Commit graph

284 commits

Author SHA1 Message Date
Christophe Leroy
e606a2f46c powerpc/time: Remove generic_suspend_{dis/en}able_irqs()
Commit d75d68cfef ("powerpc: Clean up obsolete code relating to
decrementer and timebase") made generic_suspend_enable_irqs() and
generic_suspend_disable_irqs() static.

Fold them into their only caller.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c3f9ec9950394ef939014f7934268e6ee30ca04f.1630398566.git.christophe.leroy@csgroup.eu
2021-10-22 15:22:05 +11:00
Michael Ellerman
a3314262ee Merge branch 'fixes' into next
Merge our fixes branch into next.

That lets us resolve a conflict in arch/powerpc/sysdev/xive/common.c.

Between cbc06f051c ("powerpc/xive: Do not skip CPU-less nodes when
creating the IPIs"), which moved request_irq() out of xive_init_ipis(),
and 17df41fec5 ("powerpc: use IRQF_NO_DEBUG for IPIs") which added
IRQF_NO_DEBUG to that request_irq() call, which has now moved.
2021-09-03 22:54:12 +10:00
Wan Jiabing
e225c4d6bc powerpc: Remove duplicate includes
interrupt.c: asm/interrupt.h has been included at line 12, so remove the
duplicate one at line 10.

time.c: linux/sched/clock.h has been included at line 33,so remove the
duplicate one at line 56 and move sched/cputime.h under sched including
segament.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210323062916.295346-1-wanjiabing@vivo.com
2021-08-18 09:25:23 +10:00
Christophe Leroy
98694166c2 powerpc/interrupt: Fix OOPS by not calling do_IRQ() from timer_interrupt()
An interrupt handler shall not be called from another interrupt
handler otherwise this leads to problems like the following:

  Kernel attempted to write user page (afd4fa84) - exploit attempt? (uid: 1000)
  ------------[ cut here ]------------
  Bug: Write fault blocked by KUAP!
  WARNING: CPU: 0 PID: 1617 at arch/powerpc/mm/fault.c:230 do_page_fault+0x484/0x720
  Modules linked in:
  CPU: 0 PID: 1617 Comm: sshd Tainted: G        W         5.13.0-pmac-00010-g8393422eb77 #7
  NIP:  c001b77c LR: c001b77c CTR: 00000000
  REGS: cb9e5bc0 TRAP: 0700   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  00021032 <ME,IR,DR,RI>  CR: 24942424  XER: 00000000

  GPR00: c001b77c cb9e5c80 c1582c00 00000021 3ffffbff 085b0000 00000027 c8eb644c
  GPR08: 00000023 00000000 00000000 00000000 24942424 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90
  GPR24: 00000040 afd4fa96 00000040 02000000 c1fda6c0 afd4fa84 00000300 cb9e5cc0
  NIP [c001b77c] do_page_fault+0x484/0x720
  LR [c001b77c] do_page_fault+0x484/0x720
  Call Trace:
  [cb9e5c80] [c001b77c] do_page_fault+0x484/0x720 (unreliable)
  [cb9e5cb0] [c000424c] DataAccess_virt+0xd4/0xe4
  --- interrupt: 300 at __copy_tofrom_user+0x110/0x20c
  NIP:  c001f9b4 LR: c03250a0 CTR: 00000004
  REGS: cb9e5cc0 TRAP: 0300   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  00009032 <EE,ME,IR,DR,RI>  CR: 48028468  XER: 20000000
  DAR: afd4fa84 DSISR: 0a000000
  GPR00: 20726f6f cb9e5d80 c1582c00 00000004 cb9e5e3a 00000016 afd4fa80 00000000
  GPR08: 3835202d 72777872 2d78722d 00000004 28028464 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 c07640c4 cb9e5e98 cb9e5e90
  GPR24: 00000040 afd4fa96 00000040 cb9e5e0c 00000daa a0000000 cb9e5e98 afd4fa56
  NIP [c001f9b4] __copy_tofrom_user+0x110/0x20c
  LR [c03250a0] _copy_to_iter+0x144/0x990
  --- interrupt: 300
  [cb9e5d80] [c03e89c0] n_tty_read+0xa4/0x598 (unreliable)
  [cb9e5df0] [c03e2a0c] tty_read+0xdc/0x2b4
  [cb9e5e80] [c0156bf8] vfs_read+0x274/0x340
  [cb9e5f00] [c01571ac] ksys_read+0x70/0x118
  [cb9e5f30] [c0016048] ret_from_syscall+0x0/0x28
  --- interrupt: c00 at 0xa7855c88
  NIP:  a7855c88 LR: a7855c5c CTR: 00000000
  REGS: cb9e5f40 TRAP: 0c00   Tainted: G        W          (5.13.0-pmac-00010-g8393422eb77)
  MSR:  0000d032 <EE,PR,ME,IR,DR,RI>  CR: 2402446c  XER: 00000000

  GPR00: 00000003 afd4ec70 a72137d0 0000000b afd4ecac 00004000 0065a990 00000800
  GPR08: 00000000 a7947930 00000000 00000004 c15831b0 0063f8c8 00000000 000186a0
  GPR16: afd52dd4 afd52dd0 afd52dcc afd52dc8 0065a990 0065a9e0 00000001 0065fac0
  GPR24: 00000000 00000089 00664050 00000000 00668e30 a720c8dc a7943ff4 0065f9b0
  NIP [a7855c88] 0xa7855c88
  LR [a7855c5c] 0xa7855c5c
  --- interrupt: c00
  Instruction dump:
  3884aa88 38630178 48076861 807f0080 48042e45 2f830000 419e0148 3c80c079
  3c60c076 38841be4 386301c0 4801f705 <0fe00000> 3860000b 4bfffe30 3c80c06b
  ---[ end trace fd69b91a8046c2e5 ]---

Here the problem is that by re-enterring an exception handler,
kuap_save_and_lock() is called a second time with this time KUAP
access locked, leading to regs->kuap being overwritten hence
KUAP not being unlocked at exception exit as expected.

Do not call do_IRQ() from timer_interrupt() directly. Instead,
redefine do_IRQ() as a standard function named __do_IRQ(), and
call it from both do_IRQ() and time_interrupt() handlers.

Fixes: 3a96570ffc ("powerpc: convert interrupt handlers to use wrappers")
Cc: stable@vger.kernel.org # v5.12+
Reported-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c17d234f4927d39a1d7100864a8e1145323d33a0.1628611927.git.christophe.leroy@csgroup.eu
2021-08-12 22:21:57 +10:00
Nicholas Piggin
0cdff98b39 powerpc/64s: Remove irq mask workaround in accumulate_stolen_time()
The caller has been moved to C after irq soft-mask state has been
reconciled, and Linux IRQs have been marked as disabled, so this no
longer needs to play games with IRQ internals.

Fixes: 68b34588e2 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210623022924.704645-1-npiggin@gmail.com
2021-06-25 00:07:09 +10:00
Nicholas Piggin
6ffe2c6e6d KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
irq_work's use of the DEC SPR is racy with guest<->host switch and guest
entry which flips the DEC interrupt to guest, which could lose a host
work interrupt.

This patch closes one race, and attempts to comment another class of
races.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-11-npiggin@gmail.com
2021-06-10 22:12:13 +10:00
Nicholas Piggin
1b1b6a6f4c powerpc: handle irq_enter/irq_exit in interrupt handler wrappers
Move irq_enter/irq_exit into asynchronous interrupt handler wrappers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-35-npiggin@gmail.com
2021-02-09 00:10:49 +11:00
Nicholas Piggin
3a96570ffc powerpc: convert interrupt handlers to use wrappers
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-29-npiggin@gmail.com
2021-02-09 00:02:12 +11:00
Pingfan Liu
b709e32ef5 powerpc/time: Enable sched clock for irqtime
When CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN, powerpc
does not enable "sched_clock_irqtime" and can not utilize irq time
accounting.

Like x86, powerpc does not use the sched_clock_register() interface. So it
needs an dedicated call to enable_sched_clock_irqtime() to enable irq time
accounting.

Fixes: 518470fe96 ("powerpc: Add HAVE_IRQ_TIME_ACCOUNTING")
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
[mpe: Add fixes tag]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1603349479-26185-1-git-send-email-kernelfans@gmail.com
2021-01-31 22:35:49 +11:00
Linus Torvalds
8a5be36b93 powerpc updates for 5.11
- Switch to the generic C VDSO, as well as some cleanups of our VDSO
    setup/handling code.
 
  - Support for KUAP (Kernel User Access Prevention) on systems using the hashed
    page table MMU, using memory protection keys.
 
  - Better handling of PowerVM SMT8 systems where all threads of a core do not
    share an L2, allowing the scheduler to make better scheduling decisions.
 
  - Further improvements to our machine check handling.
 
  - Show registers when unwinding interrupt frames during stack traces.
 
  - Improvements to our pseries (PowerVM) partition migration code.
 
  - Several series from Christophe refactoring and cleaning up various parts of
    the 32-bit code.
 
  - Other smaller features, fixes & cleanups.
 
 Thanks to:
   Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Ard
   Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling, Cédric Le Goater,
   Christophe Leroy, Christophe Lombard, Colin Ian King, Daniel Axtens, David
   Hildenbrand, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geert
   Uytterhoeven, Giuseppe Sacco, Greg Kurz, Harish, Jan Kratochvil, Jordan
   Niethe, Kaixu Xia, Laurent Dufour, Leonardo Bras, Madhavan Srinivasan, Mahesh
   Salgaonkar, Mathieu Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov,
   Oliver O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
   Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej Siewior ,
   Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe Kleine-König,
   Vincent Stehlé, Youling Tang, Zhang Xiaoxu.
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Merge tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Switch to the generic C VDSO, as well as some cleanups of our VDSO
   setup/handling code.

 - Support for KUAP (Kernel User Access Prevention) on systems using the
   hashed page table MMU, using memory protection keys.

 - Better handling of PowerVM SMT8 systems where all threads of a core
   do not share an L2, allowing the scheduler to make better scheduling
   decisions.

 - Further improvements to our machine check handling.

 - Show registers when unwinding interrupt frames during stack traces.

 - Improvements to our pseries (PowerVM) partition migration code.

 - Several series from Christophe refactoring and cleaning up various
   parts of the 32-bit code.

 - Other smaller features, fixes & cleanups.

Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling,
Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King,
Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar,
Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz,
Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour,
Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu
Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver
O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy
Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej
Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe
Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu.

* tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits)
  powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug
  powerpc: Add config fragment for disabling -Werror
  powerpc/configs: Add ppc64le_allnoconfig target
  powerpc/powernv: Rate limit opal-elog read failure message
  powerpc/pseries/memhotplug: Quieten some DLPAR operations
  powerpc/ps3: use dma_mapping_error()
  powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10
  powerpc/perf: Fix Threshold Event Counter Multiplier width for P10
  powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()
  KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp
  KVM: PPC: fix comparison to bool warning
  KVM: PPC: Book3S: Assign boolean values to a bool variable
  powerpc: Inline setup_kup()
  powerpc/64s: Mark the kuap/kuep functions non __init
  KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering
  powerpc/xive: Improve error reporting of OPAL calls
  powerpc/xive: Simplify xive_do_source_eoi()
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW
  powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG
  ...
2020-12-17 13:34:25 -08:00
Nicholas Piggin
59d512e437 powerpc/64: irq replay remove decrementer overflow check
This is way to catch some cases of decrementer overflow, when the
decrementer has underflowed an odd number of times, while MSR[EE] was
disabled.

With a typical small decrementer, a timer that fires when MSR[EE] is
disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and
8.6 seconds after the timer expires. In any case, the decrementer
interrupt would be taken at 8.6 seconds and the timer would be found at
that point.

So this check is for catching extreme latency events, and it prevents
those latencies from being a further few seconds long.  It's not obvious
this is a good tradeoff. This is already a watchdog magnitude event and
that situation is not improved a significantly with this check. For
large decrementers, it's useless.

Therefore remove this check, which avoids a mftb when enabling hard
disabled interrupts (e.g., when enabling after coming from hardware
interrupt handlers). Perhaps more importantly, it also removes the
clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay
which simplifies the code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
2020-12-09 23:48:15 +11:00
Christophe Leroy
ab037dd87a powerpc/vdso: Switch VDSO to generic C implementation.
With the C VDSO, the performance is slightly lower, but it is worth
it as it will ease maintenance and evolution, and also brings clocks
that are not supported with the ASM VDSO.

On an 8xx at 132 MHz, vdsotest with the ASM VDSO:
  gettimeofday:    		  vdso:  828 nsec/call
  clock-getres-realtime-coarse:   vdso:  391 nsec/call
  clock-gettime-realtime-coarse:  vdso:  614 nsec/call
  clock-getres-realtime:    	  vdso:  460 nsec/call
  clock-gettime-realtime:    	  vdso:  876 nsec/call
  clock-getres-monotonic-coarse:  vdso:  399 nsec/call
  clock-gettime-monotonic-coarse: vdso:  691 nsec/call
  clock-getres-monotonic:    	  vdso:  460 nsec/call
  clock-gettime-monotonic:    	  vdso: 1026 nsec/call

On an 8xx at 132 MHz, vdsotest with the C VDSO:
  gettimeofday:    		  vdso:  955 nsec/call
  clock-getres-realtime-coarse:   vdso:  545 nsec/call
  clock-gettime-realtime-coarse:  vdso:  592 nsec/call
  clock-getres-realtime:          vdso:  545 nsec/call
  clock-gettime-realtime:    	  vdso:  941 nsec/call
  clock-getres-monotonic-coarse:  vdso:  545 nsec/call
  clock-gettime-monotonic-coarse: vdso:  591 nsec/call
  clock-getres-monotonic:         vdso:  545 nsec/call
  clock-gettime-monotonic:        vdso:  940 nsec/call

It is even better for gettime with monotonic clocks.

Unsupported clocks with ASM VDSO:
  clock-gettime-boottime:         vdso: 3851 nsec/call
  clock-gettime-tai:      	  vdso: 3852 nsec/call
  clock-gettime-monotonic-raw:    vdso: 3396 nsec/call

Same clocks with C VDSO:
  clock-gettime-tai:              vdso:  941 nsec/call
  clock-gettime-monotonic-raw:    vdso: 1001 nsec/call
  clock-gettime-monotonic-coarse: vdso:  591 nsec/call

On an 8321E at 333 MHz, vdsotest with the ASM VDSO:
  gettimeofday:     		  vdso: 220 nsec/call
  clock-getres-realtime-coarse:   vdso: 102 nsec/call
  clock-gettime-realtime-coarse:  vdso: 178 nsec/call
  clock-getres-realtime:          vdso: 129 nsec/call
  clock-gettime-realtime:    	  vdso: 235 nsec/call
  clock-getres-monotonic-coarse:  vdso: 105 nsec/call
  clock-gettime-monotonic-coarse: vdso: 208 nsec/call
  clock-getres-monotonic:         vdso: 129 nsec/call
  clock-gettime-monotonic:        vdso: 274 nsec/call

On an 8321E at 333 MHz, vdsotest with the C VDSO:
  gettimeofday:    		  vdso: 272 nsec/call
  clock-getres-realtime-coarse:   vdso: 160 nsec/call
  clock-gettime-realtime-coarse:  vdso: 184 nsec/call
  clock-getres-realtime:          vdso: 166 nsec/call
  clock-gettime-realtime:         vdso: 281 nsec/call
  clock-getres-monotonic-coarse:  vdso: 160 nsec/call
  clock-gettime-monotonic-coarse: vdso: 184 nsec/call
  clock-getres-monotonic:         vdso: 169 nsec/call
  clock-gettime-monotonic:        vdso: 275 nsec/call

On a Power9 Nimbus DD2.2 at 3.8GHz, with the ASM VDSO:
  clock-gettime-monotonic:    	  vdso:  35 nsec/call
  clock-getres-monotonic:    	  vdso:  16 nsec/call
  clock-gettime-monotonic-coarse: vdso:  18 nsec/call
  clock-getres-monotonic-coarse:  vdso: 522 nsec/call
  clock-gettime-monotonic-raw:    vdso: 598 nsec/call
  clock-getres-monotonic-raw:     vdso: 520 nsec/call
  clock-gettime-realtime:    	  vdso:  34 nsec/call
  clock-getres-realtime:    	  vdso:  16 nsec/call
  clock-gettime-realtime-coarse:  vdso:  18 nsec/call
  clock-getres-realtime-coarse:   vdso: 517 nsec/call
  getcpu:    			  vdso:   8 nsec/call
  gettimeofday:    		  vdso:  25 nsec/call

And with the C VDSO:
  clock-gettime-monotonic:    	  vdso:  37 nsec/call
  clock-getres-monotonic:    	  vdso:  20 nsec/call
  clock-gettime-monotonic-coarse: vdso:  21 nsec/call
  clock-getres-monotonic-coarse:  vdso:  19 nsec/call
  clock-gettime-monotonic-raw:    vdso:  38 nsec/call
  clock-getres-monotonic-raw:     vdso:  20 nsec/call
  clock-gettime-realtime:    	  vdso:  37 nsec/call
  clock-getres-realtime:    	  vdso:  20 nsec/call
  clock-gettime-realtime-coarse:  vdso:  20 nsec/call
  clock-getres-realtime-coarse:   vdso:  19 nsec/call
  getcpu:    			  vdso:   8 nsec/call
  gettimeofday:    		  vdso:  28 nsec/call

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126131006.2431205-8-mpe@ellerman.id.au
2020-12-04 01:01:10 +11:00
Frederic Weisbecker
8a6a5920d3 sched/vtime: Consolidate IRQ time accounting
The 3 architectures implementing CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
all have their own version of irq time accounting that dispatch the
cputime to the appropriate index: hardirq, softirq, system, idle,
guest... from an all-in-one function.

Instead of having these ad-hoc versions, move the cputime destination
dispatch decision to the core code and leave only the actual per-index
cputime accounting to the architecture.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201202115732.27827-4-frederic@kernel.org
2020-12-02 20:20:05 +01:00
Christophe Leroy
942e89115b powerpc/time: Avoid using get_tbl() and get_tbu() internally
get_tbl() is confusing as it returns the content of TBL register
on PPC32 but the concatenation of TBL and TBU on PPC64.

Use mftb() instead.

Do the same with get_tbu() for consistency allthough it's name
is less confusing.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/41573406a4eab98838decaa91649086fef1e6119.1601556145.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:15 +11:00
Christophe Leroy
6601ec1c2b powerpc: Remove get_tb_or_rtc()
601 is gone, get_tb_or_rtc() is equivalent to get_tb().

Replace the former by the later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3e8a13ee83418630c753c30cb722ae682d5b2d39.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Christophe Leroy
a4c5a35542 powerpc: Remove __USE_RTC()
Now that PowerPC 601 is gone, __USE_RTC() is never true.

Remove it.

That also leads to removing get_rtc() and get_rtcl()

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4757e1ed21fe1968c761ae081d1f3d790a9673f8.1601362098.git.christophe.leroy@csgroup.eu
2020-10-08 21:17:14 +11:00
Peter Zijlstra
d6bdceb6c2 powerpc64: Break asm/percpu.h vs spinlock_types.h dependency
In order to use <asm/percpu.h> in lockdep.h, we need to make sure
asm/percpu.h does not itself depend on lockdep.

The below seems to make that so and builds powerpc64-defconfig +
PROVE_LOCKING.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
https://lkml.kernel.org/r/20200623083721.336906073@infradead.org
2020-07-10 12:00:01 +02:00
Nicholas Piggin
abc3fce76a Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled"
This reverts commit ebb37cf3ff.

That commit does not play well with soft-masked irq state
manipulations in idle, interrupt replay, and possibly others due to
tracing code sometimes using irq_work_queue (e.g., in
trace_hardirqs_on()). That can cause PACA_IRQ_DEC to become set when
it is not expected, and be ignored or cleared or cause warnings.

The net result seems to be missing an irq_work until the next timer
interrupt in the worst case which is usually not going to be noticed,
however it could be a long time if the tick is disabled, which is
against the spirit of irq_work and might cause real problems.

The idea is still solid, but it would need more work. It's not really
clear if it would be worth added complexity, so revert this for
now (not a straight revert, but replace with a comment explaining why
we might see interrupts happening, and gives git blame something to
find).

Fixes: ebb37cf3ff ("powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402120401.1115883-1-npiggin@gmail.com
2020-04-03 16:55:34 +11:00
Geert Uytterhoeven
60083063b7 powerpc/time: Replace <linux/clk-provider.h> by <linux/of_clk.h>
The PowerPC time code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.

Remove the #ifdef protecting the of_clk_init() call, as a stub is
available for the !CONFIG_COMMON_CLK case.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200213083804.24315-1-geert+renesas@glider.be
2020-04-03 16:17:22 +11:00
Nicholas Piggin
2babd6ea43 powerpc/64s/exception: Avoid touching the stack in hdecrementer
The hdec interrupt handler is reported to sometimes fire in Linux if
KVM leaves it pending after a guest exists. This is harmless, so there
is a no-op handler for it.

The interrupt handler currently uses the regular kernel stack. Change
this to avoid touching the stack entirely.

This should be the last place where the regular Linux stack can be
accessed with asynchronous interrupts (including PMI) soft-masked.
It might be possible to take advantage of this invariant, e.g., to
context switch the kernel stack SLB entry without clearing MSR[EE].

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-17-npiggin@gmail.com
2020-04-01 13:42:12 +11:00
Vincenzo Frascino
5522634562 powerpc: Fix vDSO clock_getres()
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:
    sec = 0;
    ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.

Fix the powerpc vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Fixes: a7f290dad3 ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Cc: stable@vger.kernel.org
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
[chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr
2019-12-05 00:13:55 +11:00
Linus Torvalds
ceb3074745 y2038: syscall implementation cleanups
This is a series of cleanups for the y2038 work, mostly intended
 for namespace cleaning: the kernel defines the traditional
 time_t, timeval and timespec types that often lead to y2038-unsafe
 code. Even though the unsafe usage is mostly gone from the kernel,
 having the types and associated functions around means that we
 can still grow new users, and that we may be missing conversions
 to safe types that actually matter.
 
 There are still a number of driver specific patches needed to
 get the last users of these types removed, those have been
 submitted to the respective maintainers.
 
 Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 cleanups from Arnd Bergmann:
 "y2038 syscall implementation cleanups

  This is a series of cleanups for the y2038 work, mostly intended for
  namespace cleaning: the kernel defines the traditional time_t, timeval
  and timespec types that often lead to y2038-unsafe code. Even though
  the unsafe usage is mostly gone from the kernel, having the types and
  associated functions around means that we can still grow new users,
  and that we may be missing conversions to safe types that actually
  matter.

  There are still a number of driver specific patches needed to get the
  last users of these types removed, those have been submitted to the
  respective maintainers"

Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/

* tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits)
  y2038: alarm: fix half-second cut-off
  y2038: ipc: fix x32 ABI breakage
  y2038: fix typo in powerpc vdso "LOPART"
  y2038: allow disabling time32 system calls
  y2038: itimer: change implementation to timespec64
  y2038: move itimer reset into itimer.c
  y2038: use compat_{get,set}_itimer on alpha
  y2038: itimer: compat handling to itimer.c
  y2038: time: avoid timespec usage in settimeofday()
  y2038: timerfd: Use timespec64 internally
  y2038: elfcore: Use __kernel_old_timeval for process times
  y2038: make ns_to_compat_timeval use __kernel_old_timeval
  y2038: socket: use __kernel_old_timespec instead of timespec
  y2038: socket: remove timespec reference in timestamping
  y2038: syscalls: change remaining timeval to __kernel_old_timeval
  y2038: rusage: use __kernel_old_timeval
  y2038: uapi: change __kernel_time_t to __kernel_old_time_t
  y2038: stat: avoid 'time_t' in 'struct stat'
  y2038: ipc: remove __kernel_time_t reference from headers
  y2038: vdso: powerpc: avoid timespec references
  ...
2019-12-01 14:00:59 -08:00
Linus Torvalds
7794b1d418 powerpc updates for 5.5
Highlights:
 
  - Infrastructure for secure boot on some bare metal Power9 machines. The
    firmware support is still in development, so the code here won't actually
    activate secure boot on any existing systems.
 
  - A change to xmon (our crash handler / pseudo-debugger) to restrict it to
    read-only mode when the kernel is lockdown'ed, otherwise it's trivial to drop
    into xmon and modify kernel data, such as the lockdown state.
 
  - Support for KASLR on 32-bit BookE machines (Freescale / NXP).
 
  - Fixes for our flush_icache_range() and __kernel_sync_dicache() (VDSO) to work
    with memory ranges >4GB.
 
  - Some reworks of the pseries CMM (Cooperative Memory Management) driver to
    make it behave more like other balloon drivers and enable some cleanups of
    generic mm code.
 
  - A series of fixes to our hardware breakpoint support to properly handle
    unaligned watchpoint addresses.
 
 Plus a bunch of other smaller improvements, fixes and cleanups.
 
 Thanks to:
   Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V, Anthony Steinhauser,
   Cédric Le Goater, Chris Packham, Chris Smart, Christophe Leroy, Christopher M.
   Riedl, Christoph Hellwig, Claudio Carvalho, Daniel Axtens, David Hildenbrand,
   Deb McLemore, Diana Craciun, Eric Richter, Geert Uytterhoeven, Greg
   Kroah-Hartman, Greg Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason
   Yan, Krzysztof Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M.
   Rodrigues, Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna
   Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes, Ravi
   Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth, Tyrel
   Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing.
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Merge tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:

   - Infrastructure for secure boot on some bare metal Power9 machines.
     The firmware support is still in development, so the code here
     won't actually activate secure boot on any existing systems.

   - A change to xmon (our crash handler / pseudo-debugger) to restrict
     it to read-only mode when the kernel is lockdown'ed, otherwise it's
     trivial to drop into xmon and modify kernel data, such as the
     lockdown state.

   - Support for KASLR on 32-bit BookE machines (Freescale / NXP).

