Commit Graph

53 Commits

Author SHA1 Message Date
Al Viro 18d8fda7c3 take init_fs to saner place
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:42 -05:00
Akira Takeuchi c7f8d6f6b5 MN10300: Give correct size when reserving interrupt vector table
Give the correct size when reserving the interrupt vector table.  It should be
a page not a single byte.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 13:34:33 -08:00
Akira Takeuchi 24646bd226 MN10300: Fix the preemption resume_kernel() routine
Fix the preemption resume_kernel() routine by inverting the test to see
whether interrupts are off (IM7 is all enabled, not all disabled).

Furthermore, interrupts should be disabled on entry to resume_kernel() so that
they're correctly set for jumping to restore_all() and doing the need
reschedule test.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 13:34:33 -08:00
Akira Takeuchi a8893fb3e6 MN10300: Discard low-priority Tx interrupts when closing an on-chip serial port
Discard low-prioriy Tx interrupts when closing an MN10300 on-chip serial port.

The MN10300 on-chip serial port uses three interrupts to manage its serial
ports:

 (1) A very high priority interrupt that drives virtual DMA for Rx.

 (2) A very high priority interrupt that drives virtual DMA for Tx.

 (3) A normal priority virtual interrupt that does the normal UART interrupt
     stuff and is shared between Rx and Tx.

mn10300_serial_stop_tx() only disables the high priority Tx interrupt.  It
doesn't also disable the normal priority one because it is shared with Rx.

However, the high priority interrupt may interrupt local_irq_disabled()
sections, and so may have queued up a low priority virtual interrupt whilst the
UART driver is asking for the Tx interrupt to be disabled.

The result of this can be an oops when we try to process the interrupt in
mn10300_serial_transmit_interrupt() as port->uart.info and port->uart.info->tty
may have gone away.

To deal with this, if either of those pointers is NULL, we make sure the
high-priority Tx interrupt is disabled and discard the interrupt.  The low
priority interrupt is disabled by the mn10300_serial_pic irq_chip table.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 13:34:33 -08:00
Cyrill Gorcunov cb32898c09 MN10300: vmlinux.lds.S cleanup - use PAGE_SIZE, PERCPU macros
Include the linux/page.h header into the MN10300 kernel linker script thus
allowing us to use PAGE_SIZE macro instead of a numeric constant.

Also use the PERCPU macro instead of an explicit section definition.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-10 13:34:33 -08:00
David Howells 004b50f4ed MN10300: Introduce barriers to replace removed volatiles in gdbstub 16550 driver
Introduce into the MN10300 gdbstub 16550 driver a couple of barrier() calls to
replace the removed volatility of the input/output index variables for the Rx
ring buffer.  A previous patch added them into the on-chip serial port driver.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-03 16:47:40 -08:00
Mark Salter 1122b19b8f MN10300: Fix application of kernel module relocations
This fixes the MN10300 kernel module linking to match the toolchain.  RELA
relocs don't use the value at the location being relocated.  This has been
working because the tools always leave the value at the target location
cleared.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-02 15:52:07 -08:00
Robert P. J. Day 499c59c429 MN10300: Tighten up the code using case ranges
Compress a set of consecutive switch cases into a case-range.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-30 11:21:18 -08:00
David Howells 58a47481b6 MN10300: Don't do misalignment handling for userspace
Don't do misalignment handling for userspace misalignment faults: just
generate an appropriate SIGBUS instead.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:18 -08:00
David Howells bd9384a9fd MN10300: Don't handle misaligned loading and storing of SP
Don't handle the misaligned loading and storing of the SP register as in C code
that's most certainly a compiler bug.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:18 -08:00
David Howells d3bd462865 MN10300: Handle misaligned SP-based operands
Support misalignment handling for instructions that have kernel SP-based
address operands, including fixing those that include IMM8 or IMM16
displacements.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:18 -08:00
David Howells 852c15b736 MN10300: Fix misaligned index-register addressing handling
Fix misalignment handling for an address calculated from the sum of two
registers.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells 6d615c78fb MN10300: Handle misaligned postinc-with-imm addressing mode correctly
Correctly handle misalignment in MOV instructions with postinc-with-immediate
addressing mode operands.  In these, the immediate value is the increment to
be applied the address register, not the displacement to the address.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells ddb6d05cba MN10300: Perform misalignment fixups of MOV_Lcc
Perform misalignment fixups of the MOV_Lcc instructions (move postinc memory
to register and conditionally loop).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells aefefbbec1 MN10300: Allow misalignment fixup in interrupt handling
Allow misalignment fixup in interrupt handling in the MN10300 arch.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells f911c685d6 MN10300: Fix register-postinc addressing misalignment handling
Fix misalignment handling of operands with register postincrement addressing.
The flag to indicate that postincrement is required should not be interpreted
as an specification of a value to be added to the address.

