[src/trunk]: src/sys/arch/arm/arm32 Implement scheduler lock protocol, this f...

[chris <chris%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/310269dcf7c4
branches:  trunk
changeset: 526955:310269dcf7c4
user:      chris <chris%NetBSD.org@localhost>
date:      Tue May 14 19:22:34 2002 +0000

description:
Implement scheduler lock protocol, this fixes PR arm/10863.

Also add correct locking when freeing pages in pmap_destroy (fix from potr)

This now means that arm32 kernels can be built with LOCKDEBUG enabled. (only tested on cats though)

diffstat:

 sys/arch/arm/arm32/cpuswitch.S |  65 ++++++++++++++++++++++++++++++++---------
 sys/arch/arm/arm32/pmap.c      |  10 +++++-
 2 files changed, 58 insertions(+), 17 deletions(-)

diffs (191 lines):

diff -r a25b81a9b170 -r 310269dcf7c4 sys/arch/arm/arm32/cpuswitch.S
--- a/sys/arch/arm/arm32/cpuswitch.S    Tue May 14 18:57:31 2002 +0000
+++ b/sys/arch/arm/arm32/cpuswitch.S    Tue May 14 19:22:34 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpuswitch.S,v 1.6 2002/01/25 19:19:24 thorpej Exp $    */
+/*     $NetBSD: cpuswitch.S,v 1.7 2002/05/14 19:22:34 chris Exp $      */
 
 /*
  * Copyright (c) 1994-1998 Mark Brinicombe.
@@ -231,30 +231,35 @@
 /*
  * Idle loop, exercised while waiting for a process to wake up.
  */
+/* LINTSTUB: Ignore */
 ASENTRY_NP(idle)
+
+#if defined(LOCKDEBUG)
+       bl      _C_LABEL(sched_unlock_idle)
+#endif
        /* Enable interrupts */
        IRQenable
 
-       /* XXX - r1 needs to be preserved for cpu_switch */
-       mov     r7, r1
        ldr     r3, Lcpufuncs
        mov     r0, #0
        add     lr, pc, #Lidle_slept - . - 8
        ldr     pc, [r3, #CF_SLEEP]
 
+       /* should also call the uvm pageidlezero stuff */
+
 Lidle_slept:
-       mov     r1, r7
 
        /* Disable interrupts while we check for an active queue */
        IRQdisable
+#if defined(LOCKDEBUG)
+       bl      _C_LABEL(sched_lock_idle)
+#endif
        ldr     r7, Lwhichqs
        ldr     r3, [r7]
        teq     r3, #0x00000000
-       bne     sw1
 
-       /* All processes are still asleep so idle a while longer */
-       b       _ASM_LABEL(idle)
-
+       beq     _ASM_LABEL(idle)
+       b       Lidle_ret
 
 /*
  * Find a new process to run, save the current context and
@@ -287,9 +292,15 @@
        ldr     r7, Lcurpcb
        str     r0, [r7]
 
-       /* Lower the spl level to spl0 and get the current spl level. */
+       /* stash the old proc */
        mov     r7, r1
 
+#if defined(LOCKDEBUG)
+       /* release the sched_lock before handling interrupts */
+       bl      _C_LABEL(sched_unlock_idle)
+#endif
+
+       /* Lower the spl level to spl0 and get the current spl level. */
 #ifdef __NEWINTR
        mov     r0, #(IPL_NONE)
        bl      _C_LABEL(_spllower)
@@ -305,14 +316,19 @@
        /* Push the old spl level onto the stack */
        str     r0, [sp, #-0x0004]!
 
-       mov     r1, r7
+       mov     r5, r7
 
        /* First phase : find a new process */
 
-       /* rem: r1 = old proc */
+       /* rem: r5 = old proc */
+
 
-switch_search:
+Lswitch_search:
        IRQdisable
+#if defined(LOCKDEBUG)
+       bl      _C_LABEL(sched_lock_idle)
+#endif
+
 
        /* Do we have any active queues  */
        ldr     r7, Lwhichqs
@@ -321,8 +337,11 @@
        /* If not we must idle until we do. */
        teq     r3, #0x00000000
        beq     _ASM_LABEL(idle)
+Lidle_ret:
 
-sw1:
+       /* restore old proc */
+       mov     r1, r5
+
        /* rem: r1 = old proc */
        /* rem: r3 = whichqs */
        /* rem: interrupts are disabled */
@@ -407,6 +426,15 @@
         */
        str     r0, [r6, #(P_BACK)]
 
+#if defined(LOCKDEBUG)
+       /*
+        * unlock the sched_lock, but leave interrupts off, for now.
+        */
+       mov     r7, r1
+       bl      _C_LABEL(sched_unlock_idle)
+       mov     r1, r7
+#endif
+
        /* p->p_cpu initialized in fork1() for single-processor */
 
        /* Process is now on a processor. */
@@ -569,7 +597,13 @@
 Lkernel_map:
        .word   _C_LABEL(kernel_map)
 
+/*
+ * void switch_exit(struct proc *p);
+ * Switch to proc0's saved context and deallocate the address space and kernel
+ * stack for p.  Then jump into cpu_switch(), as if we were in proc0 all along.
+ */
 
+/* LINTSTUB: Func: void switch_exit(struct proc *p) */
 ENTRY(switch_exit)
        /*
         * r0 = proc
@@ -633,9 +667,10 @@
        mov     r0, #0x00000000
        str     r0, [r1]
 
-        ldr     r1, Lproc0
-       b       switch_search
+       ldr     r5, Lproc0
+       b       Lswitch_search
 
+/* LINTSTUB: Func: void savectx(struct pcb *pcb) */
 ENTRY(savectx)
        /*
         * r0 = pcb
diff -r a25b81a9b170 -r 310269dcf7c4 sys/arch/arm/arm32/pmap.c
--- a/sys/arch/arm/arm32/pmap.c Tue May 14 18:57:31 2002 +0000
+++ b/sys/arch/arm/arm32/pmap.c Tue May 14 19:22:34 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.96 2002/04/24 17:35:10 thorpej Exp $        */
+/*     $NetBSD: pmap.c,v 1.97 2002/05/14 19:22:34 chris Exp $  */
 
 /*
  * Copyright (c) 2002 Wasabi Systems, Inc.
@@ -143,7 +143,7 @@
 #include <machine/param.h>
 #include <arm/arm32/katelib.h>
 
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.96 2002/04/24 17:35:10 thorpej Exp $");        
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.97 2002/05/14 19:22:34 chris Exp $");        
 #ifdef PMAP_DEBUG
 #define        PDEBUG(_lev_,_stat_) \
        if (pmap_debug_level >= (_lev_)) \
@@ -1597,11 +1597,16 @@
         * entries looking for pt's
         * taken from i386 pmap.c
         */
+       /*
+        * vmobjlock must be held while freeing pages
+        */
+       simple_lock(&pmap->pm_obj.vmobjlock);
        while ((page = TAILQ_FIRST(&pmap->pm_obj.memq)) != NULL) {
                KASSERT((page->flags & PG_BUSY) == 0);
                page->wire_count = 0;
                uvm_pagefree(page);
        }
+       simple_unlock(&pmap->pm_obj.vmobjlock);
        
        /* Free the page dir */
        pmap_freepagedir(pmap);
@@ -2999,6 +3004,7 @@
        simple_lock(&pg->mdpage.pvh_slock);
        printf("%s %08lx:", m, phys);
        if (pg->mdpage.pvh_list == NULL) {
+               simple_unlock(&pg->mdpage.pvh_slock);
                printf(" no mappings\n");
                return;
        }