   - Fixes for our flush_icache_range() and __kernel_sync_dicache()
     (VDSO) to work with memory ranges >4GB.

   - Some reworks of the pseries CMM (Cooperative Memory Management)
     driver to make it behave more like other balloon drivers and enable
     some cleanups of generic mm code.

   - A series of fixes to our hardware breakpoint support to properly
     handle unaligned watchpoint addresses.

  Plus a bunch of other smaller improvements, fixes and cleanups.

  Thanks to: Alastair D'Silva, Andrew Donnellan, Aneesh Kumar K.V,
  Anthony Steinhauser, Cédric Le Goater, Chris Packham, Chris Smart,
  Christophe Leroy, Christopher M. Riedl, Christoph Hellwig, Claudio
  Carvalho, Daniel Axtens, David Hildenbrand, Deb McLemore, Diana
  Craciun, Eric Richter, Geert Uytterhoeven, Greg Kroah-Hartman, Greg
  Kurz, Gustavo L. F. Walbon, Hari Bathini, Harish, Jason Yan, Krzysztof
  Kozlowski, Leonardo Bras, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michal Suchanek, Mimi Zohar, Nathan Chancellor, Nathan Lynch, Nayna
  Jain, Nick Desaulniers, Oliver O'Halloran, Qian Cai, Rasmus Villemoes,
  Ravi Bangoria, Sam Bobroff, Santosh Sivaraj, Scott Wood, Thomas Huth,
  Tyrel Datwyler, Vaibhav Jain, Valentin Longchamp, YueHaibing"

* tag 'powerpc-5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (144 commits)
  powerpc/fixmap: fix crash with HIGHMEM
  x86/efi: remove unused variables
  powerpc: Define arch_is_kernel_initmem_freed() for lockdep
  powerpc/prom_init: Use -ffreestanding to avoid a reference to bcmp
  powerpc: Avoid clang warnings around setjmp and longjmp
  powerpc: Don't add -mabi= flags when building with Clang
  powerpc: Fix Kconfig indentation
  powerpc/fixmap: don't clear fixmap area in paging_init()
  selftests/powerpc: spectre_v2 test must be built 64-bit
  powerpc/powernv: Disable native PCIe port management
  powerpc/kexec: Move kexec files into a dedicated subdir.
  powerpc/32: Split kexec low level code out of misc_32.S
  powerpc/sysdev: drop simple gpio
  powerpc/83xx: map IMMR with a BAT.
  powerpc/32s: automatically allocate BAT in setbat()
  powerpc/ioremap: warn on early use of ioremap()
  powerpc: Add support for GENERIC_EARLY_IOREMAP
  powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()
  powerpc/8xx: use the fixmapped IMMR in cpm_reset()
  powerpc/8xx: add __init to cpm1 init functions
  ...
2019-11-30 14:35:43 -08:00
Arnd Bergmann
176ed98c8a y2038: vdso: powerpc: avoid timespec references
As a preparation to stop using 'struct timespec' in the kernel,
change the powerpc vdso implementation:

- split up the vdso data definition to have equivalent members
   for seconds and nanoseconds instead of an xtime structure

- use timespec64 as an intermediate for the xtime update

- change the asm-offsets definition to be based the appropriate
  fixed-length types

This is only a temporary fix for changing the types, in order
to actually support a 64-bit safe vdso32 version of clock_gettime(),
the entire powerpc vdso should be replaced with the generic
lib/vdso/ implementation. If that happens first, this patch
becomes obsolete.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-11-15 14:38:28 +01:00
Michael Ellerman
eb8e20f890 powerpc/pseries: Mark accumulate_stolen_time() as notrace
accumulate_stolen_time() is called prior to interrupt state being
reconciled, which can trip the warning in arch_local_irq_restore():

  WARNING: CPU: 5 PID: 1017 at arch/powerpc/kernel/irq.c:258 .arch_local_irq_restore+0x9c/0x130
  ...
  NIP .arch_local_irq_restore+0x9c/0x130
  LR  .rb_start_commit+0x38/0x80
  Call Trace:
    .ring_buffer_lock_reserve+0xe4/0x620
    .trace_function+0x44/0x210
    .function_trace_call+0x148/0x170
    .ftrace_ops_no_ops+0x180/0x1d0
    ftrace_call+0x4/0x8
    .accumulate_stolen_time+0x1c/0xb0
    decrementer_common+0x124/0x160

For now just mark it as notrace. We may change the ordering to call it
after interrupt state has been reconciled, but that is a larger
change.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024055932.27940-1-mpe@ellerman.id.au
2019-10-28 21:54:16 +11:00
Frederic Weisbecker
f83eeb1a01 sched/cputime: Rename vtime_account_system() to vtime_account_kernel()
vtime_account_system() decides if we need to account the time to the
system (__vtime_account_system()) or to the guest (vtime_account_guest()).

So this function is a misnomer as we are on a higher level than
"system". All we know when we call that function is that we are
accounting kernel cputime. Whether it belongs to guest or system time
is a lower level detail.

