]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/mp_desc.c
xnu-3789.70.16.tar.gz
[apple/xnu.git] / osfmk / i386 / mp_desc.c
index 64f460e6910b0d1d3f74f8d43c7ddb972267b72e..a886ae73671aa6219b6192f3556d8bba68587670 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
 /*
  */
 
-
 #include <kern/cpu_number.h>
 #include <kern/kalloc.h>
 #include <kern/cpu_data.h>
 #include <mach/mach_types.h>
 #include <mach/machine.h>
 #include <mach/vm_map.h>
+#include <mach/machine/vm_param.h>
 #include <vm/vm_kern.h>
 #include <vm/vm_map.h>
 
+#include <i386/bit_routines.h>
 #include <i386/mp_desc.h>
-#include <i386/lock.h>
 #include <i386/misc_protos.h>
 #include <i386/mp.h>
 #include <i386/pmap.h>
-#include <i386/cpu_threads.h>
+#if defined(__i386__) || defined(__x86_64__)
+#include <i386/pmap_internal.h>
+#endif /* i386 */
+#if CONFIG_MCA
+#include <i386/machine_check.h>
+#endif
 
 #include <kern/misc_protos.h>
 
-#include <mach_kdb.h>
-
-/*
- * The i386 needs an interrupt stack to keep the PCB stack from being
- * overrun by interrupts.  All interrupt stacks MUST lie at lower addresses
- * than any thread`s kernel stack.
- */
+#define K_INTR_GATE (ACC_P|ACC_PL_K|ACC_INTR_GATE)
+#define U_INTR_GATE (ACC_P|ACC_PL_U|ACC_INTR_GATE)
+
+// Declare macros that will declare the externs
+#define TRAP(n, name)          extern void *name ;
+#define TRAP_ERR(n, name)      extern void *name ;
+#define TRAP_SPC(n, name)      extern void *name ;
+#define TRAP_IST1(n, name)     extern void *name ;
+#define TRAP_IST2(n, name)     extern void *name ;
+#define INTERRUPT(n)           extern void *_intr_ ## n ;
+#define USER_TRAP(n, name)     extern void *name ;
+#define USER_TRAP_SPC(n, name) extern void *name ;
+
+// Include the table to declare the externs
+#include "../x86_64/idt_table.h"
+
+// Undef the macros, then redefine them so we can declare the table
+#undef TRAP
+#undef TRAP_ERR
+#undef TRAP_SPC
+#undef TRAP_IST1
+#undef TRAP_IST2
+#undef INTERRUPT
+#undef USER_TRAP
+#undef USER_TRAP_SPC
+
+#define TRAP(n, name)                  \
+       [n] = {                         \
+               (uintptr_t)&name,       \
+               KERNEL64_CS,            \
+               0,                      \
+               K_INTR_GATE,            \
+               0                       \
+       },
+
+#define TRAP_ERR TRAP
+#define TRAP_SPC TRAP
+
+#define TRAP_IST1(n, name) \
+       [n] = {                         \
+               (uintptr_t)&name,       \
+               KERNEL64_CS,            \
+               1,                      \
+               K_INTR_GATE,            \
+               0                       \
+       },
+
+#define TRAP_IST2(n, name) \
+       [n] = {                         \
+               (uintptr_t)&name,       \
+               KERNEL64_CS,            \
+               2,                      \
+               K_INTR_GATE,            \
+               0                       \
+       },
+
+#define INTERRUPT(n) \
+       [n] = {                         \
+               (uintptr_t)&_intr_ ## n,\
+               KERNEL64_CS,            \
+               0,                      \
+               K_INTR_GATE,            \
+               0                       \
+       },
+
+#define USER_TRAP(n, name) \
+       [n] = {                         \
+               (uintptr_t)&name,       \
+               KERNEL64_CS,            \
+               0,                      \
+               U_INTR_GATE,            \
+               0                       \
+       },
+
+#define USER_TRAP_SPC USER_TRAP
+
+// Declare the table using the macros we just set up
+struct fake_descriptor64 master_idt64[IDTSZ]
+       __attribute__ ((section("__HIB,__desc")))
+       __attribute__ ((aligned(PAGE_SIZE))) = {
+#include "../x86_64/idt_table.h"
+};
 
 /*
  * First cpu`s interrupt stack.
  */
-extern uint32_t                low_intstack[]; /* bottom */
+extern uint32_t                low_intstack[];         /* bottom */
 extern uint32_t                low_eintstack[];        /* top */
 
 /*
@@ -95,21 +175,19 @@ extern uint32_t            low_eintstack[];        /* top */
  * The master cpu (cpu 0) has its data area statically allocated;
  * others are allocated dynamically and this array is updated at runtime.
  */
-cpu_data_t     cpu_data_master;
-cpu_data_t     *cpu_data_ptr[MAX_CPUS] = { [0] &cpu_data_master };
+static cpu_data_t      cpu_data_master = {
+       .cpu_this = &cpu_data_master,
+       .cpu_nanotime = &pal_rtc_nanotime_info,
+       .cpu_int_stack_top = (vm_offset_t) low_eintstack,
+};
+cpu_data_t     *cpu_data_ptr[MAX_CPUS] = { [0] = &cpu_data_master };
 
-decl_simple_lock_data(,cpu_lock);      /* protects real_ncpus */
+decl_simple_lock_data(,ncpus_lock);    /* protects real_ncpus */
 unsigned int   real_ncpus = 1;
 unsigned int   max_ncpus = MAX_CPUS;
 
-extern void *hi_remap_text;
-#define HI_TEXT(lo_text)       \
-       (((uint32_t)&lo_text - (uint32_t)&hi_remap_text) + HIGH_MEM_BASE)
-
-extern void    hi_sysenter(void);
-extern void    hi64_sysenter(void);
-extern void    hi64_syscall(void);
-
+extern void hi64_sysenter(void);
+extern void hi64_syscall(void);
 
 /*
  * Multiprocessor i386/i486 systems use a separate copy of the
@@ -124,41 +202,6 @@ extern void        hi64_syscall(void);
  * Allocate and initialize the per-processor descriptor tables.
  */
 
-struct fake_descriptor ldt_desc_pattern = {
-       (unsigned int) 0,
-       LDTSZ_MIN * sizeof(struct fake_descriptor) - 1,
-       0,
-       ACC_P|ACC_PL_K|ACC_LDT
-};
-
-struct fake_descriptor tss_desc_pattern = {
-       (unsigned int) 0,
-       sizeof(struct i386_tss) - 1,
-       0,
-       ACC_P|ACC_PL_K|ACC_TSS
-};
-
-struct fake_descriptor cpudata_desc_pattern = {
-       (unsigned int) 0,
-       sizeof(cpu_data_t)-1,
-       SZ_32,
-       ACC_P|ACC_PL_K|ACC_DATA_W
-};
-
-struct fake_descriptor userwindow_desc_pattern = {
-       (unsigned int) 0,
-       ((NBPDE * NCOPY_WINDOWS) / PAGE_SIZE) - 1,
-       SZ_32 | SZ_G,
-       ACC_P|ACC_PL_U|ACC_DATA_W
-};
-
-struct fake_descriptor physwindow_desc_pattern = {
-       (unsigned int) 0,
-       PAGE_SIZE - 1,
-       SZ_32,
-       ACC_P|ACC_PL_K|ACC_DATA_W
-};
-
 /*
  * This is the expanded, 64-bit variant of the kernel LDT descriptor.
  * When switching to 64-bit mode this replaces KERNEL_LDT entry
@@ -166,7 +209,7 @@ struct fake_descriptor physwindow_desc_pattern = {
  * in the uber-space remapping window on the kernel.
  */
 struct fake_descriptor64 kernel_ldt_desc64 = {
-       FAKE_UBER64(&master_ldt),
+       0,
        LDTSZ_MIN*sizeof(struct fake_descriptor)-1,
        0,
        ACC_P|ACC_PL_K|ACC_LDT,
@@ -178,242 +221,248 @@ struct fake_descriptor64 kernel_ldt_desc64 = {
  * It is follows pattern of the KERNEL_LDT.
  */
 struct fake_descriptor64 kernel_tss_desc64 = {
-       FAKE_UBER64(&master_ktss64),
+       0,
        sizeof(struct x86_64_tss)-1,
        0,
        ACC_P|ACC_PL_K|ACC_TSS,
        0
 };
 
+/*
+ * Convert a descriptor from fake to real format.
+ *
+ * Fake descriptor format:
+ *     bytes 0..3              base 31..0
+ *     bytes 4..5              limit 15..0
+ *     byte  6                 access byte 2 | limit 19..16
+ *     byte  7                 access byte 1
+ *
+ * Real descriptor format:
+ *     bytes 0..1              limit 15..0
+ *     bytes 2..3              base 15..0
+ *     byte  4                 base 23..16
+ *     byte  5                 access byte 1
+ *     byte  6                 access byte 2 | limit 19..16
+ *     byte  7                 base 31..24
+ *
+ * Fake gate format:
+ *     bytes 0..3              offset
+ *     bytes 4..5              selector
+ *     byte  6                 word count << 4 (to match fake descriptor)
+ *     byte  7                 access byte 1
+ *
+ * Real gate format:
+ *     bytes 0..1              offset 15..0
+ *     bytes 2..3              selector
+ *     byte  4                 word count
+ *     byte  5                 access byte 1
+ *     bytes 6..7              offset 31..16
+ */
 void
-cpu_desc_init(
-       cpu_data_t      *cdp,
-       boolean_t       is_boot_cpu)
+fix_desc(void *d, int num_desc) {
+       //early_kprintf("fix_desc(%x, %x)\n", d, num_desc);
+       uint8_t *desc = (uint8_t*) d;
+
+       do {
+               if ((desc[7] & 0x14) == 0x04) { /* gate */
+                       uint32_t offset;
+                       uint16_t selector;
+                       uint8_t wordcount;
+                       uint8_t acc;
+                       
+                       offset = *((uint32_t*)(desc));
+                       selector = *((uint32_t*)(desc+4));
+                       wordcount = desc[6] >> 4;
+                       acc = desc[7];
+
+                       *((uint16_t*)desc) = offset & 0xFFFF;
+                       *((uint16_t*)(desc+2)) = selector;
+                       desc[4] = wordcount;
+                       desc[5] = acc;
+                       *((uint16_t*)(desc+6)) = offset >> 16;
+
+               } else { /* descriptor */
+                       uint32_t base;
+                       uint16_t limit;
+                       uint8_t acc1, acc2;
+
+                       base = *((uint32_t*)(desc));
+                       limit = *((uint16_t*)(desc+4));
+                       acc2 = desc[6];
+                       acc1 = desc[7];
+
+                       *((uint16_t*)(desc)) = limit;
+                       *((uint16_t*)(desc+2)) = base & 0xFFFF;
+                       desc[4] = (base >> 16) & 0xFF;
+                       desc[5] = acc1;
+                       desc[6] = acc2;
+                       desc[7] = base >> 24;
+               }
+               desc += 8;
+       } while (--num_desc);
+}
+
+void
+fix_desc64(void *descp, int count)
 {
-       cpu_desc_table_t        *cdt = cdp->cpu_desc_tablep;
-       cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
+       struct fake_descriptor64        *fakep;
+       union {
+               struct real_gate64              gate;
+               struct real_descriptor64        desc;
+       }                               real;
+       int                             i;
+
+       fakep = (struct fake_descriptor64 *) descp;
+       
+       for (i = 0; i < count; i++, fakep++) {
+               /*
+                * Construct the real decriptor locally.
+                */
 
