linux.git/arch/frv, branch v2.6.16

[PATCH] FRV: Use virtual interrupt disablement

2006-02-15T00:09:35+00:00

Make the FRV arch use virtual interrupt disablement because accesses to the
processor status register (PSR) are relatively slow and because we will
soon have the need to deal with multiple interrupt controls at the same
time (separate h/w and inter-core interrupts).

The way this is done is to dedicate one of the four integer condition code
registers (ICC2) to maintaining a virtual interrupt disablement state
whilst inside the kernel.  This uses the ICC2.Z flag (Zero) to indicate
whether the interrupts are virtually disabled and the ICC2.C flag (Carry)
to indicate whether the interrupts are physically disabled.

ICC2.Z is set to indicate interrupts are virtually disabled.  ICC2.C is set
to indicate interrupts are physically enabled.  Under normal running
conditions Z==0 and C==1.

Disabling interrupts with local_irq_disable() doesn't then actually
physically disable interrupts - it merely sets ICC2.Z to 1.  Should an
interrupt then happen, the exception prologue will note ICC2.Z is set and
branch out of line using one instruction (an unlikely BEQ).  Here it will
physically disable interrupts and clear ICC2.C.

When it comes time to enable interrupts (local_irq_enable()), this simply
clears the ICC2.Z flag and invokes a trap #2 if both Z and C flags are
clear (the HI integer condition).  This can be done with the TIHI
conditional trap instruction.

The trap then physically reenables interrupts and sets ICC2.C again.  Upon
returning the interrupt will be taken as interrupts will then be enabled.
Note that whilst processing the trap, the whole exceptions system is
disabled, and so an interrupt can't happen till it returns.

If no pending interrupt had happened, ICC2.C would still be set, the HI
condition would not be fulfilled, and no trap will happen.

Saving interrupts (local_irq_save) is simply a matter of pulling the ICC2.Z
flag out of the CCR register, shifting it down and masking it off.  This
gives a result of 0 if interrupts were enabled and 1 if they weren't.

Restoring interrupts (local_irq_restore) is then a matter of taking the
saved value mentioned previously and XOR'ing it against 1.  If it was one,
the result will be zero, and if it was zero the result will be non-zero.
This result is then used to affect the ICC2.Z flag directly (it is a
condition code flag after all).  An XOR instruction does not affect the
Carry flag, and so that bit of state is unchanged.  The two flags can then
be sampled to see if they're both zero using the trap (TIHI) as for the
unconditional reenablement (local_irq_enable).

This patch also:

 (1) Modifies the debugging stub (break.S) to handle single-stepping crossing
     into the trap #2 handler and into virtually disabled interrupts.

 (2) Removes superseded fixup pointers from the second instructions in the trap
     tables (there's no a separate fixup table for this).

 (3) Declares the trap #3 vector for use in .org directives in the trap table.

 (4) Moves irq_enter() and irq_exit() in do_IRQ() to avoid problems with
     virtual interrupt handling, and removes the duplicate code that has now
     been folded into irq_exit() (softirq and preemption handling).

 (5) Tells the compiler in the arch Makefile that ICC2 is now reserved.

 (6) Documents the in-kernel ABI, including the virtual interrupts.

 (7) Renames the old irq management functions to different names.

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] FRV: Miscellaneous fixes

2006-02-15T00:09:35+00:00

Make various alterations and fixes to the FRV arch:

 (1) Resyncs the FRV system call collection with the i386 arch.

 (2) Discards __iounmap() as it's not used.

 (3) Fixes the use of the SWAP/SWAPI instruction to get the arguments the right
     way around in atomic.h, and also to get the asm constraints correct.

 (4) Moves copy_to/from_user_page() to asm/cacheflush.h to be consistent with
     other archs.

Signed-off-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] hrtimer: round up relative start time on low-res arches

2006-02-15T00:09:35+00:00

CONFIG_TIME_LOW_RES is a temporary way for architectures to signal that
they simply return xtime in do_gettimeoffset().  In this corner-case we
want to round up by resolution when starting a relative timer, to avoid
short timeouts.  This will go away with the GTOD framework.

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

[PATCH] Handle TIF_RESTORE_SIGMASK for FRV

2006-01-19T03:20:29+00:00

Handle TIF_RESTORE_SIGMASK as added by David Woodhouse's patch entitled:

        [PATCH] 2/3 Add TIF_RESTORE_SIGMASK support for arch/powerpc
        [PATCH] 3/3 Generic sys_rt_sigsuspend

It does the following:

 (1) Declares TIF_RESTORE_SIGMASK for FRV.

 (2) Invokes it over to do_signal() when TIF_RESTORE_SIGMASK is set.

 (3) Makes do_signal() support TIF_RESTORE_SIGMASK, using the signal mask saved
     in current->saved_sigmask.

 (4) Discards sys_rt_sigsuspend() from the arch, using the generic one instead.

 (5) Makes sys_sigsuspend() save the signal mask and set TIF_RESTORE_SIGMASK
     rather than attempting to fudge the return registers.

 (6) Makes sys_sigsuspend() return -ERESTARTNOHAND rather than looping
     intrinsically.

 (7) Makes setup_frame(), setup_rt_frame() and handle_signal() return 0 or
     -EFAULT rather than true/false to be consistent with the rest of the
      kernel.

Due to the fact do_signal() is then only called from one place:

 (8) Make do_signal() no longer have a return value is it was just being
     ignored; force_sig() takes care of this.

 (9) Discards the old sigmask argument to do_signal() as it's no longer
     necessary.

This patch depends on the FRV signalling patches as well as the
sys_rt_sigsuspend patch.

Signed-off-by: David Howells 
Signed-off-by: David Woodhouse 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] frv: task_thread_info(), task_stack_page()

2006-01-12T17:08:54+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge ssh://master.kernel.org/pub/scm/linux/kernel/git/sam/kbuild

2006-01-10T16:21:33+00:00

Fix up some trivial conflicts in {i386|ia64}/Makefile

[PATCH] dump_thread() cleanup

2006-01-10T16:01:25+00:00


)

From: Adrian Bunk 

- create one common dump_thread() prototype in kernel.h

- dump_thread() is only used in fs/binfmt_aout.c and can therefore be
  removed on all architectures where CONFIG_BINFMT_AOUT is not
  available

Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] "tiny-make-id16-support-optional" fixes

2006-01-10T16:01:23+00:00

It seems the "make UID16 support optional" patch was checked when it
edited the -tiny tree some time ago, but it wasn't checked whether it
still matches the current situation when it was submitted for inclusion
in -mm. This patch fixes the following bugs:
- ARCH_S390X does no longer exist, nowadays this has to be expressed
  through (S390 && 64BIT)
- in five architecture specific Kconfig files the UID16 options
  weren't removed

Additionally, it changes the fragile negative dependencies of UID16 to
positive dependencies (new architectures are more likely to not require
UID16 support).

Signed-off-by: Adrian Bunk 
Acked-by: Matt Mackall 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] PCI: arch: pci_find_device remove (frv/mb93090-mb00/pci-irq.c)

2006-01-09T20:13:15+00:00

Signed-off-by: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

[PATCH] PCI: pci_find_device remove (frv/mb93090-mb00/pci-frv.c)

2006-01-09T20:13:15+00:00

Signed-off-by: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman