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  1. Dec 20, 2018
  3. Dec 19, 2018
  5. Dec 17, 2018
  7. Dec 10, 2018
  9. Dec 09, 2018
    • Oliver O'Halloran's avatar
      powerpc/mm: Fallback to RAM if the altmap is unusable · 9ef34630
      Oliver O'Halloran authored 
      The "altmap" is used to provide a pool of memory that is reserved for
the vmemmap backing of hot-plugged memory. This is useful when adding
large amount of ZONE_DEVICE memory to a system with a limited amount of
normal memory.

On ppc64 we use huge pages to map the vmemmap which requires the backing
storage to be contigious and aligned to the hugepage size. The altmap
implementation allows for the altmap provider to reserve a few PFNs at
the start of the range for it's own uses and when this occurs the
first chunk of the altmap is not usable for hugepage mappings. On hash
there is no sane way to fall back to a normal sized page mapping so we
fail the allocation. This results in memory hotplug failing with
ENOMEM when the new range doesn't fall into an existing vmemmap block.

This patch handles this case by falling back to using system memory
rather than failing if we cannot allocate from the altmap. This
fallback should only ever be used for the first vmemmap block so it
should not cause excess memory consumption.

Fixes: 7b73d978

 ("mm: pass the vmem_altmap to vmemmap_populate")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      9ef34630
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Use ibm,unit-guid as the iset cookie · 43001c52
      Oliver O'Halloran authored 
      The interleave set cookie is used to determine if a label stored in the
metadata space should be applied to the current region. This is
important in the case of NVDIMMs since the firmware may change the
interleaving configuration of a DIMM which would invalidate the existing
labels. In our case the hypervisor hides those details from us so we
don't really care, but libnvdimm still requires the interleave set
cookie to be non-zero.

For our purposes we just need the set cookie to be unique and fixed for
a given PAPR SCM region and using the unit-guid (really a UUID) is fine
for this purpose.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u64)]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      43001c52
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Fix DIMM device registration race · b0d65a8c
      Oliver O'Halloran authored 
      When a new nvdimm device is registered with libnvdimm via
nvdimm_create() it is added as a device on the nvdimm bus. The probe
function for the DIMM driver is potentially quite slow so actually
registering and probing the device is done in an async domain rather
than immediately after device creation. This can result in a race where
the region device (created 2nd) is probed first and fails to activate at
boot.

To fix this we use the same approach as the ACPI/NFIT driver which is to
check that all the DIMM devices registered successfully. LibNVDIMM
provides the nvdimm_bus_count_dimms() function which synchronises with
the async domain and verifies that the dimm was successfully registered
with the bus.

If either of these does not occur then we bail.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      b0d65a8c
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Remove endian conversions · 409dd7dc
      Oliver O'Halloran authored 
      The return values of a h-call are returned in the CPU registers and
written to the provided buffer by the plpar_hcall() wrapper. As a result
the values written to memory are always in the native endian and should
not be byte swapped.

The inital implementation of the H-Call interface was done in qemu and
the returned values were byte swapped unnecessarily in both the
hypervisor and in the driver so this was only noticed when bringing up
the PowerVM implementation.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      409dd7dc
    • Oliver O'Halloran's avatar
      powerpc/papr_scm: Update DT properties · 683ec0e0
      Oliver O'Halloran authored 
      The ibm,unit-sizes property was originally specified as an array of two
u32s corresponding to the memory block size, and the number of blocks
available in that region. A fairly last-minute change to the SCM DT
specification was splitting that into two seperate u64 properties:
ibm,block-sizes and ibm,number-of-blocks that convey the same
information. No firmware / hypervisor that emitted the ibm,unit-size
property ever appeared in the wild.

Fixes: b5beae5e

 ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
[mpe: Use kernel types (u32/u64)]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      683ec0e0
  11. Dec 07, 2018
  13. Dec 06, 2018
    • Michael Ellerman's avatar
      powerpc/boot: Fix build failures with -j 1 · e41b93a6
      Michael Ellerman authored 
      In commit 5e9dcb61 ("powerpc/boot: Expose Kconfig symbols to
wrapper") we added a dependency to serial.c on autoconf.h:

  $(obj)/serial.c: $(obj)/autoconf.h

This works when building in-tree (ie. with KBUILD_OUTPUT unset)
because the obj tree is the src tree.

But when building with eg. O=build and -j 1 the build fails:

  gcc ... -I../arch/powerpc/boot -c -o arch/powerpc/boot/serial.o arch/powerpc/boot/serial.c
  gcc: error: arch/powerpc/boot/serial.c: No such file or directory

Why this is only happening with -j 1 is not clear, when building with
-j greater than 1 somehow we decide to look for serial.c in the src
tree (../), eg:

  gcc -I../arch/powerpc/boot -c -o arch/powerpc/boot/serial.o ../arch/powerpc/boot/serial.c

Regardless we shouldn't be specifying a dependency on serial.c in the
build tree, we want to add a dependency to the version in $(srctree)
so fix the rule to say that.

Fixes: 5e9dcb61

 ("powerpc/boot: Expose Kconfig symbols to wrapper")
Tested-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      e41b93a6
  15. Dec 04, 2018
    • Christophe Leroy's avatar
      powerpc/mm: dump block address translation on book3s/32 · 7c91efce
      Christophe Leroy authored 
      

This patch adds a debugfs file to dump block address translation:

~# cat /sys/kernel/debug/powerpc/block_address_translation
---[ Instruction Block Address Translations ]---
0:         -
1:         -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel EXEC coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel EXEC coherent
4:         -
5:         -
6:         -
7:         -

---[ Data Block Address Translations ]---
0:         -
1:         -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel RW coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent
4:         -
5:         -
6:         -
7:         -

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>

Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      7c91efce
    • Christophe Leroy's avatar
      powerpc/mm: dump segment registers on book3s/32 · 0261a508
      Christophe Leroy authored 
      

This patch creates a debugfs file to see content of
segment registers

  # cat /sys/kernel/debug/segment_registers
  ---[ User Segments ]---
  0x00000000-0x0fffffff Kern key 1 User key 1 VSID 0xade2b0
  0x10000000-0x1fffffff Kern key 1 User key 1 VSID 0xade3c1
  0x20000000-0x2fffffff Kern key 1 User key 1 VSID 0xade4d2
  0x30000000-0x3fffffff Kern key 1 User key 1 VSID 0xade5e3
  0x40000000-0x4fffffff Kern key 1 User key 1 VSID 0xade6f4
  0x50000000-0x5fffffff Kern key 1 User key 1 VSID 0xade805
  0x60000000-0x6fffffff Kern key 1 User key 1 VSID 0xade916
  0x70000000-0x7fffffff Kern key 1 User key 1 VSID 0xadea27
  0x80000000-0x8fffffff Kern key 1 User key 1 VSID 0xadeb38
  0x90000000-0x9fffffff Kern key 1 User key 1 VSID 0xadec49
  0xa0000000-0xafffffff Kern key 1 User key 1 VSID 0xaded5a
  0xb0000000-0xbfffffff Kern key 1 User key 1 VSID 0xadee6b

  ---[ Kernel Segments ]---
  0xc0000000-0xcfffffff Kern key 0 User key 1 VSID 0x000ccc
  0xd0000000-0xdfffffff Kern key 0 User key 1 VSID 0x000ddd
  0xe0000000-0xefffffff Kern key 0 User key 1 VSID 0x000eee
  0xf0000000-0xffffffff Kern key 0 User key 1 VSID 0x000fff

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
[mpe: Move it under /sys/kernel/debug/powerpc, make sr_init() __init]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      0261a508