Commit Graph

17 Commits

Author SHA1 Message Date
Ralf Baechle 12a0a703b3 [RTC] Consistently use of tabs for formatting. 2006-10-09 23:20:47 +01:00
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
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 <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Steven Rostedt 358333a0cb [PATCH] remove unnecessary barrier in rtc_get_rtc_time
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29 09:18:05 -07:00
Peter Zijlstra 0b16f21f14 [PATCH] rtc: lockdep fix/workaround
BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted)
 [<c04051ee>] show_trace_log_lvl+0x58/0x171
 [<c0405802>] show_trace+0xd/0x10
 [<c040591b>] dump_stack+0x19/0x1b
 [<c043abee>] trace_hardirqs_on+0xa2/0x11e
 [<c06143c3>] _spin_unlock_irq+0x22/0x26
 [<c0541540>] rtc_get_rtc_time+0x32/0x176
 [<c0419ba4>] hpet_rtc_interrupt+0x92/0x14d
 [<c0450f94>] handle_IRQ_event+0x20/0x4d
 [<c0451055>] __do_IRQ+0x94/0xef
 [<c040678d>] do_IRQ+0x9e/0xbd
 [<c0404a49>] common_interrupt+0x25/0x2c
DWARF2 unwinder stuck at common_interrupt+0x25/0x2c

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-25 17:38:35 -07:00
Ingo Molnar 0f74964627 [PATCH] lockdep: HPET/RTC fix
Joseph Fannin reported that hpet_rtc_interrupt() enables hardirqs
in irq context:

[   25.628000]  [<c014af4e>] trace_hardirqs_on+0xce/0x200
[   25.628000]  [<c036cf21>] _spin_unlock_irq+0x31/0x70
[   25.628000]  [<c0296584>] rtc_get_rtc_time+0x44/0x1a0
[   25.628000]  [<c01198bb>] hpet_rtc_interrupt+0x21b/0x280
[   25.628000]  [<c0161141>] handle_IRQ_event+0x31/0x70
[   25.628000]  [<c0162d37>] handle_edge_irq+0xe7/0x210
[   25.628000]  [<c0106192>] do_IRQ+0x92/0x120
[   25.628000]  [<c0104121>] common_interrupt+0x25/0x2c

the call of rtc_get_rtc_time() is highly suspect. At a minimum we
need the patch below to save/restore hardirq state.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Joseph Fannin <jfannin@gmail.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-12 12:52:55 -07:00
Maciej W. Rozycki 38e0e8c055 [PATCH] char/rtc: Handle memory-mapped chips properly
Handle memory-mapped chips properly, needed for example on DECstations.
This support was in Linux 2.4 but for some reason got lost in 2.6.  This
patch is taken directly from the linux-mips repository.

[akpm@osdl.org: cleanup]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Cc: Paul Gortmaker <penguin@muskoka.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10 13:24:25 -07:00
Arjan van de Ven 62322d2554 [PATCH] make more file_operation structs static
Mark the static struct file_operations in drivers/char as const.  Making
them const prevents accidental bugs, and moves them to the .rodata section
so that they no longer do any false sharing; in addition with the proper
debug option they are then protected against corruption..

[akpm@osdl.org: build fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:26:59 -07:00
Thomas Gleixner 0f2ed4c6ba [PATCH] irq-flags: drivers/char: Use the new IRQF_ constants
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02 13:58:49 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
David S. Miller 690c8fd31f [SPARC64]: Use in-kernel PROM tree for EBUS and ISA.
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-23 23:15:28 -07:00
David S. Miller c6387a48cf [SPARC]: Kill __irq_itoa().
This ugly hack was long overdue to die.

It was a way to print out Sparc interrupts in a more freindly format,
since IRQ numbers were arbitrary opaque 32-bit integers which vectored
into PIL levels.  These 32-bit integers were not necessarily in the
0-->NR_IRQS range, but the PILs they vectored to were.

The idea now is that we will increase NR_IRQS a little bit and use a
virtual<-->real IRQ number mapping scheme similar to PowerPC.

That makes this IRQ printing hack irrelevant, and furthermore only a
handful of drivers actually used __irq_itoa() making it even less
useful.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-20 01:21:29 -07:00
Alan Cox b7599587fa [PATCH] Allow reading CMOS day of week register
Someone wanted access to this usually unused (and unused by Linux) value
for the day of week.  Existing kernels have the field in the struct but
return 0 always.  This updates the kernel to fill in the field.  The usual
case of 'not set' conveniently is 0.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11 18:42:10 -08:00
Takashi Iwai c3348760aa [PATCH] Fix wrong irq enable via rtc_control()
rtc_control() may be called in the interrupt context in ALSA rtc-timer
driver.  The patch fixes the wrong irq enable in rtc.c, and also fixes
the possible race of bit flags.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-11-07 11:14:57 +01:00
David S. Miller 53d0fc27af [RTC]: Use SA_SHIRQ in sparc specific code.
Based upon a report from Jason Wever.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-05 23:33:05 -07:00
Petr Vandrovec 403fe5ae57 [PATCH] rtc: msleep() cannot be used from interrupt
Since the beginning of July my Opteron box was randomly crashing and
being rebooted by hardware watchdog.  Today it finally did it in front
of me, and this patch will hopefully fix it.

The problem is that at the end of June (the 28th, to be exact: commit
47f176fdaf, "[PATCH] Using msleep()
instead of HZ") rtc_get_rtc_time was converted to use msleep() instead
of busy waiting.  But rtc_get_rtc_time is used by hpet_rtc_interrupt,
and scheduling is not allowed during interrupt.  So I'm reverting this
part of original change, replacing msleep() back with busy loop.

The original code was busy waiting for up to 20ms, but on my hardware in
the worst case update-in-progress bit was asserted for at most 363
passes through loop (on 2GHz dual Opteron), much less than even one
jiffie, not even talking about 20ms.  So I changed code to just wait
only as long as necessary.  Otherwise when RTC was set to generate
8192Hz timer, it stopped doing anything for 20ms (160 pulses were
skipped!) from time to time, and this is rather suboptimal as far as I
can tell.

Signed-off-by: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-05 06:57:44 -07:00
Luca Falavigna 47f176fdaf [PATCH] Using msleep() instead of HZ
Use msleep() in a few places.

Signed-off-by: Luca Falavigna <dktrkranz@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28 21:20:29 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00