Also add BUGs to catch unimplemented parameter markings in the opcodes table.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells b308bf3be1 MN10300: Extract the displacement from an insn correctly in misalignment fixup
Extract the displacement from an MN10300 instruction correctly in the
misalignment fixup handler.

The code should extract the displacement in LSB order, not MSB order.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells ee6e740cf7 MN10300: Add further misalignment fixups
Add further misalignment fixup support to the MN10300 arch, notably for ABS32
and SP+disp addressing.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells 9f55588968 MN10300: Add built-in testing for misalignment handler
Add configurable built-in testing for the MN10300 misalignment handler.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
David Howells 31ea24bba7 MN10300: Clean up the misalignment handler a little
Clean up the MN10300 misalignment handler a little by:

 (1) Use ilog2() rather than doing implementing log2() locally.

 (2) Make format_tbl[] const and static.

 (3) Making the debugging prints more consistent.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 10:41:17 -08:00
Adrian Bunk f6a2298c5f mn10300: use bcd2bin/bin2bcd
Change mn10300 to use the new bcd2bin/bin2bcd functions instead of the
obsolete BCD_TO_BIN/BIN_TO_BCD macros.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:41 -07:00
Matt Helsley dc52ddc0e6 container freezer: implement freezer cgroup subsystem
This patch implements a new freezer subsystem in the control groups
framework.  It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.

The freezer subsystem in the container filesystem defines a file named
freezer.state.  Writing "FROZEN" to the state file will freeze all tasks
in the cgroup.  Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup.  Reading will return the current state.

* Examples of usage :

   # mkdir /containers/freezer
   # mount -t cgroup -ofreezer freezer  /containers
   # mkdir /containers/0
   # echo $some_pid > /containers/0/tasks

to get status of the freezer subsystem :

   # cat /containers/0/freezer.state
   RUNNING

to freeze all tasks in the container :

   # echo FROZEN > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   FREEZING
   # cat /containers/0/freezer.state
   FROZEN

to unfreeze all tasks in the container :

   # echo RUNNING > /containers/0/freezer.state
   # cat /containers/0/freezer.state
   RUNNING

This is the basic mechanism which should do the right thing for user space
task in a simple scenario.

It's important to note that freezing can be incomplete.  In that case we
return EBUSY.  This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time.  After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read.  The state will remain
"FREEZING" until one of these things happens:

	1) Userspace cancels the freezing operation by writing "RUNNING" to
		the freezer.state file
	2) Userspace retries the freezing operation by writing "FROZEN" to
		the freezer.state file (writing "FREEZING" is not legal
		and returns EIO)
	3) The tasks that blocked the cgroup from entering the "FROZEN"
		state disappear from the cgroup's set of tasks.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:34 -07:00
David Woodhouse e758936e02 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	include/asm-x86/statfs.h
2008-10-13 17:13:56 +01:00
David Howells d6478fad43 MN10300: Fix IRQ handling
Fix the IRQ handling on the MN10300 arch.

This patch makes a number of significant changes:

 (1) It separates the irq_chip definition for edge-triggered interrupts from
     the one for level-triggered interrupts.

