Commit Graph

782270 Commits

Author SHA1 Message Date
zhong jiang
cd5ff94577 powerpc/xive: Move a dereference below a NULL test
Move the dereference of xc below the NULL test.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:02 +10:00
Naveen N. Rao
9258227e9d powerpc/pseries: Fix how we iterate over the DTL entries
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we look up dtl_idx in
the lppaca to determine the number of entries in the buffer. Since
lppaca is in big endian, we need to do an endian conversion before using
this in our calculation to determine the number of entries in the
buffer. Without this, we do not iterate over the existing entries in the
DTL buffer properly.

Fixes: 7c105b63bd ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:02 +10:00
Naveen N. Rao
db787af1b8 powerpc/pseries: Fix DTL buffer registration
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we register the DTL
buffer for a cpu when the associated file under powerpc/dtl in debugfs
is opened. When doing so, we need to set the size of the buffer being
registered in the second u32 word of the buffer. This needs to be in big
endian, but we are not doing the conversion resulting in the below error
showing up in dmesg:

	dtl_start: DTL registration for cpu 0 (hw 0) failed with -4

Fix this in the obvious manner.

Fixes: 7c105b63bd ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:02 +10:00
Christophe Leroy
51423a9c9b powerpc/traps: merge unrecoverable_exception() and nonrecoverable_exception()
PPC32 uses nonrecoverable_exception() while PPC64 uses
unrecoverable_exception().

Both functions are doing almost the same thing.

This patch removes nonrecoverable_exception()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:01 +10:00
Rob Herring
b9ef7b4b86 powerpc: Convert to using %pOFn instead of device_node.name
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:01 +10:00
Rob Herring
0bdba867f0 macintosh: Convert to using %pOFn instead of device_node.name
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:01 +10:00
Rob Herring
c417596d24 powerpc/pseries: Use of_irq_get helper() in request_event_sources_irqs()
Instead of calling both of_irq_parse_one() and
irq_create_of_mapping(), call of_irq_get() instead which does
essentially the same thing. of_irq_get() also calls irq_find_host()
for deferred probe support, but this should be fine as
irq_create_of_mapping() also calls that internally. This gets us
closer to making the former 2 functions static.

In the process of simplifying request_event_sources_irqs(), combine
the the pr_err() and WARN_ON() calls to just a WARN().

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:01 +10:00
Rob Herring
8c8933eba0 powerpc/cell: Use irq_of_parse_and_map() helper
Instead of calling both of_irq_parse_one() and
irq_create_of_mapping(), call of_irq_parse_and_map() instead which
does the same thing. This gets us closer to making the former 2
functions static.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:00 +10:00
Aneesh Kumar K.V
a0820ff334 powerpc/mm:book3s: Enable THP migration support
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:00 +10:00
Aneesh Kumar K.V
8890e03380 powerpc/mm/thp: update pmd_trans_huge to check for pmd_present
We need to make sure pmd_trans_huge returns false for a pmd migration entry.
We mark the migration entry by clearing the _PAGE_PRESENT bit. We keep the
_PAGE_PTE bit set to indicate a leaf page table entry. Hence we need to make
sure we check for pmd_present() so that pmd_trans_huge won't return true on
pmd migration entry.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:40:00 +10:00
Aneesh Kumar K.V
75646c480f arch/powerpc/mm/hash: validate the pte entries before handling the hash fault
Make sure we are operating on THP and hugetlb entries in the respective hash
fault handling routines.

No functional change in this patch. If we walked the table wrongly before, we
will retry the access.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:39:59 +10:00
Aneesh Kumar K.V
ae28f17b5e powerpc/mm/book3s: Check for pmd_large instead of pmd_trans_huge
Update few code paths to check for pmd_large.

set_pmd_at:
We want to use this to store swap pte at pmd level. For swap ptes we don't want
to set H_PAGE_THP_HUGE. Hence check for pmd_large in set_pmd_at. This remove
the false WARN_ON when using this with swap pmd entry.

pmd_page:
We don't really use them on pmd migration entries. But they can also work with
migration entries and we don't differentiate at the pte level. Hence update
pmd_page to work with pmd migration entries too

__find_linux_pte:
lockless page table walk need to handle pmd migration entries. pmd_trans_huge
check will return false on them. We don't set thp = 1 for such entries, but
update hpage_shift correctly. Without this we will walk pmd migration entries
as a pte page pointer which is wrong.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:39:59 +10:00
Aneesh Kumar K.V
f1981b5b30 powerpc/mm/hugetlb/book3s: add _PAGE_PRESENT to hugepd pointer.
This make hugetlb directory pointer similar to other page able entries. A hugepd
entry is identified by lack of _PAGE_PTE bit set and directory size stored in
HUGEPD_SHIFT_MASK. We update that to also look at _PAGE_PRESENT

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:39:58 +10:00
Aneesh Kumar K.V
da7ad366b4 powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit
With this patch we use 0x8000000000000000UL (_PAGE_PRESENT) to indicate a valid
pgd/pud/pmd entry. We also switch the p**_present() to look at this bit.

With pmd_present, we have a special case. We need to make sure we consider a
pmd marked invalid during THP split as present. Right now we clear the
_PAGE_PRESENT bit during a pmdp_invalidate. Inorder to consider this special
case we add a new pte bit _PAGE_INVALID (mapped to _RPAGE_SW0). This bit is
only used with _PAGE_PRESENT cleared. Hence we are not really losing a pte bit
for this special case. pmd_present is also updated to look at _PAGE_INVALID.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:39:58 +10:00
Vaibhav Jain
8139046a5a powerpc/powernv: Make possible for user to force a full ipl cec reboot
Ever since fast reboot is enabled by default in opal,
opal_cec_reboot() will use fast-reset instead of full IPL to perform
system reboot. This leaves the user with no direct way to force a full
IPL reboot except changing an nvram setting that persistently disables
fast-reset for all subsequent reboots.

This patch provides a more direct way for the user to force a one-shot
full IPL reboot by passing the command line argument 'full' to the
reboot command. So the user will be able to tweak the reboot behavior
via:

  $ sudo reboot full	# Force a full ipl reboot skipping fast-reset

  or
  $ sudo reboot  	# default reboot path (usually fast-reset)

The reboot command passes the un-parsed command argument to the kernel
via the 'Reboot' syscall which is then passed on to the arch function
pnv_restart(). The patch updates pnv_restart() to handle this cmd-arg
and issues opal_cec_reboot2 with OPAL_REBOOT_FULL_IPL to force a full
IPL reset.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:39:45 +10:00
Michael Ellerman
db6711b7a1 powerpc/perf: Add missing break in power7_marked_instr_event()
In power7_marked_instr_event() there is a switch case that is missing
a break or an explicit fallthrough, it's not immediately clear which
it should be.

The function determines based on the PMU event code, whether the event
is a "marked" event (which then requires us to configure the PMU in a
certain way). On Power7 there is no specific bit(s) in the event to
tell us that, we just have to know.

Rather than having a full list of every event and whether they are
marked, we pull apart the event code and for events with certain
values of certain fields we can say that those are all marked events.

We take the psel (bits 0-7) of the event, and look at bits 4-7. For a
value of 6 we say that if the entire psel == 0x64 then if the pmc == 3
the event is marked, else not, and otherwise we continue.

It is then that we fallthrough to the 8 case, where we return true if
the unit == 0xd.

The question is should the 6 case also fallthrough and check for
unit == 0xd, or should it return.

Looking at the full list of events we see that there are zero events
where (psel >> 4) == 0x6 and unit == 0xd.

So the answer is it doesn't really matter, there are no valid event
codes that will return a different result whether we fallthrough or
break.

