it later and remove confusing calls of set_iommu_table_base(). This replaces set_iommu_table_base_and_group() with a couple of set_iommu_table_base() + iommu_add_device() which makes reading the code easier. This adds few comments why set_iommu_table_base() and iommu_add_device() are called where they are called. For IODA1/2, this essentially removes iommu_add_device() call from the pnv_pci_ioda_dma_dev_setup() as it will always fail at this particular place: - for physical PE, the device is already attached by iommu_add_device() in pnv_pci_ioda_setup_dma_pe(); - for virtual PE, the sysfs entries are not ready to create all symlinks so actual adding is happening in tce_iommu_bus_notifier. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/eeh/ioda2: Use device::iommu_group to check IOMMU groupAlexey Kardashevskiy2015-06-112-25/+6
| | | | | | | | | | | | | | | This relies on the fact that a PCI device always has an IOMMU table which may not be the case when we get dynamic DMA windows so let's use more reliable check for IOMMU group here. As we do not rely on the table presence here, remove the workaround from pnv_pci_ioda2_set_bypass(); also remove the @add_to_iommu_group parameter from pnv_ioda_setup_bus_dma(). Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* mtd: powernv: Add powernv flash MTD abstraction driverCyril Bur2015-06-113-0/+294
| | | | | | | | | | | | | | Powerpc powernv platforms allow access to certain system flash devices through a firmwarwe interface. This change adds an mtd driver for these flash devices. Minor updates from Jeremy Kerr and Joel Stanley. Signed-off-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Reviewed-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/mm: Add trace point for tracking hash pte faultAneesh Kumar K.V2015-06-102-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables us to understand how many hash fault we are taking when running benchmarks. For ex: -bash-4.2# ./perf stat -e powerpc:hash_fault -e page-faults /tmp/ebizzy.ppc64 -S 30 -P -n 1000 ... Performance counter stats for '/tmp/ebizzy.ppc64 -S 30 -P -n 1000': 1,10,04,075 powerpc:hash_fault 1,10,03,429 page-faults 30.865978991 seconds time elapsed NOTE: The impact of the tracepoint was not noticeable when running test. It was within the run-time variance of the test. For ex: without-patch: -------------- Performance counter stats for './a.out 3000 300': 643 page-faults # 0.089 M/sec 7.236562 task-clock (msec) # 0.928 CPUs utilized 2,179,213 stalled-cycles-frontend # 0.00% frontend cycles idle 17,174,367 stalled-cycles-backend # 0.00% backend cycles idle 0 context-switches # 0.000 K/sec 0.007794658 seconds time elapsed And with-patch: --------------- Performance counter stats for './a.out 3000 300': 643 page-faults # 0.089 M/sec 7.233746 task-clock (msec) # 0.921 CPUs utilized 0 context-switches # 0.000 K/sec 0.007854876 seconds time elapsed Performance counter stats for './a.out 3000 300': 643 page-faults # 0.087 M/sec 649 powerpc:hash_fault # 0.087 M/sec 7.430376 task-clock (msec) # 0.938 CPUs utilized 2,347,174 stalled-cycles-frontend # 0.00% frontend cycles idle 17,524,282 stalled-cycles-backend # 0.00% backend cycles idle 0 context-switches # 0.000 K/sec 0.007920284 seconds time elapsed Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add gitignore file for the new DSCR testsAnshuman Khandual2015-06-071-0/+7
| | | | | | | This patch adds .gitignore for all the newly added DSCR tests. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add thread based stress test for DSCR sysfs interfacesMichael Ellerman2015-06-072-1/+82
| | | | | | | | | | This patch adds a test to update the system wide DSCR value repeatedly and then verifies that any thread on any given CPU on the system must be able to see the same DSCR value whether its is being read through the problem state based SPR or the privilege state based SPR. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for all DSCR sysfs interfacesAnshuman Khandual2015-06-072-1/+98
| | | | | | | | | | This test continuously updates the system wide DSCR default value in the sysfs interface and makes sure that the same is reflected across all the sysfs interfaces for each individual CPUs present on the system. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for DSCR inheritence across fork & execAnshuman Khandual2015-06-072-1/+118
| | | | | | | | | | | This patch adds a test case to verify that the changed DSCR value inside any process would be inherited to it's child across the fork and exec system call. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for DSCR value inheritence across forkAnshuman Khandual2015-06-072-1/+97
| | | | | | | | | | | This patch adds a test to verify that the changed DSCR value inside any process would be inherited to it's child process across the fork system call. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for DSCR SPR numbersAnshuman Khandual2015-06-072-1/+62