-       if (is_boot_cpu) {
-           /*
-            * Master CPU uses the tables built at boot time.
-            * Just set the index pointers to the high shared-mapping space.
-            * Note that the sysenter stack uses empty space above the ktss
-            * in the HIGH_FIXED_KTSS page. In this case we don't map the
-            * the real master_sstk in low memory.
-            */
-           cdi->cdi_ktss = (struct i386_tss *)
-                               pmap_index_to_virt(HIGH_FIXED_KTSS) ;
-           cdi->cdi_sstk  = (vm_offset_t) (cdi->cdi_ktss + 1) +
-                               (vm_offset_t) &master_sstk.top -
-                               (vm_offset_t) &master_sstk;
-#if    MACH_KDB
-           cdi->cdi_dbtss = (struct i386_tss *)
-                               pmap_index_to_virt(HIGH_FIXED_DBTSS);
-#endif /* MACH_KDB */
-           cdi->cdi_gdt = (struct fake_descriptor *)
-                               pmap_index_to_virt(HIGH_FIXED_GDT);
-           cdi->cdi_idt = (struct fake_descriptor *)
-                               pmap_index_to_virt(HIGH_FIXED_IDT);
-           cdi->cdi_ldt = (struct fake_descriptor *)
-                               pmap_index_to_virt(HIGH_FIXED_LDT_BEGIN);
-
-       } else {
-
-           vm_offset_t cpu_hi_desc;
-
-           cpu_hi_desc = pmap_cpu_high_shared_remap(cdp->cpu_number,
-                                                    HIGH_CPU_DESC,
-                                                    (vm_offset_t) cdt, 1);
-
-           /*
-            * Per-cpu GDT, IDT, LDT, KTSS descriptors are allocated in one
-            * block (cpu_desc_table) and double-mapped into high shared space
-            * in one page window.
-            * Also, a transient stack for the fast sysenter path. The top of
-            * which is set at context switch time to point to the PCB using
-            * the high address.
-            */
-           cdi->cdi_gdt  = (struct fake_descriptor *) (cpu_hi_desc +
-                               offsetof(cpu_desc_table_t, gdt[0]));
-           cdi->cdi_idt  = (struct fake_descriptor *) (cpu_hi_desc +
-                               offsetof(cpu_desc_table_t, idt[0]));
-           cdi->cdi_ktss = (struct i386_tss *) (cpu_hi_desc +
-                               offsetof(cpu_desc_table_t, ktss));
-           cdi->cdi_sstk = cpu_hi_desc +
-                               offsetof(cpu_desc_table_t, sstk.top);
-                               
-           /*
-            * LDT descriptors are mapped into a seperate area.
-            */
-           cdi->cdi_ldt  = (struct fake_descriptor *)
-                               pmap_cpu_high_shared_remap(
-                                   cdp->cpu_number,
-                                   HIGH_CPU_LDT_BEGIN,
-                                   (vm_offset_t) cdp->cpu_ldtp,
-                                   HIGH_CPU_LDT_END - HIGH_CPU_LDT_BEGIN + 1);
-
-           /*
-            * Copy the tables
-            */
-           bcopy((char *)master_idt,
-                 (char *)cdt->idt,
-                 sizeof(master_idt));
-           bcopy((char *)master_gdt,
-                 (char *)cdt->gdt,
-                 sizeof(master_gdt));
-           bcopy((char *)master_ldt,
-                 (char *)cdp->cpu_ldtp,
-                 sizeof(master_ldt));
-           bzero((char *)&cdt->ktss,
-                 sizeof(struct i386_tss));
-
-#if    MACH_KDB
-           cdi->cdi_dbtss = (struct i386_tss *) (cpu_hi_desc +
-                               offsetof(cpu_desc_table_t, dbtss));
-           bcopy((char *)&master_dbtss,
-                 (char *)&cdt->dbtss,
-                 sizeof(struct i386_tss));
-#endif /* MACH_KDB */
-
-           /*
-            * Fix up the entries in the GDT to point to
-            * this LDT and this TSS.
-            */
-           cdt->gdt[sel_idx(KERNEL_LDT)] = ldt_desc_pattern;
-           cdt->gdt[sel_idx(KERNEL_LDT)].offset = (vm_offset_t) cdi->cdi_ldt;
-           fix_desc(&cdt->gdt[sel_idx(KERNEL_LDT)], 1);
-
-           cdt->gdt[sel_idx(USER_LDT)] = ldt_desc_pattern;
-           cdt->gdt[sel_idx(USER_LDT)].offset = (vm_offset_t) cdi->cdi_ldt;
-           fix_desc(&cdt->gdt[sel_idx(USER_LDT)], 1);
-
-           cdt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
-           cdt->gdt[sel_idx(KERNEL_TSS)].offset = (vm_offset_t) cdi->cdi_ktss;
-           fix_desc(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);
-
-           cdt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
-           cdt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
-           fix_desc(&cdt->gdt[sel_idx(CPU_DATA_GS)], 1);
-
-#if    MACH_KDB
-           cdt->gdt[sel_idx(DEBUG_TSS)] = tss_desc_pattern;
-           cdt->gdt[sel_idx(DEBUG_TSS)].offset = (vm_offset_t) cdi->cdi_dbtss;
-           fix_desc(&cdt->gdt[sel_idx(DEBUG_TSS)], 1);
-
-           cdt->dbtss.esp0 = (int)(db_task_stack_store +
-                   (INTSTACK_SIZE * (cdp->cpu_number)) - sizeof (natural_t));
-           cdt->dbtss.esp = cdt->dbtss.esp0;
-           cdt->dbtss.eip = (int)&db_task_start;
-#endif /* MACH_KDB */
-
-           cdt->ktss.ss0 = KERNEL_DS;
-           cdt->ktss.io_bit_map_offset = 0x0FFF;       /* no IO bitmap */
-
-           cpu_window_init(cdp->cpu_number);
+               bzero((void *) &real, sizeof(real));
+
+               switch (fakep->access & ACC_TYPE) {
+               case 0:
+                       break;
+               case ACC_CALL_GATE:
+               case ACC_INTR_GATE:
+               case ACC_TRAP_GATE:
+                       real.gate.offset_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
+                       real.gate.selector16 = fakep->lim_or_seg & 0xFFFF;
+                       real.gate.IST = fakep->size_or_IST & 0x7;
+                       real.gate.access8 = fakep->access;
+                       real.gate.offset_high16 = (uint16_t)((fakep->offset64>>16) & 0xFFFF);
+                       real.gate.offset_top32 = (uint32_t)(fakep->offset64>>32);
+                       break;
+               default:        /* Otherwise */
+                       real.desc.limit_low16 = fakep->lim_or_seg & 0xFFFF;
+                       real.desc.base_low16 = (uint16_t)(fakep->offset64 & 0xFFFF);
+                       real.desc.base_med8 = (uint8_t)((fakep->offset64 >> 16) & 0xFF);
+                       real.desc.access8 = fakep->access;
+                       real.desc.limit_high4 = (fakep->lim_or_seg >> 16) & 0xFF;
+                       real.desc.granularity4 = fakep->size_or_IST;
+                       real.desc.base_high8 = (uint8_t)((fakep->offset64 >> 24) & 0xFF);
+                       real.desc.base_top32 = (uint32_t)(fakep->offset64>>32);
+               }
 
