1 /*- 2 * Copyright (c) 2016-2017 Microsoft Corp. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * 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 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/param.h> 28 #include <sys/conf.h> 29 #include <sys/fcntl.h> 30 #include <sys/kernel.h> 31 #include <sys/malloc.h> 32 #include <sys/systm.h> 33 #include <sys/timetc.h> 34 #include <sys/vdso.h> 35 36 #include <machine/cpufunc.h> 37 #include <machine/cputypes.h> 38 #include <machine/md_var.h> 39 #include <machine/specialreg.h> 40 41 #include <vm/vm.h> 42 #include <vm/vm_extern.h> 43 #include <vm/pmap.h> 44 45 #include <dev/hyperv/include/hyperv.h> 46 #include <dev/hyperv/include/hyperv_busdma.h> 47 #include <dev/hyperv/vmbus/x86/hyperv_machdep.h> 48 #include <dev/hyperv/vmbus/x86/hyperv_reg.h> 49 #include <dev/hyperv/vmbus/hyperv_var.h> 50 #include <dev/hyperv/vmbus/hyperv_common_reg.h> 51 52 struct hyperv_reftsc_ctx { 53 struct hyperv_reftsc *tsc_ref; 54 }; 55 56 static uint32_t hyperv_tsc_vdso_timehands( 57 struct vdso_timehands *, 58 struct timecounter *); 59 60 static d_open_t hyperv_tsc_open; 61 static d_mmap_t hyperv_tsc_mmap; 62 63 static struct timecounter hyperv_tsc_timecounter = { 64 .tc_get_timecount = NULL, /* based on CPU vendor. */ 65 .tc_counter_mask = 0xffffffff, 66 .tc_frequency = HYPERV_TIMER_FREQ, 67 .tc_name = "Hyper-V-TSC", 68 .tc_quality = 3000, 69 .tc_fill_vdso_timehands = hyperv_tsc_vdso_timehands, 70 }; 71 72 static struct cdevsw hyperv_tsc_cdevsw = { 73 .d_version = D_VERSION, 74 .d_open = hyperv_tsc_open, 75 .d_mmap = hyperv_tsc_mmap, 76 .d_name = HYPERV_REFTSC_DEVNAME 77 }; 78 79 static struct hyperv_reftsc_ctx hyperv_ref_tsc; 80 81 uint64_t 82 hypercall_md(volatile void *hc_addr, uint64_t in_val, 83 uint64_t in_paddr, uint64_t out_paddr) 84 { 85 uint64_t status; 86 87 __asm__ __volatile__ ("mov %0, %%r8" : : "r" (out_paddr): "r8"); 88 __asm__ __volatile__ ("call *%3" : "=a" (status) : 89 "c" (in_val), "d" (in_paddr), "m" (hc_addr)); 90 return (status); 91 } 92 93 static int 94 hyperv_tsc_open(struct cdev *dev __unused, int oflags, int devtype __unused, 95 struct thread *td __unused) 96 { 97 98 if (oflags & FWRITE) 99 return (EPERM); 100 return (0); 101 } 102 103 static int 104 hyperv_tsc_mmap(struct cdev *dev __unused, vm_ooffset_t offset, 105 vm_paddr_t *paddr, int nprot __unused, vm_memattr_t *memattr __unused) 106 { 107 108 KASSERT(hyperv_ref_tsc.tsc_ref != NULL, ("reftsc has not been setup")); 109 110 /* 111 * NOTE: 112 * 'nprot' does not contain information interested to us; 113 * WR-open is blocked by d_open. 114 */ 115 116 if (offset != 0) 117 return (EOPNOTSUPP); 118 119 *paddr = pmap_kextract((vm_offset_t)hyperv_ref_tsc.tsc_ref); 120 return (0); 121 } 122 123 static uint32_t 124 hyperv_tsc_vdso_timehands(struct vdso_timehands *vdso_th, 125 struct timecounter *tc __unused) 126 { 127 128 vdso_th->th_algo = VDSO_TH_ALGO_X86_HVTSC; 129 vdso_th->th_x86_shift = 0; 130 vdso_th->th_x86_hpet_idx = 0; 131 vdso_th->th_x86_pvc_last_systime = 0; 132 vdso_th->th_x86_pvc_stable_mask = 0; 133 bzero(vdso_th->th_res, sizeof(vdso_th->th_res)); 134 return (1); 135 } 136 137 #define HYPERV_TSC_TIMECOUNT(fence) \ 138 static uint64_t \ 139 hyperv_tc64_tsc_##fence(void) \ 140 { \ 141 struct hyperv_reftsc *tsc_ref = hyperv_ref_tsc.tsc_ref; \ 142 uint32_t seq; \ 143 \ 144 while ((seq = atomic_load_acq_int(&tsc_ref->tsc_seq)) != 0) { \ 145 uint64_t disc, ret, tsc; \ 146 uint64_t scale = tsc_ref->tsc_scale; \ 147 int64_t ofs = tsc_ref->tsc_ofs; \ 148 \ 149 fence(); \ 150 tsc = rdtsc(); \ 151 \ 152 /* ret = ((tsc * scale) >> 64) + ofs */ \ 153 __asm__ __volatile__ ("mulq %3" : \ 154 "=d" (ret), "=a" (disc) : \ 155 "a" (tsc), "r" (scale)); \ 156 ret += ofs; \ 157 \ 158 atomic_thread_fence_acq(); \ 159 if (tsc_ref->tsc_seq == seq) \ 160 return (ret); \ 161 \ 162 /* Sequence changed; re-sync. */ \ 163 } \ 164 /* Fallback to the generic timecounter, i.e. rdmsr. */ \ 165 return (rdmsr(MSR_HV_TIME_REF_COUNT)); \ 166 } \ 167 \ 168 static u_int \ 169 hyperv_tsc_timecount_##fence(struct timecounter *tc __unused) \ 170 { \ 171 \ 172 return (hyperv_tc64_tsc_##fence()); \ 173 } \ 174 struct __hack 175 176 HYPERV_TSC_TIMECOUNT(lfence); 177 HYPERV_TSC_TIMECOUNT(mfence); 178 179 static void 180 hyperv_tsc_tcinit(void *dummy __unused) 181 { 182 hyperv_tc64_t tc64 = NULL; 183 uint64_t val, orig; 184 185 if ((hyperv_features & 186 (CPUID_HV_MSR_TIME_REFCNT | CPUID_HV_MSR_REFERENCE_TSC)) != 187 (CPUID_HV_MSR_TIME_REFCNT | CPUID_HV_MSR_REFERENCE_TSC) || 188 (cpu_feature & CPUID_SSE2) == 0) /* SSE2 for mfence/lfence */ 189 return; 190 191 switch (cpu_vendor_id) { 192 case CPU_VENDOR_AMD: 193 case CPU_VENDOR_HYGON: 194 hyperv_tsc_timecounter.tc_get_timecount = 195 hyperv_tsc_timecount_mfence; 196 tc64 = hyperv_tc64_tsc_mfence; 197 break; 198 199 case CPU_VENDOR_INTEL: 200 hyperv_tsc_timecounter.tc_get_timecount = 201 hyperv_tsc_timecount_lfence; 202 tc64 = hyperv_tc64_tsc_lfence; 203 break; 204 205 default: 206 /* Unsupported CPU vendors. */ 207 return; 208 } 209 210 hyperv_ref_tsc.tsc_ref = contigmalloc(PAGE_SIZE, M_DEVBUF, 211 M_WAITOK | M_ZERO, 0ul, ~0ul, PAGE_SIZE, 0); 212 if (hyperv_ref_tsc.tsc_ref == NULL) { 213 printf("hyperv: reftsc page allocation failed\n"); 214 return; 215 } 216 217 orig = rdmsr(MSR_HV_REFERENCE_TSC); 218 val = (pmap_kextract((vm_offset_t)hyperv_ref_tsc.tsc_ref) >> 219 PAGE_SHIFT) << MSR_HV_REFTSC_PGSHIFT; 220 val |= MSR_HV_REFTSC_ENABLE | (orig & MSR_HV_REFTSC_RSVD_MASK); 221 wrmsr(MSR_HV_REFERENCE_TSC, val); 222 223 /* Register "enlightened" timecounter. */ 224 tc_init(&hyperv_tsc_timecounter); 225 226 /* Install 64 bits timecounter method for other modules to use. */ 227 KASSERT(tc64 != NULL, ("tc64 is not set")); 228 hyperv_tc64 = tc64; 229 230 /* Add device for mmap(2). */ 231 make_dev(&hyperv_tsc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0444, 232 HYPERV_REFTSC_DEVNAME); 233 } 234 SYSINIT(hyperv_tsc_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, hyperv_tsc_tcinit, 235 NULL); 236