xen32: create initial mappings like 64-bit
[linux-2.6] / arch / x86 / xen / enlighten.c
1 /*
2  * Core of Xen paravirt_ops implementation.
3  *
4  * This file contains the xen_paravirt_ops structure itself, and the
5  * implementations for:
6  * - privileged instructions
7  * - interrupt flags
8  * - segment operations
9  * - booting and setup
10  *
11  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/preempt.h>
18 #include <linux/hardirq.h>
19 #include <linux/percpu.h>
20 #include <linux/delay.h>
21 #include <linux/start_kernel.h>
22 #include <linux/sched.h>
23 #include <linux/bootmem.h>
24 #include <linux/module.h>
25 #include <linux/mm.h>
26 #include <linux/page-flags.h>
27 #include <linux/highmem.h>
28 #include <linux/console.h>
29
30 #include <xen/interface/xen.h>
31 #include <xen/interface/physdev.h>
32 #include <xen/interface/vcpu.h>
33 #include <xen/interface/sched.h>
34 #include <xen/features.h>
35 #include <xen/page.h>
36 #include <xen/hvc-console.h>
37
38 #include <asm/paravirt.h>
39 #include <asm/page.h>
40 #include <asm/xen/hypercall.h>
41 #include <asm/xen/hypervisor.h>
42 #include <asm/fixmap.h>
43 #include <asm/processor.h>
44 #include <asm/setup.h>
45 #include <asm/desc.h>
46 #include <asm/pgtable.h>
47 #include <asm/tlbflush.h>
48 #include <asm/reboot.h>
49 #include <asm/pgalloc.h>
50
51 #include "xen-ops.h"
52 #include "mmu.h"
53 #include "multicalls.h"
54
55 EXPORT_SYMBOL_GPL(hypercall_page);
56
57 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
58 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
59
60 /*
61  * Note about cr3 (pagetable base) values:
62  *
63  * xen_cr3 contains the current logical cr3 value; it contains the
64  * last set cr3.  This may not be the current effective cr3, because
65  * its update may be being lazily deferred.  However, a vcpu looking
66  * at its own cr3 can use this value knowing that it everything will
67  * be self-consistent.
68  *
69  * xen_current_cr3 contains the actual vcpu cr3; it is set once the
70  * hypercall to set the vcpu cr3 is complete (so it may be a little
71  * out of date, but it will never be set early).  If one vcpu is
72  * looking at another vcpu's cr3 value, it should use this variable.
73  */
74 DEFINE_PER_CPU(unsigned long, xen_cr3);  /* cr3 stored as physaddr */
75 DEFINE_PER_CPU(unsigned long, xen_current_cr3);  /* actual vcpu cr3 */
76
77 struct start_info *xen_start_info;
78 EXPORT_SYMBOL_GPL(xen_start_info);
79
80 struct shared_info xen_dummy_shared_info;
81
82 /*
83  * Point at some empty memory to start with. We map the real shared_info
84  * page as soon as fixmap is up and running.
85  */
86 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
87
88 /*
89  * Flag to determine whether vcpu info placement is available on all
90  * VCPUs.  We assume it is to start with, and then set it to zero on
91  * the first failure.  This is because it can succeed on some VCPUs
92  * and not others, since it can involve hypervisor memory allocation,
93  * or because the guest failed to guarantee all the appropriate
94  * constraints on all VCPUs (ie buffer can't cross a page boundary).
95  *
96  * Note that any particular CPU may be using a placed vcpu structure,
97  * but we can only optimise if the all are.
98  *
99  * 0: not available, 1: available
100  */
101 static int have_vcpu_info_placement = 1;
102
103 static void xen_vcpu_setup(int cpu)
104 {
105         struct vcpu_register_vcpu_info info;
106         int err;
107         struct vcpu_info *vcpup;
108
109         BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
110         per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
111
112         if (!have_vcpu_info_placement)
113                 return;         /* already tested, not available */
114
115         vcpup = &per_cpu(xen_vcpu_info, cpu);
116
117         info.mfn = virt_to_mfn(vcpup);
118         info.offset = offset_in_page(vcpup);
119
120         printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
121                cpu, vcpup, info.mfn, info.offset);
122
123         /* Check to see if the hypervisor will put the vcpu_info
124            structure where we want it, which allows direct access via
125            a percpu-variable. */
126         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
127
128         if (err) {
129                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
130                 have_vcpu_info_placement = 0;
131         } else {
132                 /* This cpu is using the registered vcpu info, even if
133                    later ones fail to. */
134                 per_cpu(xen_vcpu, cpu) = vcpup;
135
136                 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
137                        cpu, vcpup);
138         }
139 }
140
141 /*
142  * On restore, set the vcpu placement up again.
143  * If it fails, then we're in a bad state, since
144  * we can't back out from using it...
145  */
146 void xen_vcpu_restore(void)
147 {
148         if (have_vcpu_info_placement) {
149                 int cpu;
150
151                 for_each_online_cpu(cpu) {
152                         bool other_cpu = (cpu != smp_processor_id());
153
154                         if (other_cpu &&
155                             HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
156                                 BUG();
157
158                         xen_vcpu_setup(cpu);
159
160                         if (other_cpu &&
161                             HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
162                                 BUG();
163                 }
164
165                 BUG_ON(!have_vcpu_info_placement);
166         }
167 }
168
169 static void __init xen_banner(void)
170 {
171         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
172                pv_info.name);
173         printk(KERN_INFO "Hypervisor signature: %s%s\n",
174                xen_start_info->magic,
175                xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
176 }
177
178 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
179                       unsigned int *cx, unsigned int *dx)
180 {
181         unsigned maskedx = ~0;
182
183         /*
184          * Mask out inconvenient features, to try and disable as many
185          * unsupported kernel subsystems as possible.
