linux-stable.git/include/linux/ide.h, branch linux-2.6.19.y

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

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: David Howells 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] ide: Fix crash on repeated reset

2006-10-03T15:04:08+00:00

Michal Miroslaw reported a problem (bugzilla #7023) where a user initiated
reset while the IDE layer was already resetting the channel caused a crash,
and provided a rough fix.

This is a slightly cleaner version of the fix which tracks the reset state
and blocks further reset requests while a reset is in progress.

Note this is not a security issue - random end users can't access the
ioctl in question anyway.

Signed-off-by: Alan Cox 
Cc: Michal Miroslaw 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ide: remove dma_base2 field from ide_hwif_t

2006-10-03T15:04:08+00:00

Remove dma_base2 field from ide_hwif_t as it's used only in 2 drivers and
without great need.

Signed-off-by: Sergei Shtylyov 
Cc: John Keller 
Signed-off-by: Jeremy Higdon 
Acked-by: Alan Cox 
Cc: Bartlomiej Zolnierkiewicz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] drivers/ide/: cleanups

2006-10-03T15:04:08+00:00

- setup-pci.c: remove the unused ide_pci_unregister_driver()
- ide-dma.c: remove the unused EXPORT_SYMBOL_GPL(ide_in_drive_list)

Signed-off-by: Adrian Bunk 
Acked-by: Alan Cox 
Cc: Bartlomiej Zolnierkiewicz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Make number of IDE interfaces configurable

2006-10-03T15:04:07+00:00

Make IDE_HWIFS configurable if EMBEDDED

This lets us lop as much as 16k off an x86 build.  It's a little ugly, but
it's dead simple.  Note the fix for HWIFS < 2.

Sizing interfaces dynamically unfortunately turns out to be pretty
major surgery.

add/remove: 0/1 grow/shrink: 0/11 up/down: 0/-16182 (-16182)
function                                     old     new   delta
ide_hwifs                                  16920    1692  -15228
init_irq                                    1113     750    -363
ideprobe_init                                283     138    -145
ide_pci_setup_ports                         1329    1193    -136
save_match                                    85       -     -85
ide_register_hw_with_fixup                   367     287     -80
ide_setup                                   1364    1308     -56
is_chipset_set                                40       4     -36
create_proc_ide_interfaces                   225     205     -20
init_ide_data                                 84      67     -17
ide_probe_for_cmd640x                       1198    1183     -15
ide_unregister                              1452    1451      -1

Signed-off-by: Matt Mackall 
Cc: Bartlomiej Zolnierkiewicz 
Acked-by: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] IDE: claim extra DMA ports regardless of channel

2006-10-03T15:04:07+00:00

- Claim extra DMA I/O ports regardless of what IDE channels are
  present/enabled.

- Remove extra ports handling from ide_mapped_mmio_dma() since it's not
  applicable to the custom-mapping IDE drivers.

Signed-off-by: Sergei Shtylyov 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Alan Cox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ide: option to disable cache flushes for buggy drives

2006-07-28T06:54:59+00:00

Some drives claim they support cache flushing, but get seriously
confused if you try. Add this option to be able to boot with
barriers enabled by default.

Signed-off-by: Jens Axboe

[PATCH] lockdep: annotate enable_in_hardirq()

2006-07-03T22:27:09+00:00

Make use of local_irq_enable_in_hardirq() API to annotate places that enable
hardirqs in hardirq context.

Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar 
Signed-off-by: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6

2006-06-29T21:19:21+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6: (22 commits)
  [PATCH] devfs: Remove it from the feature_removal.txt file
  [PATCH] devfs: Last little devfs cleanups throughout the kernel tree.
  [PATCH] devfs: Rename TTY_DRIVER_NO_DEVFS to TTY_DRIVER_DYNAMIC_DEV
  [PATCH] devfs: Remove the tty_driver devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the line_driver devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the videodevice devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the miscdevice devfs_name field as it's no longer needed
  [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree
  [PATCH] devfs: Remove devfs_remove() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_cdev() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_bdev() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_symlink() function from the kernel tree
  [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree
  [PATCH] devfs: Remove devfs_*_tape() functions from the kernel tree
  [PATCH] devfs: Remove devfs support from the sound subsystem
  [PATCH] devfs: Remove devfs support from the ide subsystem.
  [PATCH] devfs: Remove devfs support from the serial subsystem
  [PATCH] devfs: Remove devfs from the init code
  [PATCH] devfs: Remove devfs from the partition code
  ...

[PATCH] ide: fix error handling for drives which clear the FIFO on error

2006-06-28T21:59:06+00:00

If the controller FIFO cleared automatically on error we must not try
and drain it as this will hang some chips.

Based in concept on a broken patch from -mm some while back

Signed-off-by: Alan Cox 
Cc: Sergei Shtylyov 
Cc: Bartlomiej Zolnierkiewicz 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds