linux-toradex.git/drivers/block/umem.c, branch v2.6.19.2

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] pr_debug: umem: repair nonexistant bh pr_debug reference

2006-10-03T15:04:19+00:00

umem: repair nonexistant bh pr_debug reference

Signed-off-by: Zach Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] irq-flags: drivers/block Use the new IRQF_ constants

2006-07-02T20:58:49+00:00

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed

2006-06-26T19:25:08+00:00

And remove the now unneeded number field.
Also fixes all drivers that set these fields.

Signed-off-by: Greg Kroah-Hartman

[PATCH] Replace 0xff.. with correct DMA_xBIT_MASK

2006-03-28T17:16:07+00:00

Replace all occurences of 0xff..  in calls to function pci_set_dma_mask()
and pci_set_consistant_dma_mask() with the corresponding DMA_xBIT_MASK from
linux/dma-mapping.h.

Signed-off-by: Matthias Gehre 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] regularize blk_cleanup_queue() use

2006-03-18T23:34:20+00:00

Signed-off-by: Al Viro

[PATCH] umem: check pci_set_dma_mask return value correctly

2006-02-03T16:32:05+00:00

Signed-off-by: Tobias Klauser 
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] drivers/block: Replace pci_module_init() with pci_register_driver()

2006-01-09T20:13:22+00:00

Replace obsolete pci_module_init() with pci_register_driver().

Signed-off-by: Richard Knutsson 
Signed-off-by: Greg Kroah-Hartman

[PATCH] Add block_device_operations.getgeo block device method

2006-01-09T04:13:54+00:00

HDIO_GETGEO is implemented in most block drivers, and all of them have to
duplicate the code to copy the structure to userspace, as well as getting
the start sector.  This patch moves that to common code [1] and adds a
->getgeo method to fill out the raw kernel hd_geometry structure.  For many
drivers this means ->ioctl can go away now.

[1] the s390 block drivers are odd in this respect.  xpram sets ->start
    to 4 always which seems more than odd, and the dasd driver shifts
    the start offset around, probably because of it's non-standard
    sector size.

Signed-off-by: Christoph Hellwig 
Cc: Jens Axboe 
Cc: 
Cc: Jeff Dike 
Cc: Paolo Giarrusso 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Neil Brown 
Cc: Markus Lidel 
Cc: Russell King 
Cc: David Woodhouse 
Cc: Martin Schwidefsky 
Cc: James Bottomley 
Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds