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  1. 12 2月, 2007 1 次提交
  3. 08 2月, 2007 2 次提交
  5. 08 12月, 2006 1 次提交
  7. 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
  9. 01 9月, 2006 2 次提交
  11. 03 8月, 2006 1 次提交
  13. 22 6月, 2006 13 次提交
  15. 21 3月, 2006 7 次提交
  17. 01 2月, 2006 1 次提交
  19. 05 1月, 2006 2 次提交
  21. 29 10月, 2005 3 次提交
    • A
      [PATCH] UHCI: Improve handling of iso TDs · b81d3436
      由 Alan Stern 提交于 
      The uhci-hcd driver is fairly lax about the way it handles isochronous
transfers.  This patch (as579) improves it in three respects:

	TDs for a new URB aren't added to the schedule until all of
	them have been allocated.  This way there's no risk of the
	controller executing some of them when an allocation fails.

	TDs for an unlinked URB are removed from the schedule as soon
	as the URB is unlinked, rather than waiting until the URB is
	given back.  This way there's no risk of the controller still
	executing a TD after the URB completes.

	The urb->error_count values are now reported correctly.
	Although since they aren't used in any drivers except for
	debug messages in the system log, probably nobody cares.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      b81d3436
    • A
      [PATCH] USB: UHCI: Split apart the physical and logical framelist arrays · a1d59ce8
      由 Alan Stern 提交于 
      This patch (as563) splits the physical and logical framelist arrays in
uhci-hcd into two separate pieces.  This will allow slightly better memory
utilization, since each piece is no larger than a single page whereas
before the whole thing was a little bigger than two pages.  It also allows
the logical array to be allocated in non-DMA-coherent memory.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      a1d59ce8
    • A
      [PATCH] USB: UHCI: Remove unused fields and unneeded tests for NULL · 8b4cd421
      由 Alan Stern 提交于 
      This patch (as562) removes from the uhci-hcd driver a few unused fields
and some unnecessary tests against NULL and assignments to NULL.  In fact
it wasn't until fairly recently that the tests became unnecessary.
Before last winter it was possible that the driver's stop() routine would
get called even if the start() routine returned an error, but now that
can't happen.  Hence there's no longer any need to check for partial
initialization.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      8b4cd421
  23. 28 10月, 2005 1 次提交
  25. 13 9月, 2005 1 次提交
  27. 13 7月, 2005 1 次提交
  29. 28 6月, 2005 3 次提交