Overhaul of the SMP code. Several portions of the SMP kernel support have

been made machine independent and various other adjustments have been made
to support Alpha SMP.

- It splits the per-process portions of hardclock() and statclock() off
  into hardclock_process() and statclock_process() respectively.  hardclock()
  and statclock() call the *_process() functions for the current process so
  that UP systems will run as before.  For SMP systems, it is simply necessary
  to ensure that all other processors execute the *_process() functions when the
  main clock functions are triggered on one CPU by an interrupt.  For the alpha
  4100, clock interrupts are delievered in a staggered broadcast fashion, so
  we simply call hardclock/statclock on the boot CPU and call the *_process()
  functions on the secondaries.  For x86, we call statclock and hardclock as
  usual and then call forward_hardclock/statclock in the MD code to send an IPI
  to cause the AP's to execute forwared_hardclock/statclock which then call the
  *_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
  involve less hackery.  Now the cpu doing the forward sets any flags, etc. and
  sends a very simple IPI_AST to the other cpu(s).  AST IPIs now just basically
  return so that they can execute ast() and don't bother with setting the
  astpending or needresched flags themselves.  This also removes the loop in
  forward_signal() as sched_lock closes the race condition that the loop worked
  around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
  a process to act on rather than assuming curproc so that they can be used to
  implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
  header sys/smp.h declares MI SMP variables and API's.   The IPI API's from
  machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
  SLIST of globaldata structures has become MI and moved into subr_smp.c.
  Also, the globaldata list is only available if SMP support is compiled in.

Reviewed by:	jake, peter
Looked over by:	eivind

1 files changed, 43 insertions, 112 deletions

diff --git a/sys/i386/isa/apic_vector.s b/sys/i386/isa/apic_vector.s
index 3f0521f..5c68f81 100644
--- a/sys/i386/isa/apic_vector.s
+++ b/sys/i386/isa/apic_vector.s
@@ -182,7 +182,6 @@ Xspuriousint:
 
 	iret
 
-
 /*
  * Handle TLB shootdowns.
  */
@@ -211,71 +210,61 @@ Xinvltlb:
 	popl	%eax
 	iret
 
-
 /*
- * Executed by a CPU when it receives an Xcpucheckstate IPI from another CPU,
- *
- *  - Stores current cpu state in checkstate_cpustate[cpuid]
- *      0 == user, 1 == sys, 2 == intr
- *  - Stores current process in checkstate_curproc[cpuid]
- *
- *  - Signals its receipt by setting bit cpuid in checkstate_probed_cpus.
- *
- * stack: 0->ds, 4->fs, 8->ebx, 12->eax, 16->eip, 20->cs, 24->eflags
+ * Forward hardclock to another CPU.  Pushes a trapframe and calls
+ * forwarded_hardclock().
  */
-
 	.text
 	SUPERALIGN_TEXT
-	.globl Xcpucheckstate
-	.globl checkstate_cpustate
-	.globl checkstate_curproc
-	.globl checkstate_pc
-Xcpucheckstate:
-	pushl	%eax
-	pushl	%ebx		
-	pushl	%ds			/* save current data segment */
-	pushl	%fs
-
-	movl	$KDSEL, %eax
-	mov	%ax, %ds		/* use KERNEL data segment */
+	.globl Xhardclock
+Xhardclock:
+	PUSH_FRAME
+	movl	$KDSEL, %eax	/* reload with kernel's data segment */
+	mov	%ax, %ds
+	mov	%ax, %es
 	movl	$KPSEL, %eax
 	mov	%ax, %fs
 
 	movl	$0, lapic+LA_EOI	/* End Of Interrupt to APIC */
 
-	movl	$0, %ebx		
-	movl	20(%esp), %eax	
-	andl	$3, %eax
-	cmpl	$3, %eax
-	je	1f
-	testl	$PSL_VM, 24(%esp)
-	jne	1f
-	incl	%ebx			/* system or interrupt */
-1:	
-	movl	PCPU(CPUID), %eax
-	movl	%ebx, checkstate_cpustate(,%eax,4)
-	movl	PCPU(CURPROC), %ebx
-	movl	%ebx, checkstate_curproc(,%eax,4)
-
-	movl	16(%esp), %ebx
-	movl	%ebx, checkstate_pc(,%eax,4)
+	movl	PCPU(CURPROC),%ebx
+	incl	P_INTR_NESTING_LEVEL(%ebx)
+	call	forwarded_hardclock
+	decl	P_INTR_NESTING_LEVEL(%ebx)
+	MEXITCOUNT
+	jmp	doreti
 
-	lock				/* checkstate_probed_cpus |= (1<<id) */
-	btsl	%eax, checkstate_probed_cpus
+/*
+ * Forward statclock to another CPU.  Pushes a trapframe and calls
+ * forwarded_statclock().
+ */
+	.text
+	SUPERALIGN_TEXT
+	.globl Xstatclock
+Xstatclock:
+	PUSH_FRAME
+	movl	$KDSEL, %eax	/* reload with kernel's data segment */
+	mov	%ax, %ds
+	mov	%ax, %es
+	movl	$KPSEL, %eax
+	mov	%ax, %fs
 