     This is necessary because the MN10300 PIC latches the IRQ channel's
     interrupt request bit (GxICR_REQUEST), even after the device has ceased to
     assert its interrupt line and the interrupt channel has been disabled in
     the PIC.  So for level-triggered interrupts we need to clear this bit when
     we re-enable - which is achieved by setting GxICR_DETECT but not
     GxICR_REQUEST when writing to the register.

     Not doing this results in spurious interrupts occurring because calling
     mask_ack() at the start of handle_level_irq() is insufficient - it fails
     to clear the REQUEST latch because the device that caused the interrupt is
     still asserting its interrupt line at this point.

 (2) IRQ disablement [irq_chip::disable_irq()] shouldn't clear the interrupt
     request flag for edge-triggered interrupts lest it lose an interrupt.

 (3) IRQ unmasking [irq_chip::unmask_irq()] also shouldn't clear the interrupt
     request flag for edge-triggered interrupts lest it lose an interrupt.

 (4) The end() operation is now left to the default (no-operation) as
     __do_IRQ() is compiled out.  This may affect misrouted_irq(), but
     according to Thomas Gleixner it's the correct thing to do.

 (5) handle_level_irq() is used for edge-triggered interrupts rather than
     handle_edge_irq() as the MN10300 PIC latches interrupt events even on
     masked IRQ channels, thus rendering IRQ_PENDING unnecessary.  It is
     sufficient to call mask_ack() at the start and unmask() at the end.

 (6) For level-triggered interrupts, ack() is now NULL as it's not used, and
     there is no effective ACK function on the PIC.  mask_ack() is now the
     same as mask() as the latch continues to latch, even when the channel is
     masked.

Further, the patch discards the disable() op implementation as its now the same
as the mask() op implementation, which is used instead.

It also discards the enable() op implementations as they're now the same as
the unmask() op implementations, which are used instead.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-01 09:40:43 -07:00
David Howells 08ec3c2d45 MN10300: Make sched_clock() report time since boot
Make sched_clock() report time since boot rather than time since last
timer interrupt.

Make sched_clock() expand and scale the 32-bit TSC value running at
IOCLK speed (~33MHz) to a 64-bit nanosecond counter, using cnt32_to_63()
acquired from the ARM arch and without using slow DIVU instructions
every call.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-24 16:38:17 -07:00
David Howells d1c6d2e547 MN10300: Change the fault handler to check in_atomic() not in_interrupt()
Change the MN10300 fault handler to make it check in_atomic() rather than
in_interrupt() as commit 6edaf68a87 did for other
architectures:

	Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
	Date:   Wed Dec 6 20:32:18 2006 -0800

	[PATCH] mm: arch do_page_fault() vs in_atomic()

	In light of the recent pagefault and filemap_copy_from_user work I've
	gone through all the arch pagefault handlers to make sure the
	inc_preempt_count() 'feature' works as expected.

	Several sections of code (including the new filemap_copy_from_user)
	rely on the fact that faults do not take locks under increased preempt
	count.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-11 10:36:08 -07:00
David Woodhouse 6b213e1bc2 Remove redundant CONFIG_ARCH_SUPPORTS_AOUT
We don't need this any more; arguably we never really did.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-06 19:30:20 +01:00
Adrian Bunk 7a8fc9b248 removed unused #include <linux/version.h>'s
This patch lets the files using linux/version.h match the files that
#include it.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-23 12:14:12 -07:00
Paul Mundt 18f6db95dc mn10300: Fix up __bug_table handling in module loader.
Platforms that are using GENERIC_BUG must call in to
module_bug_finalize()/module_bug_cleanup() in order to scan modules with
their own __bug_table sections that are otherwise unaccounted.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-04 17:22:17 -07:00
David Howells 02c3638089 MN10300: Wire up new system calls
Wire up system calls added in the last merge window for the MN10300 arch.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-01 13:03:48 -07:00
Johannes Weiner 4984d2d888 mn10300: use generic show_mem()
Remove arch-specific show_mem() in favor of the generic version.

This also removes the following redundant information display:

	- free pages, printed by show_free_areas()
	- pages in swapcache, printed by show_swap_cache_info()

where show_mem() calls show_free_areas(), which calls
show_swap_cache_info().

