Merge pull request #302 from VisorFolks/feature/akashkollipara/301-ba…

…kerylock

<locks> Added support for bakerylock

src/lib/build.mk

@@ -16,6 +16,7 @@ include $(LIB_DIR)/libc/build.mk
 include $(LIB_DIR)/libresource/build.mk
 include $(LIB_DIR)/libsyslog/build.mk
 include $(LIB_DIR)/libccfs/build.mk
+include $(LIB_DIR)/liblocks/build.mk
 #==================================================
 
 include $(LIB_DIR)/libnmath/build.mk

src/lib/liblocks/bakerylock.c

@@ -0,0 +1,44 @@
+
+#include <status.h>
+#include <stdint.h>
+#include <arch.h>
+#include <lock/bakerylock.h>
+
+void bakerylock_acquire(bakerylock_t *key)
+{
+	unsigned int tid = arch_core_index();
+	key->protect[tid] = 1;
+	arch_dmb();
+
+	unsigned int i, n_cust, n_max = 0;
+	for(i = 0; i < N_CORES; i++)
+	{
+		n_cust = key->thread_count[i];
+		n_max = n_cust > n_max ? n_cust : n_max;
+	}
+
+	key->thread_count[tid] = n_max + 1;
+
+	arch_dmb();
+	key->protect[tid] = 0;
+	arch_dmb();
+
+	for(i = 0; i < N_CORES; i++)
+	{
+		while(key->protect[i]);
+		arch_dmb();
+
+		while(key->thread_count[i] && (
+		      (key->thread_count[i] < key->thread_count[tid]) ||
+		       ((key->thread_count[i] == key->thread_count[tid]) &&
+			(i < tid))));
+	}
+}
+
+void bakerylock_release(bakerylock_t *key)
+{
+	unsigned int tid = arch_core_index();
+	arch_dmb();
+	key->thread_count[tid] = 0;
+}
+

src/lib/liblocks/build.mk

@@ -0,0 +1,20 @@
+#
+# CYANCORE LICENSE
+# Copyrights (C) 2024, Cyancore Team
+#
+# File Name		: build.mk
+# Description		: This file accumulates sources of locks
+# Primary Author	: Akash Kollipara [[email protected]]
+# Organisation		: Cyancore Core-Team
+#
+
+LIBLOCKS_PATH	:= $(GET_PATH)
+LIB_OBJS	:=
+
+LIB		+= liblocks.a
+LIB_INCLUDE	+= $(LIBLOCKS_PATH)/include
+DEP_LIBS_ARG	+= -llocks
+
+
+DIR		:= $(LIBLOCKS_PATH)
+include mk/lib.mk

src/lib/liblocks/include/lock/bakerylock.h

@@ -0,0 +1,16 @@
+
+#pragma once
+#define _BAKERYLOCK_H_
+
+#include <stdbool.h>
+
+#pragma pack(1)
+typedef struct
+{
+	volatile uint8_t thread_count[N_CORES];
+	volatile bool protect[N_CORES];
+} bakerylock_t;
+#pragma pack()
+
+extern void bakerylock_acquire(bakerylock_t *);
+extern void bakerylock_release(bakerylock_t *);