]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/fpu.c
xnu-1699.32.7.tar.gz
[apple/xnu.git] / osfmk / i386 / fpu.c
index 34bf4752a6536eec49eb5b323af7ef6c4cee7346..478eb2b4e257ffb03b8688b9b08b274cf2193a9f 100644 (file)
@@ -1,16 +1,19 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
@@ -20,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
  * @OSF_COPYRIGHT@
 /*
  */
 
-#include <cpus.h>
 #include <platforms.h>
 
 #include <mach/exception_types.h>
 #include <mach/i386/thread_status.h>
 #include <mach/i386/fp_reg.h>
+#include <mach/branch_predicates.h>
 
 #include <kern/mach_param.h>
+#include <kern/processor.h>
 #include <kern/thread.h>
 #include <kern/zalloc.h>
 #include <kern/misc_protos.h>
 #include <kern/spl.h>
 #include <kern/assert.h>
 
-#include <i386/thread.h>
+#include <libkern/OSAtomic.h>
+
+#include <architecture/i386/pio.h>
+#include <i386/cpuid.h>
 #include <i386/fpu.h>
-#include <i386/trap.h>
-#include <i386/pio.h>
+#include <i386/proc_reg.h>
 #include <i386/misc_protos.h>
+#include <i386/thread.h>
+#include <i386/trap.h>
+
+int            fp_kind = FP_NO;        /* not inited */
+zone_t         ifps_zone;              /* zone for FPU save area */
+
+#define ALIGNED(addr,size)     (((uintptr_t)(addr)&((size)-1))==0)
+
+/* Forward */
+
+extern void            fpinit(void);
+extern void            fp_save(
+                               thread_t        thr_act);
+extern void            fp_load(
+                               thread_t        thr_act);
+
+static void configure_mxcsr_capability_mask(struct x86_avx_thread_state *fps);
+
+struct x86_avx_thread_state initial_fp_state __attribute((aligned(64)));
+
+
+/* Global MXCSR capability bitmask */
+static unsigned int mxcsr_capability_mask;
 
-#if 0
-#include <i386/ipl.h>
-extern int curr_ipl;
-#define ASSERT_IPL(L) \
-{ \
-      if (curr_ipl != L) { \
-             printf("IPL is %d, expected %d\n", curr_ipl, L); \
-             panic("fpu: wrong ipl"); \
-      } \
+#define        fninit() \
+       __asm__ volatile("fninit")
+
+#define        fnstcw(control) \
+       __asm__("fnstcw %0" : "=m" (*(unsigned short *)(control)))
+
+#define        fldcw(control) \
+       __asm__ volatile("fldcw %0" : : "m" (*(unsigned short *) &(control)) )
+
+#define        fnclex() \
+       __asm__ volatile("fnclex")
+
+#define        fnsave(state)  \
+       __asm__ volatile("fnsave %0" : "=m" (*state))
+
+#define        frstor(state) \
+       __asm__ volatile("frstor %0" : : "m" (state))
+
+#define fwait() \
+       __asm__("fwait");
+
+#define fxrstor(addr)           __asm__ __volatile__("fxrstor %0" : : "m" (*(addr)))     
+#define fxsave(addr)            __asm__ __volatile__("fxsave %0" : "=m" (*(addr)))
+
+static uint32_t        fp_register_state_size = 0;
+static uint32_t fpu_YMM_present        = FALSE;
+static uint32_t        cpuid_reevaluated = 0;
+
+static void fpu_store_registers(void *, boolean_t);
+static void fpu_load_registers(void *);
+
+extern void xsave64o(void);
+extern void xrstor64o(void);
+
+#define XMASK ((uint32_t) (XFEM_X87 | XFEM_SSE | XFEM_YMM))
+
+/* DRK: TODO replace opcodes with mnemonics when assembler support available */
+
+static inline void xsetbv(uint32_t mask_hi, uint32_t mask_lo) {
+       __asm__ __volatile__(".short 0x010F\n\t.byte 0xD1" :: "a"(mask_lo), "d"(mask_hi), "c" (XCR0));
 }
-#else
-#define ASSERT_IPL(L)
-#endif
 
-int            fp_kind = FP_387;       /* 80387 present */
-zone_t         ifps_zone;              /* zone for FPU save area */
+static inline void xsave(void *a) {
+       /* MOD 0x4, operand ECX 0x1 */
+       __asm__ __volatile__(".short 0xAE0F\n\t.byte 0x21" :: "a"(XMASK), "d"(0), "c" (a));
+}
 
-#if    NCPUS == 1
-volatile thread_act_t  fp_act = THR_ACT_NULL;
-                                   /* thread whose state is in FPU */
-                                   /* always THR_ACT_NULL if emulating FPU */
-volatile thread_act_t  fp_intr_act = THR_ACT_NULL;
+static inline void xrstor(void *a) {
+       /* MOD 0x5, operand ECX 0x1 */
+       __asm__ __volatile__(".short 0xAE0F\n\t.byte 0x29" :: "a"(XMASK), "d"(0), "c" (a));
+}
 
+static inline void xsave64(void *a) {
+       /* Out of line call that executes in 64-bit mode on K32 */
+       __asm__ __volatile__("call _xsave64o" :: "a"(XMASK), "d"(0), "c" (a));
+}
 
-#define        clear_fpu() \
-    { \
-       set_ts(); \
-       fp_act = THR_ACT_NULL; \
-    }
+static inline void xrstor64(void *a) {
+       /* Out of line call that executes in 64-bit mode on K32 */
+       __asm__ __volatile__("call _xrstor64o" :: "a"(XMASK), "d"(0), "c" (a));
+}
 
-#else  /* NCPUS > 1 */
-#define        clear_fpu() \
-    { \
-       set_ts(); \
-    }
+static inline unsigned short
+fnstsw(void)
+{
+       unsigned short status;
+       __asm__ volatile("fnstsw %0" : "=ma" (status));
+       return(status);
+}
 
-#endif
+/*
+ * Configure the initial FPU state presented to new threads.
+ * Determine the MXCSR capability mask, which allows us to mask off any
+ * potentially unsafe "reserved" bits before restoring the FPU context.
+ * *Not* per-cpu, assumes symmetry.
+ */
 
