Skip to content

K
kernel_linux

OpenHarmony / kernel_linux
上一次同步 3 年多

通知 13
Star 8
Fork 2
K
kernel_linux
切换分支/标签
  1. 07 10月, 2010 1 次提交
    • D
      Fix IRQ flag handling naming · df9ee292
      由 David Howells 提交于 
      Fix the IRQ flag handling naming.  In linux/irqflags.h under one configuration,
it maps:

	local_irq_enable() -> raw_local_irq_enable()
	local_irq_disable() -> raw_local_irq_disable()
	local_irq_save() -> raw_local_irq_save()
	...

and under the other configuration, it maps:

	raw_local_irq_enable() -> local_irq_enable()
	raw_local_irq_disable() -> local_irq_disable()
	raw_local_irq_save() -> local_irq_save()
	...

This is quite confusing.  There should be one set of names expected of the
arch, and this should be wrapped to give another set of names that are expected
by users of this facility.

Change this to have the arch provide:

	flags = arch_local_save_flags()
	flags = arch_local_irq_save()
	arch_local_irq_restore(flags)
	arch_local_irq_disable()
	arch_local_irq_enable()
	arch_irqs_disabled_flags(flags)
	arch_irqs_disabled()
	arch_safe_halt()

Then linux/irqflags.h wraps these to provide:

	raw_local_save_flags(flags)
	raw_local_irq_save(flags)
	raw_local_irq_restore(flags)
	raw_local_irq_disable()
	raw_local_irq_enable()
	raw_irqs_disabled_flags(flags)
	raw_irqs_disabled()
	raw_safe_halt()

with type checking on the flags 'arguments', and then wraps those to provide:

	local_save_flags(flags)
	local_irq_save(flags)
	local_irq_restore(flags)
	local_irq_disable()
	local_irq_enable()
	irqs_disabled_flags(flags)
	irqs_disabled()
	safe_halt()

with tracing included if enabled.

The arch functions can now all be inline functions rather than some of them
having to be macros.

Signed-off-by: David Howells <dhowells@redhat.com> [X86, FRV, MN10300]
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [Tile]
Signed-off-by: Michal Simek <monstr@monstr.eu> [Microblaze]
Tested-by: Catalin Marinas <catalin.marinas@arm.com> [ARM]
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> [AVR]
Acked-by: Tony Luck <tony.luck@intel.com> [IA-64]
Acked-by: Hirokazu Takata <takata@linux-m32r.org> [M32R]
Acked-by: Greg Ungerer <gerg@uclinux.org> [M68K/M68KNOMMU]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [MIPS]
Acked-by: Kyle McMartin <kyle@mcmartin.ca> [PA-RISC]
Acked-by: Paul Mackerras <paulus@samba.org> [PowerPC]
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [S390]
Acked-by: Chen Liqin <liqin.chen@sunplusct.com> [Score]
Acked-by: Matt Fleming <matt@console-pimps.org> [SH]
Acked-by: David S. Miller <davem@davemloft.net> [Sparc]
Acked-by: Chris Zankel <chris@zankel.net> [Xtensa]
Reviewed-by: Richard Henderson <rth@twiddle.net> [Alpha]
Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp> [H8300]
Cc: starvik@axis.com [CRIS]
Cc: jesper.nilsson@axis.com [CRIS]
Cc: linux-cris-kernel@axis.com
      df9ee292
  3. 06 10月, 2010 2 次提交
    • S
      powerpc: remove unused variable · 7c6d45e6
      由 Stephen Rothwell 提交于 
      Since powerpc uses -Werror on arch powerpc, the build was broken like
this:

  cc1: warnings being treated as errors
  arch/powerpc/kernel/module.c: In function 'module_finalize':
  arch/powerpc/kernel/module.c:66: error: unused variable 'err'
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7c6d45e6
    • L
      modules: Fix module_bug_list list corruption race · 5336377d
      由 Linus Torvalds 提交于 
      With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.

However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling.  That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.

Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.

So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.

Future fixups:
 - move the module list handling code into kernel/module.c where it
   belongs.
 - get rid of 'module_bug_list' and just use the regular list of modules
   (called 'modules' - imagine that) that we already create and maintain
   for other reasons.
Reported-and-tested-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5336377d
  5. 23 9月, 2010 1 次提交
  7. 31 8月, 2010 3 次提交
    • M
      powerpc: Don't use kernel stack with translation off · 54a83404
      由 Michael Neuling 提交于 
      In f761622e we changed
early_setup_secondary so it's called using the proper kernel stack
rather than the emergency one.

Unfortunately, this stack pointer can't be used when translation is off
on PHYP as this stack pointer might be outside the RMO.  This results in
the following on all non zero cpus:
  cpu 0x1: Vector: 300 (Data Access) at [c00000001639fd10]
      pc: 000000000001c50c
      lr: 000000000000821c
      sp: c00000001639ff90
     msr: 8000000000001000
     dar: c00000001639ffa0
   dsisr: 42000000
    current = 0xc000000016393540
    paca    = 0xc000000006e00200
      pid   = 0, comm = swapper

The original patch was only tested on bare metal system, so it never
caught this problem.

This changes __secondary_start so that we calculate the new stack
pointer but only start using it after we've called early_setup_secondary.

With this patch, the above problem goes away.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      54a83404
    • P
      powerpc/perf_event: Reduce latency of calling perf_event_do_pending · b0d278b7
      由 Paul Mackerras 提交于 
      Commit 0fe1ac48 ("powerpc/perf_event: Fix oops due to
perf_event_do_pending call") moved the call to perf_event_do_pending
in timer_interrupt() down so that it was after the irq_enter() call.
Unfortunately this moved it after the code that checks whether it
is time for the next decrementer clock event.  The result is that
the call to perf_event_do_pending() won't happen until the next
decrementer clock event is due.  This was pointed out by Milton
Miller.

This fixes it by moving the check for whether it's time for the
next decrementer clock event down to the point where we're about
to call the event handler, after we've called perf_event_do_pending.

This has the side effect that on old pre-Core99 Powermacs where we
use the ppc_n_lost_interrupts mechanism to replay interrupts, a
replayed interrupt will incur a little more latency since it will
now do the code from the irq_enter down to the irq_exit, that it
used to skip.  However, these machines are now old and rare enough
that this doesn't matter.  To make it clear that ppc_n_lost_interrupts
is only used on Powermacs, and to speed up the code slightly on
non-Powermac ppc32 machines, the code that tests ppc_n_lost_interrupts
is now conditional on CONFIG_PMAC as well as CONFIG_PPC32.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: stable@kernel.org
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      b0d278b7
    • M
      powerpc/kexec: Adds correct calling convention for kexec purgatory · 4562c986
      由 Matthew McClintock 提交于 
      Call kexec purgatory code correctly. We were getting lucky before.
If you examine the powerpc 32bit kexec "purgatory" code you will
see it expects the following:

>From kexec-tools: purgatory/arch/ppc/v2wrap_32.S
-> calling convention:
->   r3 = physical number of this cpu (all cpus)
->   r4 = address of this chunk (master only)

As such, we need to set r3 to the current core, r4 happens to be
unused by purgatory at the moment but we go ahead and set it
here as well
Signed-off-by: NMatthew McClintock <msm@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      4562c986
  9. 24 8月, 2010 11 次提交
  11. 23 8月, 2010 3 次提交
  13. 18 8月, 2010 1 次提交
    • D
      Make do_execve() take a const filename pointer · d7627467
      由 David Howells 提交于 
      Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d7627467
  15. 14 8月, 2010 1 次提交
  17. 07 8月, 2010 1 次提交
  19. 05 8月, 2010 1 次提交
  21. 03 8月, 2010 2 次提交
  23. 01 8月, 2010 2 次提交
  25. 31 7月, 2010 7 次提交
  27. 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
  29. 27 7月, 2010 2 次提交