linux/arch/arm/xen/enlighten.c
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   1#include <xen/xen.h>
   2#include <xen/events.h>
   3#include <xen/grant_table.h>
   4#include <xen/hvm.h>
   5#include <xen/interface/vcpu.h>
   6#include <xen/interface/xen.h>
   7#include <xen/interface/memory.h>
   8#include <xen/interface/hvm/params.h>
   9#include <xen/features.h>
  10#include <xen/platform_pci.h>
  11#include <xen/xenbus.h>
  12#include <xen/page.h>
  13#include <xen/interface/sched.h>
  14#include <xen/xen-ops.h>
  15#include <asm/paravirt.h>
  16#include <asm/xen/hypervisor.h>
  17#include <asm/xen/hypercall.h>
  18#include <asm/system_misc.h>
  19#include <linux/interrupt.h>
  20#include <linux/irqreturn.h>
  21#include <linux/module.h>
  22#include <linux/of.h>
  23#include <linux/of_irq.h>
  24#include <linux/of_address.h>
  25#include <linux/cpuidle.h>
  26#include <linux/cpufreq.h>
  27#include <linux/cpu.h>
  28#include <linux/console.h>
  29#include <linux/pvclock_gtod.h>
  30#include <linux/time64.h>
  31#include <linux/timekeeping.h>
  32#include <linux/timekeeper_internal.h>
  33
  34#include <linux/mm.h>
  35
  36struct start_info _xen_start_info;
  37struct start_info *xen_start_info = &_xen_start_info;
  38EXPORT_SYMBOL(xen_start_info);
  39
  40enum xen_domain_type xen_domain_type = XEN_NATIVE;
  41EXPORT_SYMBOL(xen_domain_type);
  42
  43struct shared_info xen_dummy_shared_info;
  44struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  45
  46DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  47static struct vcpu_info __percpu *xen_vcpu_info;
  48
  49/* These are unused until we support booting "pre-ballooned" */
  50unsigned long xen_released_pages;
  51struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  52
  53static __read_mostly unsigned int xen_events_irq;
  54
  55static __initdata struct device_node *xen_node;
  56
  57int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
  58                               unsigned long addr,
  59                               xen_pfn_t *gfn, int nr,
  60                               int *err_ptr, pgprot_t prot,
  61                               unsigned domid,
  62                               struct page **pages)
  63{
  64        return xen_xlate_remap_gfn_array(vma, addr, gfn, nr, err_ptr,
  65                                         prot, domid, pages);
  66}
  67EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
  68
  69/* Not used by XENFEAT_auto_translated guests. */
  70int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
  71                              unsigned long addr,
  72                              xen_pfn_t gfn, int nr,
  73                              pgprot_t prot, unsigned domid,
  74                              struct page **pages)
  75{
  76        return -ENOSYS;
  77}
  78EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
  79
  80int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
  81                               int nr, struct page **pages)
  82{
  83        return xen_xlate_unmap_gfn_range(vma, nr, pages);
  84}
  85EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
  86
  87static unsigned long long xen_stolen_accounting(int cpu)
  88{
  89        struct vcpu_runstate_info state;
  90
  91        BUG_ON(cpu != smp_processor_id());
  92
  93        xen_get_runstate_snapshot(&state);
  94
  95        WARN_ON(state.state != RUNSTATE_running);
  96
  97        return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
  98}
  99
 100static void xen_read_wallclock(struct timespec64 *ts)
 101{
 102        u32 version;
 103        struct timespec64 now, ts_monotonic;
 104        struct shared_info *s = HYPERVISOR_shared_info;
 105        struct pvclock_wall_clock *wall_clock = &(s->wc);
 106
 107        /* get wallclock at system boot */
 108        do {
 109                version = wall_clock->version;
 110                rmb();          /* fetch version before time */
 111                now.tv_sec  = ((uint64_t)wall_clock->sec_hi << 32) | wall_clock->sec;
 112                now.tv_nsec = wall_clock->nsec;
 113                rmb();          /* fetch time before checking version */
 114        } while ((wall_clock->version & 1) || (version != wall_clock->version));
 115
 116        /* time since system boot */
 117        ktime_get_ts64(&ts_monotonic);
 118        *ts = timespec64_add(now, ts_monotonic);
 119}
 120
 121static int xen_pvclock_gtod_notify(struct notifier_block *nb,
 122                                   unsigned long was_set, void *priv)
 123{
 124        /* Protected by the calling core code serialization */
 125        static struct timespec64 next_sync;
 126
 127        struct xen_platform_op op;
 128        struct timespec64 now, system_time;
 129        struct timekeeper *tk = priv;
 130
 131        now.tv_sec = tk->xtime_sec;
 132        now.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
 133        system_time = timespec64_add(now, tk->wall_to_monotonic);
 134
 135        /*
 136         * We only take the expensive HV call when the clock was set
 137         * or when the 11 minutes RTC synchronization time elapsed.
