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  1. 03 6月, 2018 7 次提交
  3. 03 4月, 2018 1 次提交
  5. 14 3月, 2018 1 次提交
  7. 19 1月, 2018 4 次提交
  9. 02 7月, 2017 1 次提交
  11. 22 6月, 2017 1 次提交
    • P
      powerpc: Convert VDSO update function to use new update_vsyscall interface · d4cfb113
      由 Paul Mackerras 提交于 
      This converts the powerpc VDSO time update function to use the new
interface introduced in commit 576094b7 ("time: Introduce new
GENERIC_TIME_VSYSCALL", 2012-09-11).  Where the old interface gave
us the time as of the last update in seconds and whole nanoseconds,
with the new interface we get the nanoseconds part effectively in
a binary fixed-point format with tk->tkr_mono.shift bits to the
right of the binary point.

With the old interface, the fractional nanoseconds got truncated,
meaning that the value returned by the VDSO clock_gettime function
would have about 1ns of jitter in it compared to the value computed
by the generic timekeeping code in the kernel.

The powerpc VDSO time functions (clock_gettime and gettimeofday)
already work in units of 2^-32 seconds, or 0.23283 ns, because that
makes it simple to split the result into seconds and fractional
seconds, and represent the fractional seconds in either microseconds
or nanoseconds.  This is good enough accuracy for now, so this patch
avoids changing how the VDSO works or the interface in the VDSO data
page.

This patch converts the powerpc update_vsyscall_old to be called
update_vsyscall and use the new interface.  We convert the fractional
second to units of 2^-32 seconds without truncating to whole nanoseconds.
(There is still a conversion to whole nanoseconds for any legacy users
of the vdso_data/systemcfg stamp_xtime field.)

In addition, this improves the accuracy of the computation of tb_to_xs
for those systems with high-frequency timebase clocks (>= 268.5 MHz)
by doing the right shift in two parts, one before the multiplication and
one after, rather than doing the right shift before the multiplication.
(We can't do all of the right shift after the multiplication unless we
use 128-bit arithmetic.)
Signed-off-by: NPaul Mackerras <paulus@ozlabs.org>
Acked-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      d4cfb113
  13. 21 6月, 2017 1 次提交
  15. 30 5月, 2017 1 次提交
  17. 15 4月, 2017 1 次提交
    • N
      powerpc/time: Set ->min_delta_ticks and ->max_delta_ticks · 115631c3
      由 Nicolai Stange 提交于 
      In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.

Make the powerpc arch's clockevent driver initialize these fields properly.

This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: NNicolai Stange <nicstange@gmail.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      115631c3
  19. 02 3月, 2017 2 次提交
  21. 23 2月, 2017 1 次提交
  23. 01 2月, 2017 6 次提交
  25. 14 1月, 2017 5 次提交
  27. 25 12月, 2016 2 次提交
  29. 15 11月, 2016 2 次提交
  31. 13 9月, 2016 1 次提交
  33. 08 8月, 2016 1 次提交
  35. 09 7月, 2016 1 次提交
  37. 05 7月, 2016 1 次提交
    • O
      powerpc/timer: Large Decrementer support · 79901024
      由 Oliver O'Halloran 提交于 
      Power ISAv3 adds a large decrementer (LD) mode which increases the size
of the decrementer register. The size of the enlarged decrementer
register is between 32 and 64 bits with the exact size being dependent
on the implementation. When in LD mode, reads are sign extended to 64
bits and a decrementer exception is raised when the high bit is set (i.e
the value goes below zero). Writes however are truncated to the physical
register width so some care needs to be taken to ensure that the high
bit is not set when reloading the decrementer. This patch adds support
for using the LD inside the host kernel on processors that support it.

When LD mode is supported firmware will supply the ibm,dec-bits property
for CPU nodes to allow the kernel to determine the maximum decrementer
value. Enabling LD mode is a hypervisor privileged operation so the kernel
can only enable it manually when running in hypervisor mode. Guests that
support LD mode can request it using the "ibm,client-architecture-support"
firmware call (not implemented in this patch) or some other platform
specific method. If this property is not supplied then the traditional
decrementer width of 32 bit is assumed and LD mode will not be enabled.

This patch was based on initial work by Jack Miller.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NBalbir Singh <bsingharora@gmail.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      79901024