+               /*
+                * Now copy back over the fake structure.
+                */
+               bcopy((void *) &real, (void *) fakep, sizeof(real));
        }
+}
+
+static void
+cpu_gdt_alias(vm_map_offset_t gdt, vm_map_offset_t alias)
+{
+       pt_entry_t *pte = NULL;
+
+       /* Require page alignment */
+       assert(page_aligned(gdt));
+       assert(page_aligned(alias));
 
+       pte = pmap_pte(kernel_pmap, alias);
+       pmap_store_pte(pte, kvtophys(gdt) | INTEL_PTE_REF
+                                         | INTEL_PTE_MOD
+                                         | INTEL_PTE_WIRED
+                                         | INTEL_PTE_VALID
+                                         | INTEL_PTE_WRITE
+                                         | INTEL_PTE_NX);
+
+       /* TLB flush unneccessry because target processor isn't running yet */
 }
 
+
 void
-cpu_desc_init64(
-       cpu_data_t      *cdp,
-       boolean_t       is_boot_cpu)
+cpu_desc_init64(cpu_data_t *cdp)
 {
-       cpu_desc_table64_t      *cdt = (cpu_desc_table64_t *)
-                                       cdp->cpu_desc_tablep;
        cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
 
-       if (is_boot_cpu) {
-           /*
-            * Master CPU uses the tables built at boot time.
-            * Just set the index pointers to the low memory space.
-            * Note that in 64-bit mode these are addressed in the
-            * double-mapped window (uber-space).
-            */
-           cdi->cdi_ktss = (struct i386_tss *) &master_ktss64;
-           cdi->cdi_sstk = (vm_offset_t) &master_sstk.top;
-           cdi->cdi_gdt  = master_gdt;
-           cdi->cdi_idt  = (struct fake_descriptor *) &master_idt64;
-           cdi->cdi_ldt  = (struct fake_descriptor *) &master_ldt;
-
-           /* Replace the expanded LDT and TSS slots in the GDT: */
-           *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_LDT)] =
-               kernel_ldt_desc64;
-           *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_TSS)] =
-               kernel_tss_desc64;
-
-           /*
-            * Fix up the expanded descriptors for 64-bit.
-            */
-           fix_desc64((void *) &master_idt64, IDTSZ);
-           fix_desc64((void *) &master_gdt[sel_idx(KERNEL_LDT)], 1);
-           fix_desc64((void *) &master_gdt[sel_idx(KERNEL_TSS)], 1);
-
-           /*
-            * Set the double-fault stack as IST1 in the 64-bit TSS 
-            */
-           master_ktss64.ist1 = UBER64(df_task_stack_end);
-
-       } else {
-           /*
-            * Per-cpu GDT, IDT, KTSS descriptors are allocated in kernel 
-            * heap (cpu_desc_table) and double-mapped in uber-space (over 4GB).
-            * LDT descriptors are mapped into a separate area.
-            */
-           cdi->cdi_gdt  = cdt->gdt;
-           cdi->cdi_idt  = (struct fake_descriptor *) cdt->idt;
-           cdi->cdi_ktss = (struct i386_tss *) &cdt->ktss;
-           cdi->cdi_sstk = (vm_offset_t) &cdt->sstk.top;
-           cdi->cdi_ldt  = cdp->cpu_ldtp;
-
-           /*
-            * Copy the tables
-            */
-           bcopy((char *)master_idt64,
-                 (char *)cdt->idt,
-                 sizeof(master_idt64));
-           bcopy((char *)master_gdt,
-                 (char *)cdt->gdt,
-                 sizeof(master_gdt));
-           bcopy((char *)master_ldt,
-                 (char *)cdp->cpu_ldtp,
-                 sizeof(master_ldt));
-           bcopy((char *)&master_ktss64,
-                 (char *)&cdt->ktss,
-                 sizeof(struct x86_64_tss));
-
-           /*
-            * Fix up the entries in the GDT to point to
-            * this LDT and this TSS.
-            */
-           kernel_ldt_desc64.offset[0] = (vm_offset_t) cdi->cdi_ldt;
-           *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_LDT)] =
-                       kernel_ldt_desc64;
-           fix_desc64(&cdt->gdt[sel_idx(KERNEL_LDT)], 1);
-
-           kernel_ldt_desc64.offset[0] = (vm_offset_t) cdi->cdi_ldt;
-           *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(USER_LDT)] =
-                       kernel_ldt_desc64;
-           fix_desc64(&cdt->gdt[sel_idx(USER_LDT)], 1);
-
-           kernel_tss_desc64.offset[0] = (vm_offset_t) cdi->cdi_ktss;
-           *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_TSS)] =
-                       kernel_tss_desc64;
-           fix_desc64(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);
-
-           cdt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
-           cdt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
-           fix_desc(&cdt->gdt[sel_idx(CPU_DATA_GS)], 1);
-
-           /* Set double-fault stack as IST1 */
-           cdt->ktss.ist1 = UBER64(cdt->dfstk + sizeof(cdt->dfstk));
-
-           /*
-            * Allocate copyio windows.
-            */
-           cpu_window_init(cdp->cpu_number);
+       if (cdp == &cpu_data_master) {
+               /*
+                * Master CPU uses the tables built at boot time.
+                * Just set the index pointers to the low memory space.
+                */
+               cdi->cdi_ktss = (void *)&master_ktss64;
+               cdi->cdi_sstk = (vm_offset_t) &master_sstk.top;
+               cdi->cdi_gdt.ptr  = (void *)MASTER_GDT_ALIAS;
+               cdi->cdi_idt.ptr  = (void *)MASTER_IDT_ALIAS;
+               cdi->cdi_ldt  = (struct fake_descriptor *) master_ldt;
+
+               /* Replace the expanded LDTs and TSS slots in the GDT */
+               kernel_ldt_desc64.offset64 = (uintptr_t) &master_ldt;
+               *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_LDT)] =
+                       kernel_ldt_desc64;
+               *(struct fake_descriptor64 *) &master_gdt[sel_idx(USER_LDT)] =
+                       kernel_ldt_desc64;
+               kernel_tss_desc64.offset64 = (uintptr_t) &master_ktss64;
+               *(struct fake_descriptor64 *) &master_gdt[sel_idx(KERNEL_TSS)] =
+                       kernel_tss_desc64;
+
+               /* Fix up the expanded descriptors for 64-bit. */
+               fix_desc64((void *) &master_idt64, IDTSZ);
+               fix_desc64((void *) &master_gdt[sel_idx(KERNEL_LDT)], 1);
+               fix_desc64((void *) &master_gdt[sel_idx(USER_LDT)], 1);
+               fix_desc64((void *) &master_gdt[sel_idx(KERNEL_TSS)], 1);
+
+               /*
+                * Set the NMI/fault stacks as IST2/IST1 in the 64-bit TSS
+                * Note: this will be dynamically re-allocated in VM later. 
+                */
+               master_ktss64.ist2 = (uintptr_t) low_eintstack;
+               master_ktss64.ist1 = (uintptr_t) low_eintstack
+                                       - sizeof(x86_64_intr_stack_frame_t);
+
+       } else if (cdi->cdi_ktss == NULL) {     /* Skipping re-init on wake */
+               cpu_desc_table64_t      *cdt = (cpu_desc_table64_t *) cdp->cpu_desc_tablep;
+
+               /*
+                * Per-cpu GDT, IDT, KTSS descriptors are allocated in kernel 
+                * heap (cpu_desc_table). 
+                * LDT descriptors are mapped into a separate area.
+                * GDT descriptors are addressed by alias to avoid sgdt leaks to user-space.
+                */
+               cdi->cdi_idt.ptr  = (void *)MASTER_IDT_ALIAS;
+               cdi->cdi_gdt.ptr  = (void *)CPU_GDT_ALIAS(cdp->cpu_number);
+               cdi->cdi_ktss = (void *)&cdt->ktss;
+               cdi->cdi_sstk = (vm_offset_t)&cdt->sstk.top;
+               cdi->cdi_ldt  = cdp->cpu_ldtp;
+
+               /* Make the virtual alias address for the GDT */
+               cpu_gdt_alias((vm_map_offset_t) &cdt->gdt,
+                             (vm_map_offset_t) cdi->cdi_gdt.ptr);
+
+               /*
+                * Copy the tables
+                */
+               bcopy((char *)master_gdt, (char *)cdt->gdt, sizeof(master_gdt));
+               bcopy((char *)master_ldt, (char *)cdp->cpu_ldtp, sizeof(master_ldt));
+               bcopy((char *)&master_ktss64, (char *)&cdt->ktss, sizeof(struct x86_64_tss));
 
