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/******************************************************************************
* os.h
*
* random collection of macros and definition
*
* $FreeBSD$
*/
#ifndef _XEN_OS_H_
#define _XEN_OS_H_
#ifdef PAE
#define CONFIG_X86_PAE
#endif
#if !defined(__XEN_INTERFACE_VERSION__)
/*
* Can update to a more recent version when we implement
* the hypercall page
*/
#define __XEN_INTERFACE_VERSION__ 0x00030204
#endif
#include <xen/interface/xen.h>
/* Force a proper event-channel callback from Xen. */
void force_evtchn_callback(void);
extern int gdtset;
extern shared_info_t *HYPERVISOR_shared_info;
/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
static inline void rep_nop(void)
{
__asm__ __volatile__ ( "rep;nop" : : : "memory" );
}
#define cpu_relax() rep_nop()
/* crude memory allocator for memory allocation early in
* boot
*/
void *bootmem_alloc(unsigned int size);
void bootmem_free(void *ptr, unsigned int size);
/* Everything below this point is not included by assembler (.S) files. */
#ifndef __ASSEMBLY__
void printk(const char *fmt, ...);
/* some function prototypes */
void trap_init(void);
#define likely(x) __builtin_expect((x),1)
#define unlikely(x) __builtin_expect((x),0)
#ifndef XENHVM
/*
* STI/CLI equivalents. These basically set and clear the virtual
* event_enable flag in the shared_info structure. Note that when
* the enable bit is set, there may be pending events to be handled.
* We may therefore call into do_hypervisor_callback() directly.
*/
#define __cli() \
do { \
vcpu_info_t *_vcpu; \
_vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \
_vcpu->evtchn_upcall_mask = 1; \
barrier(); \
} while (0)
#define __sti() \
do { \
vcpu_info_t *_vcpu; \
barrier(); \
_vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \
_vcpu->evtchn_upcall_mask = 0; \
barrier(); /* unmask then check (avoid races) */ \
if ( unlikely(_vcpu->evtchn_upcall_pending) ) \
force_evtchn_callback(); \
} while (0)
#define __restore_flags(x) \
do { \
vcpu_info_t *_vcpu; \
barrier(); \
_vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \
if ((_vcpu->evtchn_upcall_mask = (x)) == 0) { \
barrier(); /* unmask then check (avoid races) */ \
if ( unlikely(_vcpu->evtchn_upcall_pending) ) \
force_evtchn_callback(); \
} \
} while (0)
/*
* Add critical_{enter, exit}?
*
*/
#define __save_and_cli(x) \
do { \
vcpu_info_t *_vcpu; \
_vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \
(x) = _vcpu->evtchn_upcall_mask; \
_vcpu->evtchn_upcall_mask = 1; \
barrier(); \
} while (0)
#define cli() __cli()
#define sti() __sti()
#define save_flags(x) __save_flags(x)
#define restore_flags(x) __restore_flags(x)
#define save_and_cli(x) __save_and_cli(x)
#define local_irq_save(x) __save_and_cli(x)
#define local_irq_restore(x) __restore_flags(x)
#define local_irq_disable() __cli()
#define local_irq_enable() __sti()
#define mtx_lock_irqsave(lock, x) {local_irq_save((x)); mtx_lock_spin((lock));}
#define mtx_unlock_irqrestore(lock, x) {mtx_unlock_spin((lock)); local_irq_restore((x)); }
#define spin_lock_irqsave mtx_lock_irqsave
#define spin_unlock_irqrestore mtx_unlock_irqrestore
#else
#endif
#ifndef mb
#define mb() __asm__ __volatile__("mfence":::"memory")
#endif
#ifndef rmb
#define rmb() __asm__ __volatile__("lfence":::"memory");
#endif
#ifndef wmb
#define wmb() barrier()
#endif
#ifdef 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 { 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
/* This is a barrier for the compiler only, NOT the processor! */
#define barrier() __asm__ __volatile__("": : :"memory")
#define LOCK_PREFIX ""
#define LOCK ""
#define ADDR (*(volatile long *) addr)
/*
* Make sure gcc doesn't try to be clever and move things around
* on us. We need to use _exactly_ the address the user gave us,
* not some alias that contains the same information.
*/
typedef struct { volatile int counter; } atomic_t;
#define xen_xchg(ptr,v) \
((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x))
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;
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static __inline int test_and_clear_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btrl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
static __inline int constant_test_bit(int nr, const volatile void * addr)
{
return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
}
static __inline int variable_test_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__(
"btl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit)
:"m" (ADDR),"Ir" (nr));
return oldbit;
}
#define test_bit(nr,addr) \
(__builtin_constant_p(nr) ? \
constant_test_bit((nr),(addr)) : \
variable_test_bit((nr),(addr)))
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This function is atomic and may not be reordered. See __set_bit()
* if you do not require the atomic guarantees.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static __inline__ void set_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btsl %1,%0"
:"=m" (ADDR)
:"Ir" (nr));
}
/**
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* clear_bit() is atomic and may not be reordered. However, it does
* not contain a memory barrier, so if it is used for locking purposes,
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
static __inline__ void clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btrl %1,%0"
:"=m" (ADDR)
:"Ir" (nr));
}
/**
* atomic_inc - increment atomic variable
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1. Note that the guaranteed
* useful range of an atomic_t is only 24 bits.
*/
static __inline__ void atomic_inc(atomic_t *v)
{
__asm__ __volatile__(
LOCK "incl %0"
:"=m" (v->counter)
:"m" (v->counter));
}
#define rdtscll(val) \
__asm__ __volatile__("rdtsc" : "=A" (val))
#endif /* !__ASSEMBLY__ */
#endif /* _OS_H_ */
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