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  1. 27 2月, 2009 1 次提交
  3. 18 2月, 2009 1 次提交
  5. 11 1月, 2009 1 次提交
  7. 08 1月, 2009 1 次提交
  9. 22 11月, 2008 1 次提交
  11. 28 10月, 2008 1 次提交
  13. 31 5月, 2008 1 次提交
  15. 29 1月, 2008 3 次提交
  17. 11 10月, 2007 3 次提交
  19. 19 7月, 2007 1 次提交
  21. 02 7月, 2007 1 次提交
  23. 03 6月, 2007 1 次提交
  25. 09 5月, 2007 1 次提交
  27. 26 4月, 2007 2 次提交
  29. 03 3月, 2007 1 次提交
  31. 05 12月, 2006 1 次提交
  33. 22 11月, 2006 1 次提交
  35. 05 10月, 2006 1 次提交
    • D
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      由 David Howells 提交于 
      Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  37. 23 9月, 2006 1 次提交
  39. 14 9月, 2006 2 次提交
  41. 20 8月, 2006 1 次提交
  43. 06 7月, 2006 3 次提交
    • I
      [PATCH] lock validator: fix ns83820.c irq-flags bug · 3a10cceb
      由 Ingo Molnar 提交于 
      Barry K. Nathan reported the following lockdep warning:

[  197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on()
[  197.345928]  [<c010329b>] show_trace_log_lvl+0x5b/0x105
[  197.346359]  [<c0103896>] show_trace+0x1b/0x20
[  197.346759]  [<c01038ed>] dump_stack+0x1f/0x24
[  197.347159]  [<c012efa2>] trace_hardirqs_on+0xfb/0x185
[  197.348873]  [<c029b009>] _spin_unlock_irq+0x24/0x2d
[  197.350620]  [<e09034e8>] do_tx_done+0x171/0x179 [ns83820]
[  197.350895]  [<e090445c>] ns83820_irq+0x149/0x20b [ns83820]
[  197.351166]  [<c013b4b8>] handle_IRQ_event+0x1d/0x52
[  197.353216]  [<c013c6c2>] handle_level_irq+0x97/0xe1
[  197.355157]  [<c01048c3>] do_IRQ+0x8b/0xac
[  197.355612]  [<c0102d9d>] common_interrupt+0x25/0x2c

this is caused because the ns83820 driver re-enables irq flags
in hardirq context.

While legal in theory, in practice it should only be done if the
hardware is really old and has some very high overhead in its ISR.
(such as PIO IDE)

For modern hardware, running ISRs with irqs enabled is discouraged,
because 1) new hardware is fast enough to not cause latency problems
2) allowing the nesting of hardware interrupts only 'spreads out'
the handling of the current ISR, causing extra cachemisses that would
otherwise not happen. Furthermore, on architectures where ISRs share
the kernel stacks, enabling interrupts in ISRs introduces a much
higher kernel-stack-nesting and thus kernel-stack-overflow risk.
3) not managing irq-flags via the _irqsave / _irqrestore variants
is dangerous: it's easy to forget whether one function nests inside
another, and irq flags might be mismanaged.

In the few cases where re-enabling interrupts in an ISR is considered
useful (and unavoidable), it has to be taught to the lock validator
explicitly (because the lock validator needs the "no ISR ever enables
hardirqs" artificial simplification to keep the IRQ/softirq locking
dependencies manageable).

This teaching is done via the explicit use local_irq_enable_in_hardirq().
On a stock kernel this maps to local_irq_enable(). If the lock validator
is enabled then this does not enable interrupts.

Now, the analysis of drivers/net/ns83820.c's irq flags use: the
irq-enabling in irq context seems intentional, but i dont think it's
justified. Furthermore, the driver suffers from problem #3 above too,
in ns83820_tx_timeout() it disables irqs via local_irq_save(), but
then it calls do_tx_done() which does a spin_unlock_irq(),
re-enabling for a function that does not expect it! While currently
this bug seems harmless (only some debug printout seems to be
affected by it), it's nevertheless something to be fixed.

So this patch makes the ns83820 ISR irq-flags-safe, and cleans up
do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug.

From: Arjan van de Ven <arjan@linux.intel.com>

  ns83820_mib_isr takes the misc_lock in IRQ context.  All other places that
  do this in the ISR already use _irqsave versions, make this consistent at
  least.  At some point in the future someone should audit the driver to see
  if all _irqsave's in the ISR can go away, this is generally an iffy/fragile
  proposition though; for now get it safe, simple and consistent.

From: Arjan van de Ven <arjan@linux.intel.com>

ok this is a real driver deadlock:

The ns83820 driver enabled interrupts (by unlocking the misc_lock with
_irq) while still holding the rx_info.lock, which is required to be irq
safe since it's used in the ISR like this:
                writel(1, dev->base + IER);
                spin_unlock_irq(&dev->misc_lock);
                kick_rx(ndev);
                spin_unlock_irq(&dev->rx_info.lock);

This is can cause a deadlock if an irq was pending at the first
spin_unlock_irq already, or if one would hit during kick_rx().
Simply remove the first _irq solves this
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>
      3a10cceb
    • J
      [netdrvr] use dev_xxx() printk helpers, rather than dev_printk(KERN_xxx, ... · 9b91cf9d
      由 Jeff Garzik 提交于 
      Suggested by Jiri Slaby.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
      9b91cf9d
    • J
      [netdrvr] Use dev_printk() when ethernet interface isn't available · 2e8a538d
      由 Jeff Garzik 提交于 
      For messages prior to register_netdev(), prefer dev_printk() because
that prints out both our driver name and our [PCI | whatever] bus id.

Updates: 8139{cp,too}, b44, bnx2, cassini, {eepro,epic}100, fealnx,
	 hamachi, ne2k-pci, ns83820, pci-skeleton, r8169.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
      2e8a538d
  45. 03 7月, 2006 1 次提交
  47. 01 7月, 2006 1 次提交
  49. 02 4月, 2006 1 次提交
  51. 29 3月, 2006 1 次提交
  53. 04 3月, 2006 1 次提交
  55. 17 1月, 2006 1 次提交
  57. 04 1月, 2006 1 次提交
  59. 08 11月, 2005 1 次提交
    • A
      [PATCH] kill include/linux/eeprom.h · 48888cc6
      由 Adrian Bunk 提交于 
      This patch kills include/linux/eeprom.h .

Rationale:
- it was only used by one single driver
- even this driver didn't do anything useful with it
- most of this file are non-inline and non-static functions (sic)

This removes include/linux/eeprom.h and cleans drivers/net/ns83820.c up.

If you think eeprom.h should be used more extensively, please consider:
- the code has to be moved from the header file to a .c file
- the currently empty write function has to be implemented
- ns83820.c or any other driver should actually use it

Noone did any of these during the more than 3 years eeprom.h already
exists...
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      48888cc6
  61. 09 10月, 2005 1 次提交
  63. 04 10月, 2005 1 次提交