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:11 -07:00
Harvey Harrison 2682497245 mn10300: use the common ascii hex helpers
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:05 -07:00
Thomas Petazzoni 2d6ffcca62 inflate: refactor inflate malloc code
Inflate requires some dynamic memory allocation very early in the boot
process and this is provided with a set of four functions:
malloc/free/gzip_mark/gzip_release.

The old inflate code used a mark/release strategy rather than implement
free.  This new version instead keeps a count on the number of outstanding
allocations and when it hits zero, it resets the malloc arena.

This allows removing all the mark and release implementations and unifying
all the malloc/free implementations.

The architecture-dependent code must define two addresses:
 - free_mem_ptr, the address of the beginning of the area in which
   allocations should be made
 - free_mem_end_ptr, the address of the end of the area in which
   allocations should be made. If set to 0, then no check is made on
   the number of allocations, it just grows as much as needed

The architecture-dependent code can also provide an arch_decomp_wdog()
function call.  This function will be called several times during the
decompression process, and allow to notify the watchdog that the system is
still running.  If an architecture provides such a call, then it must
define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
arch_decomp_wdog().

Work initially done by Matt Mackall, updated to a recent version of the
kernel and improved by me.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:28 -07:00
Johannes Weiner 3560e249ab bootmem: replace node_boot_start in struct bootmem_data
Almost all users of this field need a PFN instead of a physical address,
so replace node_boot_start with node_min_pfn.

[Lee.Schermerhorn@hp.com: fix spurious BUG_ON() in mark_bootmem()]
Signed-off-by: Johannes Weiner <hannes@saeureba.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 10:47:20 -07:00
David Howells 34492b5834 MN10300: Fix MN10300's serial port driver to get at its tty_struct
Fix MN10300's serial port driver to get at its tty_struct as this moved
from struct uart_info into struct tty_port in patch:

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-20 17:12:35 -07:00
David Howells fc26361ef0 mn10300: provide __ucmpdi2() for MN10300
Provide __ucmpdi2() for MN10300 so that allmodconfig can be built.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:07 -07:00
David Howells 7fc7228c0b mn10300: export certain arch symbols required to build allmodconfig
Export kernel_thread() and empty_zero_page so that allmodconfig can be
built for MN10300.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-04 10:40:07 -07:00
David Howells b052beb043 MN10300: Kill linux/a.out.h inclusions
Kill linux/a.out.h inclusions in the MN10300 arch code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-16 10:20:57 -07:00
Al Viro f52111b154 [PATCH] take init_files to fs/file.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-16 17:22:20 -04:00
Robert P. J. Day 460817b9d4 mn10300: replace deprecated "TOPDIR" with newer "srctree"
This would appear to be the last reference to TOPDIR in the entire tree, after
which i'm guessing that variable can be dropped.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13 08:02:24 -07:00
Linus Torvalds 8e3e076c5a BKL: revert back to the old spinlock implementation
The generic semaphore rewrite had a huge performance regression on AIM7
(and potentially other BKL-heavy benchmarks) because the generic
semaphores had been rewritten to be simple to understand and fair.  The
latter, in particular, turns a semaphore-based BKL implementation into a
mess of scheduling.

The attempt to fix the performance regression failed miserably (see the
previous commit 00b41ec261 'Revert
"semaphore: fix"'), and so for now the simple and sane approach is to
instead just go back to the old spinlock-based BKL implementation that
never had any issues like this.

This patch also has the advantage of being reported to fix the
regression completely according to Yanmin Zhang, unlike the semaphore
hack which still left a couple percentage point regression.

As a spinlock, the BKL obviously has the potential to be a latency
issue, but it's not really any different from any other spinlock in that
respect.  We do want to get rid of the BKL asap, but that has been the
plan for several years.

These days, the biggest users are in the tty layer (open/release in
particular) and Alan holds out some hope:

  "tty release is probably a few months away from getting cured - I'm
   afraid it will almost certainly be the very last user of the BKL in
   tty to get fixed as it depends on everything else being sanely locked."

so while we're not there yet, we do have a plan of action.

