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/*
* Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef BAKERY_LOCK_H
#define BAKERY_LOCK_H
#include <platform_def.h>
#define BAKERY_LOCK_MAX_CPUS PLATFORM_CORE_COUNT
#ifndef __ASSEMBLY__
#include <cdefs.h>
#include <stdbool.h>
#include <stdint.h>
#include <lib/utils_def.h>
/*****************************************************************************
* Internal helpers used by the bakery lock implementation.
****************************************************************************/
/* Convert a ticket to priority */
static inline unsigned int bakery_get_priority(unsigned int t, unsigned int pos)
{
return (t << 8) | pos;
}
#define CHOOSING_TICKET U(0x1)
#define CHOSEN_TICKET U(0x0)
static inline bool bakery_is_choosing(unsigned int info)
{
return (info & 1U) == CHOOSING_TICKET;
}
static inline unsigned int bakery_ticket_number(unsigned int info)
{
return (info >> 1) & 0x7FFFU;
}
static inline uint16_t make_bakery_data(unsigned int choosing, unsigned int num)
{
unsigned int val = (choosing & 0x1U) | (num << 1);
return (uint16_t) val;
}
/*****************************************************************************
* External bakery lock interface.
****************************************************************************/
#if USE_COHERENT_MEM
/*
* Bakery locks are stored in coherent memory
*
* Each lock's data is contiguous and fully allocated by the compiler
*/
typedef struct bakery_lock {
/*
* The lock_data is a bit-field of 2 members:
* Bit[0] : choosing. This field is set when the CPU is
* choosing its bakery number.
* Bits[1 - 15] : number. This is the bakery number allocated.
*/
volatile uint16_t lock_data[BAKERY_LOCK_MAX_CPUS];
} bakery_lock_t;
#else
/*
* Bakery locks are stored in normal .bss memory
*
* Each lock's data is spread across multiple cache lines, one per CPU,
* but multiple locks can share the same cache line.
* The compiler will allocate enough memory for one CPU's bakery locks,
* the remaining cache lines are allocated by the linker script
*/
typedef struct bakery_info {
/*
* The lock_data is a bit-field of 2 members:
* Bit[0] : choosing. This field is set when the CPU is
* choosing its bakery number.
* Bits[1 - 15] : number. This is the bakery number allocated.
*/
volatile uint16_t lock_data;
} bakery_info_t;
typedef bakery_info_t bakery_lock_t;
#endif /* __USE_COHERENT_MEM__ */
static inline void bakery_lock_init(bakery_lock_t *bakery) {}
void bakery_lock_get(bakery_lock_t *bakery);
void bakery_lock_release(bakery_lock_t *bakery);
#define DEFINE_BAKERY_LOCK(_name) bakery_lock_t _name __section("bakery_lock")
#define DECLARE_BAKERY_LOCK(_name) extern bakery_lock_t _name
#endif /* __ASSEMBLY__ */
#endif /* BAKERY_LOCK_H */