1 files changed, 105 insertions, 0 deletions
diff --git a/include/lib/bakery_lock.h b/include/lib/bakery_lock.h
new file mode 100644
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--- /dev/null
+++ b/include/lib/bakery_lock.h
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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 __ASSEMBLER__
+#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 /* __ASSEMBLER__ */
+#endif /* BAKERY_LOCK_H */