+               /*
+                * Fix up the entries in the GDT to point to
+                * this LDT and this TSS.
+                */
+               kernel_ldt_desc64.offset64 = (uintptr_t) cdi->cdi_ldt;
+               *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_LDT)] =
+                       kernel_ldt_desc64;
+               fix_desc64(&cdt->gdt[sel_idx(KERNEL_LDT)], 1);
+
+               kernel_ldt_desc64.offset64 = (uintptr_t) cdi->cdi_ldt;
+               *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(USER_LDT)] =
+                       kernel_ldt_desc64;
+               fix_desc64(&cdt->gdt[sel_idx(USER_LDT)], 1);
+
+               kernel_tss_desc64.offset64 = (uintptr_t) cdi->cdi_ktss;
+               *(struct fake_descriptor64 *) &cdt->gdt[sel_idx(KERNEL_TSS)] =
+                       kernel_tss_desc64;
+               fix_desc64(&cdt->gdt[sel_idx(KERNEL_TSS)], 1);
+
+               /* Set (zeroed) fault stack as IST1, NMI intr stack IST2 */
+               bzero((void *) cdt->fstk, sizeof(cdt->fstk));
+               cdt->ktss.ist2 = (unsigned long)cdt->fstk + sizeof(cdt->fstk);
+               cdt->ktss.ist1 = cdt->ktss.ist2
+                                       - sizeof(x86_64_intr_stack_frame_t);
        }
 
        /* Require that the top of the sysenter stack is 16-byte aligned */
@@ -421,16 +470,46 @@ cpu_desc_init64(
                panic("cpu_desc_init64() sysenter stack not 16-byte aligned");
 }
 
+
+void
+cpu_desc_load64(cpu_data_t *cdp)
+{
+       cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
+
+       /* Stuff the kernel per-cpu data area address into the MSRs */
+       wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
+       wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);
+
+       /*
+        * Ensure the TSS segment's busy bit is clear. This is required
+        * for the case of reloading descriptors at wake to avoid
+        * their complete re-initialization.
+        */
+       gdt_desc_p(KERNEL_TSS)->access &= ~ACC_TSS_BUSY;
+
+       /* Load the GDT, LDT, IDT and TSS */
+       cdi->cdi_gdt.size = sizeof(struct real_descriptor)*GDTSZ - 1;
+       cdi->cdi_idt.size = 0x1000 + cdp->cpu_number;
+       lgdt((uintptr_t *) &cdi->cdi_gdt);
+       lidt((uintptr_t *) &cdi->cdi_idt);
+       lldt(KERNEL_LDT);
+       set_tr(KERNEL_TSS);
+
+#if GPROF // Hack to enable mcount to work on K64
+       __asm__ volatile("mov %0, %%gs" : : "rm" ((unsigned short)(KERNEL_DS)));
+#endif
+}
+
+
 /*
- * Set MSRs for sysenter/sysexit for 64-bit.
+ * Set MSRs for sysenter/sysexit and syscall/sysret for 64-bit.
  */
-void
-fast_syscall_init64(void)
+static void
+fast_syscall_init64(__unused cpu_data_t *cdp)
 {
        wrmsr64(MSR_IA32_SYSENTER_CS, SYSENTER_CS); 
-       wrmsr64(MSR_IA32_SYSENTER_EIP, UBER64(hi64_sysenter));
-       wrmsr64(MSR_IA32_SYSENTER_ESP, UBER64(current_sstk()));
-
+       wrmsr64(MSR_IA32_SYSENTER_EIP, (uintptr_t) hi64_sysenter);
+       wrmsr64(MSR_IA32_SYSENTER_ESP, current_sstk());
        /* Enable syscall/sysret */
        wrmsr64(MSR_IA32_EFER, rdmsr64(MSR_IA32_EFER) | MSR_IA32_EFER_SCE);
 
