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pic_splfuncs.c revision 1.21 
      1 /*	$NetBSD: pic_splfuncs.c,v 1.21 2021/08/10 15:31:55 jmcneill Exp $	*/
      2 /*-
      3  * Copyright (c) 2008 The NetBSD Foundation, Inc.
      4  * All rights reserved.
      5  *
      6  * This code is derived from software contributed to The NetBSD Foundation
      7  * by Matt Thomas.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     28  * POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 #include <sys/cdefs.h>
     31 __KERNEL_RCSID(0, "$NetBSD: pic_splfuncs.c,v 1.21 2021/08/10 15:31:55 jmcneill Exp $");
     32 
     33 #define _INTR_PRIVATE
     34 #include <sys/param.h>
     35 #include <sys/atomic.h>
     36 #include <sys/evcnt.h>
     37 #include <sys/lwp.h>
     38 #include <sys/kernel.h>
     39 
     40 #include <dev/cons.h>
     41 
     42 #include <arm/armreg.h>
     43 #include <arm/cpu.h>
     44 #include <arm/cpufunc.h>
     45 #include <arm/locore.h>	/* for compat aarch64 */
     46 
     47 #include <arm/pic/picvar.h>
     48 
     49 static int	pic_default_splraise(int);
     50 static int	pic_default_spllower(int);
     51 static void	pic_default_splx(int);
     52 
     53 int (*_splraise)(int) = pic_default_splraise;
     54 int (*_spllower)(int) = pic_default_spllower;
     55 void (*splx)(int) = pic_default_splx;
     56 
     57 static int
     58 pic_default_splraise(int newipl)
     59 {
     60 	struct cpu_info * const ci = curcpu();
     61 	const int oldipl = ci->ci_cpl;
     62 	KASSERT(newipl < NIPL);
     63 	if (newipl > ci->ci_cpl) {
     64 		pic_set_priority(ci, newipl);
     65 	}
     66 	return oldipl;
     67 }
     68 
     69 static int
     70 pic_default_spllower(int newipl)
     71 {
     72 	struct cpu_info * const ci = curcpu();
     73 	const int oldipl = ci->ci_cpl;
     74 	KASSERT(panicstr || newipl <= ci->ci_cpl);
     75 	if (newipl < ci->ci_cpl) {
     76 		register_t psw = DISABLE_INTERRUPT_SAVE();
     77 		ci->ci_intr_depth++;
     78 		pic_do_pending_ints(psw, newipl, NULL);
     79 		ci->ci_intr_depth--;
     80 		if ((psw & I32_bit) == 0 || newipl == IPL_NONE)
     81 			ENABLE_INTERRUPT();
     82 		cpu_dosoftints();
     83 	}
     84 	return oldipl;
     85 }
     86 
     87 static void
     88 pic_default_splx(int savedipl)
     89 {
     90 	struct cpu_info * const ci = curcpu();
     91 	KASSERT(savedipl < NIPL);
     92 
     93 	if (__predict_false(savedipl == ci->ci_cpl)) {
     94 		return;
     95 	}
     96 
     97 	register_t psw = DISABLE_INTERRUPT_SAVE();
     98 	KASSERTMSG(panicstr != NULL || savedipl < ci->ci_cpl,
     99 	    "splx(%d) to a higher ipl than %d", savedipl, ci->ci_cpl);
    100 
    101 	ci->ci_intr_depth++;
    102 	pic_do_pending_ints(psw, savedipl, NULL);
    103 	ci->ci_intr_depth--;
    104 	KASSERTMSG(ci->ci_cpl == savedipl, "cpl %d savedipl %d",
    105 	    ci->ci_cpl, savedipl);
    106 	if ((psw & I32_bit) == 0)
    107 		ENABLE_INTERRUPT();
    108 	cpu_dosoftints();
    109 	KASSERTMSG(ci->ci_cpl == savedipl, "cpl %d savedipl %d",
    110 	    ci->ci_cpl, savedipl);
    111 }
    112