Tested-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Alexander Viro <viro@ftp.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-10 20:58:02 -07:00
Ulrich Drepper d35c7b0e54 unified (weak) sys_pipe implementation
This replaces the duplicated arch-specific versions of "sys_pipe()" with
one unified implementation.  This removes almost 250 lines of duplicated
code.

It's marked __weak, so that *if* an architecture wants to override the
default implementation it can do so by simply having its own replacement
version, since many architectures use alternate calling conventions for
the 'pipe()' system call for legacy reasons (ie traditional UNIX
implementations often return the two file descriptors in registers)

I still haven't changed the cris version even though Linus says the BKL
isn't needed.  The arch maintainer can easily do it if there are really
no obstacles.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-03 13:50:33 -07:00
Christoph Lameter 59957fc31f mn10300: use kbuild.h instead of defining macros in asm-offsets.c
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:30 -07:00
Benjamin Herrenschmidt b70d3a2c59 iomap: fix 64 bits resources on 32 bits
Almost all implementations of pci_iomap() in the kernel, including the generic
lib/iomap.c one, copies the content of a struct resource into unsigned long's
which will break on 32 bits platforms with 64 bits resources.

This fixes all definitions of pci_iomap() to use resource_size_t.  I also
"fixed" the 64bits arch for consistency.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:02 -07:00
Greg Kroah-Hartman 1ba6ab11d8 PCI: remove initial bios sort of PCI devices on x86
We currently keep 2 lists of PCI devices in the system, one in the
driver core, and one all on its own.  This second list is sorted at boot
time, in "BIOS" order, to try to remain compatible with older kernels
(2.2 and earlier days).  There was also a "nosort" option to turn this
sorting off, to remain compatible with even older kernel versions, but
that just ends up being what we have been doing from 2.5 days...

Unfortunately, the second list of devices is not really ever used to 
determine the probing order of PCI devices or drivers[1].  That is done
using the driver core list instead.  This change happened back in the
early 2.5 days.

Relying on BIOS ording for the binding of drivers to specific device
names is problematic for many reasons, and userspace tools like udev
exist to properly name devices in a persistant manner if that is needed,
no reliance on the BIOS is needed.

Matt Domsch and others at Dell noticed this back in 2006, and added a
boot option to sort the PCI device lists (both of them) in a
breadth-first manner to help remain compatible with the 2.4 order, if
needed for any reason.  This option is not going away, as some systems
rely on them.

This patch removes the sorting of the internal PCI device list in "BIOS"
mode, as it's not needed at all anymore, and hasn't for many years.
I've also removed the PCI flags for this from some other arches that for
some reason defined them, but never used them.

This should not change the ordering of any drivers or device probing.

[1] The old-style pci_get_device and pci_find_device() still used this
sorting order, but there are very few drivers that use these functions,
as they are deprecated for use in this manner.  If for some reason, a
driver rely on the order and uses these functions, the breadth-first
boot option will resolve any problem.

Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-20 21:46:58 -07:00
Matthew Wilcox 64ac24e738 Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 10:42:34 -04:00
David Howells 860f7be283 MN10300: define HZ as a config option
Define HZ as a config option.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 17:12:13 -08:00
David Howells ae5e1b6cc5 MN10300: Update asb2303_defconfig
Update the ASB2303 default configuration.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-19 15:51:36 -08:00
David Howells aa409e028c MN10300: Make the kernel jump into gdbstub on a BUG
Make the kernel jump into gdbstub (if configured) on a BUG with the register
set from the BUG rather than interpolating another illegal instruction and
leaving gdbstub's idea of the process counter in unsupported_syscall() where
the original BUG was detected.

With this patch, gdbstub reports a SIGABRT to the compiler and reports the
program counter at the original BUG, allowing the execution state at the time
of the BUG to be examined with GDB.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-19 15:51:36 -08:00
David Howells 5efe92c680 MN10300: Introduce barriers to replace removed volatiles in gdbstub
Introduce into the MN10300 gdbstub a couple of barrier() calls to replace the
removed volatility of the input/output index variables for the Rx ring buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-19 15:51:36 -08:00