This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / include / asm-i386 / mach-xen / asm / system.h
diff --git a/include/asm-i386/mach-xen/asm/system.h b/include/asm-i386/mach-xen/asm/system.h
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+#ifndef __ASM_SYSTEM_H
+#define __ASM_SYSTEM_H
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <asm/segment.h>
+#include <asm/cpufeature.h>
+#include <linux/bitops.h> /* for LOCK_PREFIX */
+#include <asm/synch_bitops.h>
+#include <asm/hypervisor.h>
+
+#ifdef __KERNEL__
+
+#ifdef CONFIG_SMP
+#define __vcpu_id smp_processor_id()
+#else
+#define __vcpu_id 0
+#endif
+
+struct task_struct;    /* one of the stranger aspects of C forward declarations.. */
+extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next));
+
+#define switch_to(prev,next,last) do {                                 \
+       unsigned long esi,edi;                                          \
+       asm volatile("pushl %%ebp\n\t"                                  \
+                    "movl %%esp,%0\n\t"        /* save ESP */          \
+                    "movl %5,%%esp\n\t"        /* restore ESP */       \
+                    "movl $1f,%1\n\t"          /* save EIP */          \
+                    "pushl %6\n\t"             /* restore EIP */       \
+                    "jmp __switch_to\n"                                \
+                    "1:\t"                                             \
+                    "popl %%ebp\n\t"                                   \
+                    :"=m" (prev->thread.esp),"=m" (prev->thread.eip),  \
+                     "=a" (last),"=S" (esi),"=D" (edi)                 \
+                    :"m" (next->thread.esp),"m" (next->thread.eip),    \
+                     "2" (prev), "d" (next));                          \
+} while (0)
+
+#define _set_base(addr,base) do { unsigned long __pr; \
+__asm__ __volatile__ ("movw %%dx,%1\n\t" \
+       "rorl $16,%%edx\n\t" \
+       "movb %%dl,%2\n\t" \
+       "movb %%dh,%3" \
+       :"=&d" (__pr) \
+       :"m" (*((addr)+2)), \
+        "m" (*((addr)+4)), \
+        "m" (*((addr)+7)), \
+         "0" (base) \
+        ); } while(0)
+
+#define _set_limit(addr,limit) do { unsigned long __lr; \
+__asm__ __volatile__ ("movw %%dx,%1\n\t" \
+       "rorl $16,%%edx\n\t" \
+       "movb %2,%%dh\n\t" \
+       "andb $0xf0,%%dh\n\t" \
+       "orb %%dh,%%dl\n\t" \
+       "movb %%dl,%2" \
+       :"=&d" (__lr) \
+       :"m" (*(addr)), \
+        "m" (*((addr)+6)), \
+        "0" (limit) \
+        ); } while(0)
+
+#define set_base(ldt,base) _set_base( ((char *)&(ldt)) , (base) )
+#define set_limit(ldt,limit) _set_limit( ((char *)&(ldt)) , ((limit)-1) )
+
+/*
+ * Load a segment. Fall back on loading the zero
+ * segment if something goes wrong..
+ */
+#define loadsegment(seg,value)                 \
+       asm volatile("\n"                       \
+               "1:\t"                          \
+               "mov %0,%%" #seg "\n"           \
+               "2:\n"                          \
+               ".section .fixup,\"ax\"\n"      \
+               "3:\t"                          \
+               "pushl $0\n\t"                  \
+               "popl %%" #seg "\n\t"           \
+               "jmp 2b\n"                      \
+               ".previous\n"                   \
+               ".section __ex_table,\"a\"\n\t" \
+               ".align 4\n\t"                  \
+               ".long 1b,3b\n"                 \
+               ".previous"                     \
+               : :"rm" (value))
+
+/*
+ * Save a segment register away
+ */
+#define savesegment(seg, value) \
+       asm volatile("mov %%" #seg ",%0":"=rm" (value))
+
+/*
+ * Clear and set 'TS' bit respectively
+ */
+#define clts() (HYPERVISOR_fpu_taskswitch(0))
+#define read_cr0() ({ \
+       unsigned int __dummy; \
+       __asm__ __volatile__( \
+               "movl %%cr0,%0\n\t" \
+               :"=r" (__dummy)); \
+       __dummy; \
+})
+#define write_cr0(x) \
+       __asm__ __volatile__("movl %0,%%cr0": :"r" (x));
+
+#define read_cr2() \
+       (HYPERVISOR_shared_info->vcpu_info[smp_processor_id()].arch.cr2)
+#define write_cr2(x) \
+       __asm__ __volatile__("movl %0,%%cr2": :"r" (x));
+
+#define read_cr3() ({ \
+       unsigned int __dummy; \
+       __asm__ ( \
+               "movl %%cr3,%0\n\t" \
+               :"=r" (__dummy)); \
+       __dummy = xen_cr3_to_pfn(__dummy); \
+       mfn_to_pfn(__dummy) << PAGE_SHIFT; \
+})
+#define write_cr3(x) ({                                                \
+       unsigned int __dummy = pfn_to_mfn((x) >> PAGE_SHIFT);   \
+       __dummy = xen_pfn_to_cr3(__dummy);                      \
+       __asm__ __volatile__("movl %0,%%cr3": :"r" (__dummy));  \
+})
+
+#define read_cr4() ({ \
+       unsigned int __dummy; \
+       __asm__( \
+               "movl %%cr4,%0\n\t" \
+               :"=r" (__dummy)); \
+       __dummy; \
+})
+
+#define read_cr4_safe() ({                           \
+       unsigned int __dummy;                         \
+       /* This could fault if %cr4 does not exist */ \
+       __asm__("1: movl %%cr4, %0              \n"   \
+               "2:                             \n"   \
+               ".section __ex_table,\"a\"      \n"   \
+               ".long 1b,2b                    \n"   \
+               ".previous                      \n"   \
+               : "=r" (__dummy): "0" (0));           \
+       __dummy;                                      \
+})
+
+#define write_cr4(x) \
+       __asm__ __volatile__("movl %0,%%cr4": :"r" (x));
+#define stts() (HYPERVISOR_fpu_taskswitch(1))
+
+#endif /* __KERNEL__ */
+
+#define wbinvd() \
+       __asm__ __volatile__ ("wbinvd": : :"memory");
+
+static inline unsigned long get_limit(unsigned long segment)
+{
+       unsigned long __limit;
+       __asm__("lsll %1,%0"
+               :"=r" (__limit):"r" (segment));
+       return __limit+1;
+}
+
+#define nop() __asm__ __volatile__ ("nop")
+
+#define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
+
+#define tas(ptr) (xchg((ptr),1))
+
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((struct __xchg_dummy *)(x))
+
+
+#ifdef CONFIG_X86_CMPXCHG64
+
+/*
+ * The semantics of XCHGCMP8B are a bit strange, this is why
+ * there is a loop and the loading of %%eax and %%edx has to
+ * be inside. This inlines well in most cases, the cached
+ * cost is around ~38 cycles. (in the future we might want
+ * to do an SIMD/3DNOW!/MMX/FPU 64-bit store here, but that
+ * might have an implicit FPU-save as a cost, so it's not
+ * clear which path to go.)
+ *
+ * cmpxchg8b must be used with the lock prefix here to allow
+ * the instruction to be executed atomically, see page 3-102
+ * of the instruction set reference 24319102.pdf. We need
+ * the reader side to see the coherent 64bit value.
+ */
+static inline void __set_64bit (unsigned long long * ptr,
+               unsigned int low, unsigned int high)
+{
+       __asm__ __volatile__ (
+               "\n1:\t"
+               "movl (%0), %%eax\n\t"
+               "movl 4(%0), %%edx\n\t"
+               "lock cmpxchg8b (%0)\n\t"
+               "jnz 1b"
+               : /* no outputs */
+               :       "D"(ptr),
+                       "b"(low),
+                       "c"(high)
+               :       "ax","dx","memory");
+}
+
+static inline void __set_64bit_constant (unsigned long long *ptr,
+                                                unsigned long long value)
+{
+       __set_64bit(ptr,(unsigned int)(value), (unsigned int)((value)>>32ULL));
+}
+#define ll_low(x)      *(((unsigned int*)&(x))+0)
+#define ll_high(x)     *(((unsigned int*)&(x))+1)
+
+static inline void __set_64bit_var (unsigned long long *ptr,
+                        unsigned long long value)
+{
+       __set_64bit(ptr,ll_low(value), ll_high(value));
+}
+
+#define set_64bit(ptr,value) \
+(__builtin_constant_p(value) ? \
+ __set_64bit_constant(ptr, value) : \
+ __set_64bit_var(ptr, value) )
+
+#define _set_64bit(ptr,value) \
+(__builtin_constant_p(value) ? \
+ __set_64bit(ptr, (unsigned int)(value), (unsigned int)((value)>>32ULL) ) : \
+ __set_64bit(ptr, ll_low(value), ll_high(value)) )
+
+#endif
+
+/*
+ * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
+ * Note 2: xchg has side effect, so that attribute volatile is necessary,
+ *       but generally the primitive is invalid, *ptr is output argument. --ANK
+ */
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+       switch (size) {
+               case 1:
+                       __asm__ __volatile__("xchgb %b0,%1"
+                               :"=q" (x)
+                               :"m" (*__xg(ptr)), "0" (x)
+                               :"memory");
+                       break;
+               case 2:
+                       __asm__ __volatile__("xchgw %w0,%1"
+                               :"=r" (x)
+                               :"m" (*__xg(ptr)), "0" (x)
+                               :"memory");
+                       break;
+               case 4:
+                       __asm__ __volatile__("xchgl %0,%1"
+                               :"=r" (x)
+                               :"m" (*__xg(ptr)), "0" (x)
+                               :"memory");
+                       break;
+       }
+       return x;
+}
+
+/*
+ * Atomic compare and exchange.  Compare OLD with MEM, if identical,
+ * store NEW in MEM.  Return the initial value in MEM.  Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#ifdef CONFIG_X86_CMPXCHG
+#define __HAVE_ARCH_CMPXCHG 1
+#define cmpxchg(ptr,o,n)\
+       ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
+                                       (unsigned long)(n),sizeof(*(ptr))))
+#endif
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+                                     unsigned long new, int size)
+{
+       unsigned long prev;
+       switch (size) {
+       case 1:
+               __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
+                                    : "=a"(prev)
+                                    : "q"(new), "m"(*__xg(ptr)), "0"(old)
+                                    : "memory");
+               return prev;
+       case 2:
+               __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
+                                    : "=a"(prev)
+                                    : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                    : "memory");
+               return prev;
+       case 4:
+               __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %1,%2"
+                                    : "=a"(prev)
+                                    : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                    : "memory");
+               return prev;
+       }
+       return old;
+}
+
+#ifndef CONFIG_X86_CMPXCHG
+/*
+ * Building a kernel capable running on 80386. It may be necessary to
+ * simulate the cmpxchg on the 80386 CPU. For that purpose we define
+ * a function for each of the sizes we support.
+ */
+
+extern unsigned long cmpxchg_386_u8(volatile void *, u8, u8);
+extern unsigned long cmpxchg_386_u16(volatile void *, u16, u16);
+extern unsigned long cmpxchg_386_u32(volatile void *, u32, u32);
+
+static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
+                                     unsigned long new, int size)
+{
+       switch (size) {
+       case 1:
+               return cmpxchg_386_u8(ptr, old, new);
+       case 2:
+               return cmpxchg_386_u16(ptr, old, new);
+       case 4:
+               return cmpxchg_386_u32(ptr, old, new);
+       }
+       return old;
+}
+
+#define cmpxchg(ptr,o,n)                                               \
+({                                                                     \
+       __typeof__(*(ptr)) __ret;                                       \
+       if (likely(boot_cpu_data.x86 > 3))                              \
+               __ret = __cmpxchg((ptr), (unsigned long)(o),            \
+                                       (unsigned long)(n), sizeof(*(ptr))); \
+       else                                                            \
+               __ret = cmpxchg_386((ptr), (unsigned long)(o),          \
+                                       (unsigned long)(n), sizeof(*(ptr))); \
+       __ret;                                                          \
+})
+#endif
+
+#ifdef CONFIG_X86_CMPXCHG64
+
+static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long long old,
+                                     unsigned long long new)
+{
+       unsigned long long prev;
+       __asm__ __volatile__(LOCK_PREFIX "cmpxchg8b %3"
+                            : "=A"(prev)
+                            : "b"((unsigned long)new),
+                              "c"((unsigned long)(new >> 32)),
+                              "m"(*__xg(ptr)),
+                              "0"(old)
+                            : "memory");
+       return prev;
+}
+
+#define cmpxchg64(ptr,o,n)\
+       ((__typeof__(*(ptr)))__cmpxchg64((ptr),(unsigned long long)(o),\
+                                       (unsigned long long)(n)))
+
+#endif
+    
+/*
+ * Force strict CPU ordering.
+ * And yes, this is required on UP too when we're talking
+ * to devices.
+ *
+ * For now, "wmb()" doesn't actually do anything, as all
+ * Intel CPU's follow what Intel calls a *Processor Order*,
+ * in which all writes are seen in the program order even
+ * outside the CPU.
+ *
+ * I expect future Intel CPU's to have a weaker ordering,
+ * but I'd also expect them to finally get their act together
+ * and add some real memory barriers if so.
+ *
+ * Some non intel clones support out of order store. wmb() ceases to be a
+ * nop for these.
+ */
+
+/* 
+ * Actually only lfence would be needed for mb() because all stores done 
+ * by the kernel should be already ordered. But keep a full barrier for now. 
+ */
+
+#define mb() alternative("lock; addl $0,0(%%esp)", "mfence", X86_FEATURE_XMM2)
+#define rmb() alternative("lock; addl $0,0(%%esp)", "lfence", X86_FEATURE_XMM2)
+
+/**
+ * read_barrier_depends - Flush all pending reads that subsequents reads
+ * depend on.
+ *
+ * No data-dependent reads from memory-like regions are ever reordered
+ * over this barrier.  All reads preceding this primitive are guaranteed
+ * to access memory (but not necessarily other CPUs' caches) before any
+ * reads following this primitive that depend on the data return by
+ * any of the preceding reads.  This primitive is much lighter weight than
+ * rmb() on most CPUs, and is never heavier weight than is
+ * rmb().
+ *
+ * These ordering constraints are respected by both the local CPU
+ * and the compiler.
+ *
+ * Ordering is not guaranteed by anything other than these primitives,
+ * not even by data dependencies.  See the documentation for
+ * memory_barrier() for examples and URLs to more information.
+ *
+ * For example, the following code would force ordering (the initial
+ * value of "a" is zero, "b" is one, and "p" is "&a"):
+ *
+ * <programlisting>
+ *     CPU 0                           CPU 1
+ *
+ *     b = 2;
+ *     memory_barrier();
+ *     p = &b;                         q = p;
+ *                                     read_barrier_depends();
+ *                                     d = *q;
+ * </programlisting>
+ *
+ * because the read of "*q" depends on the read of "p" and these
+ * two reads are separated by a read_barrier_depends().  However,
+ * the following code, with the same initial values for "a" and "b":
+ *
+ * <programlisting>
+ *     CPU 0                           CPU 1
+ *
+ *     a = 2;
+ *     memory_barrier();
+ *     b = 3;                          y = b;
+ *                                     read_barrier_depends();
+ *                                     x = a;
+ * </programlisting>
+ *
+ * does not enforce ordering, since there is no data dependency between
+ * the read of "a" and the read of "b".  Therefore, on some CPUs, such
+ * as Alpha, "y" could be set to 3 and "x" to 0.  Use rmb()
+ * in cases like thiswhere there are no data dependencies.
+ **/
+
+#define read_barrier_depends() do { } while(0)
+
+#ifdef CONFIG_X86_OOSTORE
+/* Actually there are no OOO store capable CPUs for now that do SSE, 
+   but make it already an possibility. */
+#define wmb() alternative("lock; addl $0,0(%%esp)", "sfence", X86_FEATURE_XMM)
+#else
+#define wmb()  __asm__ __volatile__ ("": : :"memory")
+#endif
+
+#ifdef CONFIG_SMP
+#define smp_mb()       mb()
+#define smp_rmb()      rmb()
+#define smp_wmb()      wmb()
+#define smp_read_barrier_depends()     read_barrier_depends()
+#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
+#else
+#define smp_mb()       barrier()
+#define smp_rmb()      barrier()
+#define smp_wmb()      barrier()
+#define smp_read_barrier_depends()     do { } while(0)
+#define set_mb(var, value) do { var = value; barrier(); } while (0)
+#endif
+
+#define set_wmb(var, value) do { var = value; wmb(); } while (0)
+
+/* interrupt control.. */
+
+/* 
+ * The use of 'barrier' in the following reflects their use as local-lock
+ * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following
+ * critical operations are executed. All critical operations must complete
+ * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also
+ * includes these barriers, for example.
+ */
+
+#define __cli()                                                                \
+do {                                                                   \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       _vcpu->evtchn_upcall_mask = 1;                                  \
+       preempt_enable_no_resched();                                    \
+       barrier();                                                      \
+} while (0)
+
+#define __sti()                                                                \
+do {                                                                   \
+       vcpu_info_t *_vcpu;                                             \
+       barrier();                                                      \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       _vcpu->evtchn_upcall_mask = 0;                                  \
+       barrier(); /* unmask then check (avoid races) */                \
+       if (unlikely(_vcpu->evtchn_upcall_pending))                     \
+               force_evtchn_callback();                                \
+       preempt_enable();                                               \
+} while (0)
+
+#define __save_flags(x)                                                        \
+do {                                                                   \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       (x) = _vcpu->evtchn_upcall_mask;                                \
+       preempt_enable();                                               \
+} while (0)
+
+#define __restore_flags(x)                                             \
+do {                                                                   \
+       vcpu_info_t *_vcpu;                                             \
+       barrier();                                                      \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       if ((_vcpu->evtchn_upcall_mask = (x)) == 0) {                   \
+               barrier(); /* unmask then check (avoid races) */        \
+               if (unlikely(_vcpu->evtchn_upcall_pending))             \
+                       force_evtchn_callback();                        \
+               preempt_enable();                                       \
+       } else                                                          \
+               preempt_enable_no_resched();                            \
+} while (0)
+
+void safe_halt(void);
+void halt(void);
+
+#define __save_and_cli(x)                                              \
+do {                                                                   \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       (x) = _vcpu->evtchn_upcall_mask;                                \
+       _vcpu->evtchn_upcall_mask = 1;                                  \
+       preempt_enable_no_resched();                                    \
+       barrier();                                                      \
+} while (0)
+
+#define local_irq_save(x)      __save_and_cli(x)
+#define local_irq_restore(x)   __restore_flags(x)
+#define local_save_flags(x)    __save_flags(x)
+#define local_irq_disable()    __cli()
+#define local_irq_enable()     __sti()
+
+/* Cannot use preempt_enable() here as we would recurse in preempt_sched(). */
+#define irqs_disabled()                                                        \
+({     int ___x;                                                       \
+       vcpu_info_t *_vcpu;                                             \
+       preempt_disable();                                              \
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];          \
+       ___x = (_vcpu->evtchn_upcall_mask != 0);                        \
+       preempt_enable_no_resched();                                    \
+       ___x; })
+
+/*
+ * disable hlt during certain critical i/o operations
+ */
+#define HAVE_DISABLE_HLT
+void disable_hlt(void);
+void enable_hlt(void);
+
+extern int es7000_plat;
+void cpu_idle_wait(void);
+
+/*
+ * On SMP systems, when the scheduler does migration-cost autodetection,
+ * it needs a way to flush as much of the CPU's caches as possible:
+ */
+static inline void sched_cacheflush(void)
+{
+       wbinvd();
+}
+
+extern unsigned long arch_align_stack(unsigned long sp);
+extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
+
+void default_idle(void);
+
+#endif