1 /* 2 ** Copyright 2002/03, Thomas Kurschel. All rights reserved. 3 ** Distributed under the terms of the OpenBeOS License. 4 */ 5 6 /* 7 Part of Open SCSI bus manager 8 9 Special locks 10 11 The only one defined herein is a spinlock that automatically 12 disabled IRQs on enter and restores them on leave. Probably, 13 this should be made public as it's quite basic. 14 */ 15 16 #ifndef __SCSI_LOCK_H__ 17 #define __SCSI_LOCK_H__ 18 19 #include <KernelExport.h> 20 21 22 // enhanced spinlock that automatically disables irqs when lock is hold 23 typedef struct spinlock_irq { 24 spinlock lock; // normal spinlock 25 cpu_status prev_irq_state; // irq state before spinlock was entered 26 } spinlock_irq; 27 28 29 static inline void 30 spinlock_irq_init(spinlock_irq *lock) 31 { 32 B_INITIALIZE_SPINLOCK(&lock->lock); 33 } 34 35 static inline void 36 acquire_spinlock_irq(spinlock_irq *lock) 37 { 38 cpu_status prev_irq_state = disable_interrupts(); 39 40 acquire_spinlock(&lock->lock); 41 lock->prev_irq_state = prev_irq_state; 42 } 43 44 static inline void 45 release_spinlock_irq(spinlock_irq *lock) 46 { 47 cpu_status prev_irq_state = lock->prev_irq_state; 48 49 release_spinlock(&lock->lock); 50 restore_interrupts(prev_irq_state); 51 } 52 53 #endif 54