But equally, testing the 6 case events against unit == 0xd is slightly
bogus, as there are no such events. So to make the code clearer, and
avoid any future confusion, have the 6 case break rather than falling
through.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
2018-10-03 15:39:45 +10:00
Michael Ellerman
54be0b9c7c Revert "convert SLB miss handlers to C" and subsequent commits
This reverts commits:
  5e46e29e6a ("powerpc/64s/hash: convert SLB miss handlers to C")
  8fed04d0f6 ("powerpc/64s/hash: remove user SLB data from the paca")
  655deecf67 ("powerpc/64s/hash: SLB allocation status bitmaps")
  2e1626744e ("powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup")
  89ca4e126a ("powerpc/64s/hash: Add a SLB preload cache")

This series had a few bugs, and the fixes are not all trivial. So
revert most of it for now.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-03 15:32:49 +10:00
Hari Bathini
0823c68b05 powerpc/fadump: re-register firmware-assisted dump if already registered
Firmware-Assisted Dump (FADump) needs to be registered again after any
memory hot add/remove operation to update the crash memory ranges. But
currently, the kernel returns '-EEXIST' if we try to register without
uregistering it first. This could expose the system to racing issues
while unregistering and registering FADump from userspace during udev
events. Spare the userspace of this and let it be taken care of in the
kernel space for a simpler interface.

Since this change, running 'echo 1 > /sys/kernel/fadump_registered'
would result in re-regisering (unregistering and registering) FADump,
if it was already registered.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Suraj Jitindar Singh
74422e2b19 powerpc/pseries: Remove VLA from lparcfg_write()
In lparcfg_write we hard code kbuf_sz and then use this as the variable
length of kbuf creating a variable length array. Since we're hard coding
the length anyway just define the array using this as the length and
remove the need for kbuf_sz, thus removing the variable length array.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Suraj Jitindar Singh
ab91239942 powerpc/prom: Remove VLA in prom_check_platform_support()
In prom_check_platform_support() we retrieve and parse the
"ibm,arch-vec-5-platform-support" property of the chosen node.
Currently we use a variable length array however to avoid this use an
array of constant length 8.

This property is used to indicate the supported options of vector 5
bytes 23-26 of the ibm,architecture.vec node. Each of these options
is a pair of bytes, thus for 4 options we have a max length of 8 bytes.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Anton Blanchard
e00d93ac9a powerpc: Fix duplicate const clang warning in user access code
This re-applies commit b91c1e3e7a ("powerpc: Fix duplicate const
clang warning in user access code") (Jun 2015) which was undone in
commits:
  f2ca809059 ("powerpc/sparse: Constify the address pointer in __get_user_nosleep()") (Feb 2017)
  d466f6c5ca ("powerpc/sparse: Constify the address pointer in __get_user_nocheck()") (Feb 2017)
  f84ed59a61 ("powerpc/sparse: Constify the address pointer in __get_user_check()") (Feb 2017)

We see a large number of duplicate const errors in the user access
code when building with llvm/clang:

  include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier [-Wduplicate-decl-specifier]
        ret = __get_user(c, uaddr);

The problem is we are doing const __typeof__(*(ptr)), which will hit
the warning if ptr is marked const.

Removing const does not seem to have any effect on GCC code
generation.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Joel Stanley
ee9d21b3b3 powerpc/boot: Ensure _zimage_start is a weak symbol
When building with clang crt0's _zimage_start is not marked weak, which
breaks the build when linking the kernel image:

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058 g       .text  0000000000000000 _zimage_start

 ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start':
 (.text+0x58): multiple definition of '_zimage_start';
 arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here

Clang requires the .weak directive to appear after the symbol is
declared. The binutils manual says:

 This directive sets the weak attribute on the comma separated list of
 symbol names. If the symbols do not already exist, they will be
 created.

So it appears this is different with clang. The only reference I could
see for this was an OpenBSD mailing list post[1].

Changing it to be after the declaration fixes building with Clang, and
still works with GCC.