-/* Forward */
+static void
+configure_mxcsr_capability_mask(struct x86_avx_thread_state *fps)
+{
+       /* XSAVE requires a 64 byte aligned store */
+       assert(ALIGNED(fps, 64));
+       /* Clear, to prepare for the diagnostic FXSAVE */
+       bzero(fps, sizeof(*fps));
+
+       fpinit();
+       fpu_store_registers(fps, FALSE);
+
+       mxcsr_capability_mask = fps->fx_MXCSR_MASK;
+
+       /* Set default mask value if necessary */
+       if (mxcsr_capability_mask == 0)
+               mxcsr_capability_mask = 0xffbf;
+       
+       /* Clear vector register store */
+       bzero(&fps->fx_XMM_reg[0][0], sizeof(fps->fx_XMM_reg));
+       bzero(&fps->x_YMMH_reg[0][0], sizeof(fps->x_YMMH_reg));
+
+       fps->fp_valid = TRUE;
+       fps->fp_save_layout = fpu_YMM_present ? XSAVE32: FXSAVE32;
+       fpu_load_registers(fps);
+
+       /* Poison values to trap unsafe usage */
+       fps->fp_valid = 0xFFFFFFFF;
+       fps->fp_save_layout = FP_UNUSED;
+
+       /* Re-enable FPU/SSE DNA exceptions */
+       set_ts();
+}
 
-extern void            fpinit(void);
-extern void            fp_save(
-                               thread_act_t    thr_act);
-extern void            fp_load(
-                               thread_act_t    thr_act);
 
 /*
  * Look for FPU and initialize it.
@@ -126,193 +220,371 @@ extern void             fp_load(
 void
 init_fpu(void)
 {
-       unsigned short  status, control;
-
+#if    DEBUG   
+       unsigned short  status;
+       unsigned short  control;
+#endif
        /*
         * Check for FPU by initializing it,
         * then trying to read the correct bit patterns from
         * the control and status registers.
         */
-       set_cr0(get_cr0() & ~(CR0_EM|CR0_TS));  /* allow use of FPU */
-
+       set_cr0((get_cr0() & ~(CR0_EM|CR0_TS)) | CR0_NE);       /* allow use of FPU */
        fninit();
+#if    DEBUG   
        status = fnstsw();
        fnstcw(&control);
+       
+       assert(((status & 0xff) == 0) && ((control & 0x103f) == 0x3f));
+#endif
+       /* Advertise SSE support */
+       if (cpuid_features() & CPUID_FEATURE_FXSR) {
+               fp_kind = FP_FXSR;
+               set_cr4(get_cr4() | CR4_OSFXS);
+               /* And allow SIMD exceptions if present */
+               if (cpuid_features() & CPUID_FEATURE_SSE) {
+                       set_cr4(get_cr4() | CR4_OSXMM);
+               }
+               fp_register_state_size = sizeof(struct x86_fx_thread_state);
 