186          */
187         if (*ax == 1)
188                 maskedx = ~((1 << X86_FEATURE_APIC) |  /* disable APIC */
189                             (1 << X86_FEATURE_ACPI) |  /* disable ACPI */
190                             (1 << X86_FEATURE_MCE)  |  /* disable MCE */
191                             (1 << X86_FEATURE_MCA)  |  /* disable MCA */
192                             (1 << X86_FEATURE_ACC));   /* thermal monitoring */
193
194         asm(XEN_EMULATE_PREFIX "cpuid"
195                 : "=a" (*ax),
196                   "=b" (*bx),
197                   "=c" (*cx),
198                   "=d" (*dx)
199                 : "0" (*ax), "2" (*cx));
200         *dx &= maskedx;
201 }
202
203 static void xen_set_debugreg(int reg, unsigned long val)
204 {
205         HYPERVISOR_set_debugreg(reg, val);
206 }
207
208 static unsigned long xen_get_debugreg(int reg)
209 {
210         return HYPERVISOR_get_debugreg(reg);
211 }
212
213 static unsigned long xen_save_fl(void)
214 {
215         struct vcpu_info *vcpu;
216         unsigned long flags;
217
218         vcpu = x86_read_percpu(xen_vcpu);
219
220         /* flag has opposite sense of mask */
221         flags = !vcpu->evtchn_upcall_mask;
222
223         /* convert to IF type flag
224            -0 -> 0x00000000
225            -1 -> 0xffffffff
226         */
227         return (-flags) & X86_EFLAGS_IF;
228 }
229
230 static void xen_restore_fl(unsigned long flags)
231 {
232         struct vcpu_info *vcpu;
233
234         /* convert from IF type flag */
235         flags = !(flags & X86_EFLAGS_IF);
236
237         /* There's a one instruction preempt window here.  We need to
238            make sure we're don't switch CPUs between getting the vcpu
239            pointer and updating the mask. */
240         preempt_disable();
241         vcpu = x86_read_percpu(xen_vcpu);
242         vcpu->evtchn_upcall_mask = flags;
243         preempt_enable_no_resched();
244
245         /* Doesn't matter if we get preempted here, because any
246            pending event will get dealt with anyway. */
247
248         if (flags == 0) {
249                 preempt_check_resched();
250                 barrier(); /* unmask then check (avoid races) */
251                 if (unlikely(vcpu->evtchn_upcall_pending))
252                         force_evtchn_callback();
253         }
254 }
255
256 static void xen_irq_disable(void)
257 {
258         /* There's a one instruction preempt window here.  We need to
259            make sure we're don't switch CPUs between getting the vcpu
260            pointer and updating the mask. */
261         preempt_disable();
262         x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
263         preempt_enable_no_resched();
264 }
265
266 static void xen_irq_enable(void)
267 {
268         struct vcpu_info *vcpu;
269
270         /* We don't need to worry about being preempted here, since
271            either a) interrupts are disabled, so no preemption, or b)
272            the caller is confused and is trying to re-enable interrupts
273            on an indeterminate processor. */
274
275         vcpu = x86_read_percpu(xen_vcpu);
276         vcpu->evtchn_upcall_mask = 0;
277
278         /* Doesn't matter if we get preempted here, because any
279            pending event will get dealt with anyway. */
280
281         barrier(); /* unmask then check (avoid races) */
282         if (unlikely(vcpu->evtchn_upcall_pending))
283                 force_evtchn_callback();
284 }
285
286 static void xen_safe_halt(void)
287 {
288         /* Blocking includes an implicit local_irq_enable(). */
289         if (HYPERVISOR_sched_op(SCHEDOP_block, NULL) != 0)
290                 BUG();
291 }
292
293 static void xen_halt(void)
294 {
295         if (irqs_disabled())
296                 HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
297         else
298                 xen_safe_halt();
299 }
300
301 static void xen_leave_lazy(void)
302 {
303         paravirt_leave_lazy(paravirt_get_lazy_mode());
304         xen_mc_flush();
305 }
306
307 static unsigned long xen_store_tr(void)
308 {
309         return 0;
310 }
311
312 static void xen_set_ldt(const void *addr, unsigned entries)
313 {
314         struct mmuext_op *op;
315         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
316
317         op = mcs.args;
318         op->cmd = MMUEXT_SET_LDT;
319         op->arg1.linear_addr = (unsigned long)addr;
320         op->arg2.nr_ents = entries;
321
322         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
323
324         xen_mc_issue(PARAVIRT_LAZY_CPU);
325 }
326
327 static void xen_load_gdt(const struct desc_ptr *dtr)
328 {
329         unsigned long *frames;
330         unsigned long va = dtr->address;
331         unsigned int size = dtr->size + 1;
332         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
333         int f;
334         struct multicall_space mcs;
335
336         /* A GDT can be up to 64k in size, which corresponds to 8192
337            8-byte entries, or 16 4k pages.. */
338
339         BUG_ON(size > 65536);
340         BUG_ON(va & ~PAGE_MASK);
341
342         mcs = xen_mc_entry(sizeof(*frames) * pages);
343         frames = mcs.args;
344
345         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
346                 frames[f] = virt_to_mfn(va);
347                 make_lowmem_page_readonly((void *)va);
348         }
349
350         MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct));
351
352         xen_mc_issue(PARAVIRT_LAZY_CPU);
353 }
354
355 static void load_TLS_descriptor(struct thread_struct *t,
356                                 unsigned int cpu, unsigned int i)
357 {
358         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
359         xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
360         struct multicall_space mc = __xen_mc_entry(0);
361
362         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
363 }
364
365 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
366 {
367         xen_mc_batch();
368
369         load_TLS_descriptor(t, cpu, 0);
370         load_TLS_descriptor(t, cpu, 1);
371         load_TLS_descriptor(t, cpu, 2);
372
373         xen_mc_issue(PARAVIRT_LAZY_CPU);
374
375         /*
376          * XXX sleazy hack: If we're being called in a lazy-cpu zone,
377          * it means we're in a context switch, and %gs has just been
378          * saved.  This means we can zero it out to prevent faults on
379          * exit from the hypervisor if the next process has no %gs.
380          * Either way, it has been saved, and the new value will get
381          * loaded properly.  This will go away as soon as Xen has been
382          * modified to not save/restore %gs for normal hypercalls.
383          */
384         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU)
385                 loadsegment(gs, 0);
386 }
387
388 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
389                                 const void *ptr)
390 {
391         unsigned long lp = (unsigned long)&dt[entrynum];
392         xmaddr_t mach_lp = virt_to_machine(lp);
393         u64 entry = *(u64 *)ptr;
394
395         preempt_disable();
396
397         xen_mc_flush();
398         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
399                 BUG();
400
401         preempt_enable();
402 }
403
404 static int cvt_gate_to_trap(int vector, u32 low, u32 high,
405                             struct trap_info *info)
406 {
407         u8 type, dpl;
408
409         type = (high >> 8) & 0x1f;
410         dpl = (high >> 13) & 3;
411
412         if (type != 0xf && type != 0xe)
413                 return 0;
414
415         info->vector = vector;
416         info->address = (high & 0xffff0000) | (low & 0x0000ffff);
417         info->cs = low >> 16;
418         info->flags = dpl;
419         /* interrupt gates clear IF */
420         if (type == 0xe)
421                 info->flags |= 4;
422
423         return 1;
424 }
425
426 /* Locations of each CPU's IDT */
427 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
428
429 /* Set an IDT entry.  If the entry is part of the current IDT, then
430    also update Xen. */
431 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
432 {
433         unsigned long p = (unsigned long)&dt[entrynum];
434         unsigned long start, end;
435
436         preempt_disable();
437
438         start = __get_cpu_var(idt_desc).address;
439         end = start + __get_cpu_var(idt_desc).size + 1;
440
441         xen_mc_flush();
442
443         native_write_idt_entry(dt, entrynum, g);
444
445         if (p >= start && (p + 8) <= end) {
446                 struct trap_info info[2];
447                 u32 *desc = (u32 *)g;
448
449                 info[1].address = 0;
450
451                 if (cvt_gate_to_trap(entrynum, desc[0], desc[1], &info[0]))
452                         if (HYPERVISOR_set_trap_table(info))
453                                 BUG();
454         }
455
456         preempt_enable();
457 }
458
459 static void xen_convert_trap_info(const struct desc_ptr *desc,
460                                   struct trap_info *traps)
461 {
462         unsigned in, out, count;
463
464         count = (desc->size+1) / 8;
465         BUG_ON(count > 256);
466
467         for (in = out = 0; in < count; in++) {
468                 const u32 *entry = (u32 *)(desc->address + in * 8);
469
470                 if (cvt_gate_to_trap(in, entry[0], entry[1], &traps[out]))
471                         out++;
472         }
473         traps[out].address = 0;
474 }
475
476 void xen_copy_trap_info(struct trap_info *traps)
477 {
478         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
479
480         xen_convert_trap_info(desc, traps);
481 }
482
483 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
484    hold a spinlock to protect the static traps[] array (static because
485    it avoids allocation, and saves stack space). */
486 static void xen_load_idt(const struct desc_ptr *desc)
487 {
488         static DEFINE_SPINLOCK(lock);
489         static struct trap_info traps[257];
490
491         spin_lock(&lock);
492
493         __get_cpu_var(idt_desc) = *desc;
494
495         xen_convert_trap_info(desc, traps);
496
497         xen_mc_flush();
498         if (HYPERVISOR_set_trap_table(traps))
499                 BUG();
500
501         spin_unlock(&lock);
502 }
503
504 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
505    they're handled differently. */
506 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
507                                 const void *desc, int type)
508 {
509         preempt_disable();
510
511         switch (type) {
512         case DESC_LDT:
513         case DESC_TSS:
514                 /* ignore */
515                 break;
516
517         default: {
518                 xmaddr_t maddr = virt_to_machine(&dt[entry]);
519
520                 xen_mc_flush();
521                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
522                         BUG();
523         }
524
525         }
526
527         preempt_enable();
528 }
529
530 static void xen_load_sp0(struct tss_struct *tss,
531                           struct thread_struct *thread)
532 {
533         struct multicall_space mcs = xen_mc_entry(0);
534         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
535         xen_mc_issue(PARAVIRT_LAZY_CPU);
536 }
537
538 static void xen_set_iopl_mask(unsigned mask)
539 {
540         struct physdev_set_iopl set_iopl;
541
542         /* Force the change at ring 0. */
543         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
544         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
545 }
546
547 static void xen_io_delay(void)
548 {
549 }
550
551 #ifdef CONFIG_X86_LOCAL_APIC
552 static u32 xen_apic_read(unsigned long reg)
553 {
554         return 0;
555 }
556
557 static void xen_apic_write(unsigned long reg, u32 val)
558 {
559         /* Warn to see if there's any stray references */
560         WARN_ON(1);
561 }
562 #endif
563
564 static void xen_flush_tlb(void)
565 {
566         struct mmuext_op *op;
567         struct multicall_space mcs;
568
569         preempt_disable();
570
571         mcs = xen_mc_entry(sizeof(*op));
572
573         op = mcs.args;
574         op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
575         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
576
577         xen_mc_issue(PARAVIRT_LAZY_MMU);
578
579         preempt_enable();
580 }
581
582 static void xen_flush_tlb_single(unsigned long addr)
583 {
584         struct mmuext_op *op;
585         struct multicall_space mcs;
586
587         preempt_disable();
588
589         mcs = xen_mc_entry(sizeof(*op));
590         op = mcs.args;
591         op->cmd = MMUEXT_INVLPG_LOCAL;
592         op->arg1.linear_addr = addr & PAGE_MASK;
593         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
594
595         xen_mc_issue(PARAVIRT_LAZY_MMU);
596
597         preempt_enable();
598 }
599
600 static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
601                                  unsigned long va)
602 {
603         struct {
604                 struct mmuext_op op;
605                 cpumask_t mask;
606         } *args;
607         cpumask_t cpumask = *cpus;
608         struct multicall_space mcs;
609
610         /*
611          * A couple of (to be removed) sanity checks:
612          *
613          * - current CPU must not be in mask
614          * - mask must exist :)
615          */
616         BUG_ON(cpus_empty(cpumask));
617         BUG_ON(cpu_isset(smp_processor_id(), cpumask));
618         BUG_ON(!mm);
619
620         /* If a CPU which we ran on has gone down, OK. */
621         cpus_and(cpumask, cpumask, cpu_online_map);
622         if (cpus_empty(cpumask))
623                 return;
624
625         mcs = xen_mc_entry(sizeof(*args));
626         args = mcs.args;
627         args->mask = cpumask;
628         args->op.arg2.vcpumask = &args->mask;
629
630         if (va == TLB_FLUSH_ALL) {
631                 args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
632         } else {
633                 args->op.cmd = MMUEXT_INVLPG_MULTI;
634                 args->op.arg1.linear_addr = va;
635         }
636
637         MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
638
639         xen_mc_issue(PARAVIRT_LAZY_MMU);
640 }
641
642 static void xen_clts(void)
643 {
644         struct multicall_space mcs;
645
646         mcs = xen_mc_entry(0);
647
648         MULTI_fpu_taskswitch(mcs.mc, 0);
649
650         xen_mc_issue(PARAVIRT_LAZY_CPU);
651 }
652
653 static void xen_write_cr0(unsigned long cr0)
654 {
655         struct multicall_space mcs;
656
657         /* Only pay attention to cr0.TS; everything else is
658            ignored. */
659         mcs = xen_mc_entry(0);
660
661         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
662
663         xen_mc_issue(PARAVIRT_LAZY_CPU);
664 }
665
666 static void xen_write_cr2(unsigned long cr2)
667 {
668         x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
669 }
670
671 static unsigned long xen_read_cr2(void)
672 {
673         return x86_read_percpu(xen_vcpu)->arch.cr2;
674 }
675
676 static unsigned long xen_read_cr2_direct(void)
677 {
678         return x86_read_percpu(xen_vcpu_info.arch.cr2);
679 }
680
681 static void xen_write_cr4(unsigned long cr4)
682 {
683         cr4 &= ~X86_CR4_PGE;
684         cr4 &= ~X86_CR4_PSE;
685
686         native_write_cr4(cr4);
687 }
688
689 static unsigned long xen_read_cr3(void)
690 {
691         return x86_read_percpu(xen_cr3);
692 }
693
694 static void set_current_cr3(void *v)
695 {
696         x86_write_percpu(xen_current_cr3, (unsigned long)v);
697 }
698
699 static void xen_write_cr3(unsigned long cr3)
700 {
701         struct mmuext_op *op;
702         struct multicall_space mcs;
703         unsigned long mfn = pfn_to_mfn(PFN_DOWN(cr3));
704
705         BUG_ON(preemptible());
706
707         mcs = xen_mc_entry(sizeof(*op));  /* disables interrupts */
708
709         /* Update while interrupts are disabled, so its atomic with
710            respect to ipis */
711         x86_write_percpu(xen_cr3, cr3);
712
713         op = mcs.args;
714         op->cmd = MMUEXT_NEW_BASEPTR;
715         op->arg1.mfn = mfn;
716
717         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
718
719         /* Update xen_update_cr3 once the batch has actually
720            been submitted. */
721         xen_mc_callback(set_current_cr3, (void *)cr3);
722
723         xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
724 }
725
726 /* Early in boot, while setting up the initial pagetable, assume
727    everything is pinned. */
728 static __init void xen_alloc_pte_init(struct mm_struct *mm, u32 pfn)
729 {
730 #ifdef CONFIG_FLATMEM
731         BUG_ON(mem_map);        /* should only be used early */
732 #endif
733         make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
734 }
735
736 /* Early release_pte assumes that all pts are pinned, since there's
737    only init_mm and anything attached to that is pinned. */
738 static void xen_release_pte_init(u32 pfn)
739 {
740         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
741 }
742
743 static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
744 {
745         struct mmuext_op op;
746         op.cmd = cmd;
747         op.arg1.mfn = pfn_to_mfn(pfn);
748         if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
749                 BUG();
750 }
751
752 /* This needs to make sure the new pte page is pinned iff its being
753    attached to a pinned pagetable. */
754 static void xen_alloc_ptpage(struct mm_struct *mm, u32 pfn, unsigned level)
755 {
756         struct page *page = pfn_to_page(pfn);
757
758         if (PagePinned(virt_to_page(mm->pgd))) {
759                 SetPagePinned(page);
760
761                 if (!PageHighMem(page)) {
762                         make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
763                         if (level == PT_PTE)
764                                 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
765                 } else
766                         /* make sure there are no stray mappings of
767                            this page */
768                         kmap_flush_unused();
769         }
770 }
771
772 static void xen_alloc_pte(struct mm_struct *mm, u32 pfn)
773 {
774         xen_alloc_ptpage(mm, pfn, PT_PTE);
775 }
776
777 static void xen_alloc_pmd(struct mm_struct *mm, u32 pfn)
778 {
779         xen_alloc_ptpage(mm, pfn, PT_PMD);
780 }
781
782 /* This should never happen until we're OK to use struct page */
783 static void xen_release_ptpage(u32 pfn, unsigned level)
784 {
785         struct page *page = pfn_to_page(pfn);
786
787         if (PagePinned(page)) {
788                 if (!PageHighMem(page)) {
789                         if (level == PT_PTE)
790                                 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
791                         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
792                 }
793                 ClearPagePinned(page);
794         }
795 }
796
797 static void xen_release_pte(u32 pfn)
798 {
799         xen_release_ptpage(pfn, PT_PTE);
800 }
801
802 static void xen_release_pmd(u32 pfn)
803 {
804         xen_release_ptpage(pfn, PT_PMD);
805 }
806
807 #if PAGETABLE_LEVELS == 4
808 static void xen_alloc_pud(struct mm_struct *mm, u32 pfn)
809 {
810         xen_alloc_ptpage(mm, pfn, PT_PUD);
811 }
812
813 static void xen_release_pud(u32 pfn)
814 {
815         xen_release_ptpage(pfn, PT_PUD);
816 }
817 #endif
818
819 #ifdef CONFIG_HIGHPTE
820 static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
821 {
822         pgprot_t prot = PAGE_KERNEL;
823
824         if (PagePinned(page))
825                 prot = PAGE_KERNEL_RO;
826
827         if (0 && PageHighMem(page))
828                 printk("mapping highpte %lx type %d prot %s\n",
829                        page_to_pfn(page), type,
830                        (unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ");
831
832         return kmap_atomic_prot(page, type, prot);
833 }
834 #endif
835
836 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
837 {
838         /* If there's an existing pte, then don't allow _PAGE_RW to be set */
839         if (pte_val_ma(*ptep) & _PAGE_PRESENT)
840                 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
841                                pte_val_ma(pte));
842
843         return pte;
844 }
845
846 /* Init-time set_pte while constructing initial pagetables, which
847    doesn't allow RO pagetable pages to be remapped RW */
848 static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
849 {
850         pte = mask_rw_pte(ptep, pte);
851
852         xen_set_pte(ptep, pte);
853 }
854
855 static __init void xen_pagetable_setup_start(pgd_t *base)
856 {
857 }
858
859 void xen_setup_shared_info(void)
860 {
861         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
862                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
863                            xen_start_info->shared_info);
864
865                 HYPERVISOR_shared_info =
866                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
867         } else
868                 HYPERVISOR_shared_info =
869                         (struct shared_info *)__va(xen_start_info->shared_info);
870
871 #ifndef CONFIG_SMP
872         /* In UP this is as good a place as any to set up shared info */
873         xen_setup_vcpu_info_placement();
874 #endif
875
876         xen_setup_mfn_list_list();
877 }
878
879 static __init void xen_pagetable_setup_done(pgd_t *base)
880 {
881         /* This will work as long as patching hasn't happened yet
882            (which it hasn't) */
883         pv_mmu_ops.alloc_pte = xen_alloc_pte;
884         pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
885         pv_mmu_ops.release_pte = xen_release_pte;
886         pv_mmu_ops.release_pmd = xen_release_pmd;
887 #if PAGETABLE_LEVELS == 4
888         pv_mmu_ops.alloc_pud = xen_alloc_pud;
889         pv_mmu_ops.release_pud = xen_release_pud;
890 #endif
891
892         pv_mmu_ops.set_pte = xen_set_pte;
893
894         xen_setup_shared_info();
895 }
896
897 static __init void xen_post_allocator_init(void)
898 {
899         pv_mmu_ops.set_pmd = xen_set_pmd;
900         pv_mmu_ops.set_pud = xen_set_pud;
901 #if PAGETABLE_LEVELS == 4
902         pv_mmu_ops.set_pgd = xen_set_pgd;
903 #endif
904
905         xen_mark_init_mm_pinned();
906 }
907
908 /* This is called once we have the cpu_possible_map */
909 void xen_setup_vcpu_info_placement(void)
910 {
911         int cpu;
912
913         for_each_possible_cpu(cpu)
914                 xen_vcpu_setup(cpu);
915
916         /* xen_vcpu_setup managed to place the vcpu_info within the
917            percpu area for all cpus, so make use of it */
918 #ifdef CONFIG_X86_32
919         if (have_vcpu_info_placement) {
920                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
921
922                 pv_irq_ops.save_fl = xen_save_fl_direct;
923                 pv_irq_ops.restore_fl = xen_restore_fl_direct;
924                 pv_irq_ops.irq_disable = xen_irq_disable_direct;
925                 pv_irq_ops.irq_enable = xen_irq_enable_direct;
926                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
927         }
928 #endif
929 }
930
931 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
932                           unsigned long addr, unsigned len)
933 {
934         char *start, *end, *reloc;
935         unsigned ret;
936
937         start = end = reloc = NULL;
938
939 #define SITE(op, x)                                                     \
940         case PARAVIRT_PATCH(op.x):                                      \
941         if (have_vcpu_info_placement) {                                 \
942                 start = (char *)xen_##x##_direct;                       \
943                 end = xen_##x##_direct_end;                             \
944                 reloc = xen_##x##_direct_reloc;                         \
945         }                                                               \
946         goto patch_site
947
948         switch (type) {
949 #ifdef CONFIG_X86_32
950                 SITE(pv_irq_ops, irq_enable);
951                 SITE(pv_irq_ops, irq_disable);
952                 SITE(pv_irq_ops, save_fl);
953                 SITE(pv_irq_ops, restore_fl);
954 #endif /* CONFIG_X86_32 */
955 #undef SITE
956
957         patch_site:
958                 if (start == NULL || (end-start) > len)
959                         goto default_patch;
960
961                 ret = paravirt_patch_insns(insnbuf, len, start, end);
962
963                 /* Note: because reloc is assigned from something that
964                    appears to be an array, gcc assumes it's non-null,
965                    but doesn't know its relationship with start and
966                    end. */
967                 if (reloc > start && reloc < end) {
968                         int reloc_off = reloc - start;
969                         long *relocp = (long *)(insnbuf + reloc_off);
970                         long delta = start - (char *)addr;
971
972                         *relocp += delta;
973                 }
974                 break;
975
976         default_patch:
977         default:
978                 ret = paravirt_patch_default(type, clobbers, insnbuf,
979                                              addr, len);
980                 break;
981         }
982
983         return ret;
984 }
985
986 static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot)
987 {
988         pte_t pte;
989
990         phys >>= PAGE_SHIFT;
991
992         switch (idx) {
993         case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
994 #ifdef CONFIG_X86_F00F_BUG
995         case FIX_F00F_IDT:
996 #endif
997 #ifdef CONFIG_X86_32
998         case FIX_WP_TEST:
999         case FIX_VDSO:
1000         case FIX_KMAP_BEGIN ... FIX_KMAP_END:
1001 #else
1002         case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
1003 #endif
1004 #ifdef CONFIG_X86_LOCAL_APIC
1005         case FIX_APIC_BASE:     /* maps dummy local APIC */
1006 #endif
1007                 pte = pfn_pte(phys, prot);
1008                 break;
1009
1010         default:
1011                 pte = mfn_pte(phys, prot);
1012                 break;
1013         }
1014
1015         __native_set_fixmap(idx, pte);
1016 }
1017
1018 static const struct pv_info xen_info __initdata = {
1019         .paravirt_enabled = 1,
1020         .shared_kernel_pmd = 0,
1021
1022         .name = "Xen",
1023 };
1024
1025 static const struct pv_init_ops xen_init_ops __initdata = {
1026         .patch = xen_patch,
1027
1028         .banner = xen_banner,
1029         .memory_setup = xen_memory_setup,
1030         .arch_setup = xen_arch_setup,
1031         .post_allocator_init = xen_post_allocator_init,
1032 };
1033
1034 static const struct pv_time_ops xen_time_ops __initdata = {
1035         .time_init = xen_time_init,
1036
1037         .set_wallclock = xen_set_wallclock,