@@ -439,37 +518,20 @@ fast_syscall_init64(void)
         * Note USER_CS because sysret uses this + 16 when returning to
         * 64-bit code.
         */
-       wrmsr64(MSR_IA32_LSTAR, UBER64(hi64_syscall));
-       wrmsr64(MSR_IA32_STAR, (((uint64_t)USER_CS)     << 48) |
-                              (((uint64_t)KERNEL64_CS) << 32));
+       wrmsr64(MSR_IA32_LSTAR, (uintptr_t) hi64_syscall);
+       wrmsr64(MSR_IA32_STAR, (((uint64_t)USER_CS) << 48) |
+                               (((uint64_t)KERNEL64_CS) << 32));
        /*
         * Emulate eflags cleared by sysenter but note that
         * we also clear the trace trap to avoid the complications
-        * of single-stepping into a syscall. We also clear
-        * the nested task bit to avoid a spurious "task switch"
-        * on IRET.
+        * of single-stepping into a syscall. The nested task bit
+        * is also cleared to avoid a spurious "task switch"
+        * should we choose to return via an IRET.
         */
        wrmsr64(MSR_IA32_FMASK, EFL_DF|EFL_IF|EFL_TF|EFL_NT);
 
-       /*
-        * Set the Kermel GS base MSR to point to per-cpu data in uber-space.
-        * The uber-space handler (hi64_syscall) uses the swapgs instruction.
-        */
-       wrmsr64(MSR_IA32_KERNEL_GS_BASE, UBER64(current_cpu_datap()));
-       kprintf("fast_syscall_init64() KERNEL_GS_BASE=0x%016llx\n",
-               rdmsr64(MSR_IA32_KERNEL_GS_BASE));
 }
 
-/*
- * Set MSRs for sysenter/sysexit
- */
-void
-fast_syscall_init(void)
-{
-       wrmsr(MSR_IA32_SYSENTER_CS, SYSENTER_CS, 0); 
-       wrmsr(MSR_IA32_SYSENTER_EIP, HI_TEXT(hi_sysenter), 0);
-       wrmsr(MSR_IA32_SYSENTER_ESP, current_sstk(), 0);
-}
 
 cpu_data_t *
 cpu_data_alloc(boolean_t is_boot_cpu)
@@ -479,29 +541,21 @@ cpu_data_alloc(boolean_t is_boot_cpu)
 
        if (is_boot_cpu) {
                assert(real_ncpus == 1);
-               simple_lock_init(&cpu_lock, 0);
-               cdp = &cpu_data_master;
+               cdp = cpu_datap(0);
                if (cdp->cpu_processor == NULL) {
+                       simple_lock_init(&ncpus_lock, 0);
                        cdp->cpu_processor = cpu_processor_alloc(TRUE);
+#if NCOPY_WINDOWS > 0
                        cdp->cpu_pmap = pmap_cpu_alloc(TRUE);
-                       cdp->cpu_this = cdp;
-                       cdp->cpu_is64bit = FALSE;
-                       cdp->cpu_int_stack_top = (vm_offset_t) low_eintstack;
-                       cpu_desc_init(cdp, TRUE);
-                       fast_syscall_init();
+#endif
                }
                return cdp;
        }
 
-       /* Check count before making allocations */
-       if (real_ncpus >= max_ncpus)
-               return NULL;
-
        /*
         * Allocate per-cpu data:
         */
-       ret = kmem_alloc(kernel_map, 
-                        (vm_offset_t *) &cdp, sizeof(cpu_data_t));
+       ret = kmem_alloc(kernel_map, (vm_offset_t *) &cdp, sizeof(cpu_data_t), VM_KERN_MEMORY_CPU);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() failed, ret=%d\n", ret);
                goto abort;
@@ -509,15 +563,12 @@ cpu_data_alloc(boolean_t is_boot_cpu)
        bzero((void*) cdp, sizeof(cpu_data_t));
        cdp->cpu_this = cdp;
 
-       /* Propagate mode */
-       cdp->cpu_is64bit = cpu_mode_is64bit();
-
        /*
         * Allocate interrupt stack:
         */
        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_int_stack_top,
-                        INTSTACK_SIZE);
+                        INTSTACK_SIZE, VM_KERN_MEMORY_CPU);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() int stack failed, ret=%d\n", ret);
                goto abort;
@@ -527,12 +578,11 @@ cpu_data_alloc(boolean_t is_boot_cpu)
 
        /*
         * Allocate descriptor table:
-        * Size depends on cpu mode.
         */
        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_desc_tablep,
-                        cdp->cpu_is64bit ? sizeof(cpu_desc_table64_t)
-                                         : sizeof(cpu_desc_table_t));
+                        sizeof(cpu_desc_table64_t),
+                        VM_KERN_MEMORY_CPU);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() desc_table failed, ret=%d\n", ret);
                goto abort;
@@ -543,27 +593,42 @@ cpu_data_alloc(boolean_t is_boot_cpu)
         */
        ret = kmem_alloc(kernel_map, 
                         (vm_offset_t *) &cdp->cpu_ldtp,
-                        sizeof(struct real_descriptor) * LDTSZ);
+                        sizeof(struct real_descriptor) * LDTSZ,
+                        VM_KERN_MEMORY_CPU);
        if (ret != KERN_SUCCESS) {
                printf("cpu_data_alloc() ldt failed, ret=%d\n", ret);
                goto abort;
        }
 
-       simple_lock(&cpu_lock);
-       if (real_ncpus >= max_ncpus) {
-               simple_unlock(&cpu_lock);
-               goto abort;
-       }
+#if CONFIG_MCA
+       /* Machine-check shadow register allocation. */
+       mca_cpu_alloc(cdp);
+#endif
+
+       simple_lock(&ncpus_lock);
+
        cpu_data_ptr[real_ncpus] = cdp;
        cdp->cpu_number = real_ncpus;
        real_ncpus++;
-       simple_unlock(&cpu_lock);
+       simple_unlock(&ncpus_lock);
+
+       /*
+        * Before this cpu has been assigned a real thread context,
+        * we give it a fake, unique, non-zero thread id which the locking
+        * primitives use as their lock value.
+        * Note that this does not apply to the boot processor, cpu 0, which
+        * transitions to a thread context well before other processors are
+        * started.
+        */
+       cdp->cpu_active_thread = (thread_t) (uintptr_t) cdp->cpu_number;
+
+       cdp->cpu_nanotime = &pal_rtc_nanotime_info;
 