-       if ((status & 0xff) == 0 &&
-           (control & 0x103f) == 0x3f)
-       {
-#if 0
-           /*
-            * We have a FPU of some sort.
-            * Compare -infinity against +infinity
-            * to check whether we have a 287 or a 387.
-            */
-           volatile double fp_infinity, fp_one, fp_zero;
-           fp_one = 1.0;
-           fp_zero = 0.0;
-           fp_infinity = fp_one / fp_zero;
-           if (fp_infinity == -fp_infinity) {
-               /*
-                * We have an 80287.
-                */
-               fp_kind = FP_287;
-               __asm__ volatile(".byte 0xdb; .byte 0xe4");     /* fnsetpm */
-           }
-           else
+       } else
+               panic("fpu is not FP_FXSR");
+
+       /* Configure the XSAVE context mechanism if the processor supports
+        * AVX/YMM registers
+        */
+       if (cpuid_features() & CPUID_FEATURE_XSAVE) {
+               cpuid_xsave_leaf_t *xsp = &cpuid_info()->cpuid_xsave_leaf;
+               if (xsp->extended_state[0] & (uint32_t)XFEM_YMM) {
+                       assert(xsp->extended_state[0] & (uint32_t) XFEM_SSE);
+                       /* XSAVE container size for all features */
+                       assert(xsp->extended_state[2] == sizeof(struct x86_avx_thread_state));
+                       fp_register_state_size = sizeof(struct x86_avx_thread_state);
+                       fpu_YMM_present = TRUE;
+                       set_cr4(get_cr4() | CR4_OSXSAVE);
+                       xsetbv(0, XMASK);
+                       /* Re-evaluate CPUID, once, to reflect OSXSAVE */
+                       if (OSCompareAndSwap(0, 1, &cpuid_reevaluated))
+                               cpuid_set_info();
+                       /* DRK: consider verifying AVX offset with cpuid(d, ECX:2) */
+               }
+       }
+       else
+               fpu_YMM_present = FALSE;
+
+       fpinit();
+
+       /*
+        * Trap wait instructions.  Turn off FPU for now.
+        */
+       set_cr0(get_cr0() | CR0_TS | CR0_MP);
+}
+
+/*
+ * Allocate and initialize FP state for current thread.
+ * Don't load state.
+ */
+static void *
+fp_state_alloc(void)
+{
+       void *ifps = zalloc(ifps_zone);
+
+#if    DEBUG   
+       if (!(ALIGNED(ifps,64))) {
+               panic("fp_state_alloc: %p, %u, %p, %u", ifps, (unsigned) ifps_zone->elem_size, (void *) ifps_zone->free_elements, (unsigned) ifps_zone->alloc_size);
+       }
 #endif
-                {
-               /*
-                * We have a 387.
-                */
-               fp_kind = FP_387;
-           }
-           /*
-            * Trap wait instructions.  Turn off FPU for now.
-            */
-           set_cr0(get_cr0() | CR0_TS | CR0_MP);
+       return ifps;
+}
+
+static inline void
+fp_state_free(void *ifps)
+{
+       zfree(ifps_zone, ifps);
+}
+
+void clear_fpu(void)
+{
+       set_ts();
+}
+
+
+static void fpu_load_registers(void *fstate) {
+       struct x86_fx_thread_state *ifps = fstate;
+       fp_save_layout_t layout = ifps->fp_save_layout;
+
+       assert(layout == FXSAVE32 || layout == FXSAVE64 || layout == XSAVE32 || layout == XSAVE64);
+       assert(ALIGNED(ifps, 64));
+       assert(ml_get_interrupts_enabled() == FALSE);
+
+#if    DEBUG   
+       if (layout == XSAVE32 || layout == XSAVE64) {
+               struct x86_avx_thread_state *iavx = fstate;
+               unsigned i;
+               /* Verify reserved bits in the XSAVE header*/
+               if (iavx->_xh.xsbv & ~7)
+                       panic("iavx->_xh.xsbv: 0x%llx", iavx->_xh.xsbv);
+               for (i = 0; i < sizeof(iavx->_xh.xhrsvd); i++)
+                       if (iavx->_xh.xhrsvd[i])
+                               panic("Reserved bit set");
+       }
+       if (fpu_YMM_present) {
+               if (layout != XSAVE32 && layout != XSAVE64)
+                       panic("Inappropriate layout: %u\n", layout);
+       }
+#endif /* DEBUG */
+
+#if defined(__i386__)
+       if (layout == FXSAVE32) {
+               /* Restore the compatibility/legacy mode XMM+x87 state */
+               fxrstor(ifps);
+       }
+       else if (layout == FXSAVE64) {
+               fxrstor64(ifps);
+       }
+       else if (layout == XSAVE32) {
+               xrstor(ifps);
        }
+       else if (layout == XSAVE64) {
+               xrstor64(ifps);
+       }
+#elif defined(__x86_64__)
+       if ((layout == XSAVE64) || (layout == XSAVE32))
+               xrstor(ifps);
        else
-       {
-           /*
-            * NO FPU.
-            */
-           fp_kind = FP_NO;
-           set_cr0(get_cr0() | CR0_EM);
+               fxrstor(ifps);
+#endif
+}
+
+static void fpu_store_registers(void *fstate, boolean_t is64) {
+       struct x86_fx_thread_state *ifps = fstate;
+       assert(ALIGNED(ifps, 64));
+#if defined(__i386__)
+       if (!is64) {
+               if (fpu_YMM_present) {
+                       xsave(ifps);
+                       ifps->fp_save_layout = XSAVE32;
+               }
+               else {
+                       /* save the compatibility/legacy mode XMM+x87 state */
+                       fxsave(ifps);
+                       ifps->fp_save_layout = FXSAVE32;
+               }
+       }
+       else {
+               if (fpu_YMM_present) {
+                       xsave64(ifps);
+                       ifps->fp_save_layout = XSAVE64;
+               }
+               else {
+                       fxsave64(ifps);
+                       ifps->fp_save_layout = FXSAVE64;
+               }
        }
+#elif defined(__x86_64__)
+       if (fpu_YMM_present) {
+               xsave(ifps);
+               ifps->fp_save_layout = is64 ? XSAVE64 : XSAVE32;
+       }
+       else {
+               fxsave(ifps);
+               ifps->fp_save_layout = is64 ? FXSAVE64 : FXSAVE32;
+       }
+#endif
 }
 
 /*
  * Initialize FP handling.
  */
+
 void
 fpu_module_init(void)
 {
-       ifps_zone = zinit(sizeof(struct i386_fpsave_state),
-                         THREAD_MAX * sizeof(struct i386_fpsave_state),
-                         THREAD_CHUNK * sizeof(struct i386_fpsave_state),
-                         "i386 fpsave state");
+       if ((fp_register_state_size != sizeof(struct x86_fx_thread_state)) &&
+           (fp_register_state_size != sizeof(struct x86_avx_thread_state)))
+               panic("fpu_module_init: incorrect savearea size %u\n", fp_register_state_size);
+
+       assert(fpu_YMM_present != 0xFFFFFFFF);
+
+       /* We explicitly choose an allocation size of 64
+        * to eliminate waste for the 832 byte sized
+        * AVX XSAVE register save area.
+        */
+       ifps_zone = zinit(fp_register_state_size,
+                         thread_max * fp_register_state_size,
+                         64 * fp_register_state_size,
+                         "x86 fpsave state");
+
+#if    ZONE_DEBUG
+       /* To maintain the required alignment, disable
+        * zone debugging for this zone as that appends
+        * 16 bytes to each element.
+        */
+       zone_debug_disable(ifps_zone);
+#endif 
+       /* Determine MXCSR reserved bits and configure initial FPU state*/
+       configure_mxcsr_capability_mask(&initial_fp_state);
 }
 
 /*
- * Free a FPU save area.
- * Called only when thread terminating - no locking necessary.
+ * Save thread`s FPU context.
  */
 void
-fp_free(fps)
-       struct i386_fpsave_state *fps;
+fpu_save_context(thread_t thread)
 {
-ASSERT_IPL(SPL0);
-#if    NCPUS == 1
-       if ((fp_act != THR_ACT_NULL) && (fp_act->mact.pcb->ims.ifps == fps)) {
-               /* 
-                * Make sure we don't get FPU interrupts later for
-                * this thread
-                */
-               fwait();
+       struct x86_fx_thread_state *ifps;
 
-               /* Mark it free and disable access */
-           clear_fpu();
+       assert(ml_get_interrupts_enabled() == FALSE);
+       ifps = (thread)->machine.ifps;
+#if    DEBUG
+       if (ifps && ((ifps->fp_valid != FALSE) && (ifps->fp_valid != TRUE))) {
+               panic("ifps->fp_valid: %u\n", ifps->fp_valid);
        }
-#endif /* NCPUS == 1 */
-       zfree(ifps_zone, (vm_offset_t) fps);
+#endif
+       if (ifps != 0 && (ifps->fp_valid == FALSE)) {
+               /* Clear CR0.TS in preparation for the FP context save. In
+                * theory, this shouldn't be necessary since a live FPU should
+                * indicate that TS is clear. However, various routines
+                * (such as sendsig & sigreturn) manipulate TS directly.
+                */
+               clear_ts();
+               /* registers are in FPU - save to memory */
+               fpu_store_registers(ifps, (thread_is_64bit(thread) && is_saved_state64(thread->machine.iss)));
+               ifps->fp_valid = TRUE;
+       }
+       set_ts();
+}
+
+
+/*
+ * Free a FPU save area.
+ * Called only when thread terminating - no locking necessary.
+ */
+void
+fpu_free(void *fps)
+{
+       fp_state_free(fps);
 }
 
 /*
- * Set the floating-point state for a thread.
+ * Set the floating-point state for a thread based 
+ * on the FXSave formatted data. This is basically  
+ * the same as fpu_set_state except it uses the 
+ * expanded data structure. 
  * If the thread is not the current thread, it is
  * not running (held).  Locking needed against
  * concurrent fpu_set_state or fpu_get_state.
  */
 kern_return_t
-fpu_set_state(
-       thread_act_t            thr_act,
-       struct i386_float_state *state)
+fpu_set_fxstate(
+       thread_t        thr_act,
+       thread_state_t  tstate,
+       thread_flavor_t f)
 {
-       register pcb_t  pcb;
-       register struct i386_fpsave_state *ifps;
-       register struct i386_fpsave_state *new_ifps;
-
-ASSERT_IPL(SPL0);
+       struct x86_fx_thread_state *ifps;
+       struct x86_fx_thread_state *new_ifps;
+       x86_float_state64_t     *state;
+       pcb_t   pcb;
+       size_t  state_size = sizeof(struct x86_fx_thread_state);
+       boolean_t       old_valid;
        if (fp_kind == FP_NO)
            return KERN_FAILURE;
 
-       assert(thr_act != THR_ACT_NULL);
-       pcb = thr_act->mact.pcb;
-
-#if    NCPUS == 1
+       state = (x86_float_state64_t *)tstate;
 
-       /*
-        * If this thread`s state is in the FPU,
-        * discard it; we are replacing the entire
-        * FPU state.
-        */
-       if (fp_act == thr_act) {
-           fwait();                    /* wait for possible interrupt */
-           clear_fpu();                /* no state in FPU */
-       }
-#endif
+       assert(thr_act != THREAD_NULL);
+       pcb = THREAD_TO_PCB(thr_act);
 
-       if (state->initialized == 0) {
+       if (state == NULL) {
            /*
             * new FPU state is 'invalid'.
             * Deallocate the fp state if it exists.
             */
            simple_lock(&pcb->lock);
-           ifps = pcb->ims.ifps;
-           pcb->ims.ifps = 0;
+
+               ifps = pcb->ifps;
+               pcb->ifps = 0;
+
            simple_unlock(&pcb->lock);
 
-           if (ifps != 0) {
-               zfree(ifps_zone, (vm_offset_t) ifps);
-           }
-       }
-       else {
+               if (ifps != 0)
+               fp_state_free(ifps);
+       } else {
            /*
             * Valid state.  Allocate the fp state if there is none.
             */
-           register struct i386_fp_save *user_fp_state;
-           register struct i386_fp_regs *user_fp_regs;
-
-           user_fp_state = (struct i386_fp_save *) &state->hw_state[0];
-           user_fp_regs  = (struct i386_fp_regs *)
-                       &state->hw_state[sizeof(struct i386_fp_save)];
-
            new_ifps = 0;
        Retry:
            simple_lock(&pcb->lock);
-           ifps = pcb->ims.ifps;
+
+               ifps = pcb->ifps;
            if (ifps == 0) {
                if (new_ifps == 0) {
                    simple_unlock(&pcb->lock);
-                   new_ifps = (struct i386_fpsave_state *) zalloc(ifps_zone);
+                   new_ifps = fp_state_alloc();
                    goto Retry;
                }
                ifps = new_ifps;
                new_ifps = 0;
-               pcb->ims.ifps = ifps;
+               pcb->ifps = ifps;
            }
+           /*
+            * now copy over the new data.
+            */
+           old_valid = ifps->fp_valid;
 
+#if    DEBUG       
+           if ((old_valid == FALSE) && (thr_act != current_thread())) {
+                   panic("fpu_set_fxstate inconsistency, thread: %p not stopped", thr_act);
+           }
+#endif
            /*
-            * Ensure that reserved parts of the environment are 0.
+            * Clear any reserved bits in the MXCSR to prevent a GPF
+            * when issuing an FXRSTOR.
             */
-           bzero((char *)&ifps->fp_save_state, sizeof(struct i386_fp_save));
-
-           ifps->fp_save_state.fp_control = user_fp_state->fp_control;
-           ifps->fp_save_state.fp_status  = user_fp_state->fp_status;
-           ifps->fp_save_state.fp_tag     = user_fp_state->fp_tag;
-           ifps->fp_save_state.fp_eip     = user_fp_state->fp_eip;
-           ifps->fp_save_state.fp_cs      = user_fp_state->fp_cs;
-           ifps->fp_save_state.fp_opcode  = user_fp_state->fp_opcode;
-           ifps->fp_save_state.fp_dp      = user_fp_state->fp_dp;
-           ifps->fp_save_state.fp_ds      = user_fp_state->fp_ds;
-           ifps->fp_regs = *user_fp_regs;
+
+           state->fpu_mxcsr &= mxcsr_capability_mask;
+
+           bcopy((char *)&state->fpu_fcw, (char *)ifps, state_size);
+
+           if (fpu_YMM_present) {
+               struct x86_avx_thread_state *iavx = (void *) ifps;
+               uint32_t fpu_nyreg = 0;
+
+               if (f == x86_AVX_STATE32)
+                       fpu_nyreg = 8;
+               else if (f == x86_AVX_STATE64)
+                       fpu_nyreg = 16;
+
+               if (fpu_nyreg) {
+                       x86_avx_state64_t *ystate = (x86_avx_state64_t *) state;
+                       bcopy(&ystate->__fpu_ymmh0, &iavx->x_YMMH_reg[0][0], fpu_nyreg * sizeof(_STRUCT_XMM_REG));
+               }
+
+               iavx->fp_save_layout = thread_is_64bit(thr_act) ? XSAVE64 : XSAVE32;
+               /* Sanitize XSAVE header */
+               bzero(&iavx->_xh.xhrsvd[0], sizeof(iavx->_xh.xhrsvd));
+               if (state_size == sizeof(struct x86_avx_thread_state))
+                       iavx->_xh.xsbv = (XFEM_YMM | XFEM_SSE | XFEM_X87);
+               else
+                       iavx->_xh.xsbv = (XFEM_SSE | XFEM_X87);
+           }
+           else
+               ifps->fp_save_layout = thread_is_64bit(thr_act) ? FXSAVE64 : FXSAVE32;
+           ifps->fp_valid = old_valid;
+
+           if (old_valid == FALSE) {
+                   boolean_t istate = ml_set_interrupts_enabled(FALSE);
+                   ifps->fp_valid = TRUE;
+                   set_ts();
+                   ml_set_interrupts_enabled(istate);
+           }
 
            simple_unlock(&pcb->lock);
+
            if (new_ifps != 0)
-               zfree(ifps_zone, (vm_offset_t) ifps);
+               fp_state_free(new_ifps);
        }
-
        return KERN_SUCCESS;
 }
 
@@ -323,98 +595,164 @@ ASSERT_IPL(SPL0);
  * concurrent fpu_set_state or fpu_get_state.
  */
 kern_return_t
-fpu_get_state(
-       thread_act_t                            thr_act,
-       register struct i386_float_state        *state)
+fpu_get_fxstate(
+       thread_t        thr_act,
+       thread_state_t  tstate,
+       thread_flavor_t f)
 {
-       register pcb_t  pcb;
-       register struct i386_fpsave_state *ifps;
+       struct x86_fx_thread_state      *ifps;
+       x86_float_state64_t     *state;
+       kern_return_t   ret = KERN_FAILURE;
+       pcb_t   pcb;
+       size_t  state_size = sizeof(struct x86_fx_thread_state);
 
-ASSERT_IPL(SPL0);
        if (fp_kind == FP_NO)
-           return KERN_FAILURE;
+               return KERN_FAILURE;
+
+       state = (x86_float_state64_t *)tstate;
 
-       assert(thr_act != THR_ACT_NULL);
-       pcb = thr_act->mact.pcb;
+       assert(thr_act != THREAD_NULL);
+       pcb = THREAD_TO_PCB(thr_act);
 
        simple_lock(&pcb->lock);
-       ifps = pcb->ims.ifps;
+
+       ifps = pcb->ifps;
        if (ifps == 0) {
-           /*
-            * No valid floating-point state.
-            */
-           simple_unlock(&pcb->lock);
-           bzero((char *)state, sizeof(struct i386_float_state));
-           return KERN_SUCCESS;
+               /*
+                * No valid floating-point state.
+                */
+
+               bcopy((char *)&initial_fp_state, (char *)&state->fpu_fcw,
+                   state_size);
+
+               simple_unlock(&pcb->lock);
+
+               return KERN_SUCCESS;
        }
+       /*
+        * Make sure we`ve got the latest fp state info
+        * If the live fpu state belongs to our target
+        */
+       if (thr_act == current_thread()) {
+               boolean_t       intr;
 
-       /* Make sure we`ve got the latest fp state info */
-       /* If the live fpu state belongs to our target */
-#if    NCPUS == 1
-       if (thr_act == fp_act)
-#else
-       if (thr_act == current_act())
-#endif
-       {
-           clear_ts();
-           fp_save(thr_act);
-           clear_fpu();
+               intr = ml_set_interrupts_enabled(FALSE);
+
+               clear_ts();
+               fp_save(thr_act);
+               clear_fpu();
+
+               (void)ml_set_interrupts_enabled(intr);
        }
+       if (ifps->fp_valid) {
+               bcopy((char *)ifps, (char *)&state->fpu_fcw, state_size);
+               if (fpu_YMM_present) {
+                       struct x86_avx_thread_state *iavx = (void *) ifps;
+                       uint32_t fpu_nyreg = 0;
+
+                       if (f == x86_AVX_STATE32)
+                               fpu_nyreg = 8;
+                       else if (f == x86_AVX_STATE64)
+                               fpu_nyreg = 16;
+
+                       if (fpu_nyreg) {
+                               x86_avx_state64_t *ystate = (x86_avx_state64_t *) state;
+                               bcopy(&iavx->x_YMMH_reg[0][0], &ystate->__fpu_ymmh0, fpu_nyreg * sizeof(_STRUCT_XMM_REG));
+                       }
+               }
 
-       state->fpkind = fp_kind;
-       state->exc_status = 0;
+               ret = KERN_SUCCESS;
+       }
+       simple_unlock(&pcb->lock);
 
-       {
-           register struct i386_fp_save *user_fp_state;
-           register struct i386_fp_regs *user_fp_regs;
+       return ret;
+}
 
-           state->initialized = ifps->fp_valid;
 
-           user_fp_state = (struct i386_fp_save *) &state->hw_state[0];
-           user_fp_regs  = (struct i386_fp_regs *)
-                       &state->hw_state[sizeof(struct i386_fp_save)];
 
-           /*
-            * Ensure that reserved parts of the environment are 0.
-            */
-           bzero((char *)user_fp_state,  sizeof(struct i386_fp_save));
-
-           user_fp_state->fp_control = ifps->fp_save_state.fp_control;
-           user_fp_state->fp_status  = ifps->fp_save_state.fp_status;
-           user_fp_state->fp_tag     = ifps->fp_save_state.fp_tag;
-           user_fp_state->fp_eip     = ifps->fp_save_state.fp_eip;
-           user_fp_state->fp_cs      = ifps->fp_save_state.fp_cs;
-           user_fp_state->fp_opcode  = ifps->fp_save_state.fp_opcode;
-           user_fp_state->fp_dp      = ifps->fp_save_state.fp_dp;
-           user_fp_state->fp_ds      = ifps->fp_save_state.fp_ds;
-           *user_fp_regs = ifps->fp_regs;
+/*
+ * the child thread is 'stopped' with the thread
+ * mutex held and is currently not known by anyone
+ * so no way for fpu state to get manipulated by an
+ * outside agency -> no need for pcb lock
+ */
+
+void
+fpu_dup_fxstate(
+       thread_t        parent,
+       thread_t        child)
+{
+       struct x86_fx_thread_state *new_ifps = NULL;
+       boolean_t       intr;
+       pcb_t           ppcb;
+
+       ppcb = THREAD_TO_PCB(parent);
+
+       if (ppcb->ifps == NULL)
+               return;
+
+        if (child->machine.ifps)
+               panic("fpu_dup_fxstate: child's ifps non-null");
+
+       new_ifps = fp_state_alloc();
+
+       simple_lock(&ppcb->lock);
+
+       if (ppcb->ifps != NULL) {
+               struct x86_fx_thread_state *ifps = ppcb->ifps;
+               /*
+                * Make sure we`ve got the latest fp state info
+                */
+               intr = ml_set_interrupts_enabled(FALSE);
+               assert(current_thread() == parent);
+               clear_ts();
+               fp_save(parent);
+               clear_fpu();
+
+               (void)ml_set_interrupts_enabled(intr);
+
+               if (ifps->fp_valid) {
+                       child->machine.ifps = new_ifps;
+                       assert((fp_register_state_size == sizeof(struct x86_fx_thread_state)) ||
+                           (fp_register_state_size == sizeof(struct x86_avx_thread_state)));
+                       bcopy((char *)(ppcb->ifps),
+                           (char *)(child->machine.ifps), fp_register_state_size);
+
+                       /* Mark the new fp saved state as non-live. */
+                       /* Temporarily disabled: radar 4647827
+                        * new_ifps->fp_valid = TRUE;
+                        */
+
+                       /*
+                        * Clear any reserved bits in the MXCSR to prevent a GPF
+                        * when issuing an FXRSTOR.
+                        */
+                       new_ifps->fx_MXCSR &= mxcsr_capability_mask;
+                       new_ifps = NULL;
+               }
        }
-       simple_unlock(&pcb->lock);
+       simple_unlock(&ppcb->lock);
 
-       return KERN_SUCCESS;
+       if (new_ifps != NULL)
+               fp_state_free(new_ifps);
 }
 
+
 /*
  * Initialize FPU.
  *
- * Raise exceptions for:
- *     invalid operation
- *     divide by zero
- *     overflow
- *
- * Use 53-bit precision.
  */
+
 void
 fpinit(void)
 {
        unsigned short  control;
 
-ASSERT_IPL(SPL0);
        clear_ts();
        fninit();
        fnstcw(&control);
        control &= ~(FPC_PC|FPC_RC); /* Clear precision & rounding control */
-       control |= (FPC_PC_53 |         /* Set precision */ 
+       control |= (FPC_PC_64 |         /* Set precision */ 
                        FPC_RC_RN |     /* round-to-nearest */
                        FPC_ZE |        /* Suppress zero-divide */
                        FPC_OE |        /*  and overflow */
@@ -423,6 +761,9 @@ ASSERT_IPL(SPL0);
                        FPC_DE |        /* Allow denorms as operands  */
                        FPC_PE);        /* No trap for precision loss */
        fldcw(control);
+
+       /* Initialize SSE/SSE2 */
+       __builtin_ia32_ldmxcsr(0x1f80);
 }
 
 /*
@@ -432,41 +773,52 @@ ASSERT_IPL(SPL0);
 void
 fpnoextflt(void)
 {
-       /*
-        * Enable FPU use.
-        */
-ASSERT_IPL(SPL0);
-       clear_ts();
-#if    NCPUS == 1
-
-       /*
-        * If this thread`s state is in the FPU, we are done.
-        */
-       if (fp_act == current_act())
-           return;
-
-       /* Make sure we don't do fpsave() in fp_intr while doing fpsave()
-        * here if the current fpu instruction generates an error.
-        */
-       fwait();
-       /*
-        * If another thread`s state is in the FPU, save it.
-        */
-       if (fp_act != THR_ACT_NULL) {
-           fp_save(fp_act);
+       boolean_t       intr;
+       thread_t        thr_act;
+       pcb_t           pcb;
+       struct x86_fx_thread_state *ifps = 0;
+
+       thr_act = current_thread();
+       pcb = THREAD_TO_PCB(thr_act);
+
+       assert(fp_register_state_size != 0);
+
+       if (pcb->ifps == 0 && !get_interrupt_level()) {
+               ifps = fp_state_alloc();
+               bcopy((char *)&initial_fp_state, (char *)ifps,
+                   fp_register_state_size);
+               if (!thread_is_64bit(thr_act)) {
+                       ifps->fp_save_layout = fpu_YMM_present ? XSAVE32 : FXSAVE32;
+               }
+               else
+                       ifps->fp_save_layout = fpu_YMM_present ? XSAVE64 : FXSAVE64;
+               ifps->fp_valid = TRUE;
        }
+       intr = ml_set_interrupts_enabled(FALSE);
 
-       /*
-        * Give this thread the FPU.
-        */
-       fp_act = current_act();
+       clear_ts();                     /*  Enable FPU use */
 
-#endif /* NCPUS == 1 */
+       if (__improbable(get_interrupt_level())) {
+               /*
+                * Save current coprocessor context if valid
+                * Initialize coprocessor live context
+                */
+               fp_save(thr_act);
+               fpinit();
+       } else {
+               if (pcb->ifps == 0) {
+                       pcb->ifps = ifps;
+                       ifps = 0;
+               }
+               /*
+                * Load this thread`s state into coprocessor live context.
+                */
+               fp_load(thr_act);
+       }
+       (void)ml_set_interrupts_enabled(intr);
 
-       /*
-        * Load this thread`s state into the FPU.
-        */
-       fp_load(current_act());
+       if (ifps)
+               fp_state_free(ifps);
 }
 
 /*
@@ -477,29 +829,26 @@ ASSERT_IPL(SPL0);
 void
 fpextovrflt(void)
 {
-       register thread_act_t   thr_act = current_act();
-       register pcb_t          pcb;
-       register struct i386_fpsave_state *ifps;
+       thread_t        thr_act = current_thread();
+       pcb_t           pcb;
+       struct x86_fx_thread_state *ifps;
+       boolean_t       intr;
 
-#if    NCPUS == 1
+       intr = ml_set_interrupts_enabled(FALSE);
 
-       /*
-        * Is exception for the currently running thread?
-        */
-       if (fp_act != thr_act) {
-           /* Uh oh... */
-           panic("fpextovrflt");
-       }
-#endif
+       if (get_interrupt_level())
+               panic("FPU segment overrun exception  at interrupt context\n");
+       if (current_task() == kernel_task)
+               panic("FPU segment overrun exception in kernel thread context\n");
 
        /*
         * This is a non-recoverable error.
         * Invalidate the thread`s FPU state.
         */
-       pcb = thr_act->mact.pcb;
+       pcb = THREAD_TO_PCB(thr_act);
        simple_lock(&pcb->lock);
-       ifps = pcb->ims.ifps;
-       pcb->ims.ifps = 0;
+       ifps = pcb->ifps;
+       pcb->ifps = 0;
        simple_unlock(&pcb->lock);
 
        /*
@@ -513,8 +862,10 @@ fpextovrflt(void)
         */
        clear_fpu();
 
+       (void)ml_set_interrupts_enabled(intr);
+
        if (ifps)
-           zfree(ifps_zone, (vm_offset_t) ifps);
+           zfree(ifps_zone, ifps);
 
        /*
         * Raise exception.
@@ -530,52 +881,33 @@ fpextovrflt(void)
 void
 fpexterrflt(void)
 {
-       register thread_act_t   thr_act = current_act();
+       thread_t        thr_act = current_thread();
+       struct x86_fx_thread_state *ifps = thr_act->machine.ifps;
+       boolean_t       intr;
 
-ASSERT_IPL(SPL0);
-#if    NCPUS == 1
-       /*
-        * Since FPU errors only occur on ESC or WAIT instructions,
-        * the current thread should own the FPU.  If it didn`t,
-        * we should have gotten the task-switched interrupt first.
-        */
-       if (fp_act != THR_ACT_NULL) {
-           panic("fpexterrflt");
-               return;
-       }
+       intr = ml_set_interrupts_enabled(FALSE);
+
+       if (get_interrupt_level())
+               panic("FPU error exception at interrupt context\n");
+       if (current_task() == kernel_task)
+               panic("FPU error exception in kernel thread context\n");
 
-       /*
-        * Check if we got a context switch between the interrupt and the AST
-        * This can happen if the interrupt arrived after the FPU AST was
-        * checked. In this case, raise the exception in fp_load when this
-        * thread next time uses the FPU. Remember exception condition in
-        * fp_valid (extended boolean 2).
-        */
-       if (fp_intr_act != thr_act) {
-               if (fp_intr_act == THR_ACT_NULL) {
-                       panic("fpexterrflt: fp_intr_act == THR_ACT_NULL");
-                       return;
-               }
-               fp_intr_act->mact.pcb->ims.ifps->fp_valid = 2;
-               fp_intr_act = THR_ACT_NULL;
-               return;
-       }
-       fp_intr_act = THR_ACT_NULL;
-#else  /* NCPUS == 1 */
        /*
         * Save the FPU state and turn off the FPU.
         */
        fp_save(thr_act);
-#endif /* NCPUS == 1 */
+
+       (void)ml_set_interrupts_enabled(intr);
 
        /*
         * Raise FPU exception.
-        * Locking not needed on pcb->ims.ifps,
+        * Locking not needed on pcb->ifps,
         * since thread is running.
         */
        i386_exception(EXC_ARITHMETIC,
                       EXC_I386_EXTERR,
-                      thr_act->mact.pcb->ims.ifps->fp_save_state.fp_status);
+                      ifps->fx_status);
+
        /*NOTREACHED*/
 }
 
@@ -586,19 +918,22 @@ ASSERT_IPL(SPL0);
  * .   if called from fpu_get_state, pcb already locked.
  * .   if called from fpnoextflt or fp_intr, we are single-cpu
  * .   otherwise, thread is running.
+ * N.B.: Must be called with interrupts disabled
  */
 
 void
 fp_save(
-       thread_act_t    thr_act)
+       thread_t        thr_act)
 {
-       register pcb_t pcb = thr_act->mact.pcb;
-       register struct i386_fpsave_state *ifps = pcb->ims.ifps;
+       pcb_t pcb = THREAD_TO_PCB(thr_act);
+       struct x86_fx_thread_state *ifps = pcb->ifps;
 
+       assert(ifps != 0);
        if (ifps != 0 && !ifps->fp_valid) {
-           /* registers are in FPU */
-           ifps->fp_valid = TRUE;
-           fnsave(&ifps->fp_save_state);
+               assert((get_cr0() & CR0_TS) == 0);
+               /* registers are in FPU */
+               ifps->fp_valid = TRUE;
+               fpu_store_registers(ifps, thread_is_64bit(thr_act));
        }
 }
 
@@ -610,157 +945,76 @@ fp_save(
 
 void
 fp_load(
-       thread_act_t    thr_act)
+       thread_t        thr_act)
 {
-       register pcb_t pcb = thr_act->mact.pcb;
-       register struct i386_fpsave_state *ifps;
+       pcb_t pcb = THREAD_TO_PCB(thr_act);
+       struct x86_fx_thread_state *ifps = pcb->ifps;
 
-ASSERT_IPL(SPL0);
-       ifps = pcb->ims.ifps;
-       if (ifps == 0) {
-           ifps = (struct i386_fpsave_state *) zalloc(ifps_zone);
-           bzero((char *)ifps, sizeof *ifps);
-           pcb->ims.ifps = ifps;
-           fpinit();
-#if 1
-/* 
- * I'm not sure this is needed. Does the fpu regenerate the interrupt in
- * frstor or not? Without this code we may miss some exceptions, with it
- * we might send too many exceptions.
- */
-       } else if (ifps->fp_valid == 2) {
-               /* delayed exception pending */
+       assert(ifps);
+       assert(ifps->fp_valid == FALSE || ifps->fp_valid == TRUE);
 
-               ifps->fp_valid = TRUE;
-               clear_fpu();
-               /*
-                * Raise FPU exception.
-                * Locking not needed on pcb->ims.ifps,
-                * since thread is running.
-                */
-               i386_exception(EXC_ARITHMETIC,
-                      EXC_I386_EXTERR,
-                      thr_act->mact.pcb->ims.ifps->fp_save_state.fp_status);
-               /*NOTREACHED*/
-#endif
+       if (ifps->fp_valid == FALSE) {
+               fpinit();
        } else {
-           frstor(ifps->fp_save_state);
+               fpu_load_registers(ifps);
        }
        ifps->fp_valid = FALSE;         /* in FPU */
 }
 
 /*
- * Allocate and initialize FP state for current thread.
- * Don't load state.
- *
- * Locking not needed; always called on the current thread.
+ * SSE arithmetic exception handling code.
+ * Basically the same as the x87 exception handler with a different subtype
  */
-void
-fp_state_alloc(void)
-{
-       pcb_t   pcb = current_act()->mact.pcb;
-       struct i386_fpsave_state *ifps;
-
-       ifps = (struct i386_fpsave_state *)zalloc(ifps_zone);
-       bzero((char *)ifps, sizeof *ifps);
-       pcb->ims.ifps = ifps;
-
-       ifps->fp_valid = TRUE;
-       ifps->fp_save_state.fp_control = (0x037f
-                       & ~(FPC_IM|FPC_ZM|FPC_OM|FPC_PC))
-                       | (FPC_PC_53|FPC_IC_AFF);
-       ifps->fp_save_state.fp_status = 0;
-       ifps->fp_save_state.fp_tag = 0xffff;    /* all empty */
-}
 
-
-/*
- * fpflush(thread_act_t)
- *     Flush the current act's state, if needed
- *     (used by thread_terminate_self to ensure fp faults
- *     aren't satisfied by overly general trap code in the
- *     context of the reaper thread)
- */
 void
-fpflush(thread_act_t thr_act)
+fpSSEexterrflt(void)
 {
-#if    NCPUS == 1
-       if (fp_act && thr_act == fp_act) {
-           clear_ts();
-           fwait();
-           clear_fpu();
-       }
-#else
-       /* not needed on MP x86s; fp not lazily evaluated */
-#endif
-}
+       thread_t        thr_act = current_thread();
+       struct x86_fx_thread_state *ifps = thr_act->machine.ifps;
+       boolean_t       intr;
 
+       intr = ml_set_interrupts_enabled(FALSE);
 
-/*
- *     Handle a coprocessor error interrupt on the AT386.
- *     This comes in on line 5 of the slave PIC at SPL1.
- */
+       if (get_interrupt_level())
+               panic("SSE exception at interrupt context\n");
+       if (current_task() == kernel_task)
+               panic("SSE exception in kernel thread context\n");
 
-void
-fpintr(void)
-{
-       spl_t   s;
-       thread_act_t thr_act = current_act();
-
-ASSERT_IPL(SPL1);
        /*
-        * Turn off the extended 'busy' line.
+        * Save the FPU state and turn off the FPU.
         */
-       outb(0xf0, 0);
+       fp_save(thr_act);
 
+       (void)ml_set_interrupts_enabled(intr);
        /*
-        * Save the FPU context to the thread using it.
+        * Raise FPU exception.
+        * Locking not needed on pcb->ifps,
+        * since thread is running.
         */
-#if    NCPUS == 1
-       if (fp_act == THR_ACT_NULL) {
-               printf("fpintr: FPU not belonging to anyone!\n");
-               clear_ts();
-               fninit();
-               clear_fpu();
-               return;
-       }
+       assert(ifps->fp_save_layout == FXSAVE32 || ifps->fp_save_layout == FXSAVE64);
+       i386_exception(EXC_ARITHMETIC,
+                      EXC_I386_SSEEXTERR,
+                      ifps->fx_MXCSR);
+       /*NOTREACHED*/
+}
 
-       if (fp_act != thr_act) {
-           /*
-            * FPU exception is for a different thread.
-            * When that thread again uses the FPU an exception will be
-            * raised in fp_load. Remember the condition in fp_valid (== 2).
-            */
-           clear_ts();
-           fp_save(fp_act);
-           fp_act->mact.pcb->ims.ifps->fp_valid = 2;
-           fninit();
-           clear_fpu();
-           /* leave fp_intr_act THR_ACT_NULL */
-           return;
-       }
-       if (fp_intr_act != THR_ACT_NULL)
-           panic("fp_intr: already caught intr");
-       fp_intr_act = thr_act;
-#endif /* NCPUS == 1 */
+void
+fp_setvalid(boolean_t value) {
+        thread_t       thr_act = current_thread();
+       struct x86_fx_thread_state *ifps = thr_act->machine.ifps;
 
-       clear_ts();
-       fp_save(thr_act);
-       fninit();
-       clear_fpu();
+       if (ifps) {
+               ifps->fp_valid = value;
 
-       /*
-        * Since we are running on the interrupt stack, we must
-        * signal the thread to take the exception when we return
-        * to user mode.  Use an AST to do this.
-        *
-        * Don`t set the thread`s AST field.  If the thread is
-        * descheduled before it takes the AST, it will notice
-        * the FPU error when it reloads its FPU state.
-        */
-       s = splsched();
-       mp_disable_preemption();
-       ast_on(AST_I386_FP);
-       mp_enable_preemption();
-       splx(s);
+               if (value == TRUE) {
+                       boolean_t istate = ml_set_interrupts_enabled(FALSE);
+                       clear_fpu();
+                       ml_set_interrupts_enabled(istate);
+               }
+       }
+}
+
+__private_extern__ boolean_t
+ml_fpu_avx_enabled(void) {
+       return (fpu_YMM_present == TRUE);
 }