1038         .get_wallclock = xen_get_wallclock,
1039         .get_tsc_khz = xen_tsc_khz,
1040         .sched_clock = xen_sched_clock,
1041 };
1042
1043 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
1044         .cpuid = xen_cpuid,
1045
1046         .set_debugreg = xen_set_debugreg,
1047         .get_debugreg = xen_get_debugreg,
1048
1049         .clts = xen_clts,
1050
1051         .read_cr0 = native_read_cr0,
1052         .write_cr0 = xen_write_cr0,
1053
1054         .read_cr4 = native_read_cr4,
1055         .read_cr4_safe = native_read_cr4_safe,
1056         .write_cr4 = xen_write_cr4,
1057
1058         .wbinvd = native_wbinvd,
1059
1060         .read_msr = native_read_msr_safe,
1061         .write_msr = native_write_msr_safe,
1062         .read_tsc = native_read_tsc,
1063         .read_pmc = native_read_pmc,
1064
1065         .iret = xen_iret,
1066         .irq_enable_sysexit = xen_sysexit,
1067
1068         .load_tr_desc = paravirt_nop,
1069         .set_ldt = xen_set_ldt,
1070         .load_gdt = xen_load_gdt,
1071         .load_idt = xen_load_idt,
1072         .load_tls = xen_load_tls,
1073
1074         .store_gdt = native_store_gdt,
1075         .store_idt = native_store_idt,
1076         .store_tr = xen_store_tr,
1077
1078         .write_ldt_entry = xen_write_ldt_entry,
1079         .write_gdt_entry = xen_write_gdt_entry,
1080         .write_idt_entry = xen_write_idt_entry,
1081         .load_sp0 = xen_load_sp0,
1082
1083         .set_iopl_mask = xen_set_iopl_mask,
1084         .io_delay = xen_io_delay,
1085
1086         .lazy_mode = {
1087                 .enter = paravirt_enter_lazy_cpu,
1088                 .leave = xen_leave_lazy,
1089         },
1090 };
1091
1092 static const struct pv_irq_ops xen_irq_ops __initdata = {
1093         .init_IRQ = xen_init_IRQ,
1094         .save_fl = xen_save_fl,
1095         .restore_fl = xen_restore_fl,
1096         .irq_disable = xen_irq_disable,
1097         .irq_enable = xen_irq_enable,
1098         .safe_halt = xen_safe_halt,
1099         .halt = xen_halt,
1100 #ifdef CONFIG_X86_64
1101         .adjust_exception_frame = paravirt_nop,
1102 #endif
1103 };
1104
1105 static const struct pv_apic_ops xen_apic_ops __initdata = {
1106 #ifdef CONFIG_X86_LOCAL_APIC
1107         .apic_write = xen_apic_write,
1108         .apic_write_atomic = xen_apic_write,
1109         .apic_read = xen_apic_read,
1110         .setup_boot_clock = paravirt_nop,
1111         .setup_secondary_clock = paravirt_nop,
1112         .startup_ipi_hook = paravirt_nop,
1113 #endif
1114 };
1115
1116 static const struct pv_mmu_ops xen_mmu_ops __initdata = {
1117         .pagetable_setup_start = xen_pagetable_setup_start,
1118         .pagetable_setup_done = xen_pagetable_setup_done,
1119
1120         .read_cr2 = xen_read_cr2,
1121         .write_cr2 = xen_write_cr2,
1122
1123         .read_cr3 = xen_read_cr3,
1124         .write_cr3 = xen_write_cr3,
1125
1126         .flush_tlb_user = xen_flush_tlb,
1127         .flush_tlb_kernel = xen_flush_tlb,
1128         .flush_tlb_single = xen_flush_tlb_single,
1129         .flush_tlb_others = xen_flush_tlb_others,
1130
1131         .pte_update = paravirt_nop,
1132         .pte_update_defer = paravirt_nop,
1133
1134         .pgd_alloc = __paravirt_pgd_alloc,
1135         .pgd_free = paravirt_nop,
1136
1137         .alloc_pte = xen_alloc_pte_init,
1138         .release_pte = xen_release_pte_init,
1139         .alloc_pmd = xen_alloc_pte_init,
1140         .alloc_pmd_clone = paravirt_nop,
1141         .release_pmd = xen_release_pte_init,
1142
1143 #ifdef CONFIG_HIGHPTE
1144         .kmap_atomic_pte = xen_kmap_atomic_pte,
1145 #endif
1146
1147 #ifdef CONFIG_X86_64
1148         .set_pte = xen_set_pte,
1149 #else
1150         .set_pte = xen_set_pte_init,
1151 #endif
1152         .set_pte_at = xen_set_pte_at,
1153         .set_pmd = xen_set_pmd_hyper,
1154
1155         .ptep_modify_prot_start = __ptep_modify_prot_start,
1156         .ptep_modify_prot_commit = __ptep_modify_prot_commit,
1157
1158         .pte_val = xen_pte_val,
1159         .pte_flags = native_pte_val,
1160         .pgd_val = xen_pgd_val,
1161
1162         .make_pte = xen_make_pte,
1163         .make_pgd = xen_make_pgd,
1164
1165 #ifdef CONFIG_X86_PAE
1166         .set_pte_atomic = xen_set_pte_atomic,
1167         .set_pte_present = xen_set_pte_at,
1168         .pte_clear = xen_pte_clear,
1169         .pmd_clear = xen_pmd_clear,
1170 #endif  /* CONFIG_X86_PAE */
1171         .set_pud = xen_set_pud_hyper,
1172
1173         .make_pmd = xen_make_pmd,
1174         .pmd_val = xen_pmd_val,
1175
1176 #if PAGETABLE_LEVELS == 4
1177         .pud_val = xen_pud_val,
1178         .make_pud = xen_make_pud,
1179         .set_pgd = xen_set_pgd_hyper,
1180
1181         .alloc_pud = xen_alloc_pte_init,
1182         .release_pud = xen_release_pte_init,
1183 #endif  /* PAGETABLE_LEVELS == 4 */
1184
1185         .activate_mm = xen_activate_mm,
1186         .dup_mmap = xen_dup_mmap,
1187         .exit_mmap = xen_exit_mmap,
1188
1189         .lazy_mode = {
1190                 .enter = paravirt_enter_lazy_mmu,
1191                 .leave = xen_leave_lazy,
1192         },
1193
1194         .set_fixmap = xen_set_fixmap,
1195 };
1196
1197 static void xen_reboot(int reason)
1198 {
1199         struct sched_shutdown r = { .reason = reason };
1200
1201 #ifdef CONFIG_SMP
1202         smp_send_stop();
1203 #endif
1204
1205         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1206                 BUG();
1207 }
1208
1209 static void xen_restart(char *msg)
1210 {
1211         xen_reboot(SHUTDOWN_reboot);
1212 }
1213
1214 static void xen_emergency_restart(void)
1215 {
1216         xen_reboot(SHUTDOWN_reboot);
1217 }
1218
1219 static void xen_machine_halt(void)
1220 {
1221         xen_reboot(SHUTDOWN_poweroff);
1222 }
1223
1224 static void xen_crash_shutdown(struct pt_regs *regs)
1225 {
1226         xen_reboot(SHUTDOWN_crash);
1227 }
1228
1229 static const struct machine_ops __initdata xen_machine_ops = {
1230         .restart = xen_restart,
1231         .halt = xen_machine_halt,
1232         .power_off = xen_machine_halt,
1233         .shutdown = xen_machine_halt,
1234         .crash_shutdown = xen_crash_shutdown,
1235         .emergency_restart = xen_emergency_restart,
1236 };
1237
1238
1239 static void __init xen_reserve_top(void)
1240 {
1241 #ifdef CONFIG_X86_32
1242         unsigned long top = HYPERVISOR_VIRT_START;
1243         struct xen_platform_parameters pp;
1244
1245         if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
1246                 top = pp.virt_start;
1247
1248         reserve_top_address(-top + 2 * PAGE_SIZE);
1249 #endif  /* CONFIG_X86_32 */
1250 }
1251
1252 /*
1253  * Like __va(), but returns address in the kernel mapping (which is
1254  * all we have until the physical memory mapping has been set up.