-       kprintf("cpu_data_alloc(%d) 0x%x desc_table: 0x%x "
-               "ldt: 0x%x "
-               "int_stack: 0x%x-0x%x\n",
+       kprintf("cpu_data_alloc(%d) %p desc_table: %p "
+               "ldt: %p "
+               "int_stack: 0x%lx-0x%lx\n",
                cdp->cpu_number, cdp, cdp->cpu_desc_tablep, cdp->cpu_ldtp,
-               cdp->cpu_int_stack_top - INTSTACK_SIZE, cdp->cpu_int_stack_top);
+               (long)(cdp->cpu_int_stack_top - INTSTACK_SIZE), (long)(cdp->cpu_int_stack_top));
 
        return cdp;
 
@@ -571,7 +636,7 @@ abort:
        if (cdp) {
                if (cdp->cpu_desc_tablep)
                        kfree((void *) cdp->cpu_desc_tablep,
-                               sizeof(*cdp->cpu_desc_tablep));
+                               sizeof(cpu_desc_table64_t));
                if (cdp->cpu_int_stack_top)
                        kfree((void *) (cdp->cpu_int_stack_top - INTSTACK_SIZE),
                                INTSTACK_SIZE);
@@ -580,48 +645,111 @@ abort:
        return NULL;
 }
 
+boolean_t
+valid_user_data_selector(uint16_t selector)
+{
+    sel_t      sel = selector_to_sel(selector);
+    
+    if (selector == 0)
+       return (TRUE);
+
+    if (sel.ti == SEL_LDT)
+       return (TRUE);
+    else if (sel.index < GDTSZ) {
+       if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
+           return (TRUE);
+    }
+               
+    return (FALSE);
+}
+
+boolean_t
+valid_user_code_selector(uint16_t selector)
+{
+    sel_t      sel = selector_to_sel(selector);
+    
+    if (selector == 0)
+       return (FALSE);
+
+    if (sel.ti == SEL_LDT) {
+       if (sel.rpl == USER_PRIV)
+           return (TRUE);
+    }
+    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
+       if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
+           return (TRUE);
+       /* Explicitly validate the system code selectors
+        * even if not instantaneously privileged,
+        * since they are dynamically re-privileged
+        * at context switch
+        */
+       if ((selector == USER_CS) || (selector == USER64_CS))
+               return (TRUE);
+    }
+
+    return (FALSE);
+}
+
+boolean_t
+valid_user_stack_selector(uint16_t selector)
+{
+    sel_t      sel = selector_to_sel(selector);
+    
+    if (selector == 0)
+       return (FALSE);
+
+    if (sel.ti == SEL_LDT) {
+       if (sel.rpl == USER_PRIV)
+           return (TRUE);
+    }
+    else if (sel.index < GDTSZ && sel.rpl == USER_PRIV) {
+       if ((gdt_desc_p(selector)->access & ACC_PL_U) == ACC_PL_U)
+           return (TRUE);
+    }
+               
+    return (FALSE);
+}
+
 boolean_t
 valid_user_segment_selectors(uint16_t cs,
-                            uint16_t ss,
-                            uint16_t ds,
-                            uint16_t es,
-                            uint16_t fs,
-                            uint16_t gs)
+               uint16_t ss,
+               uint16_t ds,
+               uint16_t es,
+               uint16_t fs,
+               uint16_t gs)
 {      
        return valid_user_code_selector(cs)  &&
-              valid_user_stack_selector(ss) &&
-              valid_user_data_selector(ds)  &&
-              valid_user_data_selector(es)  &&
-              valid_user_data_selector(fs)  &&
-              valid_user_data_selector(gs);
+               valid_user_stack_selector(ss) &&
+               valid_user_data_selector(ds)  &&
+               valid_user_data_selector(es)  &&
+               valid_user_data_selector(fs)  &&
+               valid_user_data_selector(gs);
 }
 
+#if NCOPY_WINDOWS > 0
 
 static vm_offset_t user_window_base = 0;
-static vm_offset_t phys_window_base = 0;
 
 void
-cpu_window_init(int cpu)
+cpu_userwindow_init(int cpu)
 {
        cpu_data_t              *cdp = cpu_data_ptr[cpu];
-       cpu_desc_index_t        *cdi;
-        vm_offset_t            user_window;
-        vm_offset_t            phys_window;
-        vm_offset_t            vaddr;
+       vm_offset_t             user_window;
+       vm_offset_t             vaddr;
        int                     num_cpus;
 
        num_cpus = ml_get_max_cpus();
 
        if (cpu >= num_cpus)
-               panic("copy_window_init: cpu > num_cpus");
+               panic("cpu_userwindow_init: cpu > num_cpus");
 
        if (user_window_base == 0) {
 
-               if (vm_allocate(kernel_map, &vaddr,
-                               (NBPDE * NCOPY_WINDOWS * num_cpus) + NBPDE,
-                               VM_FLAGS_ANYWHERE) != KERN_SUCCESS)
-                       panic("copy_window_init: "
-                               "couldn't allocate user map window");
+               if (vm_allocate(kernel_map, &vaddr,
+                                       (NBPDE * NCOPY_WINDOWS * num_cpus) + NBPDE,
+                                       VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_KERN_MEMORY_CPU)) != KERN_SUCCESS)
+                       panic("cpu_userwindow_init: "
+                                       "couldn't allocate user map window");
 
                /*
                 * window must start on a page table boundary
@@ -645,79 +773,108 @@ cpu_window_init(int cpu)
                                (vaddr +
                                 ((NBPDE * NCOPY_WINDOWS * num_cpus) + NBPDE)) -
                                 user_window);
-
-               if (vm_allocate(kernel_map, &phys_window_base,
-                               PAGE_SIZE * num_cpus, VM_FLAGS_ANYWHERE)
-                                       != KERN_SUCCESS)
-                       panic("copy_window_init: "
-                               "couldn't allocate phys map window");
        }
 
-       user_window = user_window_base + (cpu * NCOPY_WINDOWS * NBPDE);
-       phys_window = phys_window_base + (cpu * PAGE_SIZE);
+       user_window = user_window_base + (cpu * NCOPY_WINDOWS * NBPDE);
 
