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  1. 29 7月, 2010 2 次提交
    • P
      powerpc: Clean up obsolete code relating to decrementer and timebase · d75d68cf
      由 Paul Mackerras 提交于 
      Since the decrementer and timekeeping code was moved over to using
the generic clockevents and timekeeping infrastructure, several
variables and functions have been obsolete and effectively unused.
This deletes them.

In particular, wakeup_decrementer() is no longer needed since the
generic code reprograms the decrementer as part of the process of
resuming the timekeeping code, which happens during sysdev resume.
Thus the wakeup_decrementer calls in the suspend_enter methods for
52xx platforms have been removed.  The call in the powermac cpu
frequency change code has been replaced by set_dec(1), which will
cause a timer interrupt as soon as interrupts are enabled, and the
generic code will then reprogram the decrementer with the correct
value.

This also simplifies the generic_suspend_en/disable_irqs functions
and makes them static since they are not referenced outside time.c.
The preempt_enable/disable calls are removed because the generic
code has disabled all but the boot cpu at the point where these
functions are called, so we can't be moved to another cpu.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      d75d68cf
    • P
      powerpc: Rework VDSO gettimeofday to prevent time going backwards · 0e469db8
      由 Paul Mackerras 提交于 
      Currently it is possible for userspace to see the result of
gettimeofday() going backwards by 1 microsecond, assuming that
userspace is using the gettimeofday() in the VDSO.  The VDSO
gettimeofday() algorithm computes the time in "xsecs", which are
units of 2^-20 seconds, or approximately 0.954 microseconds,
using the algorithm

	now = (timebase - tb_orig_stamp) * tb_to_xs + stamp_xsec

and then converts the time in xsecs to seconds and microseconds.

The kernel updates the tb_orig_stamp and stamp_xsec values every
tick in update_vsyscall().  If the length of the tick is not an
integer number of xsecs, then some precision is lost in converting
the current time to xsecs.  For example, with CONFIG_HZ=1000, the
tick is 1ms long, which is 1048.576 xsecs.  That means that
stamp_xsec will advance by either 1048 or 1049 on each tick.
With the right conditions, it is possible for userspace to get
(timebase - tb_orig_stamp) * tb_to_xs being 1049 if the kernel is
slightly late in updating the vdso_datapage, and then for stamp_xsec
to advance by 1048 when the kernel does update it, and for userspace
to then see (timebase - tb_orig_stamp) * tb_to_xs being zero due to
integer truncation.  The result is that time appears to go backwards
by 1 microsecond.

To fix this we change the VDSO gettimeofday to use a new field in the
VDSO datapage which stores the nanoseconds part of the time as a
fractional number of seconds in a 0.32 binary fraction format.
(Or put another way, as a 32-bit number in units of 0.23283 ns.)
This is convenient because we can use the mulhwu instruction to
convert it to either microseconds or nanoseconds.

Since it turns out that computing the time of day using this new field
is simpler than either using stamp_xsec (as gettimeofday does) or
stamp_xtime.tv_nsec (as clock_gettime does), this converts both
gettimeofday and clock_gettime to use the new field.  The existing
__do_get_tspec function is converted to use the new field and take
a parameter in r7 that indicates the desired resolution, 1,000,000
for microseconds or 1,000,000,000 for nanoseconds.  The __do_get_xsec
function is then unused and is deleted.

The new algorithm is

	now = ((timebase - tb_orig_stamp) << 12) * tb_to_xs
		+ (stamp_xtime_seconds << 32) + stamp_sec_fraction

with 'now' in units of 2^-32 seconds.  That is then converted to
seconds and either microseconds or nanoseconds with

	seconds = now >> 32
	partseconds = ((now & 0xffffffff) * resolution) >> 32

The 32-bit VDSO code also makes a further simplification: it ignores
the bottom 32 bits of the tb_to_xs value, which is a 0.64 format binary
fraction.  Doing so gets rid of 4 multiply instructions.  Assuming
a timebase frequency of 1GHz or less and an update interval of no
more than 10ms, the upper 32 bits of tb_to_xs will be at least
4503599, so the error from ignoring the low 32 bits will be at most
2.2ns, which is more than an order of magnitude less than the time
taken to do gettimeofday or clock_gettime on our fastest processors,
so there is no possibility of seeing inconsistent values due to this.

This also moves update_gtod() down next to its only caller, and makes
update_vsyscall use the time passed in via the wall_time argument rather
than accessing xtime directly.  At present, wall_time always points to
xtime, but that could change in future.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      0e469db8
  3. 23 7月, 2010 6 次提交
  5. 14 7月, 2010 1 次提交
  7. 12 7月, 2010 4 次提交
    • M
      powerpc/fsl-booke: Fix address issue when using relocatable kernels · 77154a20
      由 Matthew McClintock 提交于 
      When booting a relocatable kernel it needs to jump to the correct
start address, which for BookE parts is usually unchanged
regardless of the physical memory offset.

Recent changes cause problems with how we calculate the start
address, it was always adding the RMO into the start address
which is incorrect. This patch only adds in the RMO offset
if we are in the kexec code path, as it needs the RMO to work
correctly.

Instead of adding the RMO offset in in the common code path, we
can just set r6 to the RMO offset in the kexec code path instead
of to zero, and finally perform the masking in the common code
path
Signed-off-by: NMatthew McClintock <msm@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      77154a20
    • A
      powerpc/cpm1: Mark micropatch code/data static and __init · af71bcfe
      由 Anton Vorontsov 提交于 
      This saves runtime memory and fixes lots of sparse warnings like this:

    CHECK   arch/powerpc/sysdev/micropatch.c
  arch/powerpc/sysdev/micropatch.c:27:6: warning: symbol 'patch_2000'
  was not declared. Should it be static?
  arch/powerpc/sysdev/micropatch.c:146:6: warning: symbol 'patch_2f00'
  was not declared. Should it be static?
  ...
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      af71bcfe
    • A
      powerpc/cpm1: Fix build with various CONFIG_*_UCODE_PATCH combinations · 2069a6ae
      由 Anton Vorontsov 提交于 
      Warnings are treated as errors for arch/powerpc code, so build fails
with CONFIG_I2C_SPI_UCODE_PATCH=y:

    CC      arch/powerpc/sysdev/micropatch.o
  cc1: warnings being treated as errors
  arch/powerpc/sysdev/micropatch.c: In function 'cpm_load_patch':
  arch/powerpc/sysdev/micropatch.c:630: warning: unused variable 'smp'
  make[1]: *** [arch/powerpc/sysdev/micropatch.o] Error 1

And with CONFIG_USB_SOF_UCODE_PATCH=y:

  CC      arch/powerpc/sysdev/micropatch.o
  cc1: warnings being treated as errors
  arch/powerpc/sysdev/micropatch.c: In function 'cpm_load_patch':
  arch/powerpc/sysdev/micropatch.c:629: warning: unused variable 'spp'
  arch/powerpc/sysdev/micropatch.c:628: warning: unused variable 'iip'
  make[1]: *** [arch/powerpc/sysdev/micropatch.o] Error 1

This patch fixes these issues by introducing proper #ifdefs.

Cc: <stable@kernel.org> [ .33, .34 ]
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      2069a6ae
    • A
      powerpc/cpm: Reintroduce global spi_pram struct (fixes build issue) · 56825c88
      由 Anton Vorontsov 提交于 
      spi_t was removed in commit 644b2a68
("powerpc/cpm: Remove SPI defines and spi structs"), the commit assumed
that spi_t isn't used anywhere outside of the spi_mpc8xxx driver. But
it appears that the struct is needed for micropatch code. So, let's
reintroduce the struct.

Fixes the following build issue:

    CC      arch/powerpc/sysdev/micropatch.o
  micropatch.c: In function 'cpm_load_patch':
  micropatch.c:629: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token
  micropatch.c:629: error: 'spp' undeclared (first use in this function)
  micropatch.c:629: error: (Each undeclared identifier is reported only once
  micropatch.c:629: error: for each function it appears in.)
Reported-by: NLEROY Christophe <christophe.leroy@c-s.fr>
Reported-by: NTony Breeds <tony@bakeyournoodle.com>
Cc: <stable@kernel.org> [ .33, .34 ]
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      56825c88
  9. 08 7月, 2010 10 次提交
  11. 16 6月, 2010 2 次提交
  13. 15 6月, 2010 9 次提交
  15. 12 6月, 2010 1 次提交
  17. 09 6月, 2010 1 次提交
  19. 07 6月, 2010 1 次提交
  21. 03 6月, 2010 1 次提交
  23. 02 6月, 2010 2 次提交