arch/ia64/xen/xen_pv_ops.c

   1 /******************************************************************************
   2  * arch/ia64/xen/xen_pv_ops.c
   3  *
   4  * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
   5  *                    VA Linux Systems Japan K.K.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  */
  22
  23 #include <linux/console.h>
  24 #include <linux/irq.h>
  25 #include <linux/kernel.h>
  26 #include <linux/pm.h>
  27
  28 #include <asm/xen/hypervisor.h>
  29 #include <asm/xen/xencomm.h>
  30 #include <asm/xen/privop.h>
  31
  32 #include "irq_xen.h"
  33 #include "time.h"
  34
  35 /***************************************************************************
  36  * general info
  37  */
  38 static struct pv_info xen_info __initdata = {
  39         .kernel_rpl = 2,        /* or 1: determin at runtime */
  40         .paravirt_enabled = 1,
  41         .name = "Xen/ia64",
  42 };
  43
  44 #define IA64_RSC_PL_SHIFT       2
  45 #define IA64_RSC_PL_BIT_SIZE    2
  46 #define IA64_RSC_PL_MASK        \
  47         (((1UL << IA64_RSC_PL_BIT_SIZE) - 1) << IA64_RSC_PL_SHIFT)
  48
  49 static void __init
  50 xen_info_init(void)
  51 {
  52         /* Xenified Linux/ia64 may run on pl = 1 or 2.
  53          * determin at run time. */
  54         unsigned long rsc = ia64_getreg(_IA64_REG_AR_RSC);
  55         unsigned int rpl = (rsc & IA64_RSC_PL_MASK) >> IA64_RSC_PL_SHIFT;
  56         xen_info.kernel_rpl = rpl;
  57 }
  58
  59 /***************************************************************************
  60  * pv_init_ops
  61  * initialization hooks.
  62  */
  63
  64 static void
  65 xen_panic_hypercall(struct unw_frame_info *info, void *arg)
  66 {
  67         current->thread.ksp = (__u64)info->sw - 16;
  68         HYPERVISOR_shutdown(SHUTDOWN_crash);
  69         /* we're never actually going to get here... */
  70 }
  71
  72 static int
  73 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
  74 {
  75         unw_init_running(xen_panic_hypercall, NULL);
  76         /* we're never actually going to get here... */
  77         return NOTIFY_DONE;
  78 }
  79
  80 static struct notifier_block xen_panic_block = {
  81         xen_panic_event, NULL, 0 /* try to go last */
  82 };
  83
  84 static void xen_pm_power_off(void)
  85 {
  86         local_irq_disable();
  87         HYPERVISOR_shutdown(SHUTDOWN_poweroff);
  88 }
  89
  90 static void __init
  91 xen_banner(void)
  92 {
  93         printk(KERN_INFO
  94                "Running on Xen! pl = %d start_info_pfn=0x%lx nr_pages=%ld "
  95                "flags=0x%x\n",
  96                xen_info.kernel_rpl,
  97                HYPERVISOR_shared_info->arch.start_info_pfn,
  98                xen_start_info->nr_pages, xen_start_info->flags);
  99 }
 100
 101 static int __init
 102 xen_reserve_memory(struct rsvd_region *region)
 103 {
 104         region->start = (unsigned long)__va(
 105                 (HYPERVISOR_shared_info->arch.start_info_pfn << PAGE_SHIFT));
 106         region->end   = region->start + PAGE_SIZE;
 107         return 1;
 108 }
 109
 110 static void __init
 111 xen_arch_setup_early(void)
 112 {
 113         struct shared_info *s;
 114         BUG_ON(!xen_pv_domain());
 115
 116         s = HYPERVISOR_shared_info;
 117         xen_start_info = __va(s->arch.start_info_pfn << PAGE_SHIFT);
 118
 119         /* Must be done before any hypercall.  */
 120         xencomm_initialize();
 121
 122         xen_setup_features();
 123         /* Register a call for panic conditions. */
 124         atomic_notifier_chain_register(&panic_notifier_list,
 125                                        &xen_panic_block);
 126         pm_power_off = xen_pm_power_off;
 127
 128         xen_ia64_enable_opt_feature();
 129 }
 130
 131 static void __init
 132 xen_arch_setup_console(char **cmdline_p)
 133 {
 134         add_preferred_console("xenboot", 0, NULL);
 135         add_preferred_console("tty", 0, NULL);
 136         /* use hvc_xen */
 137         add_preferred_console("hvc", 0, NULL);
 138
 139 #if !defined(CONFIG_VT) || !defined(CONFIG_DUMMY_CONSOLE)
 140         conswitchp = NULL;
 141 #endif
 142 }
 143
 144 static int __init
 145 xen_arch_setup_nomca(void)
 146 {
 147         return 1;
 148 }
 149
 150 static void __init
