# git rev-parse -q --verify 11f5acce2fa43b015a8120fa7620fa4efd0a2952^{commit}
11f5acce2fa43b015a8120fa7620fa4efd0a2952
already have revision, skipping fetch
# git checkout -q -f -B kisskb 11f5acce2fa43b015a8120fa7620fa4efd0a2952
# git clean -qxdf
# < git log -1
# commit 11f5acce2fa43b015a8120fa7620fa4efd0a2952
# Author: Alexey Kardashevskiy <aik@ozlabs.ru>
# Date:   Wed Feb 13 14:38:18 2019 +1100
# 
#     powerpc/powernv/ioda: Fix locked_vm counting for memory used by IOMMU tables
#     
#     We store 2 multilevel tables in iommu_table - one for the hardware and
#     one with the corresponding userspace addresses. Before allocating
#     the tables, the iommu_table_group_ops::get_table_size() hook returns
#     the combined size of the two and VFIO SPAPR TCE IOMMU driver adjusts
#     the locked_vm counter correctly. When the table is actually allocated,
#     the amount of allocated memory is stored in iommu_table::it_allocated_size
#     and used to decrement the locked_vm counter when we release the memory
#     used by the table; .get_table_size() and .create_table() calculate it
#     independently but the result is expected to be the same.
#     
#     However the allocator does not add the userspace table size to
#     .it_allocated_size so when we destroy the table because of VFIO PCI
#     unplug (i.e. VFIO container is gone but the userspace keeps running),
#     we decrement locked_vm by just a half of size of memory we are
#     releasing.
#     
#     To make things worse, since we enabled on-demand allocation of
#     indirect levels, it_allocated_size contains only the amount of memory
#     actually allocated at the table creation time which can just be a
#     fraction. It is not a problem with incrementing locked_vm (as
#     get_table_size() value is used) but it is with decrementing.
#     
#     As the result, we leak locked_vm and may not be able to allocate more
#     IOMMU tables after few iterations of hotplug/unplug.
#     
#     This sets it_allocated_size in the pnv_pci_ioda2_ops::create_table()
#     hook to what pnv_pci_ioda2_get_table_size() returns so from now on we
#     have a single place which calculates the maximum memory a table can
#     occupy. The original meaning of it_allocated_size is somewhat lost now
#     though.
#     
#     We do not ditch it_allocated_size whatsoever here and we do not call
#     get_table_size() from vfio_iommu_spapr_tce.c when decrementing
#     locked_vm as we may have multiple IOMMU groups per container and even
#     though they all are supposed to have the same get_table_size()
#     implementation, there is a small chance for failure or confusion.
#     
#     Fixes: 090bad39b237 ("powerpc/powernv: Add indirect levels to it_userspace")
#     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>
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 11f5acce2fa43b015a8120fa7620fa4efd0a2952
# < make -s -j 10 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  defconfig
# make -s -j 10 ARCH=arm64 O=/kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  
arch/arm64/Makefile:27: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum
arch/arm64/Makefile:40: LSE atomics not supported by binutils
/kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru-bob.dts:25.9-29.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port'
/kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-gru-kevin.dts:46.9-50.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port'
/kisskb/src/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts:94.9-98.5: Warning (graph_port): /edp-panel/ports: graph port node name should be 'port'
In file included from /kisskb/src/include/linux/rwsem.h:16:0,
                 from /kisskb/src/include/linux/notifier.h:15,
                 from /kisskb/src/include/linux/clk.h:17,
                 from /kisskb/src/drivers/tty/serial/sh-sci.c:24:
/kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_submit_rx':
/kisskb/src/include/linux/spinlock.h:279:3: warning: 'flags' may be used uninitialized in this function [-Wmaybe-uninitialized]
   _raw_spin_unlock_irqrestore(lock, flags); \
   ^
/kisskb/src/drivers/tty/serial/sh-sci.c:1338:16: note: 'flags' was declared here
  unsigned long flags;
                ^
Completed OK
# rm -rf /kisskb/build/powerpc-next_arm64-defconfig_arm64-gcc5.4
# Build took: 0:04:55.692106