1 /* $NetBSD: xen_ipi.c,v 1.11 2012/12/27 06:42:14 cherry Exp $ */ 2 3 /*- 4 * Copyright (c) 2011 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Cherry G. Mathew <cherry@zyx.in> 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> /* RCS ID macro */ 33 34 /* 35 * Based on: x86/ipi.c 36 * __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.11 2012/12/27 06:42:14 cherry Exp $"); 37 */ 38 39 __KERNEL_RCSID(0, "$NetBSD: xen_ipi.c,v 1.11 2012/12/27 06:42:14 cherry Exp $"); 40 41 #include <sys/types.h> 42 43 #include <sys/atomic.h> 44 #include <sys/cpu.h> 45 #include <sys/mutex.h> 46 #include <sys/device.h> 47 #include <sys/xcall.h> 48 #include <sys/errno.h> 49 #include <sys/systm.h> 50 51 #ifdef __x86_64__ 52 #include <machine/fpu.h> 53 #else 54 #include <machine/npx.h> 55 #endif /* __x86_64__ */ 56 #include <machine/frame.h> 57 #include <machine/segments.h> 58 59 #include <xen/evtchn.h> 60 #include <xen/intr.h> 61 #include <xen/intrdefs.h> 62 #include <xen/hypervisor.h> 63 #include <xen/xen-public/vcpu.h> 64 65 #ifdef __x86_64__ 66 extern void ddb_ipi(struct trapframe); 67 #else 68 extern void ddb_ipi(int, struct trapframe); 69 #endif /* __x86_64__ */ 70 71 static void xen_ipi_halt(struct cpu_info *, struct intrframe *); 72 static void xen_ipi_synch_fpu(struct cpu_info *, struct intrframe *); 73 static void xen_ipi_ddb(struct cpu_info *, struct intrframe *); 74 static void xen_ipi_xcall(struct cpu_info *, struct intrframe *); 75 static void xen_ipi_hvcb(struct cpu_info *, struct intrframe *); 76 77 static void (*ipifunc[XEN_NIPIS])(struct cpu_info *, struct intrframe *) = 78 { /* In order of priority (see: xen/include/intrdefs.h */ 79 xen_ipi_halt, 80 xen_ipi_synch_fpu, 81 xen_ipi_ddb, 82 xen_ipi_xcall, 83 xen_ipi_hvcb 84 }; 85 86 static void 87 xen_ipi_handler(struct cpu_info *ci, struct intrframe *regs) 88 { 89 uint32_t pending; 90 int bit; 91 92 pending = atomic_swap_32(&ci->ci_ipis, 0); 93 94 KDASSERT((pending >> XEN_NIPIS) == 0); 95 while ((bit = ffs(pending)) != 0) { 96 bit--; 97 pending &= ~(1 << bit); 98 ci->ci_ipi_events[bit].ev_count++; 99 if (ipifunc[bit] != NULL) { 100 (*ipifunc[bit])(ci, regs); 101 } else { 102 panic("ipifunc[%d] unsupported!\n", bit); 103 /* NOTREACHED */ 104 } 105 } 106 } 107 108 /* Must be called once for every cpu that expects to send/recv ipis */ 109 void 110 xen_ipi_init(void) 111 { 112 cpuid_t vcpu; 113 evtchn_port_t evtchn; 114 struct cpu_info *ci; 115 116 ci = curcpu(); 117 118 vcpu = ci->ci_cpuid; 119 KASSERT(vcpu < XEN_LEGACY_MAX_VCPUS); 120 121 evtchn = bind_vcpu_to_evtch(vcpu); 122 ci->ci_ipi_evtchn = evtchn; 123 124 KASSERT(evtchn != -1 && evtchn < NR_EVENT_CHANNELS); 125 126 if (0 != event_set_handler(evtchn, (int (*)(void *))xen_ipi_handler, 127 ci, IPL_HIGH, "ipi")) { 128 panic("event_set_handler(...) KPI violation\n"); 129 /* NOTREACHED */ 130 } 131 132 hypervisor_enable_event(evtchn); 133 } 134 135 /* prefer this to global variable */ 136 static inline u_int max_cpus(void) 137 { 138 return maxcpus; 139 } 140 141 static inline bool /* helper */ 142 valid_ipimask(uint32_t ipimask) 143 { 144 uint32_t masks = XEN_IPI_HVCB | XEN_IPI_XCALL | 145 XEN_IPI_DDB | XEN_IPI_SYNCH_FPU | 146 XEN_IPI_HALT | XEN_IPI_KICK; 147 148 if (ipimask & ~masks) { 149 return false; 150 } else { 151 return true; 152 } 153 154 } 155 156 int 157 xen_send_ipi(struct cpu_info *ci, uint32_t ipimask) 158 { 159 evtchn_port_t evtchn; 160 161 KASSERT(ci != NULL || ci != curcpu()); 162 163 if ((ci->ci_flags & CPUF_RUNNING) == 0) { 164 return ENOENT; 165 } 166 167 evtchn = ci->ci_ipi_evtchn; 168 169 KASSERTMSG(valid_ipimask(ipimask) == true, 170 "xen_send_ipi() called with invalid ipimask\n"); 171 172 atomic_or_32(&ci->ci_ipis, ipimask); 173 hypervisor_notify_via_evtchn(evtchn); 174 175 return 0; 176 } 177 178 void 179 xen_broadcast_ipi(uint32_t ipimask) 180 { 181 struct cpu_info *ci, *self = curcpu(); 182 CPU_INFO_ITERATOR cii; 183 184 KASSERTMSG(valid_ipimask(ipimask) == true, 185 "xen_broadcast_ipi() called with invalid ipimask\n"); 186 187 /* 188 * XXX-cherry: there's an implicit broadcast sending order 189 * which I dislike. Randomise this ? :-) 190 */ 191 192 for (CPU_INFO_FOREACH(cii, ci)) { 193 if (ci == NULL) 194 continue; 195 if (ci == self) 196 continue; 197 if (ci->ci_data.cpu_idlelwp == NULL) 198 continue; 199 if ((ci->ci_flags & CPUF_PRESENT) == 0) 200 continue; 201 if (ci->ci_flags & (CPUF_RUNNING)) { 202 if (0 != xen_send_ipi(ci, ipimask)) { 203 panic("xen_ipi of %x from %s to %s failed\n", 204 ipimask, cpu_name(curcpu()), 205 cpu_name(ci)); 206 } 207 } 208 } 209 } 210 211 /* MD wrapper for the xcall(9) callback. */ 212 #define PRIuCPUID "lu" /* XXX: move this somewhere more appropriate */ 213 214 static void 215 xen_ipi_halt(struct cpu_info *ci, struct intrframe *intrf) 216 { 217 KASSERT(ci == curcpu()); 218 KASSERT(ci != NULL); 219 if (HYPERVISOR_vcpu_op(VCPUOP_down, ci->ci_cpuid, NULL)) { 220 panic("vcpu%" PRIuCPUID "shutdown failed.\n", ci->ci_cpuid); 221 } 222 223 } 224 225 static void 226 xen_ipi_synch_fpu(struct cpu_info *ci, struct intrframe *intrf) 227 { 228 KASSERT(ci != NULL); 229 KASSERT(intrf != NULL); 230 231 #ifdef __x86_64__ 232 fpusave_cpu(true); 233 #else 234 npxsave_cpu(true); 235 #endif /* __x86_64__ */ 236 } 237 238 static void 239 xen_ipi_ddb(struct cpu_info *ci, struct intrframe *intrf) 240 { 241 KASSERT(ci != NULL); 242 KASSERT(intrf != NULL); 243 244 #ifdef __x86_64__ 245 ddb_ipi(intrf->if_tf); 246 #else 247 struct trapframe tf; 248 tf.tf_gs = intrf->if_gs; 249 tf.tf_fs = intrf->if_fs; 250 tf.tf_es = intrf->if_es; 251 tf.tf_ds = intrf->if_ds; 252 tf.tf_edi = intrf->if_edi; 253 tf.tf_esi = intrf->if_esi; 254 tf.tf_ebp = intrf->if_ebp; 255 tf.tf_ebx = intrf->if_ebx; 256 tf.tf_ecx = intrf->if_ecx; 257 tf.tf_eax = intrf->if_eax; 258 tf.tf_trapno = intrf->__if_trapno; 259 tf.tf_err = intrf->__if_err; 260 tf.tf_eip = intrf->if_eip; 261 tf.tf_cs = intrf->if_cs; 262 tf.tf_eflags = intrf->if_eflags; 263 tf.tf_esp = intrf->if_esp; 264 tf.tf_ss = intrf->if_ss; 265 266 /* XXX: does i386/Xen have vm86 support ? 267 tf.tf_vm86_es; 268 tf.tf_vm86_ds; 269 tf.tf_vm86_fs; 270 tf.tf_vm86_gs; 271 :XXX */ 272 273 ddb_ipi(SEL_KPL, tf); 274 #endif 275 } 276 277 static void 278 xen_ipi_xcall(struct cpu_info *ci, struct intrframe *intrf) 279 { 280 KASSERT(ci != NULL); 281 KASSERT(intrf != NULL); 282 283 xc_ipi_handler(); 284 } 285 286 void 287 xc_send_ipi(struct cpu_info *ci) 288 { 289 290 KASSERT(kpreempt_disabled()); 291 KASSERT(curcpu() != ci); 292 if (ci) { 293 if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) { 294 panic("xen_send_ipi(XEN_IPI_XCALL) failed\n"); 295 } 296 } else { 297 xen_broadcast_ipi(XEN_IPI_XCALL); 298 } 299 } 300 301 static void 302 xen_ipi_hvcb(struct cpu_info *ci, struct intrframe *intrf) 303 { 304 KASSERT(ci != NULL); 305 KASSERT(intrf != NULL); 306 KASSERT(ci == curcpu()); 307 KASSERT(!ci->ci_vcpu->evtchn_upcall_mask); 308 309 hypervisor_force_callback(); 310 } 311