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  1. 02 12月, 2006 2 次提交
  3. 11 10月, 2006 1 次提交
  5. 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
  7. 04 10月, 2006 2 次提交
  9. 01 10月, 2006 1 次提交
  11. 24 9月, 2006 1 次提交
    • R
      [MMC] MMC_CAP_BYTEBLOCK flag for non-log2 block sizes capable hosts · 42431acb
      由 Russell King 提交于 
      Some MMC hosts can only handle log2 block sizes.  Unfortunately,
the MMC password support needs to be able to send non-log2 block
sizes.  Provide a capability so that the MMC password support can
decide whether it should use this support or not.

The unfortunate side effect of this host limitation is that any
MMC card protected by a password which is not a log2 block size
can not be accessed on a host which only allows a log2 block size.

This change just adds the flag.  The MMC password support code
needs updating to use it (if and when it is finally submitted.)
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      42431acb
  13. 16 9月, 2006 1 次提交
    • R
      [MMC] Add multi block-write capability · db53f28b
      由 Russell King 提交于 
      Add a capability flag for drivers to set when they can perform multi-
block transfers to cards _and_ correctly report the number of bytes
transferred should an error occur.

The last point is very important - if a driver reports more bytes than
were actually accepted by the card and an error occurs, there is the
possibility for data loss.

Pierre Ossman provided the patch for wbsd and sdhci.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      db53f28b
  15. 13 7月, 2006 2 次提交
  17. 03 7月, 2006 4 次提交
  19. 02 7月, 2006 17 次提交
  21. 19 6月, 2006 1 次提交
    • R
      [MMC] Convert all hosts except mmci to use data->blksz · a3fd4a1b
      由 Russell King 提交于 
      The MMC specification allows non-power of two block sizes.  As such,
we should not pass the log2 block size to host drivers, but instead
pass the byte size.

However, ARM MMCI can only work with log2 block size, so continue to
pass both the log2 block size and byte block size.  This means that
for the moment, the byte block size must remain a power of two, but
this is the first stage of removing this restriction for other hosts.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      a3fd4a1b
  23. 13 6月, 2006 1 次提交
  25. 05 5月, 2006 1 次提交
  27. 29 3月, 2006 1 次提交
  29. 24 3月, 2006 1 次提交