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058  w      .text	0000000000000000 _zimage_start

Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921

[1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY

Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Joel Stanley
cbc39809a3 powerpc/configs: Update skiroot defconfig
Disable new features from recent releases, and clean out some other
unused options:

  - Enable EXPERT, so we can disable some things
  - Disable non-powerpc BPF decoders
  - Disable TASKSTATS
  - Disable unused syscalls
  - Set more things to be modules
  - Turn off unused network vendors
  - PPC_OF_BOOT_TRAMPOLINE and FB_OF are unused on powernv
  - Drop unused Radeon and Matrox GPU drivers
  - IPV6 support landed in petitboot
  - Bringup related command line powersave=off dropped, switch to quiet

Set CONFIG_I2C_CHARDEV=y as the module is not loaded automatically, and
without this i2cget etc. will fail in the skiroot environment.

This defconfig gets us build coverage of KERNEL_XZ, which was broken in
the 4.19 merge window for powerpc.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Nathan Fontenot
85a88cabad powerpc/pseries: Disable CPU hotplug across migrations
When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.

During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.

To prevent this this patch disables CPU hotplug during the migration
process.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Nathan Fontenot
fd12527a1d powerpc/pseries: Remove unneeded uses of dlpar work queue
There are three instances in which dlpar hotplug events are invoked;
handling a hotplug interrupt (in a kvm guest), handling a dlpar
request through sysfs, and updating LMB affinity when handling a
PRRN event. Only in the case of handling a hotplug interrupt do we
have to put the work on a workqueue, the other cases can handle the
dlpar request directly.

This patch exports the handle_dlpar_errorlog() function so that
dlpar hotplug events can be handled directly and updates the two
instances mentioned above to use the direct invocation.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Nathan Fontenot
cd24e457fd powerpc/pseries: Remove prrn_work workqueue
When a PRRN event is received we are already running in a worker
thread. Instead of spawning off another worker thread on the prrn_work
workqueue to handle the PRRN event we can just call the PRRN handler
routine directly.

With this update we can also pass the scope variable for the PRRN
event directly to the handler instead of it being a global variable.

This patch fixes the following oops mnessage we are seeing in PRRN testing:

  Oops: Bad kernel stack pointer, sig: 6 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
  Supported: Yes, External                                                     54
  CPU: 7 PID: 18967 Comm: kworker/u96:0 Tainted: G                 X 4.4.126-94.22-default #1
  Workqueue: pseries hotplug workque pseries_hp_work_fn
  task: c000000775367790 ti: c00000001ebd4000 task.ti: c00000070d140000
  NIP: 0000000000000000 LR: 000000001fb3d050 CTR: 0000000000000000
  REGS: c00000001ebd7d40 TRAP: 0700   Tainted: G                 X  (4.4.126-94.22-default)
  MSR: 8000000102081000 <41,VEC,ME5  CR: 28000002  XER: 20040018   4
  CFAR: 000000001fb3d084 40 419   1                                3
  GPR00: 000000000000000040000000000010007 000000001ffff400 000000041fffe200
  GPR04: 000000000000008050000000000000000 000000001fb15fa8 0000000500000500
  GPR08: 000000000001f40040000000000000001 0000000000000000 000005:5200040002
  GPR12: 00000000000000005c000000007a05400 c0000000000e89f8 000000001ed9f668
  GPR16: 000000001fbeff944000000001fbeff94 000000001fb545e4 0000006000000060
  GPR20: ffffffffffffffff4ffffffffffffffff 0000000000000000 0000000000000000
  GPR24: 00000000000000005400000001fb3c000 0000000000000000 000000001fb1b040
  GPR28: 000000001fb240004000000001fb440d8 0000000000000008 0000000000000000
  NIP [0000000000000000] 5         (null)
  LR [000000001fb3d050] 031fb3d050
  Call Trace:            4
  Instruction dump:      4                                       5:47 12    2
  XXXXXXXX XXXXXXXX XXXXX4XX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  XXXXXXXX XXXXXXXX XXXXX5XX XXXXXXXX 60000000 60000000 60000000 60000000
  ---[ end trace aa5627b04a7d9d6b ]---                                       3NMI watchdog: BUG: soft lockup - CPU#27 stuck for 23s! [kworker/27:0:13903]
  Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
  Supported: Yes, External
  CPU: 27 PID: 13903 Comm: kworker/27:0 Tainted: G      D          X 4.4.126-94.22-default #1
  Workqueue: events prrn_work_fn
  task: c000000747cfa390 ti: c00000074712c000 task.ti: c00000074712c000
  NIP: c0000000008002a8 LR: c000000000090770 CTR: 000000000032e088
  REGS: c00000074712f7b0 TRAP: 0901   Tainted: G      D          X  (4.4.126-94.22-default)
  MSR: 8000000100009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 22482044  XER: 20040000
  CFAR: c0000000008002c4 SOFTE: 1
  GPR00: c000000000090770 c00000074712fa30 c000000000f09800 c000000000fa1928 6:02
  GPR04: c000000775f5e000 fffffffffffffffe 0000000000000001 c000000000f42db8
  GPR08: 0000000000000001 0000000080000007 0000000000000000 0000000000000000
  GPR12: 8006210083180000 c000000007a14400
  NIP [c0000000008002a8] _raw_spin_lock+0x68/0xd0
  LR [c000000000090770] mobility_rtas_call+0x50/0x100
  Call Trace:            59                                        5
  [c00000074712fa60] [c000000000090770] mobility_rtas_call+0x50/0x100
  [c00000074712faf0] [c000000000090b08] pseries_devicetree_update+0xf8/0x530
  [c00000074712fc20] [c000000000031ba4] prrn_work_fn+0x34/0x50
  [c00000074712fc40] [c0000000000e0390] process_one_work+0x1a0/0x4e0
  [c00000074712fcd0] [c0000000000e0870] worker_thread+0x1a0/0x6105:57       2
  [c00000074712fd80] [c0000000000e8b18] kthread+0x128/0x150
  [c00000074712fe30] [c0000000000096f8] ret_from_kernel_thread+0x5c/0x64
  Instruction dump:
  2c090000 40c20010 7d40192d 40c2fff0 7c2004ac 2fa90000 40de0018 5:540030   3
  e8010010 ebe1fff8 7c0803a6 4e800020 <7c210b78> e92d0000 89290009 792affe3

Signed-off-by: John Allen <jallen@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Nathan Fontenot
063b8b1251 powerpc/pseries/memory-hotplug: Only update DT once per memory DLPAR request
The updates to powerpc numa and memory hotplug code now use the
in-kernel LMB array instead of the device tree. This change allows the
pseries memory DLPAR code to only update the device tree once after
successfully handling a DLPAR request.

Prior to the in-kernel LMB array, the numa code looked up the affinity
for memory being added in the device tree, the code now looks this up
in the LMB array. This change means the memory hotplug code can just
update the affinity for an LMB in the LMB array instead of updating
the device tree.

This also provides a savings in kernel memory. When updating the
device tree old properties are never free'ed since there is no
usecount on properties. This behavior leads to a new copy of the
property being allocated every time a LMB is added or removed (i.e. a
request to add 100 LMBs creates 100 new copies of the property). With
this update only a single new property is created when a DLPAR request
completes successfully.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:08:12 +10:00
Nicholas Piggin
6977f95e63 powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
2a056f58fd powerpc: consolidate -mno-sched-epilog into FTRACE flags
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
f2910f0e68 powerpc: remove old GCC version checks
GCC 4.6 is the minimum supported now.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
89ca4e126a powerpc/64s/hash: Add a SLB preload cache
When switching processes, currently all user SLBEs are cleared, and a
few (exec_base, pc, and stack) are preloaded. In trivial testing with
small apps, this tends to miss the heap and low 256MB segments, and it
will also miss commonly accessed segments on large memory workloads.

Add a simple round-robin preload cache that just inserts the last SLB
miss into the head of the cache and preloads those at context switch
time. Every 256 context switches, the oldest entry is removed from the
cache to shrink the cache and require fewer slbmte if they are unused.

