1. 10 Oct, 2006 1 commit
  2. 05 Oct, 2006 1 commit
    • David Howells's avatar
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      David Howells authored
      
      
      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: default avatarDavid Howells <dhowells@redhat.com>
      (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  3. 04 Oct, 2006 2 commits
  4. 01 Oct, 2006 1 commit
  5. 24 Sep, 2006 1 commit
    • Russell King's avatar
      [MMC] MMC_CAP_BYTEBLOCK flag for non-log2 block sizes capable hosts · 42431acb
      Russell King authored
      
      
      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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      42431acb
  6. 16 Sep, 2006 1 commit
    • Russell King's avatar
      [MMC] Add multi block-write capability · db53f28b
      Russell King authored
      
      
      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: default avatarPierre Ossman <drzeus@drzeus.cx>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      db53f28b
  7. 13 Jul, 2006 2 commits
  8. 02 Jul, 2006 21 commits
  9. 19 Jun, 2006 1 commit
    • Russell King's avatar
      [MMC] Convert all hosts except mmci to use data->blksz · a3fd4a1b
      Russell King authored
      
      
      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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      a3fd4a1b
  10. 12 Jun, 2006 1 commit
  11. 04 May, 2006 1 commit
  12. 29 Mar, 2006 1 commit
  13. 24 Mar, 2006 1 commit