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/******************************************************************************
* os.h
*
* random collection of macros and definition
*/
#ifndef _OS_H_
#define _OS_H_
#define NULL 0
/*
* These are the segment descriptors provided for us by the hypervisor.
* For now, these are hardwired -- guest OSes cannot update the GDT
* or LDT.
*
* It shouldn't be hard to support descriptor-table frobbing -- let me
* know if the BSD or XP ports require flexibility here.
*/
/*
* these are also defined in hypervisor-if.h but can't be pulled in as
* they are used in start of day assembly. Need to clean up the .h files
* a bit more...
*/
#ifndef FLAT_RING1_CS
#define FLAT_RING1_CS 0x0819
#define FLAT_RING1_DS 0x0821
#define FLAT_RING3_CS 0x082b
#define FLAT_RING3_DS 0x0833
#endif
#define __KERNEL_CS FLAT_RING1_CS
#define __KERNEL_DS FLAT_RING1_DS
/* Everything below this point is not included by assembler (.S) files. */
#ifndef __ASSEMBLY__
#include <types.h>
#include <hypervisor-ifs/hypervisor-if.h>
/* this struct defines the way the registers are stored on the
stack during an exception or interrupt. */
struct pt_regs {
long ebx;
long ecx;
long edx;
long esi;
long edi;
long ebp;
long eax;
int xds;
int xes;
long orig_eax;
long eip;
int xcs;
long eflags;
long esp;
int xss;
};
/*
* STI/CLI equivalents. These basically set and clear the virtual
* event_enable flag in teh 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 unlikely(x) __builtin_expect((x),0)
#define __save_flags(x) \
do { \
(x) = test_bit(EVENTS_MASTER_ENABLE_BIT, \
&HYPERVISOR_shared_info->events_mask); \
barrier(); \
} while (0)
#define __restore_flags(x) \
do { \
shared_info_t *_shared = HYPERVISOR_shared_info; \
if (x) set_bit(EVENTS_MASTER_ENABLE_BIT, &_shared->events_mask); \
barrier(); \
if ( unlikely(_shared->events) && (x) ) do_hypervisor_callback(NULL); \
} while (0)
#define __cli() \
do { \
clear_bit(EVENTS_MASTER_ENABLE_BIT, &HYPERVISOR_shared_info->events_mask);\
barrier(); \
} while (0)
#define __sti() \
do { \
shared_info_t *_shared = HYPERVISOR_shared_info; \
set_bit(EVENTS_MASTER_ENABLE_BIT, &_shared->events_mask); \
barrier(); \
if ( unlikely(_shared->events) ) do_hypervisor_callback(NULL); \
} 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 save_and_sti(x) __save_and_sti(x)
/* 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;
/*
* This XCHG macro is straight from Linux. It is gross.
*/
#define xchg(ptr,v) \
((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((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));
}
/* useful hypervisor macros */
struct desc_struct {
unsigned long a,b;
};
extern struct desc_struct default_ldt[];
#define asmlinkage __attribute__((regparm(0)))
/*
* some random linux macros
*/
#define rdtscll(val) \
__asm__ __volatile__("rdtsc" : "=A" (val))
#endif /* !__ASSEMBLY__ */
#endif /* _OS_H_ */
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