spinlock.h File Reference

#include <asm/alternative.h>
#include <asm/lse.h>
#include <asm/rwonce.h>

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Classes
union	hyp_spinlock

Macros
#define	__HYP_SPIN_LOCK_INITIALIZER    { .__val = 0 }
#define	__HYP_SPIN_LOCK_UNLOCKED    ((hyp_spinlock_t) __HYP_SPIN_LOCK_INITIALIZER)
#define	DEFINE_HYP_SPINLOCK(x)   hyp_spinlock_t x = __HYP_SPIN_LOCK_UNLOCKED
#define	hyp_spin_lock_init(l)

Typedefs
typedef union hyp_spinlock	hyp_spinlock_t

Functions
static void	hyp_spin_lock (hyp_spinlock_t *lock)
static void	hyp_spin_unlock (hyp_spinlock_t *lock)
static bool	hyp_spin_is_locked (hyp_spinlock_t *lock)
static void	hyp_assert_lock_held (hyp_spinlock_t *lock)

Macro Definition Documentation

__HYP_SPIN_LOCK_INITIALIZER

#define __HYP_SPIN_LOCK_INITIALIZER    { .__val = 0 }

Definition at line 31 of file spinlock.h.

__HYP_SPIN_LOCK_UNLOCKED

#define __HYP_SPIN_LOCK_UNLOCKED    ((hyp_spinlock_t) __HYP_SPIN_LOCK_INITIALIZER)

Definition at line 34 of file spinlock.h.

DEFINE_HYP_SPINLOCK

#define DEFINE_HYP_SPINLOCK

(

x

)

hyp_spinlock_t x = __HYP_SPIN_LOCK_UNLOCKED

Definition at line 37 of file spinlock.h.

hyp_spin_lock_init

#define hyp_spin_lock_init

(

l

)

Value:

do {                                    \
    *(l) = __HYP_SPIN_LOCK_UNLOCKED;                \
} while (0)

Definition at line 39 of file spinlock.h.

Typedef Documentation

hyp_spinlock_t

typedef union hyp_spinlock hyp_spinlock_t

Function Documentation

hyp_assert_lock_held()

static void hyp_assert_lock_held ( hyp_spinlock_t *  lock )

inlinestatic

Definition at line 122 of file spinlock.h.

{ }

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hyp_spin_is_locked()

static bool hyp_spin_is_locked ( hyp_spinlock_t *  lock )

inlinestatic

Definition at line 101 of file spinlock.h.

{
    hyp_spinlock_t lockval = READ_ONCE(*lock);
 
    return lockval.owner != lockval.next;
}

hyp_spin_lock()

static void hyp_spin_lock ( hyp_spinlock_t *  lock )

inlinestatic

Definition at line 44 of file spinlock.h.

{
    u32 tmp;
    hyp_spinlock_t lockval, newval;
 
    asm volatile(
    /* Atomically increment the next ticket. */
    ARM64_LSE_ATOMIC_INSN(
    /* LL/SC */
"   prfm    pstl1strm, %3\n"
"1: ldaxr   %w0, %3\n"
"   add %w1, %w0, #(1 << 16)\n"
"   stxr    %w2, %w1, %3\n"
"   cbnz    %w2, 1b\n",
    /* LSE atomics */
"   mov %w2, #(1 << 16)\n"
"   ldadda  %w2, %w0, %3\n"
    __nops(3))
 
    /* Did we get the lock? */
"   eor %w1, %w0, %w0, ror #16\n"
"   cbz %w1, 3f\n"
    /*
     * No: spin on the owner. Send a local event to avoid missing an
     * unlock before the exclusive load.
     */
"   sevl\n"
"2: wfe\n"
"   ldaxrh  %w2, %4\n"
"   eor %w1, %w2, %w0, lsr #16\n"
"   cbnz    %w1, 2b\n"
    /* We got the lock. Critical section starts here. */
"3:"
    : "=&r" (lockval), "=&r" (newval), "=&r" (tmp), "+Q" (*lock)
    : "Q" (lock->owner)
    : "memory");
}

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hyp_spin_unlock()

static void hyp_spin_unlock ( hyp_spinlock_t *  lock )

inlinestatic

Definition at line 82 of file spinlock.h.

{
    u64 tmp;
 
    asm volatile(
    ARM64_LSE_ATOMIC_INSN(
    /* LL/SC */
    "   ldrh    %w1, %0\n"
    "   add %w1, %w1, #1\n"
    "   stlrh   %w1, %0",
    /* LSE atomics */
    "   mov %w1, #1\n"
    "   staddlh %w1, %0\n"
    __nops(1))
    : "=Q" (lock->owner), "=&r" (tmp)
    :
    : "memory");
}

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