From fe8c5e17acbb049222347358029f10e2909c06f7 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Sun, 7 Dec 2003 04:20:40 +0000
Subject: [PATCH] Add additional functionality to the upcall support to allow
 us to wait for an upcall instead of spin.

Also fix a bug in the trap code.  %gs faults have to be handled in nested
interrupts because %gs is not saved and restored.  It is also possible that
%fs may have to be handled the same way, but I am not sure yet.
---
 sys/i386/i386/trap.c          | 17 +++++++++++------
 sys/kern/kern_upcall.c        | 10 +++++++++-
 sys/platform/pc32/i386/trap.c | 17 +++++++++++------
 sys/sys/proc.h                |  3 ++-
 sys/sys/thread.h              |  4 ++--
 sys/sys/upcall.h              |  3 ++-
 6 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index 21f1e259f6..1c56b05731 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -36,7 +36,7 @@
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
  * $FreeBSD: src/sys/i386/i386/trap.c,v 1.147.2.11 2003/02/27 19:09:59 luoqi Exp $
- * $DragonFly: src/sys/i386/i386/Attic/trap.c,v 1.43 2003/11/21 05:29:07 dillon Exp $
+ * $DragonFly: src/sys/i386/i386/Attic/trap.c,v 1.44 2003/12/07 04:20:39 dillon Exp $
  */
 
 /*
@@ -634,6 +634,16 @@ kernel_trap:
 			goto out2;					\
 		}							\
 	} while (0)
+			/*
+			 * Since we don't save %gs across an interrupt
+			 * frame this check must occur outside the intr
+			 * nesting level check.
+			 */
+			if (frame.tf_eip == (int)cpu_switch_load_gs) {
+				curthread->td_pcb->pcb_gs = 0;
+				psignal(p, SIGBUS);
+				goto out2;
+			}
 			if (mycpu->gd_intr_nesting_level == 0) {
 				/*
 				 * Invalid %fs's and %gs's can be created using
@@ -644,11 +654,6 @@ kernel_trap:
 				 * (XXX) so that we can continue, and generate
 				 * a signal.
 				 */
-				if (frame.tf_eip == (int)cpu_switch_load_gs) {
-					curthread->td_pcb->pcb_gs = 0;
-					psignal(p, SIGBUS);
-					goto out2;
-				}
 				MAYBE_DORETI_FAULT(doreti_iret,
 						   doreti_iret_fault);
 				MAYBE_DORETI_FAULT(doreti_popl_ds,
diff --git a/sys/kern/kern_upcall.c b/sys/kern/kern_upcall.c
index cbbdbe81db..2e1d381f62 100644
--- a/sys/kern/kern_upcall.c
+++ b/sys/kern/kern_upcall.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $DragonFly: src/sys/kern/kern_upcall.c,v 1.3 2003/12/04 20:35:09 dillon Exp $
+ * $DragonFly: src/sys/kern/kern_upcall.c,v 1.4 2003/12/07 04:20:40 dillon Exp $
  */
 
 /*
@@ -137,6 +137,8 @@ upc_control(struct upc_control_args *uap)
 		error = 0;
 		targp = vu->vu_proc;
 		targp->p_flag |= P_UPCALLPEND;
+		if (targp->p_flag & P_UPCALLWAIT)
+		    wakeup(&targp->p_upcall);
 #ifdef SMP
 		if (targp->p_thread->td_gd != mycpu)
 		    lwkt_send_ipiq(targp->p_thread->td_gd->gd_cpuid, sigupcall_remote, targp);
@@ -205,6 +207,7 @@ upc_control(struct upc_control_args *uap)
 	break;
     case UPC_CONTROL_POLL:
     case UPC_CONTROL_POLLANDCLEAR:
+    case UPC_CONTROL_WAIT:
 	/*
 	 * If upcid is -1 poll for the first pending upcall and return the
 	 * id or 0 if no upcalls are pending.
@@ -229,6 +232,11 @@ upc_control(struct upc_control_args *uap)
 		break;
 	    }
 	}
+	if (uap->cmd == UPC_CONTROL_WAIT && vu == NULL) {
+	    p->p_flag |= P_UPCALLWAIT;
+	    tsleep(&p->p_upcall, PCATCH, "wupcall", 0);
+	    p->p_flag &= ~P_UPCALLWAIT;
+	}
 	break;
     default:
 	error = EINVAL;
diff --git a/sys/platform/pc32/i386/trap.c b/sys/platform/pc32/i386/trap.c
index b7acd58bfd..08b0b2274b 100644
--- a/sys/platform/pc32/i386/trap.c
+++ b/sys/platform/pc32/i386/trap.c
@@ -36,7 +36,7 @@
  *
  *	from: @(#)trap.c	7.4 (Berkeley) 5/13/91
  * $FreeBSD: src/sys/i386/i386/trap.c,v 1.147.2.11 2003/02/27 19:09:59 luoqi Exp $
- * $DragonFly: src/sys/platform/pc32/i386/trap.c,v 1.43 2003/11/21 05:29:07 dillon Exp $
+ * $DragonFly: src/sys/platform/pc32/i386/trap.c,v 1.44 2003/12/07 04:20:39 dillon Exp $
  */
 
 /*
@@ -634,6 +634,16 @@ kernel_trap:
 			goto out2;					\
 		}							\
 	} while (0)
+			/*
+			 * Since we don't save %gs across an interrupt
+			 * frame this check must occur outside the intr
+			 * nesting level check.
+			 */
+			if (frame.tf_eip == (int)cpu_switch_load_gs) {
+				curthread->td_pcb->pcb_gs = 0;
+				psignal(p, SIGBUS);
+				goto out2;
+			}
 			if (mycpu->gd_intr_nesting_level == 0) {
 				/*
 				 * Invalid %fs's and %gs's can be created using
@@ -644,11 +654,6 @@ kernel_trap:
 				 * (XXX) so that we can continue, and generate
 				 * a signal.
 				 */
-				if (frame.tf_eip == (int)cpu_switch_load_gs) {
-					curthread->td_pcb->pcb_gs = 0;
-					psignal(p, SIGBUS);
-					goto out2;
-				}
 				MAYBE_DORETI_FAULT(doreti_iret,
 						   doreti_iret_fault);
 				MAYBE_DORETI_FAULT(doreti_popl_ds,
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 224a79e560..fe26459015 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -37,7 +37,7 @@
  *
  *	@(#)proc.h	8.15 (Berkeley) 5/19/95
  * $FreeBSD: src/sys/sys/proc.h,v 1.99.2.9 2003/06/06 20:21:32 tegge Exp $
- * $DragonFly: src/sys/sys/proc.h,v 1.37 2003/11/21 22:46:13 dillon Exp $
+ * $DragonFly: src/sys/sys/proc.h,v 1.38 2003/12/07 04:20:38 dillon Exp $
  */
 
 #ifndef _SYS_PROC_H_
@@ -287,6 +287,7 @@ struct	proc {
 #define	P_ALTSTACK	0x4000000 /* have alternate signal stack */
 #define	P_INEXEC	0x8000000 /* Process is in execve(). */
 #define P_PASSIVE_ACQ	0x10000000 /* Passive acquire cpu (see kern_switch) */
+#define	P_UPCALLWAIT	0x20000000 /* Wait for upcall or signal */
 
 #ifdef _KERNEL
 
diff --git a/sys/sys/thread.h b/sys/sys/thread.h
index b03d1f201f..9cbe1774c5 100644
--- a/sys/sys/thread.h
+++ b/sys/sys/thread.h
@@ -7,7 +7,7 @@
  * Types which must already be defined when this header is included by
  * userland:	struct md_thread
  * 
- * $DragonFly: src/sys/sys/thread.h,v 1.37 2003/11/21 22:46:13 dillon Exp $
+ * $DragonFly: src/sys/sys/thread.h,v 1.38 2003/12/07 04:20:38 dillon Exp $
  */
 
 #ifndef _SYS_THREAD_H_
@@ -191,7 +191,7 @@ struct thread {
 #define TDF_PREEMPT_DONE	0x0008	/* acknowledge preemption complete */
 #define TDF_IDLE_NOHLT		0x0010	/* we need to spin */
 
-#define TDF_UNUSED0100		0x0100
+#define TDF_SYSTHREAD		0x0100	/* system thread */
 #define TDF_ALLOCATED_THREAD	0x0200	/* zalloc allocated thread */
 #define TDF_ALLOCATED_STACK	0x0400	/* zalloc allocated stack */
 #define TDF_VERBOSE		0x0800	/* verbose on exit */
diff --git a/sys/sys/upcall.h b/sys/sys/upcall.h
index 18deca7bc2..bf7b279e43 100644
--- a/sys/sys/upcall.h
+++ b/sys/sys/upcall.h
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $DragonFly: src/sys/sys/upcall.h,v 1.6 2003/12/07 02:14:20 dillon Exp $
+ * $DragonFly: src/sys/sys/upcall.h,v 1.7 2003/12/07 04:20:38 dillon Exp $
  */
 
 #ifndef _SYS_UPCALL_H_
@@ -46,6 +46,7 @@ struct upcall {
 #define UPC_CONTROL_DELETE		3
 #define UPC_CONTROL_POLL		4
 #define UPC_CONTROL_POLLANDCLEAR	5
+#define UPC_CONTROL_WAIT		6
 
 #define UPC_CRITADD			32	/* NOTE! same as TDPRI_CRIT */
 
-- 
2.41.0