kern: Introduce high-level spinlock interface

Signed-off-by: Ian Moffett <ian@osmora.org>

2 files changed, 146 insertions, 0 deletions

diff --git a/sys/inc/kern/spinlock.h b/sys/inc/kern/spinlock.h
new file mode 100644
index 0000000..76a2c3f
--- /dev/null
+++ b/sys/inc/kern/spinlock.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _KERN_SPINLOCK_H_
+#define _KERN_SPINLOCK_H_ 1
+
+#include <sys/types.h>
+#include <lib/stdbool.h>
+
+#define SPINLOCK_NAMELEN 32
+
+struct spinlock {
+    char name[SPINLOCK_NAMELEN];
+    volatile size_t lock;
+};
+
+/*
+ * Initialize a named spinlock
+ *
+ * @name: Spinlock name
+ * @lock: Lock to initialize
+ *
+ * Returns zero on success
+ */
+int spinlock_init(const char *name, struct spinlock *lock);
+
+/*
+ * Acquire a spinlock
+ *
+ * @lock: Lock to acquire
+ * @irqclr: Mask interrupts
+ */
+void spinlock_acquire(struct spinlock *lock, bool irqclr);
+
+/*
+ * Release a spinlock
+ *
+ * @lock: Lock to release
+ * @irqset: Unmask interrupts
+ */
+void spinlock_release(struct spinlock *lock, bool irqset);
+
+#endif  /* !_KERN_SPINLOCK_H_ */
diff --git a/sys/kern/kern_spinlock.c b/sys/kern/kern_spinlock.c
new file mode 100644
index 0000000..85dee80
--- /dev/null
+++ b/sys/kern/kern_spinlock.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/errno.h>
+#include <mu/spinlock.h>
+#include <kern/spinlock.h>
+#include <lib/string.h>
+
+int
+spinlock_init(const char *name, struct spinlock *lock)
+{
+    size_t name_len;
+
+    if (name == NULL || lock == NULL) {
+        return -EINVAL;
+    }
+
+    name_len = strlen(name);
+    if (name_len >= SPINLOCK_NAMELEN - 1) {
+        return -ENAMETOOLONG;
+    }
+
+    memcpy(lock->name, name, name_len);
+    lock->name[name_len] = '\0';
+    lock->lock = 0;
+    return 0;
+}
+
+void
+spinlock_acquire(struct spinlock *lock, bool irqclr)
+{
+    int flags = 0;
+
+    if (irqclr) {
+        flags |= SPINLOCK_INTTOG;
+    }
+
+    mu_spinlock_acq(&lock->lock, flags);
+}
+
+void
+spinlock_release(struct spinlock *lock, bool irqset)
+{
+    int flags = 0;
+
+    if (irqset) {
+        flags |= SPINLOCK_INTTOG;
+    }
+
+    mu_spinlock_rel(&lock->lock, flags);
+}