 151 xen_post_smp_prepare_boot_cpu(void)
 152 {
 153         xen_setup_vcpu_info_placement();
 154 }
 155
 156 static const struct pv_init_ops xen_init_ops __initdata = {
 157         .banner = xen_banner,
 158
 159         .reserve_memory = xen_reserve_memory,
 160
 161         .arch_setup_early = xen_arch_setup_early,
 162         .arch_setup_console = xen_arch_setup_console,
 163         .arch_setup_nomca = xen_arch_setup_nomca,
 164
 165         .post_smp_prepare_boot_cpu = xen_post_smp_prepare_boot_cpu,
 166 };
 167
 168 /***************************************************************************
 169  * pv_cpu_ops
 170  * intrinsics hooks.
 171  */
 172
 173 static void xen_setreg(int regnum, unsigned long val)
 174 {
 175         switch (regnum) {
 176         case _IA64_REG_AR_KR0 ... _IA64_REG_AR_KR7:
 177                 xen_set_kr(regnum - _IA64_REG_AR_KR0, val);
 178                 break;
 179 #ifdef CONFIG_IA32_SUPPORT
 180         case _IA64_REG_AR_EFLAG:
 181                 xen_set_eflag(val);
 182                 break;
 183 #endif
 184         case _IA64_REG_CR_TPR:
 185                 xen_set_tpr(val);
 186                 break;
 187         case _IA64_REG_CR_ITM:
 188                 xen_set_itm(val);
 189                 break;
 190         case _IA64_REG_CR_EOI:
 191                 xen_eoi(val);
 192                 break;
 193         default:
 194                 ia64_native_setreg_func(regnum, val);
 195                 break;
 196         }
 197 }
 198
 199 static unsigned long xen_getreg(int regnum)
 200 {
 201         unsigned long res;
 202
 203         switch (regnum) {
 204         case _IA64_REG_PSR:
 205                 res = xen_get_psr();
 206                 break;
 207 #ifdef CONFIG_IA32_SUPPORT
 208         case _IA64_REG_AR_EFLAG:
 209                 res = xen_get_eflag();
 210                 break;
 211 #endif
 212         case _IA64_REG_CR_IVR:
 213                 res = xen_get_ivr();
 214                 break;
 215         case _IA64_REG_CR_TPR:
 216                 res = xen_get_tpr();
 217                 break;
 218         default:
 219                 res = ia64_native_getreg_func(regnum);
 220                 break;
 221         }
 222         return res;
 223 }
 224
 225 /* turning on interrupts is a bit more complicated.. write to the
 226  * memory-mapped virtual psr.i bit first (to avoid race condition),
 227  * then if any interrupts were pending, we have to execute a hyperprivop
 228  * to ensure the pending interrupt gets delivered; else we're done! */
 229 static void
 230 xen_ssm_i(void)
 231 {
 232         int old = xen_get_virtual_psr_i();
 233         xen_set_virtual_psr_i(1);
 234         barrier();
 235         if (!old && xen_get_virtual_pend())
 236                 xen_hyper_ssm_i();
 237 }
 238
 239 /* turning off interrupts can be paravirtualized simply by writing
 240  * to a memory-mapped virtual psr.i bit (implemented as a 16-bit bool) */
 241 static void
 242 xen_rsm_i(void)
 243 {
 244         xen_set_virtual_psr_i(0);
 245         barrier();
 246 }
 247
 248 static unsigned long
 249 xen_get_psr_i(void)
 250 {
 251         return xen_get_virtual_psr_i() ? IA64_PSR_I : 0;
 252 }
 253
 254 static void
 255 xen_intrin_local_irq_restore(unsigned long mask)
 256 {
 257         if (mask & IA64_PSR_I)
 258                 xen_ssm_i();
 259         else
 260                 xen_rsm_i();
 261 }
 262
 263 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
 264         .fc             = xen_fc,
 265         .thash          = xen_thash,
 266         .get_cpuid      = xen_get_cpuid,
 267         .get_pmd        = xen_get_pmd,
 268         .getreg         = xen_getreg,
 269         .setreg         = xen_setreg,
 270         .ptcga          = xen_ptcga,
 271         .get_rr         = xen_get_rr,
 272         .set_rr         = xen_set_rr,
 273         .set_rr0_to_rr4 = xen_set_rr0_to_rr4,
 274         .ssm_i          = xen_ssm_i,
 275         .rsm_i          = xen_rsm_i,
 276         .get_psr_i      = xen_get_psr_i,
 277         .intrin_local_irq_restore
 278                         = xen_intrin_local_irq_restore,
 279 };
 280
 281 /******************************************************************************
 282  * replacement of hand written assembly codes.