Much more could go into this, including into the SLB entry reclaim
side to track some LRU information etc, which would require a study of
large memory workloads. But this is a simple thing we can do now that
is an obvious win for common workloads.

With the full series, process switching speed on the context_switch
benchmark on POWER9/hash (with kernel speculation security masures
disabled) increases from 140K/s to 178K/s (27%).

POWER8 does not change much (within 1%), it's unclear why it does not
see a big gain like POWER9.

Booting to busybox init with 256MB segments has SLB misses go down
from 945 to 69, and with 1T segments 900 to 21. These could almost all
be eliminated by preloading a bit more carefully with ELF binary
loading.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
2e1626744e powerpc/64s/hash: provide arch_setup_exec hooks for hash slice setup
This will be used by the SLB code in the next patch, but for now this
sets the slb_addr_limit to the correct size for 32-bit tasks.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
e83cbf7fb7 powerpc/64s: xmon do not dump hash fields when using radix mode
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
655deecf67 powerpc/64s/hash: SLB allocation status bitmaps
Add 32-entry bitmaps to track the allocation status of the first 32
SLB entries, and whether they are user or kernel entries. These are
used to allocate free SLB entries first, before resorting to the round
robin allocator.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:56 +10:00
Nicholas Piggin
8fed04d0f6 powerpc/64s/hash: remove user SLB data from the paca
User SLB mappig data is copied into the PACA from the mm->context so
it can be accessed by the SLB miss handlers.

After the C conversion, SLB miss handlers now run with relocation on,
and user SLB misses are able to take recursive kernel SLB misses, so
the user SLB mapping data can be removed from the paca and accessed
directly.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 22:01:46 +10:00
Nicholas Piggin
5e46e29e6a powerpc/64s/hash: convert SLB miss handlers to C
This patch moves SLB miss handlers completely to C, using the standard
exception handler macros to set up the stack and branch to C.

This can be done because the segment containing the kernel stack is
always bolted, so accessing it with relocation on will not cause an
SLB exception.

Arbitrary kernel memory may not be accessed when handling kernel space
SLB misses, so care should be taken there. However user SLB misses can
access any kernel memory, which can be used to move some fields out of
the paca (in later patches).

User SLB misses could quite easily reconcile IRQs and set up a first
class kernel environment and exit via ret_from_except, however that
doesn't seem to be necessary at the moment, so we only do that if a
bad fault is encountered.

[ Credit to Aneesh for bug fixes, error checks, and improvements to bad
  address handling, etc ]

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Since RFC:
- Added MSR[RI] handling
- Fixed up a register loss bug exposed by irq tracing (Aneesh)
- Reject misses outside the defined kernel regions (Aneesh)
- Added several more sanity checks and error handling (Aneesh), we may
  look at consolidating these tests and tightenig up the code but for
  a first pass we decided it's better to check carefully.

Since v1:
- Fixed SLB cache corruption (Aneesh)
- Fixed untidy SLBE allocation "leak" in get_vsid error case
- Now survives some stress testing on real hardware

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Nicholas Piggin
82d8f4c22f powerpc/64s/hash: Use POWER9 SLBIA IH=3 variant in switch_slb
POWER9 introduces SLBIA IH=3, which invalidates all SLB entries and
associated lookaside information that have a class value of 1, which
Linux assigns to user addresses. This matches what switch_slb wants,
and allows a simple fast implementation that avoids the slb_cache
complexity.

As a side-effect, the POWER5 < DD2.1 SLB invalidation workaround is
also avoided on POWER9.

Process context switching rate is improved about 2.2% for a small
process that hits the slb cache which is the best case for the current
code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:44 +10:00
Nicholas Piggin
5141c182d7 powerpc/64s/hash: Use POWER6 SLBIA IH=1 variant in switch_slb
The SLBIA IH=1 hint will remove all non-zero SLBEs, but only
invalidate ERAT entries associated with a class value of 1, for
processors that support the hint (e.g., POWER6 and newer), which
Linux assigns to user addresses.

