1 /****************************************************************************** 2 * os.h 3 * 4 * random collection of macros and definition 5 */ 6 7 #ifndef _XEN_OS_H_ 8 #define _XEN_OS_H_ 9 10 #ifdef PAE 11 #define CONFIG_X86_PAE 12 #endif 13 14 #if !defined(__XEN_INTERFACE_VERSION__) 15 /* 16 * Can update to a more recent version when we implement 17 * the hypercall page 18 */ 19 #define __XEN_INTERFACE_VERSION__ 0x00030204 20 #endif 21 22 #include <xen/interface/xen.h> 23 24 /* Force a proper event-channel callback from Xen. */ 25 void force_evtchn_callback(void); 26 27 extern int gdtset; 28 29 extern shared_info_t *HYPERVISOR_shared_info; 30 31 /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */ 32 static inline void rep_nop(void) 33 { 34 __asm__ __volatile__ ( "rep;nop" : : : "memory" ); 35 } 36 #define cpu_relax() rep_nop() 37 38 /* crude memory allocator for memory allocation early in 39 * boot 40 */ 41 void *bootmem_alloc(unsigned int size); 42 void bootmem_free(void *ptr, unsigned int size); 43 44 45 /* Everything below this point is not included by assembler (.S) files. */ 46 #ifndef __ASSEMBLY__ 47 48 void printk(const char *fmt, ...); 49 50 /* some function prototypes */ 51 void trap_init(void); 52 53 #define likely(x) __builtin_expect((x),1) 54 #define unlikely(x) __builtin_expect((x),0) 55 56 #ifndef XENHVM 57 58 /* 59 * STI/CLI equivalents. These basically set and clear the virtual 60 * event_enable flag in teh shared_info structure. Note that when 61 * the enable bit is set, there may be pending events to be handled. 62 * We may therefore call into do_hypervisor_callback() directly. 63 */ 64 65 #define __cli() \ 66 do { \ 67 vcpu_info_t *_vcpu; \ 68 _vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \ 69 _vcpu->evtchn_upcall_mask = 1; \ 70 barrier(); \ 71 } while (0) 72 73 #define __sti() \ 74 do { \ 75 vcpu_info_t *_vcpu; \ 76 barrier(); \ 77 _vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \ 78 _vcpu->evtchn_upcall_mask = 0; \ 79 barrier(); /* unmask then check (avoid races) */ \ 80 if ( unlikely(_vcpu->evtchn_upcall_pending) ) \ 81 force_evtchn_callback(); \ 82 } while (0) 83 84 #define __restore_flags(x) \ 85 do { \ 86 vcpu_info_t *_vcpu; \ 87 barrier(); \ 88 _vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \ 89 if ((_vcpu->evtchn_upcall_mask = (x)) == 0) { \ 90 barrier(); /* unmask then check (avoid races) */ \ 91 if ( unlikely(_vcpu->evtchn_upcall_pending) ) \ 92 force_evtchn_callback(); \ 93 } \ 94 } while (0) 95 96 /* 97 * Add critical_{enter, exit}? 98 * 99 */ 100 #define __save_and_cli(x) \ 101 do { \ 102 vcpu_info_t *_vcpu; \ 103 _vcpu = &HYPERVISOR_shared_info->vcpu_info[PCPU_GET(cpuid)]; \ 104 (x) = _vcpu->evtchn_upcall_mask; \ 105 _vcpu->evtchn_upcall_mask = 1; \ 106 barrier(); \ 107 } while (0) 108 109 110 #define cli() __cli() 111 #define sti() __sti() 112 #define save_flags(x) __save_flags(x) 113 #define restore_flags(x) __restore_flags(x) 114 #define save_and_cli(x) __save_and_cli(x) 115 116 #define local_irq_save(x) __save_and_cli(x) 117 #define local_irq_restore(x) __restore_flags(x) 118 #define local_irq_disable() __cli() 119 #define local_irq_enable() __sti() 120 121 #define mtx_lock_irqsave(lock, x) {local_irq_save((x)); mtx_lock_spin((lock));} 122 #define mtx_unlock_irqrestore(lock, x) {mtx_unlock_spin((lock)); local_irq_restore((x)); } 123 #define spin_lock_irqsave mtx_lock_irqsave 124 #define spin_unlock_irqrestore mtx_unlock_irqrestore 125 126 #else 127 #endif 128 129 #ifndef mb 130 #define mb() __asm__ __volatile__("mfence":::"memory") 131 #endif 132 #ifndef rmb 133 #define rmb() __asm__ __volatile__("lfence":::"memory"); 134 #endif 135 #ifndef wmb 136 #define wmb() barrier() 137 #endif 138 #ifdef SMP 139 #define smp_mb() mb() 140 #define smp_rmb() rmb() 141 #define smp_wmb() wmb() 142 #define smp_read_barrier_depends() read_barrier_depends() 143 #define set_mb(var, value) do { xchg(&var, value); } while (0) 144 #else 145 #define smp_mb() barrier() 146 #define smp_rmb() barrier() 147 #define smp_wmb() barrier() 148 #define smp_read_barrier_depends() do { } while(0) 149 #define set_mb(var, value) do { var = value; barrier(); } while (0) 150 #endif 151 152 153 /* This is a barrier for the compiler only, NOT the processor! */ 154 #define barrier() __asm__ __volatile__("": : :"memory") 155 156 #define LOCK_PREFIX "" 157 #define LOCK "" 158 #define ADDR (*(volatile long *) addr) 159 /* 160 * Make sure gcc doesn't try to be clever and move things around 161 * on us. We need to use _exactly_ the address the user gave us, 162 * not some alias that contains the same information. 163 */ 164 typedef struct { volatile int counter; } atomic_t; 165 166 167 168 #define xen_xchg(ptr,v) \ 169 ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr)))) 170 struct __xchg_dummy { unsigned long a[100]; }; 171 #define __xg(x) ((volatile struct __xchg_dummy *)(x)) 172 static __inline unsigned long __xchg(unsigned long x, volatile void * ptr, 173 int size) 174 { 175 switch (size) { 176 case 1: 177 __asm__ __volatile__("xchgb %b0,%1" 178 :"=q" (x) 179 :"m" (*__xg(ptr)), "0" (x) 180 :"memory"); 181 break; 182 case 2: 183 __asm__ __volatile__("xchgw %w0,%1" 184 :"=r" (x) 185 :"m" (*__xg(ptr)), "0" (x) 186 :"memory"); 187 break; 188 case 4: 189 __asm__ __volatile__("xchgl %0,%1" 190 :"=r" (x) 191 :"m" (*__xg(ptr)), "0" (x) 192 :"memory"); 193 break; 194 } 195 return x; 196 } 197 198 /** 199 * test_and_clear_bit - Clear a bit and return its old value 200 * @nr: Bit to set 201 * @addr: Address to count from 202 * 203 * This operation is atomic and cannot be reordered. 204 * It also implies a memory barrier. 205 */ 206 static __inline int test_and_clear_bit(int nr, volatile void * addr) 207 { 208 int oldbit; 209 210 __asm__ __volatile__( LOCK_PREFIX 211 "btrl %2,%1\n\tsbbl %0,%0" 212 :"=r" (oldbit),"=m" (ADDR) 213 :"Ir" (nr) : "memory"); 214 return oldbit; 215 } 216 217 static __inline int constant_test_bit(int nr, const volatile void * addr) 218 { 219 return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0; 220 } 221 222 static __inline int variable_test_bit(int nr, volatile void * addr) 223 { 224 int oldbit; 225 226 __asm__ __volatile__( 227 "btl %2,%1\n\tsbbl %0,%0" 228 :"=r" (oldbit) 229 :"m" (ADDR),"Ir" (nr)); 230 return oldbit; 231 } 232 233 #define test_bit(nr,addr) \ 234 (__builtin_constant_p(nr) ? \ 235 constant_test_bit((nr),(addr)) : \ 236 variable_test_bit((nr),(addr))) 237 238 239 /** 240 * set_bit - Atomically set a bit in memory 241 * @nr: the bit to set 242 * @addr: the address to start counting from 243 * 244 * This function is atomic and may not be reordered. See __set_bit() 245 * if you do not require the atomic guarantees. 246 * Note that @nr may be almost arbitrarily large; this function is not 247 * restricted to acting on a single-word quantity. 248 */ 249 static __inline__ void set_bit(int nr, volatile void * addr) 250 { 251 __asm__ __volatile__( LOCK_PREFIX 252 "btsl %1,%0" 253 :"=m" (ADDR) 254 :"Ir" (nr)); 255 } 256 257 /** 258 * clear_bit - Clears a bit in memory 259 * @nr: Bit to clear 260 * @addr: Address to start counting from 261 * 262 * clear_bit() is atomic and may not be reordered. However, it does 263 * not contain a memory barrier, so if it is used for locking purposes, 264 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() 265 * in order to ensure changes are visible on other processors. 266 */ 267 static __inline__ void clear_bit(int nr, volatile void * addr) 268 { 269 __asm__ __volatile__( LOCK_PREFIX 270 "btrl %1,%0" 271 :"=m" (ADDR) 272 :"Ir" (nr)); 273 } 274 275 /** 276 * atomic_inc - increment atomic variable 277 * @v: pointer of type atomic_t 278 * 279 * Atomically increments @v by 1. Note that the guaranteed 280 * useful range of an atomic_t is only 24 bits. 281 */ 282 static __inline__ void atomic_inc(atomic_t *v) 283 { 284 __asm__ __volatile__( 285 LOCK "incl %0" 286 :"=m" (v->counter) 287 :"m" (v->counter)); 288 } 289 290 291 #define rdtscll(val) \ 292 __asm__ __volatile__("rdtsc" : "=A" (val)) 293 294 #endif /* !__ASSEMBLY__ */ 295 296 #endif /* _OS_H_ */ 297