-       cdi = &cdp->cpu_desc_index;
-         
        cdp->cpu_copywindow_base = user_window;
-       cdp->cpu_copywindow_pdp  = pmap_pde(kernel_pmap, user_window);
-
-       cdi->cdi_gdt[sel_idx(USER_WINDOW_SEL)] = userwindow_desc_pattern;
-       cdi->cdi_gdt[sel_idx(USER_WINDOW_SEL)].offset = user_window;
-
-       fix_desc(&cdi->cdi_gdt[sel_idx(USER_WINDOW_SEL)], 1);
-
-       cdp->cpu_physwindow_base = phys_window;
-
        /*
-        * make sure the page that encompasses the
-        * pte pointer we're interested in actually
-        * exists in the page table
+        * Abuse this pdp entry, the pdp now actually points to 
+        * an array of copy windows addresses.
         */
-       pmap_expand(kernel_pmap, phys_window);
+       cdp->cpu_copywindow_pdp  = pmap_pde(kernel_pmap, user_window);
 
-       cdp->cpu_physwindow_ptep = vtopte(phys_window);
+}
 
-       cdi->cdi_gdt[sel_idx(PHYS_WINDOW_SEL)] = physwindow_desc_pattern;
-       cdi->cdi_gdt[sel_idx(PHYS_WINDOW_SEL)].offset = phys_window;
+void
+cpu_physwindow_init(int cpu)
+{
+       cpu_data_t              *cdp = cpu_data_ptr[cpu];
+        vm_offset_t            phys_window = cdp->cpu_physwindow_base;
 
-       fix_desc(&cdi->cdi_gdt[sel_idx(PHYS_WINDOW_SEL)], 1);
-}
+       if (phys_window == 0) {
+               if (vm_allocate(kernel_map, &phys_window,
+                               PAGE_SIZE, VM_FLAGS_ANYWHERE | VM_MAKE_TAG(VM_KERN_MEMORY_CPU))
+                               != KERN_SUCCESS)
+                       panic("cpu_physwindow_init: "
+                               "couldn't allocate phys map window");
 
+               /*
+                * make sure the page that encompasses the
+                * pte pointer we're interested in actually
+                * exists in the page table
+                */
+               pmap_expand(kernel_pmap, phys_window, PMAP_EXPAND_OPTIONS_NONE);
 
-typedef struct {
-       uint16_t        length;
-       uint32_t        offset[2];
-} __attribute__((__packed__)) table_descriptor64_t;
+               cdp->cpu_physwindow_base = phys_window;
+               cdp->cpu_physwindow_ptep = vtopte(phys_window);
+       }
+}
+#endif /* NCOPY_WINDOWS > 0 */
 
-extern table_descriptor64_t    gdtptr64;
-extern table_descriptor64_t    idtptr64;
 /*
  * Load the segment descriptor tables for the current processor.
  */
 void
-cpu_desc_load64(cpu_data_t *cdp)
+cpu_mode_init(cpu_data_t *cdp)
 {
-       cpu_desc_index_t        *cdi = &cdp->cpu_desc_index;
+       fast_syscall_init64(cdp);
+}
 
-       /*
-        * Load up the new descriptors etc
-        * ml_load_desc64() expects these global pseudo-descriptors:
-        *   gdtptr64 -> master_gdt
-        *   idtptr64 -> master_idt64
-        * These are 10-byte descriptors with 64-bit addresses into
-        * uber-space.
-        */
-       gdtptr64.length = sizeof(master_gdt) - 1;
-       gdtptr64.offset[0] = (uint32_t) cdi->cdi_gdt;
-       gdtptr64.offset[1] = KERNEL_UBER_BASE_HI32;
-       idtptr64.length = sizeof(master_idt64) - 1;
-       idtptr64.offset[0] = (uint32_t) cdi->cdi_idt;
-       idtptr64.offset[1] = KERNEL_UBER_BASE_HI32;
-
-       /* Make sure busy bit is cleared in the TSS */
-       gdt_desc_p(KERNEL_TSS)->access &= ~ACC_TSS_BUSY;
-       
-       ml_load_desc64();
+/*
+ * Allocate a new interrupt stack for the boot processor from the
+ * heap rather than continue to use the statically allocated space.
+ * Also switch to a dynamically allocated cpu data area.
+ */
+void
+cpu_data_realloc(void)
+{
+       int             ret;
+       vm_offset_t     istk;
+       vm_offset_t     fstk;
+       cpu_data_t      *cdp;
+       boolean_t       istate;
 
-       kprintf("64-bit descriptor tables loaded\n");
+       ret = kmem_alloc(kernel_map, &istk, INTSTACK_SIZE, VM_KERN_MEMORY_CPU);
+       if (ret != KERN_SUCCESS) {
+               panic("cpu_data_realloc() stack alloc, ret=%d\n", ret);
+       }
+       bzero((void*) istk, INTSTACK_SIZE);
+       istk += INTSTACK_SIZE;
+
+       ret = kmem_alloc(kernel_map, (vm_offset_t *) &cdp, sizeof(cpu_data_t), VM_KERN_MEMORY_CPU);
+       if (ret != KERN_SUCCESS) {
+               panic("cpu_data_realloc() cpu data alloc, ret=%d\n", ret);
+       }
+
+       /* Copy old contents into new area and make fix-ups */
+       assert(cpu_number() == 0);
+       bcopy((void *) cpu_data_ptr[0], (void*) cdp, sizeof(cpu_data_t));
+       cdp->cpu_this = cdp;
+       cdp->cpu_int_stack_top = istk;
+       timer_call_queue_init(&cdp->rtclock_timer.queue);
+
+       /* Allocate the separate fault stack */
+       ret = kmem_alloc(kernel_map, &fstk, PAGE_SIZE, VM_KERN_MEMORY_CPU);
+       if (ret != KERN_SUCCESS) {
+               panic("cpu_data_realloc() fault stack alloc, ret=%d\n", ret);
+       }
+       bzero((void*) fstk, PAGE_SIZE);
+       fstk += PAGE_SIZE;
+
+       /*
+        * With interrupts disabled commmit the new areas.
+        */
+       istate = ml_set_interrupts_enabled(FALSE);
+       cpu_data_ptr[0] = cdp;
+       master_ktss64.ist2 = (uintptr_t) fstk;
+       master_ktss64.ist1 = (uintptr_t) fstk
+                               - sizeof(x86_64_intr_stack_frame_t);
+       wrmsr64(MSR_IA32_GS_BASE, (uintptr_t) cdp);
+       wrmsr64(MSR_IA32_KERNEL_GS_BASE, (uintptr_t) cdp);
+       (void) ml_set_interrupts_enabled(istate);
+
+       kprintf("Reallocated master cpu data: %p,"
+               " interrupt stack: %p, fault stack: %p\n",
+               (void *) cdp, (void *) istk, (void *) fstk);
 }