1. 14 Feb, 2006 2 commits
    • David Howells's avatar
      [PATCH] FRV: Use virtual interrupt disablement · 28baebae
      David Howells authored
      
      
      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: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      28baebae
    • David Howells's avatar
      [PATCH] FRV: Miscellaneous fixes · 68f624fc
      David Howells authored
      
      
      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: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      68f624fc
  2. 18 Jan, 2006 1 commit
    • David Howells's avatar
      [PATCH] Handle TIF_RESTORE_SIGMASK for FRV · a411aee9
      David Howells authored
      
      
      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: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      a411aee9
  3. 12 Jan, 2006 1 commit
  4. 10 Jan, 2006 1 commit
  5. 08 Jan, 2006 4 commits
  6. 06 Jan, 2006 3 commits
  7. 28 Nov, 2005 1 commit
    • David Howells's avatar
      [PATCH] FRV: Make the FRV arch work again · 8080f231
      David Howells authored
      
      
      The attached patch implements a bunch of small changes to the FRV arch to
      make it work again.
      
      It deals with the following problems:
      
       (1) SEM_DEBUG should be SEMAPHORE_DEBUG.
      
       (2) The argument list to pcibios_penalize_isa_irq() has changed.
      
       (3) CONFIG_HIGHMEM can't be used directly in #if as it may not be defined.
      
       (4) page->private is no longer directly accessible.
      
       (5) linux/hardirq.h assumes asm/hardirq.h will include linux/irq.h
      
       (6) The IDE MMIO access functions are given pointers, not integers, and so
           get type casting errors.
      
       (7) __pa() is passed an explicit u64 type in drivers/char/mem.c, but that
           can't be cast directly to a pointer on a 32-bit platform.
      
       (8) SEMAPHORE_DEBUG should not be contingent on WAITQUEUE_DEBUG as that no
           longer exists.
      
       (9) PREEMPT_ACTIVE is too low a value.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8080f231
  8. 13 Nov, 2005 1 commit
  9. 09 Nov, 2005 1 commit
    • Nick Piggin's avatar
      [PATCH] sched: disable preempt in idle tasks · 5bfb5d69
      Nick Piggin authored
      
      
      Run idle threads with preempt disabled.
      
      Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()).
      How did it ever work before?
      
      Might fix the CPU hotplugging hang which Nigel Cunningham noted.
      
      We think the bug hits if the idle thread is preempted after checking
      need_resched() and before going to sleep, then the CPU offlined.
      
      After calling stop_machine_run, the CPU eventually returns from preemption and
      into the idle thread and goes to sleep.  The CPU will continue executing
      previous idle and have no chance to call play_dead.
      
      By disabling preemption until we are ready to explicitly schedule, this bug is
      fixed and the idle threads generally become more robust.
      
      From: alexs <ashepard@u.washington.edu>
      
        PPC build fix
      
      From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
      
        MIPS build fix
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Signed-off-by: default avatarYoichi Yuasa <yuasa@hh.iij4u.or.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5bfb5d69
  10. 07 Nov, 2005 1 commit
  11. 30 Oct, 2005 2 commits
  12. 29 Oct, 2005 1 commit
  13. 09 Sep, 2005 1 commit
  14. 07 Sep, 2005 1 commit
  15. 05 Sep, 2005 1 commit
  16. 29 Aug, 2005 1 commit
    • Steven Rostedt's avatar
      [PATCH] convert signal handling of NODEFER to act like other Unix boxes. · 69be8f18
      Steven Rostedt authored
      
      
      It has been reported that the way Linux handles NODEFER for signals is
      not consistent with the way other Unix boxes handle it.  I've written a
      program to test the behavior of how this flag affects signals and had
      several reports from people who ran this on various Unix boxes,
      confirming that Linux seems to be unique on the way this is handled.
      
      The way NODEFER affects signals on other Unix boxes is as follows:
      
      1) If NODEFER is set, other signals in sa_mask are still blocked.
      
      2) If NODEFER is set and the signal is in sa_mask, then the signal is
      still blocked. (Note: this is the behavior of all tested but Linux _and_
      NetBSD 2.0 *).
      
      The way NODEFER affects signals on Linux:
      
      1) If NODEFER is set, other signals are _not_ blocked regardless of
      sa_mask (Even NetBSD doesn't do this).
      
      2) If NODEFER is set and the signal is in sa_mask, then the signal being
      handled is not blocked.
      
      The patch converts signal handling in all current Linux architectures to
      the way most Unix boxes work.
      
      Unix boxes that were tested:  DU4, AIX 5.2, Irix 6.5, NetBSD 2.0, SFU
      3.5 on WinXP, AIX 5.3, Mac OSX, and of course Linux 2.6.13-rcX.
      
      * NetBSD was the only other Unix to behave like Linux on point #2. The
      main concern was brought up by point #1 which even NetBSD isn't like
      Linux.  So with this patch, we leave NetBSD as the lonely one that
      behaves differently here with #2.
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      69be8f18
  17. 25 Jun, 2005 2 commits
    • Christoph Lameter's avatar
      [PATCH] Cleanup patch for process freezing · 3e1d1d28
      Christoph Lameter authored
      
      
      1. Establish a simple API for process freezing defined in linux/include/sched.h:
      
         frozen(process)		Check for frozen process
         freezing(process)		Check if a process is being frozen
         freeze(process)		Tell a process to freeze (go to refrigerator)
         thaw_process(process)	Restart process
         frozen_process(process)	Process is frozen now
      
      2. Remove all references to PF_FREEZE and PF_FROZEN from all
         kernel sources except sched.h
      
      3. Fix numerous locations where try_to_freeze is manually done by a driver
      
      4. Remove the argument that is no longer necessary from two function calls.
      
      5. Some whitespace cleanup
      
      6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
         cleared before setting PF_FROZEN, recalc_sigpending does not check
         PF_FROZEN).
      
      This patch does not address the problem of freeze_processes() violating the rule
      that a task may only modify its own flags by setting PF_FREEZE. This is not clean
      in an SMP environment. freeze(process) is therefore not SMP safe!
      Signed-off-by: default avatarChristoph Lameter <christoph@lameter.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3e1d1d28
    • Russell King's avatar
      [PATCH] Serial: remove unnecessary register_serial/unregister_serial · 7919a693
      Russell King authored
      
      
      A couple of drivers declare register_serial/unregister_serial prototypes
      but don't use them.  FRV contains a commented out call to register_serial.
      Since these are deprecated, remove these unnecessary references.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      7919a693
  18. 01 May, 2005 1 commit
  19. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      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!
      1da177e4