Rename this function to vtime_account_kernel(). This will clarify things
and avoid too many underscored vtime_account_system() versions.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Link: https://lkml.kernel.org/r/20191003161745.28464-2-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09 12:39:25 +02:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Mahesh Salgaonkar
de269129a4 powerpc/hmi: Fix kernel hang when TB is in error state.
On TOD/TB errors timebase register stops/freezes until HMI error recovery
gets TOD/TB back into running state. On successful recovery, TB starts
running again and udelay() that relies on TB value continues to function
properly. But in case when HMI fails to recover from TOD/TB errors, the
TB register stay freezed. With TB not running the __delay() function
keeps looping and never return. If __delay() is called while in panic
path then system hangs and never reboots after panic.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:54:57 +10:00
Jagadeesh Pagadala
6917735e8f powerpc: Remove duplicate headers
Remove duplicate headers inclusions.

Signed-off-by: Jagadeesh Pagadala <jagdsh.linux@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-20 22:02:44 +10:00
Brajeswar Ghosh
75f8a37580 powerpc/kernel/time: Remove duplicate header
Remove linux/rtc.h which is included more than once

Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-30 23:42:31 +11:00
Christophe Leroy
51eeef9e13 powerpc/time: no steal_time when CONFIG_PPC_SPLPAR is not selected
If CONFIG_PPC_SPLPAR is not selected, steal_time will always
be NUL, so accounting it is pointless

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-20 13:26:47 +11:00
Christophe Leroy
abcff86df2 powerpc/time: Only set CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC64
scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

Removing it on PPC32 significantly reduces the size of
vtime_account_system() and vtime_account_idle() on an 8xx:

Before:
00000000 l     F .text	000000a8 vtime_delta
00000280 g     F .text	0000010c vtime_account_system
0000038c g     F .text	00000048 vtime_account_idle

After:
(vtime_delta gets inlined inside the two functions)
000001d8 g     F .text	000000a0 vtime_account_system
00000278 g     F .text	00000038 vtime_account_idle

In terms of performance, we also get approximatly 7% improvement on
task switch. The following small benchmark app is run with perf stat:

void *thread(void *arg)
{
	int i;

	for (i = 0; i < atoi((char*)arg); i++)
		pthread_yield();
}

int main(int argc, char **argv)
{
	pthread_t th1, th2;

	pthread_create(&th1, NULL, thread, argv[1]);
	pthread_create(&th2, NULL, thread, argv[1]);
	pthread_join(th1, NULL);
	pthread_join(th2, NULL);

	return 0;
}

Before the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       8228.476465      task-clock (msec)         #    0.954 CPUs utilized            ( +-  0.23% )
            200004      context-switches          #    0.024 M/sec                    ( +-  0.00% )

After the patch:

 Performance counter stats for 'chrt -f 98 ./sched 100000' (50 runs):

       7649.070444      task-clock (msec)         #    0.955 CPUs utilized            ( +-  0.27% )
            200004      context-switches          #    0.026 M/sec                    ( +-  0.00% )

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-20 13:26:47 +11:00
Christophe Leroy
b38a181c11 powerpc/time: isolate scaled cputime accounting in dedicated functions.
scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

In preparation of the following patch that will remove
CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves
all scaled cputing accounting logic into dedicated functions.

This patch doesn't change any functionality. It's only code
reorganisation.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-20 13:26:47 +11:00
Michael Ellerman
b4d16ab58c powerpc/time: Fix clockevent_decrementer initalisation for PR KVM
In the recent commit 8b78fdb045 ("powerpc/time: Use
clockevents_register_device(), fixing an issue with large
decrementer") we changed the way we initialise the decrementer
clockevent(s).

We no longer initialise the mult & shift values of
decrementer_clockevent itself.

This has the effect of breaking PR KVM, because it uses those values
in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
mid-way through boot.

For now fix it by assigning back to decrementer_clockevent the mult
and shift values.

Fixes: 8b78fdb045 ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-19 15:09:04 +11:00
Anton Blanchard
817593604e powerpc/time: Add set_state_oneshot_stopped decrementer callback
If CONFIG_PPC_WATCHDOG is enabled we always cap the decrementer to
0x7fffffff:

       if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
                set_dec(0x7fffffff);
        else
                set_dec(decrementer_max);

If there are no future events, we don't reprogram the decrementer
after this and we end up with 0x7fffffff even on a large decrementer
capable system.

As suggested by Nick, add a set_state_oneshot_stopped callback
so we program the decrementer with decrementer_max if there are
no future events.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-04 23:00:31 +10:00
Anton Blanchard
8b78fdb045 powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer
We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.

Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-04 23:00:30 +10:00
Christophe Leroy
60f1d2893e powerpc/time: inline arch_vtime_task_switch()
arch_vtime_task_switch() is a small function which is called
only from vtime_common_task_switch(), so it is worth inlining

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-04 00:39:20 +10:00
Arnd Bergmann
34efabe418 powerpc: remove unused to_tm() helper
to_tm() is now completely unused, the only reference being in the
_dump_time() helper that is also unused. This removes both, leaving
the rest of the powerpc RTC code y2038 safe to as far as the hardware
supports.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:43:34 +10:00
Arnd Bergmann
5235afa89a powerpc: use time64_t in update_persistent_clock
update_persistent_clock() is deprecated because it suffers from overflow
in 2038 on 32-bit architectures. This changes powerpc to use the
update_persistent_clock64() replacement, and to pass down 64-bit
timestamps consistently.

This is now simpler, as we no longer have to worry about the offset
numbers in tm_year and tm_mon that are different between the Linux
conventions and RTAS.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:43:34 +10:00
Arnd Bergmann
5bfd643583 powerpc: use time64_t in read_persistent_clock
Looking through the remaining users of the deprecated mktime()
function, I found the powerpc rtc handlers, which use it in
place of rtc_tm_to_time64().

To clean this up, I'm changing over the read_persistent_clock()
function to the read_persistent_clock64() variant, and change
all the platform specific handlers along with it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:43:33 +10:00
Nicholas Piggin
e360cd37f0 powerpc/time: account broadcast timer event interrupts separately
These are not local timer interrupts but IPIs. It's good to be able
to see how timer offloading is behaving, so split these out into
their own category.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:29 +10:00
Nicholas Piggin
bc90711331 powerpc: move timer broadcast code under GENERIC_CLOCKEVENTS_BROADCAST ifdef
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:28 +10:00
Nicholas Piggin
a7cba02dec powerpc: allow soft-NMI watchdog to cover timer interrupts with large decrementers
Large decrementers (e.g., POWER9) can take a very long time to wrap,
so when the timer iterrupt handler sets the decrementer to max so as
to avoid taking another decrementer interrupt when hard enabling
interrupts before running timers, it effectively disables the soft
NMI coverage for timer interrupts.

Fix this by using the traditional 31-bit value instead, which wraps
after a few seconds. masked interrupt code does the same thing, and
in normal operation neither of these paths would ever wrap even the
31 bit value.

Note: the SMP watchdog should catch timer interrupt lockups, but it
is preferable for the local soft-NMI to catch them, mainly to avoid
the IPI.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:28 +10:00
Nicholas Piggin
3f984620f9 powerpc: generic clockevents broadcast receiver call tick_receive_broadcast
The broadcast tick recipient can call tick_receive_broadcast rather
than re-running the full timer interrupt.

It does not have to check for the next event time, because the sender
already determined the timer has expired. It does not have to test
irq_work_pending, because that's a direct decrementer interrupt and
does not go through the clock events subsystem. And it does not have
to read PURR because that was removed with the previous patch.

This results in no code size change, but both the decrementer and
broadcast path lengths are reduced.

Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:27 +10:00
Nicholas Piggin
3d3a6021dd powerpc/pseries: lparcfg calculate PURR on demand
For SPLPAR, lparcfg provides a sum of PURR registers for all CPUs.
Currently this is done by reading PURR in context switch and timer
interrupt, and storing that into a per-CPU variable. These are summed
to provide the value.

This does not work with all timer schemes (e.g., NO_HZ_FULL), and it
is sub-optimal for performance because it reads the PURR register on
every context switch, although that's been difficult to distinguish
from noise in the contxt_switch microbenchmark.

This patch implements the sum by calling a function on each CPU, to
read and add PURR values of each CPU.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:27 +10:00
Nicholas Piggin
ebb37cf3ff powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled
irq_work_raise should not cause a decrementer exception unless it is
called from NMI context. Doing so often just results in an immediate
masked decrementer interrupt:

   <...>-550    90d...    4us : update_curr_rt <-dequeue_task_rt
   <...>-550    90d...    5us : dbs_update_util_handler <-update_curr_rt
   <...>-550    90d...    6us : arch_irq_work_raise <-irq_work_queue
   <...>-550    90d...    7us : soft_nmi_interrupt <-soft_nmi_common
   <...>-550    90d...    7us : printk_nmi_enter <-soft_nmi_interrupt
   <...>-550    90d.Z.    8us : rcu_nmi_enter <-soft_nmi_interrupt
   <...>-550    90d.Z.    9us : rcu_nmi_exit <-soft_nmi_interrupt
   <...>-550    90d...    9us : printk_nmi_exit <-soft_nmi_interrupt
   <...>-550    90d...   10us : cpuacct_charge <-update_curr_rt

The soft_nmi_interrupt here is the call into the watchdog, due to the
decrementer interrupt firing with irqs soft-disabled. This is
harmless, but sub-optimal.

When it's not called from NMI context or with interrupts enabled, mark
the decrementer pending in the irq_happened mask directly, rather than
having the masked decrementer interupt handler do it. This will be
replayed at the next local_irq_enable. See the comment for details.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03 20:40:25 +10:00
Aneesh Kumar K.V
a6201da34f powerpc: Fix oops due to bad access of lppaca on bare metal
Commit 8e0b634b13 ("powerpc/64s: Do not allocate lppaca if we are
not virtualized") removed allocation of lppaca on bare metal
platforms. But with CONFIG_PPC_SPLPAR enabled, we still access the
lppaca on bare metal in some code paths.

Fix this but adding runtime checks for SPLPAR (shared processor LPAR).

Fixes: 8e0b634b13 ("powerpc/64s: Do not allocate lppaca if we are not virtualized")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-03 21:50:07 +10:00
Alexandre Belloni
890ae79797 powerpc/time: stop validating rtc_time in .read_time
The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-14 22:27:33 +11:00
Madhavan Srinivasan
4e26bc4a4e powerpc/64: Rename soft_enabled to irq_soft_mask
Rename the paca->soft_enabled to paca->irq_soft_mask as it is no
longer used as a flag for interrupt state, but a mask.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:37:01 +11:00
Madhavan Srinivasan
e0b5687bed powerpc/64: Implement and use soft_enabled_return API
Add a new wrapper function, soft_enabled_return(), added to return
paca->soft_enabled value.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-01-19 22:36:59 +11:00