1255  */
1256 static void *__ka(phys_addr_t paddr)
1257 {
1258 #ifdef CONFIG_X86_64
1259         return (void *)(paddr + __START_KERNEL_map);
1260 #else
1261         return __va(paddr);
1262 #endif
1263 }
1264
1265 /* Convert a machine address to physical address */
1266 static unsigned long m2p(phys_addr_t maddr)
1267 {
1268         phys_addr_t paddr;
1269
1270         maddr &= PTE_MASK;
1271         paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
1272
1273         return paddr;
1274 }
1275
1276 /* Convert a machine address to kernel virtual */
1277 static void *m2v(phys_addr_t maddr)
1278 {
1279         return __ka(m2p(maddr));
1280 }
1281
1282 #ifdef CONFIG_X86_64
1283 static void walk(pgd_t *pgd, unsigned long addr)
1284 {
1285         unsigned l4idx = pgd_index(addr);
1286         unsigned l3idx = pud_index(addr);
1287         unsigned l2idx = pmd_index(addr);
1288         unsigned l1idx = pte_index(addr);
1289         pgd_t l4;
1290         pud_t l3;
1291         pmd_t l2;
1292         pte_t l1;
1293
1294         xen_raw_printk("walk %p, %lx -> %d %d %d %d\n",
1295                        pgd, addr, l4idx, l3idx, l2idx, l1idx);
1296
1297         l4 = pgd[l4idx];
1298         xen_raw_printk("  l4: %016lx\n", l4.pgd);
1299         xen_raw_printk("      %016lx\n", pgd_val(l4));
1300
1301         l3 = ((pud_t *)(m2v(l4.pgd)))[l3idx];
1302         xen_raw_printk("  l3: %016lx\n", l3.pud);
1303         xen_raw_printk("      %016lx\n", pud_val(l3));
1304
1305         l2 = ((pmd_t *)(m2v(l3.pud)))[l2idx];
1306         xen_raw_printk("  l2: %016lx\n", l2.pmd);
1307         xen_raw_printk("      %016lx\n", pmd_val(l2));
1308
1309         l1 = ((pte_t *)(m2v(l2.pmd)))[l1idx];
1310         xen_raw_printk("  l1: %016lx\n", l1.pte);
1311         xen_raw_printk("      %016lx\n", pte_val(l1));
1312 }
1313 #endif
1314
1315 static void set_page_prot(void *addr, pgprot_t prot)
1316 {
1317         unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
1318         pte_t pte = pfn_pte(pfn, prot);
1319
1320         xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016llx pte=%016llx\n",
1321                        addr, pfn, get_phys_to_machine(pfn),
1322                        pgprot_val(prot), pte.pte);
1323
1324         if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
1325                 BUG();
1326 }
1327
1328 /*
1329  * Identity map, in addition to plain kernel map.  This needs to be
1330  * large enough to allocate page table pages to allocate the rest.
1331  * Each page can map 2MB.
1332  */
1333 static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
1334
1335 static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
1336 {
1337         unsigned pmdidx, pteidx;
1338         unsigned ident_pte;
1339         unsigned long pfn;
1340
1341         ident_pte = 0;
1342         pfn = 0;
1343         for(pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
1344                 pte_t *pte_page;
1345
1346                 /* Reuse or allocate a page of ptes */
1347                 if (pmd_present(pmd[pmdidx]))
1348                         pte_page = m2v(pmd[pmdidx].pmd);
1349                 else {
1350                         /* Check for free pte pages */
1351                         if (ident_pte == ARRAY_SIZE(level1_ident_pgt))
1352                                 break;
1353
1354                         pte_page = &level1_ident_pgt[ident_pte];
1355                         ident_pte += PTRS_PER_PTE;
1356
1357                         pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
1358                 }
1359
1360                 /* Install mappings */
1361                 for(pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
1362                         pte_t pte;
1363
1364                         if (pfn > max_pfn_mapped)
1365                                 max_pfn_mapped = pfn;
1366
1367                         if (!pte_none(pte_page[pteidx]))
1368                                 continue;
1369
1370                         pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
1371                         pte_page[pteidx] = pte;
1372                 }
1373         }
1374
1375         for(pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
1376                 set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
1377
1378         set_page_prot(pmd, PAGE_KERNEL_RO);
1379 }
1380
1381 #ifdef CONFIG_X86_64
1382 static void convert_pfn_mfn(void *v)
1383 {
1384         pte_t *pte = v;
1385         int i;
1386
1387         /* All levels are converted the same way, so just treat them
1388            as ptes. */
1389         for(i = 0; i < PTRS_PER_PTE; i++)
1390                 pte[i] = xen_make_pte(pte[i].pte);
1391 }
1392
1393 /*
1394  * Set up the inital kernel pagetable.
