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xen_intr.c revision 1.4 
      1 /*	$NetBSD: xen_intr.c,v 1.4 2008/04/21 15:15:34 cegger Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998, 2001 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum, and by Jason R. Thorpe.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: xen_intr.c,v 1.4 2008/04/21 15:15:34 cegger Exp $");
     41 
     42 #include <sys/param.h>
     43 
     44 #include <machine/cpu.h>
     45 #include <machine/intr.h>
     46 
     47 /*
     48  * Add a mask to cpl, and return the old value of cpl.
     49  */
     50 int
     51 splraise(int nlevel)
     52 {
     53 	int olevel;
     54 	struct cpu_info *ci = curcpu();
     55 
     56 	olevel = ci->ci_ilevel;
     57 	if (nlevel > olevel)
     58 		ci->ci_ilevel = nlevel;
     59 	__insn_barrier();
     60 	return (olevel);
     61 }
     62 
     63 /*
     64  * Restore a value to cpl (unmasking interrupts).  If any unmasked
     65  * interrupts are pending, call Xspllower() to process them.
     66  */
     67 void
     68 spllower(int nlevel)
     69 {
     70 	struct cpu_info *ci = curcpu();
     71 	uint32_t imask;
     72 	u_long psl;
     73 
     74 	__insn_barrier();
     75 
     76 	imask = IUNMASK(ci, nlevel);
     77 	psl = x86_read_psl();
     78 	x86_disable_intr();
     79 	if (ci->ci_ipending & imask) {
     80 		Xspllower(nlevel);
     81 		/* Xspllower does enable_intr() */
     82 	} else {
     83 		ci->ci_ilevel = nlevel;
     84 		x86_write_psl(psl);
     85 	}
     86 }
     87 
     88 #ifndef __x86_64__
     89 
     90 /*
     91  * Software interrupt registration
     92  *
     93  * We hand-code this to ensure that it's atomic.
     94  *
     95  * XXX always scheduled on the current CPU.
     96  */
     97 void
     98 softintr(int sir)
     99 {
    100 	struct cpu_info *ci = curcpu();
    101 
    102 	__asm volatile("orl %1, %0" : "=m"(ci->ci_ipending) : "ir" (1 << sir));
    103 }
    104 #endif
    105 
    106 void
    107 x86_disable_intr(void)
    108 {
    109 	__cli();
    110 }
    111 
    112 void
    113 x86_enable_intr(void)
    114 {
    115 	__sti();
    116 }
    117 
    118 u_long
    119 x86_read_psl(void)
    120 {
    121 
    122 	return (curcpu()->ci_vcpu->evtchn_upcall_mask);
    123 }
    124 
    125 void
    126 x86_write_psl(u_long psl)
    127 {
    128 	struct cpu_info *ci = curcpu();
    129 
    130 	ci->ci_vcpu->evtchn_upcall_mask = psl;
    131 	x86_lfence();
    132 	if (ci->ci_vcpu->evtchn_upcall_pending && psl == 0) {
    133 	    	hypervisor_force_callback();
    134 	}
    135 }
    136