 138         */
 139        if (!was_set && timespec64_compare(&now, &next_sync) < 0)
 140                return NOTIFY_OK;
 141
 142        op.cmd = XENPF_settime64;
 143        op.u.settime64.mbz = 0;
 144        op.u.settime64.secs = now.tv_sec;
 145        op.u.settime64.nsecs = now.tv_nsec;
 146        op.u.settime64.system_time = timespec64_to_ns(&system_time);
 147        (void)HYPERVISOR_platform_op(&op);
 148
 149        /*
 150         * Move the next drift compensation time 11 minutes
 151         * ahead. That's emulating the sync_cmos_clock() update for
 152         * the hardware RTC.
 153         */
 154        next_sync = now;
 155        next_sync.tv_sec += 11 * 60;
 156
 157        return NOTIFY_OK;
 158}
 159
 160static struct notifier_block xen_pvclock_gtod_notifier = {
 161        .notifier_call = xen_pvclock_gtod_notify,
 162};
 163
 164static void xen_percpu_init(void)
 165{
 166        struct vcpu_register_vcpu_info info;
 167        struct vcpu_info *vcpup;
 168        int err;
 169        int cpu = get_cpu();
 170
 171        /* 
 172         * VCPUOP_register_vcpu_info cannot be called twice for the same
 173         * vcpu, so if vcpu_info is already registered, just get out. This
 174         * can happen with cpu-hotplug.
 175         */
 176        if (per_cpu(xen_vcpu, cpu) != NULL)
 177                goto after_register_vcpu_info;
 178
 179        pr_info("Xen: initializing cpu%d\n", cpu);
 180        vcpup = per_cpu_ptr(xen_vcpu_info, cpu);
 181
 182        info.mfn = virt_to_gfn(vcpup);
 183        info.offset = xen_offset_in_page(vcpup);
 184
 185        err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
 186        BUG_ON(err);
 187        per_cpu(xen_vcpu, cpu) = vcpup;
 188
 189        xen_setup_runstate_info(cpu);
 190
 191after_register_vcpu_info:
 192        enable_percpu_irq(xen_events_irq, 0);
 193        put_cpu();
 194}
 195
 196static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 197{
 198        struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
 199        int rc;
 200        rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 201        BUG_ON(rc);
 202}
 203
 204static void xen_power_off(void)
 205{
 206        struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
 207        int rc;
 208        rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
 209        BUG_ON(rc);
 210}
 211
 212static int xen_cpu_notification(struct notifier_block *self,
 213                                unsigned long action,
 214                                void *hcpu)
 215{
 216        switch (action) {
 217        case CPU_STARTING:
 218                xen_percpu_init();
 219                break;
 220        case CPU_DYING:
 221                disable_percpu_irq(xen_events_irq);
 222                break;
 223        default:
 224                break;
 225        }
 226
 227        return NOTIFY_OK;
 228}
 229
 230static struct notifier_block xen_cpu_notifier = {
 231        .notifier_call = xen_cpu_notification,
 232};
 233
 234static irqreturn_t xen_arm_callback(int irq, void *arg)
 235{
 236        xen_hvm_evtchn_do_upcall();
 237        return IRQ_HANDLED;
 238}
 239
 240/*
 241 * see Documentation/devicetree/bindings/arm/xen.txt for the
 242 * documentation of the Xen Device Tree format.
 243 */
 244#define GRANT_TABLE_PHYSADDR 0
 245void __init xen_early_init(void)
 246{
 247        int len;
 248        const char *s = NULL;
 249        const char *version = NULL;
 250        const char *xen_prefix = "xen,xen-";
 251
 252        xen_node = of_find_compatible_node(NULL, NULL, "xen,xen");
 253        if (!xen_node) {
 254                pr_debug("No Xen support\n");
 255                return;
 256        }
 257        s = of_get_property(xen_node, "compatible", &len);
 258        if (strlen(xen_prefix) + 3  < len &&
 259                        !strncmp(xen_prefix, s, strlen(xen_prefix)))
 260                version = s + strlen(xen_prefix);
 261        if (version == NULL) {
 262                pr_debug("Xen version not found\n");
 263                return;
 264        }
 265
 266        pr_info("Xen %s support found\n", version);
 267
 268        xen_domain_type = XEN_HVM_DOMAIN;
 269
 270        xen_setup_features();
 271
 272        if (xen_feature(XENFEAT_dom0))
 273                xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 274        else
 275                xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
 276
 277        if (!console_set_on_cmdline && !xen_initial_domain())
 278                add_preferred_console("hvc", 0, NULL);
 279}
 280
 281static int __init xen_guest_init(void)
 282{
 283        struct xen_add_to_physmap xatp;
 284        struct shared_info *shared_info_page = NULL;
 285        struct resource res;
 286        phys_addr_t grant_frames;
 287
 288        if (!xen_domain())
 289                return 0;
 290
 291        if (of_address_to_resource(xen_node, GRANT_TABLE_PHYSADDR, &res)) {
 292                pr_err("Xen grant table base address not found\n");
 293                return -ENODEV;
 294        }
 295        grant_frames = res.start;
 296
 297        xen_events_irq = irq_of_parse_and_map(xen_node, 0);
 298        if (!xen_events_irq) {
 299                pr_err("Xen event channel interrupt not found\n");
 300                return -ENODEV;
 301        }
 302
 303        shared_info_page = (struct shared_info *)get_zeroed_page(GFP_KERNEL);
 304
 305        if (!shared_info_page) {
 306                pr_err("not enough memory\n");
 307                return -ENOMEM;
 308        }
 309        xatp.domid = DOMID_SELF;
 310        xatp.idx = 0;
 311        xatp.space = XENMAPSPACE_shared_info;
 312        xatp.gpfn = virt_to_gfn(shared_info_page);
 313        if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 314                BUG();
 315
 316        HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 317
 318        /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 319         * page, we use it in the event channel upcall and in some pvclock
 320         * related functions. 
 321         * The shared info contains exactly 1 CPU (the boot CPU). The guest
 322         * is required to use VCPUOP_register_vcpu_info to place vcpu info
 323         * for secondary CPUs as they are brought up.
 324         * For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
 325         */
 326        xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
 327                                               sizeof(struct vcpu_info));
 328        if (xen_vcpu_info == NULL)
 329                return -ENOMEM;
 330
 331        if (gnttab_setup_auto_xlat_frames(grant_frames)) {
 332                free_percpu(xen_vcpu_info);
 333                return -ENOMEM;
 334        }
 335        gnttab_init();
 336        if (!xen_initial_domain())
 337                xenbus_probe(NULL);
 338
 339        /*
 340         * Making sure board specific code will not set up ops for
 341         * cpu idle and cpu freq.
 342         */
 343        disable_cpuidle();
 344        disable_cpufreq();
 345
 346        xen_init_IRQ();
 347
 348        if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 349                               "events", &xen_vcpu)) {
 350                pr_err("Error request IRQ %d\n", xen_events_irq);
 351                return -EINVAL;
 352        }
 353
 354        xen_percpu_init();
 355
 356        register_cpu_notifier(&xen_cpu_notifier);
 357
 358        pv_time_ops.steal_clock = xen_stolen_accounting;
 359        static_key_slow_inc(&paravirt_steal_enabled);
 360        if (xen_initial_domain())
 361                pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 362
 363        return 0;
 364}
 365early_initcall(xen_guest_init);
 366
 367static int __init xen_pm_init(void)
 368{
 369        if (!xen_domain())
 370                return -ENODEV;
 371
 372        pm_power_off = xen_power_off;
 373        arm_pm_restart = xen_restart;
 374        if (!xen_initial_domain()) {
 375                struct timespec64 ts;
 376                xen_read_wallclock(&ts);
 377                do_settimeofday64(&ts);
 378        }
 379
 380        return 0;
 381}
 382late_initcall(xen_pm_init);
 383
 384
 385/* empty stubs */
 386void xen_arch_pre_suspend(void) { }
 387void xen_arch_post_suspend(int suspend_cancelled) { }
 388void xen_timer_resume(void) { }
 389void xen_arch_resume(void) { }
 390void xen_arch_suspend(void) { }
 391
 392
 393/* In the hypercall.S file. */
 394EXPORT_SYMBOL_GPL(HYPERVISOR_event_channel_op);
 395EXPORT_SYMBOL_GPL(HYPERVISOR_grant_table_op);
 396EXPORT_SYMBOL_GPL(HYPERVISOR_xen_version);
 397EXPORT_SYMBOL_GPL(HYPERVISOR_console_io);
 398EXPORT_SYMBOL_GPL(HYPERVISOR_sched_op);
 399EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 400EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 401EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
 402EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 403EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op);
 404EXPORT_SYMBOL_GPL(HYPERVISOR_platform_op);
 405EXPORT_SYMBOL_GPL(HYPERVISOR_multicall);
 406EXPORT_SYMBOL_GPL(privcmd_call);
 407