1395  *
1396  * We can construct this by grafting the Xen provided pagetable into
1397  * head_64.S's preconstructed pagetables.  We copy the Xen L2's into
1398  * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt.  This
1399  * means that only the kernel has a physical mapping to start with -
1400  * but that's enough to get __va working.  We need to fill in the rest
1401  * of the physical mapping once some sort of allocator has been set
1402  * up.
1403  */
1404 static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
1405 {
1406         pud_t *l3;
1407         pmd_t *l2;
1408
1409         /* Zap identity mapping */
1410         init_level4_pgt[0] = __pgd(0);
1411
1412         /* Pre-constructed entries are in pfn, so convert to mfn */
1413         convert_pfn_mfn(init_level4_pgt);
1414         convert_pfn_mfn(level3_ident_pgt);
1415         convert_pfn_mfn(level3_kernel_pgt);
1416
1417         l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
1418         l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);
1419
1420         memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1421         memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1422
1423         l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd);
1424         l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud);
1425         memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1426
1427         /* Set up identity map */
1428         xen_map_identity_early(level2_ident_pgt, max_pfn);
1429
1430         /* Make pagetable pieces RO */
1431         set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
1432         set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
1433         set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
1434         set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
1435         set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);
1436
1437         /* Pin down new L4 */
1438         pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
1439                           PFN_DOWN(__pa_symbol(init_level4_pgt)));
1440
1441         /* Unpin Xen-provided one */
1442         pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1443
1444         /* Switch over */
1445         pgd = init_level4_pgt;
1446         xen_write_cr3(__pa(pgd));
1447
1448         reserve_early(__pa(xen_start_info->pt_base),
1449                       __pa(xen_start_info->pt_base +
1450                            xen_start_info->nr_pt_frames * PAGE_SIZE),
1451                       "XEN PAGETABLES");
1452
1453         return pgd;
1454 }
1455 #else   /* !CONFIG_X86_64 */
1456 static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss;
1457
1458 static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
1459 {
1460         pmd_t *kernel_pmd;
1461
1462         init_pg_tables_start = __pa(pgd);
1463         init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
1464         max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024);
1465
1466         kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
1467         memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
1468
1469         xen_map_identity_early(level2_kernel_pgt, max_pfn);
1470
1471         memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
1472         set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],
1473                         __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));
1474
1475         set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
1476         set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
1477         set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
1478
1479         pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1480
1481         xen_write_cr3(__pa(swapper_pg_dir));
1482
1483         pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
1484
1485         return swapper_pg_dir;
1486 }
1487 #endif  /* CONFIG_X86_64 */
1488
1489 /* First C function to be called on Xen boot */
1490 asmlinkage void __init xen_start_kernel(void)
1491 {
1492         pgd_t *pgd;
1493
1494         if (!xen_start_info)
1495                 return;
1496
1497         BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
1498
1499         xen_setup_features();
1500
1501         /* Install Xen paravirt ops */
1502         pv_info = xen_info;
1503         pv_init_ops = xen_init_ops;
1504         pv_time_ops = xen_time_ops;
1505         pv_cpu_ops = xen_cpu_ops;
1506         pv_irq_ops = xen_irq_ops;
1507         pv_apic_ops = xen_apic_ops;
1508         pv_mmu_ops = xen_mmu_ops;
1509
1510         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1511                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1512                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1513         }
1514
1515         machine_ops = xen_machine_ops;
1516
1517 #ifdef CONFIG_X86_64
1518         /* Disable until direct per-cpu data access. */
1519         have_vcpu_info_placement = 0;
1520         x86_64_init_pda();
1521 #endif
1522
1523         xen_smp_init();
1524
1525         /* Get mfn list */
1526         if (!xen_feature(XENFEAT_auto_translated_physmap))
1527                 xen_build_dynamic_phys_to_machine();
1528
1529         pgd = (pgd_t *)xen_start_info->pt_base;
1530
1531         /* Prevent unwanted bits from being set in PTEs. */
1532         __supported_pte_mask &= ~_PAGE_GLOBAL;
1533         if (!is_initial_xendomain())
1534                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1535
1536         /* Don't do the full vcpu_info placement stuff until we have a
1537            possible map and a non-dummy shared_info. */
1538         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1539
1540         xen_raw_console_write("mapping kernel into physical memory\n");
1541         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1542
1543         init_mm.pgd = pgd;
1544
1545         /* keep using Xen gdt for now; no urgent need to change it */
1546
1547         pv_info.kernel_rpl = 1;
1548         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1549                 pv_info.kernel_rpl = 0;
1550
1551         /* set the limit of our address space */
1552         xen_reserve_top();
1553
1554 #ifdef CONFIG_X86_32
1555         /* set up basic CPUID stuff */
1556         cpu_detect(&new_cpu_data);
1557         new_cpu_data.hard_math = 1;
1558         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1559 #endif
1560
1561         /* Poke various useful things into boot_params */
1562         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1563         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1564                 ? __pa(xen_start_info->mod_start) : 0;
1565         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1566
1567         if (!is_initial_xendomain()) {
1568                 add_preferred_console("xenboot", 0, NULL);
1569                 add_preferred_console("tty", 0, NULL);
1570                 add_preferred_console("hvc", 0, NULL);
1571         }
1572
1573         xen_raw_console_write("about to get started...\n");
1574
1575 #if 0
1576         xen_raw_printk("&boot_params=%p __pa(&boot_params)=%lx __va(__pa(&boot_params))=%lx\n",
1577                        &boot_params, __pa_symbol(&boot_params),
1578                        __va(__pa_symbol(&boot_params)));
1579
1580         walk(pgd, &boot_params);
1581         walk(pgd, __va(__pa(&boot_params)));
1582 #endif
1583
1584         /* Start the world */
1585 #ifdef CONFIG_X86_32
1586         i386_start_kernel();
1587 #else
1588         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1589 #endif
1590 }