drivers/hv/hv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *
  21  */
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/mm.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/hyperv.h>
  29 #include <linux/version.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/clockchips.h>
  32 #include <asm/hyperv.h>
  33 #include <asm/mshyperv.h>
  34 #include "hyperv_vmbus.h"
  35
  36 /* The one and only */
  37 struct hv_context hv_context = {
  38         .synic_initialized      = false,
  39 };
  40
  41 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
  42 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
  43 #define HV_MIN_DELTA_TICKS 1
  44
  45 /*
  46  * hv_init - Main initialization routine.
  47  *
  48  * This routine must be called before any other routines in here are called
  49  */
  50 int hv_init(void)
  51 {
  52         if (!hv_is_hypercall_page_setup())
  53                 return -ENOTSUPP;
  54
  55         hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
  56         if (!hv_context.cpu_context)
  57                 return -ENOMEM;
  58
  59         return 0;
  60 }
  61
  62 /*
  63  * hv_post_message - Post a message using the hypervisor message IPC.
  64  *
  65  * This involves a hypercall.
  66  */
  67 int hv_post_message(union hv_connection_id connection_id,
  68                   enum hv_message_type message_type,
  69                   void *payload, size_t payload_size)
  70 {
  71         struct hv_input_post_message *aligned_msg;
  72         struct hv_per_cpu_context *hv_cpu;
  73         u64 status;
  74
  75         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
  76                 return -EMSGSIZE;
  77
  78         hv_cpu = get_cpu_ptr(hv_context.cpu_context);
  79         aligned_msg = hv_cpu->post_msg_page;
  80         aligned_msg->connectionid = connection_id;
  81         aligned_msg->reserved = 0;
  82         aligned_msg->message_type = message_type;
  83         aligned_msg->payload_size = payload_size;
  84         memcpy((void *)aligned_msg->payload, payload, payload_size);
  85         put_cpu_ptr(hv_cpu);
  86
  87         status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
  88
  89         return status & 0xFFFF;
  90 }
  91
  92 static int hv_ce_set_next_event(unsigned long delta,
  93                                 struct clock_event_device *evt)
  94 {
  95         u64 current_tick;
  96
  97         WARN_ON(!clockevent_state_oneshot(evt));
  98
  99         hv_get_current_tick(current_tick);
 100         current_tick += delta;
 101         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, current_tick);
 102         return 0;
 103 }
 104
 105 static int hv_ce_shutdown(struct clock_event_device *evt)
 106 {
 107         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, 0);
 108         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, 0);
 109
 110         return 0;
 111 }
 112
 113 static int hv_ce_set_oneshot(struct clock_event_device *evt)
 114 {
 115         union hv_timer_config timer_cfg;
 116
 117         timer_cfg.enable = 1;
 118         timer_cfg.auto_enable = 1;
 119         timer_cfg.sintx = VMBUS_MESSAGE_SINT;
 120         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
 121
 122         return 0;
 123 }
 124
 125 static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
 126 {
 127         dev->name = "Hyper-V clockevent";
 128         dev->features = CLOCK_EVT_FEAT_ONESHOT;
 129         dev->cpumask = cpumask_of(cpu);
 130         dev->rating = 1000;
 131         /*
 132          * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
 133          * result in clockevents_config_and_register() taking additional
 134          * references to the hv_vmbus module making it impossible to unload.
 135          */
 136
 137         dev->set_state_shutdown = hv_ce_shutdown;
 138         dev->set_state_oneshot = hv_ce_set_oneshot;
 139         dev->set_next_event = hv_ce_set_next_event;
 140 }
 141
 142
 143 int hv_synic_alloc(void)
 144 {
 145         int cpu;
 146
 147         hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
 148                                          GFP_ATOMIC);
 149         if (hv_context.hv_numa_map == NULL) {
 150                 pr_err("Unable to allocate NUMA map\n");
 151                 goto err;
 152         }
 153
 154         for_each_present_cpu(cpu) {
 155                 struct hv_per_cpu_context *hv_cpu
 156                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 157
 158                 memset(hv_cpu, 0, sizeof(*hv_cpu));
 159                 tasklet_init(&hv_cpu->msg_dpc,
 160                              vmbus_on_msg_dpc, (unsigned long) hv_cpu);
 161
 162                 hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
 163                                           GFP_KERNEL);
 164                 if (hv_cpu->clk_evt == NULL) {
 165                         pr_err("Unable to allocate clock event device\n");
 166                         goto err;
 167                 }
 168                 hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
 169
 170                 hv_cpu->synic_message_page =
 171                         (void *)get_zeroed_page(GFP_ATOMIC);
 172                 if (hv_cpu->synic_message_page == NULL) {
 173                         pr_err("Unable to allocate SYNIC message page\n");
 174                         goto err;
 175                 }
 176
 177                 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
 178                 if (hv_cpu->synic_event_page == NULL) {
 179                         pr_err("Unable to allocate SYNIC event page\n");
 180                         goto err;
 181                 }
 182
 183                 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
 184                 if (hv_cpu->post_msg_page == NULL) {
 185                         pr_err("Unable to allocate post msg page\n");
 186                         goto err;
 187                 }
 188
 189                 INIT_LIST_HEAD(&hv_cpu->chan_list);
 190         }
 191
 192         return 0;
 193 err:
 194         return -ENOMEM;
 195 }
 196
 197
 198 void hv_synic_free(void)
 199 {
 200         int cpu;
 201
 202         for_each_present_cpu(cpu) {
 203                 struct hv_per_cpu_context *hv_cpu
 204                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 205
 206                 if (hv_cpu->synic_event_page)
 207                         free_page((unsigned long)hv_cpu->synic_event_page);
 208                 if (hv_cpu->synic_message_page)
 209                         free_page((unsigned long)hv_cpu->synic_message_page);
 210                 if (hv_cpu->post_msg_page)
 211                         free_page((unsigned long)hv_cpu->post_msg_page);
 212         }
 213
 214         kfree(hv_context.hv_numa_map);
 215 }
 216
 217 /*
 218  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 219  *
 220  * If it is already initialized by another entity (ie x2v shim), we need to
 221  * retrieve the initialized message and event pages.  Otherwise, we create and
 222  * initialize the message and event pages.
 223  */
 224 int hv_synic_init(unsigned int cpu)
 225 {
 226         struct hv_per_cpu_context *hv_cpu
 227                 = per_cpu_ptr(hv_context.cpu_context, cpu);
 228         union hv_synic_simp simp;
 229         union hv_synic_siefp siefp;
 230         union hv_synic_sint shared_sint;
 231         union hv_synic_scontrol sctrl;
 232         u64 vp_index;
 233
 234         /* Setup the Synic's message page */
 235         hv_get_simp(simp.as_uint64);
 236         simp.simp_enabled = 1;
 237         simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
 238                 >> PAGE_SHIFT;
 239
 240         hv_set_simp(simp.as_uint64);
 241
 242         /* Setup the Synic's event page */
 243         hv_get_siefp(siefp.as_uint64);
 244         siefp.siefp_enabled = 1;
 245         siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
 246                 >> PAGE_SHIFT;
 247
 248         hv_set_siefp(siefp.as_uint64);
 249
 250         /* Setup the shared SINT. */
 251         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 252                             shared_sint.as_uint64);
 253
 254         shared_sint.as_uint64 = 0;
 255         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
 256         shared_sint.masked = false;
 257         shared_sint.auto_eoi = true;
 258
 259         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 260                             shared_sint.as_uint64);
 261
 262         /* Enable the global synic bit */
 263         hv_get_synic_state(sctrl.as_uint64);
 264         sctrl.enable = 1;
 265
 266         hv_set_synic_state(sctrl.as_uint64);
 267
 268         hv_context.synic_initialized = true;
 269
 270         /*
 271          * Setup the mapping between Hyper-V's notion
 272          * of cpuid and Linux' notion of cpuid.