| | | | | | | | | | | | This patch adds a test which verifies that the DSCR privilege and problem state SPR read & write accesses while making sure that the results are always the same irrespective of which SPR number is being used. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for explicitly changing DSCR valueAnshuman Khandual2015-06-072-1/+72
| | | | | | | | | | | This patch adds a test which modifies the DSCR using mtspr instruction and verifies the change using mfspr instruction. It uses both the privilege state SPR as well as the problem state SPR for the purpose. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* selftests/powerpc: Add test for system wide DSCR defaultAnshuman Khandual2015-06-074-1/+267
| | | | | | | | | | | | This patch adds a test case for the system wide DSCR default value, which when changed through it's sysfs interface must be visible to all threads reading DSCR either through the privilege state SPR or the problem state SPR. The DSCR value change should be immediate as well. Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/dscr: Add documentation for DSCR supportAnshuman Khandual2015-06-072-0/+85
| | | | | | | | | | | This patch adds a new documentation file explaining the DSCR support on powerpc platforms. This explains DSCR related data structure, code paths and also available user interfaces. Any further functional changes to the DSCR support in the kernel should definitely update the documentation here. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/dscr: Add some in-code documentationAnshuman Khandual2015-06-072-0/+47
| | | | | | | | This patch adds some in-code documentation to the DSCR related code to make it more readable without having any functional change to it. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/kernel: Rename PACA_DSCR to PACA_DSCR_DEFAULTAnshuman Khandual2015-06-074-5/+5
| | | | | | | | | PACA_DSCR offset macro tracks dscr_default element in the paca structure. Better change the name of this macro to match that of the data element it tracks. Makes the code more readable. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/kernel: Remove the unused extern dscr_defaultAnshuman Khandual2015-06-071-1/+0
| | | | | | | | | | | The process context switch code no longer uses dscr_default variable from the sysfs.c file. The variable became unused when we started storing the CPU specific DSCR value in the PACA structure instead. This patch just removes this extern declaration. It was originally added by the following commit. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Fix handling of DSCR related facility unavailable exceptionAnshuman Khandual2015-06-071-5/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently DSCR (Data Stream Control Register) can be accessed with mfspr or mtspr instructions inside a thread via two different SPR numbers. One being the user accessible problem state SPR number 0x03 and the other being the privilege state SPR number 0x11. All access through the privilege state SPR number get emulated through illegal instruction exception. Any access through the problem state SPR number raises one facility unavailable exception which sets the thread based dscr_inherit bit and enables DSCR facility through FSCR register thus allowing direct access to DSCR without going through this exception in the future. We set the thread.dscr_inherit bit whether the access was with mfspr or mtspr instruction which is neither correct nor does it match the behaviour through the instruction emulation code path driven from privilege state SPR number. User currently observes two different kind of behaviour when accessing the DSCR through these two SPR numbers. This problem can be observed through these two test cases by replacing the privilege state SPR number with the problem state SPR number. (1) http://ozlabs.org/~anton/junkcode/dscr_default_test.c (2) http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c This patch fixes the problem by making sure that the behaviour visible to the user remains the same irrespective of which SPR number is being used. Inside facility unavailable exception, we check whether it was cuased by a mfspr or a mtspr isntrucction. In case of mfspr instruction, just emulate the instruction. In case of mtspr instruction, set the thread based dscr_inherit bit and also enable the facility through FSCR. All user SPR based mfspr instruction will be emulated till one user SPR based mtspr has been executed. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* cxl: Reset default context for vPHB on releaseMichael Neuling2015-06-071-0/+1
| | | | | | | | When we release the device, we should also invalidate the default context. With this cxl_get_context() will return null after removal. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-01 05:16:55 +0000