This prevents kernel ERAT entries from being invalidated when
context switchig (if the thread faulted in more than 8 user SLBEs).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Nicholas Piggin
85376e2a17 powerpc/64s/hash: remove the vmalloc segment from the bolted SLB
Remove the vmalloc segment from bolted SLBEs. This is not required to
be bolted, and seems like it was added to help pre-load the SLB on
context switch. However there are now other segments like the vmemmap
segment and non-zero node memory that often take misses after a context
switch, so it is better to solve this in a more general way.

A subsequent change will track free SLB entries and uses those rather
than round-robin overwrite valid entries, which makes it far less
likely for kernel SLBEs to be evicted after they are installed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Nicholas Piggin
8b92887ced powerpc/64s/hash: move POWER5 < DD2.1 slbie workaround where it is needed
The POWER5 < DD2.1 issue is that slbie needs to be issued more than
once. It came in with this change:

ChangeSet@1.1608, 2004-04-29 07:12:31-07:00, david@gibson.dropbear.id.au
  [PATCH] POWER5 erratum workaround

  Early POWER5 revisions (<DD2.1) have a problem requiring slbie
  instructions to be repeated under some circumstances.  The patch below
  adds a workaround (patch made by Anton Blanchard).

(aka. 3e4520f7605243abf66a7ccd3d2e49e48e8c0483 in the full history tree)

The extra slbie in switch_slb is done even for the case where slbia is
called (slb_flush_and_rebolt). I don't believe that is required
because there are other slb_flush_and_rebolt callers which do not
issue the workaround slbie, which would be broken if it was required.

It also seems to be fine inside the isync with the first slbie, as it
is in the kernel stack switch code.

So move this workaround to where it is required. This is not much of
an optimisation because this is the fast path, but it makes the code
more understandable and neater.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Retain slbie_data initialisation to avoid compiler warning]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Nicholas Piggin
505ea82eab powerpc/64s/hash: avoid the POWER5 < DD2.1 slb invalidate workaround on POWER8/9
I only have POWER8/9 to test, so just remove it for those.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Nicholas Piggin
09b4438db1 powerpc/64s/hash: Fix stab_rr off by one initialization
This causes SLB alloation to start 1 beyond the start of the SLB.
There is no real problem because after it wraps it stats behaving
properly, it's just surprisig to see when looking at SLB traces.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Mahesh Salgaonkar
db7d31ac04 powernv/pseries: consolidate code for mce early handling.
Now that other platforms also implements real mode mce handler,
lets consolidate the code by sharing existing powernv machine check
early code. Rename machine_check_powernv_early to
machine_check_common_early and reuse the code.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Mahesh Salgaonkar
c6d15258cd powerpc/pseries: Dump the SLB contents on SLB MCE errors.
If we get a machine check exceptions due to SLB errors then dump the
current SLB contents which will be very much helpful in debugging the
root cause of SLB errors. Introduce an exclusive buffer per cpu to hold
faulty SLB entries. In real mode mce handler saves the old SLB contents
into this buffer accessible through paca and print it out later in virtual
mode.

With this patch the console will log SLB contents like below on SLB MCE
errors:

[  507.297236] SLB contents of cpu 0x1
[  507.297237] Last SLB entry inserted at slot 16
[  507.297238] 00 c000000008000000 400ea1b217000500
[  507.297239]   1T  ESID=   c00000  VSID=      ea1b217 LLP:100
[  507.297240] 01 d000000008000000 400d43642f000510
[  507.297242]   1T  ESID=   d00000  VSID=      d43642f LLP:110
[  507.297243] 11 f000000008000000 400a86c85f000500
[  507.297244]   1T  ESID=   f00000  VSID=      a86c85f LLP:100
[  507.297245] 12 00007f0008000000 4008119624000d90
[  507.297246]   1T  ESID=       7f  VSID=      8119624 LLP:110
[  507.297247] 13 0000000018000000 00092885f5150d90
[  507.297247]  256M ESID=        1  VSID=   92885f5150 LLP:110
[  507.297248] 14 0000010008000000 4009e7cb50000d90
[  507.297249]   1T  ESID=        1  VSID=      9e7cb50 LLP:110
[  507.297250] 15 d000000008000000 400d43642f000510
[  507.297251]   1T  ESID=   d00000  VSID=      d43642f LLP:110
[  507.297252] 16 d000000008000000 400d43642f000510
[  507.297253]   1T  ESID=   d00000  VSID=      d43642f LLP:110
[  507.297253] ----------------------------------
[  507.297254] SLB cache ptr value = 3
[  507.297254] Valid SLB cache entries:
[  507.297255] 00 EA[0-35]=    7f000
[  507.297256] 01 EA[0-35]=        1
[  507.297257] 02 EA[0-35]=     1000
[  507.297257] Rest of SLB cache entries:
[  507.297258] 03 EA[0-35]=    7f000
[  507.297258] 04 EA[0-35]=        1
[  507.297259] 05 EA[0-35]=     1000
[  507.297260] 06 EA[0-35]=       12
[  507.297260] 07 EA[0-35]=    7f000

Suggested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Mahesh Salgaonkar
8f0b80561f powerpc/pseries: Display machine check error details.
Extract the MCE error details from RTAS extended log and display it to
console.

With this patch you should now see mce logs like below:

[  142.371818] Severe Machine check interrupt [Recovered]
[  142.371822]   NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel]
[  142.371822]   Initiator: CPU
[  142.371823]   Error type: SLB [Multihit]
[  142.371824]     Effective address: d00000000ca70000

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:41 +10:00
Mahesh Salgaonkar
a43c159042 powerpc/pseries: Flush SLB contents on SLB MCE errors.
On pseries, as of today system crashes if we get a machine check
exceptions due to SLB errors. These are soft errors and can be fixed
by flushing the SLBs so the kernel can continue to function instead of
system crash. We do this in real mode before turning on MMU. Otherwise
we would run into nested machine checks. This patch now fetches the
rtas error log in real mode and flushes the SLBs on SLB/ERAT errors.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:59:22 +10:00
Mahesh Salgaonkar
04fce21c9d powerpc/pseries: Define MCE error event section.
On pseries, the machine check error details are part of RTAS extended
event log passed under Machine check exception section. This patch adds
the definition of rtas MCE event section and related helper
functions.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:58:09 +10:00
Breno Leitao
44d947eff1 selftests/powerpc: Do not fail with reschedule
There are cases where the test is not expecting to have the transaction
aborted, but, the test process might have been rescheduled, either in the
OS level or by KVM (if it is running on a KVM guest machine). The process
reschedule will cause a treclaim/recheckpoint which will cause the
transaction to doom, aborting the transaction as soon as the process is
rescheduled back to the CPU. This might cause the test to fail, but this is
not a failure in essence.

If that is the case, TEXASR[FC] is indicated with either
TM_CAUSE_RESCHEDULE or TM_CAUSE_KVM_RESCHEDULE for KVM interruptions.

In this scenario, ignore these two failures and avoid the whole test to
return failure.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Gustavo Romero <gromero@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:58:09 +10:00
Breno Leitao
984ecdd68d powerpc/iommu: Avoid derefence before pointer check
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.

Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:58:09 +10:00
Breno Leitao
8ac9e5bfd8 powerpc/xive: Use xive_cpu->chip_id instead of looking it up again
Function xive_native_get_ipi() might use chip_id without it being
initialized, if the CPU node is not found, as reported by smatch:

  error: uninitialized symbol 'chip_id'

As suggested by Cédric, we can use xc->chip_id instead of consulting
the device tree for chip id, which is safe since xive_prepare_cpu()
should have initialized ->chip_id by the time xive_native_get_ipi() is
called.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[mpe: Tweak change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-09-19 21:58:09 +10:00