linux-toradex.git/drivers/scsi/dpt_i2o.c, branch v2.6.19.3

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)

[SCSI] scsi: remove hosts.h

2006-10-04T18:10:52+00:00

Remove the obsolete hosts.h file under drivers/scsi.

Signed-off-by: Henrik Kretzschmar 
Signed-off-by: James Bottomley

[SCSI] Switch some more scsi drivers to pci_get_device and refcounted pci structures

2006-09-24T01:32:52+00:00

Signed-off-by: Alan Cox 
Signed-off-by: James Bottomley

[SCSI] remove unnecessary includes of linux/config.h from drivers/scsi/

2006-08-19T20:39:11+00:00

kbuild includes this automatically these days.

Signed-off-by: Dave Jones 
Signed-off-by: James Bottomley

[PATCH] irq-flags: scsi: Use the new IRQF_ constants

2006-07-02T20:58:53+00:00

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

[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

[SCSI] I2O: move pci_request_regions() just behind pci_enable_device()

2006-01-14T16:54:54+00:00

The problem in dpt_i2o could be the pci config space accesses it
triggers as it loads, dangerous to do if there is any I/O activity going
on in the other driver (probable if a boot driver I guess).

I approve this patch to dpt_i2o.c, and am applying it to the Adaptec
branch of the driver.

Thanks for the investigation Ryoji.

---

In linux 2.6.15, data transfer does hang when both dpt_i2o
and i2o_block drivers are loaded.
It seems that location of pci_request_regions() are wrong.
I moved it just behind pci_enable_device() like other drivers,
and it becomes fine.

Signed-off-by: Ryoji Kamei 
Signed-off-by: James Bottomley

[SCSI] turn most scsi semaphores into mutexes

2006-01-12T17:53:11+00:00

the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead

Signed-off-by: Arjan van de Ven 
Signed-off-by: James Bottomley

[PATCH] dpt_i2o fix for deadlock condition

2005-12-18T19:19:44+00:00

Miquel van Smoorenburg  forwarded me this fix to
resolve a deadlock condition that occurs due to the API change in
2.6.13+ kernels dropping the host locking when entering the error
handling.  They all end up calling adpt_i2o_post_wait(), which if you
call it unlocked, might return with host_lock locked anyway and that
causes a deadlock.

Signed-off-by: Mark Salyzyn 
Cc: James Bottomley 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] drivers/scsi/dpt_i2o.c: fix a NULL pointer dereference

2005-11-28T04:23:46+00:00

The Coverity checker spotted this obvious NULL pointer dereference.

Signed-off-by: Adrian Bunk 
Acked-by: Mark Salyzyn 
Signed-off-by: Linus Torvalds