a9973e913d
Previously, futex code of McKerenl was called by mccontrol, but there ware some problems with this method. (Mainly, location of McKernel image on memory) Call futex code in mcctrl instead of the one in McKernel image, giving the following benefits: 1. Not relying on shared kernel virtual address space with Linux any more 2. The cpu id store / retrieve is not needed and resulting in the code Change-Id: Ic40929b64a655b270c435859fa287fedb713ee5c refe: #1428
107 lines
2.2 KiB
C
107 lines
2.2 KiB
C
/* This is copy of the necessary part from McKernel, for uti-futex */
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#ifndef __HEADER_X86_COMMON_ARCH_LOCK
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#define __HEADER_X86_COMMON_ARCH_LOCK
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#include <linux/preempt.h>
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#include <cpu.h>
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#define ihk_mc_spinlock_lock __ihk_mc_spinlock_lock
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#define ihk_mc_spinlock_unlock __ihk_mc_spinlock_unlock
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#define ihk_mc_spinlock_lock_noirq __ihk_mc_spinlock_lock_noirq
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#define ihk_mc_spinlock_unlock_noirq __ihk_mc_spinlock_unlock_noirq
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typedef unsigned short __ticket_t;
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typedef unsigned int __ticketpair_t;
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/* arch/x86/include/asm/spinlock_types.h defines struct __raw_tickets */
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typedef struct ihk_spinlock {
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union {
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__ticketpair_t head_tail;
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struct ihk__raw_tickets {
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__ticket_t head, tail;
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} tickets;
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};
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} _ihk_spinlock_t;
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static inline void ihk_mc_spinlock_init(_ihk_spinlock_t *lock)
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{
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lock->head_tail = 0;
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}
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static inline void __ihk_mc_spinlock_lock_noirq(_ihk_spinlock_t *lock)
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{
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register struct ihk__raw_tickets inc = { .tail = 0x0002 };
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preempt_disable();
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asm volatile ("lock xaddl %0, %1\n"
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: "+r" (inc), "+m" (*(lock)) : : "memory", "cc");
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if (inc.head == inc.tail)
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goto out;
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for (;;) {
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if (*((volatile __ticket_t *)&lock->tickets.head) == inc.tail)
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goto out;
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cpu_pause();
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}
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out:
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barrier(); /* make sure nothing creeps before the lock is taken */
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}
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static inline void __ihk_mc_spinlock_unlock_noirq(_ihk_spinlock_t *lock)
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{
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__ticket_t inc = 0x0002;
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asm volatile ("lock addw %1, %0\n"
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: "+m" (lock->tickets.head)
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: "ri" (inc) : "memory", "cc");
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preempt_enable();
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}
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static inline unsigned long __ihk_mc_spinlock_lock(_ihk_spinlock_t *lock)
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{
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unsigned long flags;
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flags = cpu_disable_interrupt_save();
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__ihk_mc_spinlock_lock_noirq(lock);
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return flags;
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}
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static inline void __ihk_mc_spinlock_unlock(_ihk_spinlock_t *lock,
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unsigned long flags)
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{
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__ihk_mc_spinlock_unlock_noirq(lock);
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cpu_restore_interrupt(flags);
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}
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typedef struct mcs_rwlock_lock {
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_ihk_spinlock_t slock;
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#ifndef ENABLE_UBSAN
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} __aligned(64) mcs_rwlock_lock_t;
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#else
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} mcs_rwlock_lock_t;
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#endif
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static inline void
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mcs_rwlock_writer_lock_noirq(struct mcs_rwlock_lock *lock)
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{
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ihk_mc_spinlock_lock_noirq(&lock->slock);
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}
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static inline void
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mcs_rwlock_writer_unlock_noirq(struct mcs_rwlock_lock *lock)
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{
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ihk_mc_spinlock_unlock_noirq(&lock->slock);
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}
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#endif
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