linux-toradex.git/arch/ia64/kernel/mca.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] proper flags type of spin_lock_irqsave()

2006-10-01T07:39:21+00:00

Convert various spin_lock_irqsave() callers to correctly use `unsigned long'.

Signed-off-by: Alexey Dobriyan 
Cc: Miles Bader 
Cc: "Luck, Tony" 
Acked-by: Kyle McMartin 
Cc: Jean Delvare 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[IA64] CMC/CPE: Reverse the order of fetching log and checking poll threshold

2006-09-26T22:27:56+00:00

This patch reverses the order of fetching log from SAL and
checking poll threshold. This will fix following trivial issues:

- If SAL_GET_SATE_INFO is unbelievably slow (due to huge system
   or just its silly implementation) and if it takes more than
   1/5 sec, CMCI/CPEI will never switch to CMCP/CPEP.
- Assuming terrible flood of interrupt (continuous corrected
   errors let all CPUs enter to handler at once and bind them
   in it), CPUs will be serialized by IA64_LOG_LOCK(*).
   Now we check the poll threshold after the lock and log fetch,
   so we need to call SAL_GET_STATE_INFO (num_online_cpus() + 4)
   times in the worst case.
   if we can check the threshold before the lock, we can shut up
   interrupts quickly without waiting preceding log fetches, and
   the number of times will be reduced to (num_online_cpus()) in
   the same situation.

Signed-off-by: Hidetoshi Seto 
Signed-off-by: Tony Luck

[IA64] printing support for MCA/INIT

2006-09-26T21:44:37+00:00

Printing message to console from MCA/INIT handler is useful,
however doing oops_in_progress = 1 in them exactly makes
something in kernel wrong. Especially it sounds ugly if
system goes wrong after returning from recoverable MCA.

This patch adds ia64_mca_printk() function that collects
messages into temporary-not-so-large message buffer during
in MCA/INIT environment and print them out later, after
returning to normal context or when handlers determine to
down the system.

Also this print function is exported for use in extensional
MCA handler. It would be useful to describe detail about
recovery.

NOTE:
I don't think it is sane thing if temporary message buffer
is enlarged enough to hold whole stack dumps from INIT, so
buffering is disabled during stack dump from INIT-monarch
(= default_monarch_init_process). please fix it in future.

Signed-off-by: Hidetoshi Seto 
Acked-by: Russ Anderson 
Signed-off-by: Tony Luck

[PATCH] sched: cleanup, remove task_t, convert to struct task_struct

2006-07-03T22:27:11+00:00

cleanup: remove task_t and convert all the uses to struct task_struct. I
introduced it for the scheduler anno and it was a mistake.

Conversion was mostly scripted, the result was reviewed and all
secondary whitespace and style impact (if any) was fixed up by hand.

Signed-off-by: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] irq-flags: IA64: Use the new IRQF_ constants

2006-07-02T20:58:47+00:00

Use the new IRQF_ constants and remove the SA_INTERRUPT define

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Cc: "Luck, Tony" 
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] genirq: cleanup: remove irq_descp()

2006-06-29T17:26:22+00:00

Cleanup: remove irq_descp() - explicit use of irq_desc[] is shorter and more
readable.

Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[IA64] ia64_wait_for_slaves() incorrectly reports MCA

2006-04-13T21:57:18+00:00

ia64_wait_for_slaves() was changed in 2.6.17-rc1 to report the slave
state.  It incorrectly assumes that all slaves are for MCA, but
ia64_wait_for_slaves() is also called from the INIT monarch handler.
The existing message is very misleading, so correct it.

Signed-off-by: Keith Owens 
Signed-off-by: Tony Luck

[IA64] Pass more data to the MCA/INIT notify_die hooks

2006-04-08T05:51:51+00:00

The MCA/INIT handlers maintain important state in the SAL to OS (sos)
area and in the monarch_cpu flag.  Kernel debuggers (such as KDB) need
this data, and may need to adjust the monarch_cpu field so make the
data available to the notify_die hooks.  Define two more events for
calling the functions on the notify_die chain.

Signed-off-by: Keith Owens 
Signed-off-by: Tony Luck