1 /* $NetBSD: arm11_pmc.c,v 1.7 2020/06/20 07:01:16 skrll Exp $ */ 2 3 /* Copyright (c) 2007 Microsoft 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Microsoft 17 * 18 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 19 * 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 WASABI SYSTEMS, INC 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 31 32 /* 33 * support for ARM 11 Performance Monitor Counters 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: arm11_pmc.c,v 1.7 2020/06/20 07:01:16 skrll Exp $"); 38 #include <sys/types.h> 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/time.h> 43 #include <sys/timetc.h> 44 #include <dev/clock_subr.h> 45 #include <arm/armreg.h> 46 #include <arm/cpufunc.h> 47 48 #ifndef ARM11_PMC_CCNT_HZ 49 # define ARM11_PMC_CCNT_HZ 400000000 /* 400MHz */ 50 #endif 51 52 void arm11_pmc_ccnt_init(void); 53 54 #define COUNTS_PER_USEC (ARM11_PMC_CCNT_HZ / 1000000) 55 56 static uint32_t counts_per_wrap = ~0UL; /* XXX off by 1 */ 57 58 static inline uint32_t 59 arm11_pmc_ctrl_read(void) 60 { 61 uint32_t val; 62 63 __asm volatile ("mrc p15, 0, %0, c15, c12, 0" : "=r" (val)); 64 65 return val; 66 } 67 68 static inline void 69 arm11_pmc_ctrl_write(uint32_t val) 70 { 71 __asm volatile ("mcr p15, 0, %0, c15, c12, 0" :: "r" (val)); 72 } 73 74 static inline uint32_t 75 arm11_pmc_ccnt_read(void) 76 { 77 uint32_t val; 78 79 __asm volatile ("mrc p15, 0, %0, c15, c12, 1" : "=r" (val)); 80 81 return val; 82 } 83 84 __unused static inline void 85 arm11_pmc_ccnt_write(uint32_t val) 86 { 87 __asm volatile ("mcr p15, 0, %0, c15, c12, 1;" :: "r" (val)); 88 } 89 90 /* 91 * enable the PMC CCNT for delay() 92 */ 93 void 94 arm11_pmc_ccnt_init(void) 95 { 96 uint32_t val; 97 98 val = ARM11_PMCCTL_E | ARM11_PMCCTL_P | ARM11_PMCCTL_C; 99 100 arm11_pmc_ctrl_write(val); 101 } 102 103 /* 104 * delay - for "at least" arg usec 105 * 106 * NOTE: at 400MHz we are restricted to (uint32_t)~0 "counts" 107 * if this is a problem, accumulate counts in LL vars 108 */ 109 #define DELAY_ARG_LIMIT (((uint32_t)~0) / COUNTS_PER_USEC) /* about 10 sec */ 110 void 111 delay(u_int arg) 112 { 113 uint32_t ctrl; 114 uint32_t cur; 115 uint32_t last; 116 uint32_t delta = 0; 117 uint32_t usecs = 0; 118 119 if (arg > DELAY_ARG_LIMIT) 120 panic("delay: arg %u overflow, limit is %d usec\n", arg, DELAY_ARG_LIMIT); 121 122 last = arm11_pmc_ccnt_read(); 123 delta = usecs = 0; 124 125 while (arg > usecs) { 126 cur = arm11_pmc_ccnt_read(); 127 ctrl = arm11_pmc_ctrl_read(); 128 if (ctrl & ARM11_PMCCTL_CCR) { 129 /* 130 * reset CCR, do not reset other write-to-clear flags; 131 * keep the rest of the PMC Control Reg configuration 132 */ 133 ctrl &= ~(ARM11_PMCCTL_CR0|ARM11_PMCCTL_CR1); 134 arm11_pmc_ctrl_write(ctrl); 135 delta += (last + (counts_per_wrap - cur)); 136 } else { 137 delta += (cur - last); 138 } 139 last = cur; 140 if (delta >= COUNTS_PER_USEC) { 141 usecs += delta / COUNTS_PER_USEC; 142 delta %= COUNTS_PER_USEC; 143 } 144 } 145 } 146