-	popl	%fs
-	popl	%ds			/* restore previous data segment */
-	popl	%ebx
-	popl	%eax
-	iret
+	movl	$0, lapic+LA_EOI	/* End Of Interrupt to APIC */
 
+	FAKE_MCOUNT(13*4(%esp))
+	movl	PCPU(CURPROC),%ebx
+	incl	P_INTR_NESTING_LEVEL(%ebx)
+	call	forwarded_statclock
+	decl	P_INTR_NESTING_LEVEL(%ebx)
+	MEXITCOUNT
+	jmp	doreti
 
 /*
  * Executed by a CPU when it receives an Xcpuast IPI from another CPU,
  *
- *  - Signals its receipt by clearing bit cpuid in checkstate_need_ast.
- *
- *  - We need a better method of triggering asts on other cpus.
+ * The other CPU has already executed aston() or need_resched() on our
+ * current process, so we simply need to ack the interrupt and return
+ * via doreti to run ast().
  */
 
 	.text
@@ -289,40 +278,12 @@ Xcpuast:
 	movl	$KPSEL, %eax
 	mov	%ax, %fs
 
-	movl	PCPU(CPUID), %eax
-	lock				/* checkstate_need_ast &= ~(1<<id) */
-	btrl	%eax, checkstate_need_ast
 	movl	$0, lapic+LA_EOI	/* End Of Interrupt to APIC */
 
-	lock
-	btsl	%eax, checkstate_pending_ast
-	jc	1f
-
 	FAKE_MCOUNT(13*4(%esp))
 
-	MTX_LOCK_SPIN(sched_lock, 0)
-	movl	PCPU(CURPROC),%ebx
-	orl	$PS_ASTPENDING, P_SFLAG(%ebx)
-	
-	movl	PCPU(CPUID), %eax
-	lock	
-	btrl	%eax, checkstate_pending_ast
-	lock	
-	btrl	%eax, CNAME(resched_cpus)
-	jnc	2f
-	orl	$PS_NEEDRESCHED, P_SFLAG(%ebx)
-	lock
-	incl	CNAME(want_resched_cnt)
-2:		
-	MTX_UNLOCK_SPIN(sched_lock)
-	lock
-	incl	CNAME(cpuast_cnt)
 	MEXITCOUNT
 	jmp	doreti
-1:
-	/* We are already in the process of delivering an ast for this CPU */
-	POP_FRAME
-	iret			
 
 /*
  * Executed by a CPU when it receives an Xcpustop IPI from another CPU,
@@ -331,7 +292,6 @@ Xcpuast:
  *  - Waits for permission to restart.
  *  - Signals its restart.
  */
-
 	.text
 	SUPERALIGN_TEXT
 	.globl Xcpustop
@@ -357,20 +317,19 @@ Xcpustop:
 	pushl	%eax
 	call	CNAME(savectx)		/* Save process context */
 	addl	$4, %esp
-	
 		
 	movl	PCPU(CPUID), %eax
 
 	lock
-	btsl	%eax, stopped_cpus	/* stopped_cpus |= (1<<id) */
+	btsl	%eax, CNAME(stopped_cpus) /* stopped_cpus |= (1<<id) */
 1:
-	btl	%eax, started_cpus	/* while (!(started_cpus & (1<<id))) */
+	btl	%eax, CNAME(started_cpus) /* while (!(started_cpus & (1<<id))) */
 	jnc	1b
 
 	lock
-	btrl	%eax, started_cpus	/* started_cpus &= ~(1<<id) */
+	btrl	%eax, CNAME(started_cpus) /* started_cpus &= ~(1<<id) */
 	lock
-	btrl	%eax, stopped_cpus	/* stopped_cpus &= ~(1<<id) */
+	btrl	%eax, CNAME(stopped_cpus) /* stopped_cpus &= ~(1<<id) */
 
 	test	%eax, %eax
 	jnz	2f
@@ -492,34 +451,6 @@ _xhits:
 	.space	(NCPU * 4), 0
 #endif /* COUNT_XINVLTLB_HITS */
 
-/* variables used by stop_cpus()/restart_cpus()/Xcpustop */
-	.globl stopped_cpus, started_cpus
-stopped_cpus:
-	.long	0
-started_cpus:
-	.long	0
-
-	.globl checkstate_probed_cpus
-checkstate_probed_cpus:
-	.long	0	
-	.globl checkstate_need_ast
-checkstate_need_ast:
-	.long	0
-checkstate_pending_ast:
-	.long	0
-	.globl CNAME(resched_cpus)
-	.globl CNAME(want_resched_cnt)
-	.globl CNAME(cpuast_cnt)
-	.globl CNAME(cpustop_restartfunc)
-CNAME(resched_cpus):
-	.long 0
-CNAME(want_resched_cnt):
-	.long 0
-CNAME(cpuast_cnt):
-	.long 0
-CNAME(cpustop_restartfunc):
-	.long 0
-
 	.globl	apic_pin_trigger
 apic_pin_trigger:
 	.long	0