 273          * This array will be indexed using Linux cpuid.
 274          */
 275         hv_get_vp_index(vp_index);
 276         hv_context.vp_index[cpu] = (u32)vp_index;
 277
 278         /*
 279          * Register the per-cpu clockevent source.
 280          */
 281         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
 282                 clockevents_config_and_register(hv_cpu->clk_evt,
 283                                                 HV_TIMER_FREQUENCY,
 284                                                 HV_MIN_DELTA_TICKS,
 285                                                 HV_MAX_MAX_DELTA_TICKS);
 286         return 0;
 287 }
 288
 289 /*
 290  * hv_synic_clockevents_cleanup - Cleanup clockevent devices
 291  */
 292 void hv_synic_clockevents_cleanup(void)
 293 {
 294         int cpu;
 295
 296         if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
 297                 return;
 298
 299         for_each_present_cpu(cpu) {
 300                 struct hv_per_cpu_context *hv_cpu
 301                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 302
 303                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 304         }
 305 }
 306
 307 /*
 308  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 309  */
 310 int hv_synic_cleanup(unsigned int cpu)
 311 {
 312         union hv_synic_sint shared_sint;
 313         union hv_synic_simp simp;
 314         union hv_synic_siefp siefp;
 315         union hv_synic_scontrol sctrl;
 316         struct vmbus_channel *channel, *sc;
 317         bool channel_found = false;
 318         unsigned long flags;
 319
 320         if (!hv_context.synic_initialized)
 321                 return -EFAULT;
 322
 323         /*
 324          * Search for channels which are bound to the CPU we're about to
 325          * cleanup. In case we find one and vmbus is still connected we need to
 326          * fail, this will effectively prevent CPU offlining. There is no way
 327          * we can re-bind channels to different CPUs for now.
 328          */
 329         mutex_lock(&vmbus_connection.channel_mutex);
 330         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 331                 if (channel->target_cpu == cpu) {
 332                         channel_found = true;
 333                         break;
 334                 }
 335                 spin_lock_irqsave(&channel->lock, flags);
 336                 list_for_each_entry(sc, &channel->sc_list, sc_list) {
 337                         if (sc->target_cpu == cpu) {
 338                                 channel_found = true;
 339                                 break;
 340                         }
 341                 }
 342                 spin_unlock_irqrestore(&channel->lock, flags);
 343                 if (channel_found)
 344                         break;
 345         }
 346         mutex_unlock(&vmbus_connection.channel_mutex);
 347
 348         if (channel_found && vmbus_connection.conn_state == CONNECTED)
 349                 return -EBUSY;
 350
 351         /* Turn off clockevent device */
 352         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) {
 353                 struct hv_per_cpu_context *hv_cpu
 354                         = this_cpu_ptr(hv_context.cpu_context);
 355
 356                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 357                 hv_ce_shutdown(hv_cpu->clk_evt);
 358                 put_cpu_ptr(hv_cpu);
 359         }
 360
 361         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 362                             shared_sint.as_uint64);
 363
 364         shared_sint.masked = 1;
 365
 366         /* Need to correctly cleanup in the case of SMP!!! */
 367         /* Disable the interrupt */
 368         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 369                             shared_sint.as_uint64);
 370
 371         hv_get_simp(simp.as_uint64);
 372         simp.simp_enabled = 0;
 373         simp.base_simp_gpa = 0;
 374
 375         hv_set_simp(simp.as_uint64);
 376
 377         hv_get_siefp(siefp.as_uint64);
 378         siefp.siefp_enabled = 0;
 379         siefp.base_siefp_gpa = 0;
 380
 381         hv_set_siefp(siefp.as_uint64);
 382
 383         /* Disable the global synic bit */
 384         hv_get_synic_state(sctrl.as_uint64);
 385         sctrl.enable = 0;
 386         hv_set_synic_state(sctrl.as_uint64);
 387
 388         return 0;
 389 }