 283  */
 284
 285 extern char xen_switch_to;
 286 extern char xen_leave_syscall;
 287 extern char xen_work_processed_syscall;
 288 extern char xen_leave_kernel;
 289
 290 const struct pv_cpu_asm_switch xen_cpu_asm_switch = {
 291         .switch_to              = (unsigned long)&xen_switch_to,
 292         .leave_syscall          = (unsigned long)&xen_leave_syscall,
 293         .work_processed_syscall = (unsigned long)&xen_work_processed_syscall,
 294         .leave_kernel           = (unsigned long)&xen_leave_kernel,
 295 };
 296
 297 /***************************************************************************
 298  * pv_iosapic_ops
 299  * iosapic read/write hooks.
 300  */
 301 static void
 302 xen_pcat_compat_init(void)
 303 {
 304         /* nothing */
 305 }
 306
 307 static struct irq_chip*
 308 xen_iosapic_get_irq_chip(unsigned long trigger)
 309 {
 310         return NULL;
 311 }
 312
 313 static unsigned int
 314 xen_iosapic_read(char __iomem *iosapic, unsigned int reg)
 315 {
 316         struct physdev_apic apic_op;
 317         int ret;
 318
 319         apic_op.apic_physbase = (unsigned long)iosapic -
 320                                         __IA64_UNCACHED_OFFSET;
 321         apic_op.reg = reg;
 322         ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
 323         if (ret)
 324                 return ret;
 325         return apic_op.value;
 326 }
 327
 328 static void
 329 xen_iosapic_write(char __iomem *iosapic, unsigned int reg, u32 val)
 330 {
 331         struct physdev_apic apic_op;
 332
 333         apic_op.apic_physbase = (unsigned long)iosapic -
 334                                         __IA64_UNCACHED_OFFSET;
 335         apic_op.reg = reg;
 336         apic_op.value = val;
 337         HYPERVISOR_physdev_op(PHYSDEVOP_apic_write, &apic_op);
 338 }
 339
 340 static const struct pv_iosapic_ops xen_iosapic_ops __initdata = {
 341         .pcat_compat_init = xen_pcat_compat_init,
 342         .__get_irq_chip = xen_iosapic_get_irq_chip,
 343
 344         .__read = xen_iosapic_read,
 345         .__write = xen_iosapic_write,
 346 };
 347
 348 /***************************************************************************
 349  * pv_ops initialization
 350  */
 351
 352 void __init
 353 xen_setup_pv_ops(void)
 354 {
 355         xen_info_init();
 356         pv_info = xen_info;
 357         pv_init_ops = xen_init_ops;
 358         pv_cpu_ops = xen_cpu_ops;
 359         pv_iosapic_ops = xen_iosapic_ops;
 360         pv_irq_ops = xen_irq_ops;
 361         pv_time_ops = xen_time_ops;
 362
 363         paravirt_cpu_asm_init(&xen_cpu_asm_switch);
 364 }