kern: os: Add initial kalloc subsystem

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

1 files changed, 94 insertions, 0 deletions

diff --git a/src/sys/os/os_kalloc.c b/src/sys/os/os_kalloc.c
new file mode 100644
index 0000000..53e2e13
--- /dev/null
+++ b/src/sys/os/os_kalloc.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2025 Ian Marco Moffett and L5 engineers
+ * 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 the project 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/panic.h>
+#include <os/kalloc.h>
+#include <os/spinlock.h>
+#include <vm/tlsf.h>
+#include <vm/physseg.h>
+#include <vm/vm.h>
+#include <stdbool.h>
+
+#define KALLOC_POOL_PAGES     (KALLOC_POOL_SZ / DEFAULT_PAGESIZE)
+#define KALLOC_POOL_SZ        0x400000  /* 4 MiB */
+
+void __kalloc_init(void);
+
+static struct spinlock lock;
+static tlsf_t tlsf_ctx;
+static paddr_t pool = 0;
+static void *pool_va = 0;
+static bool is_init = false;
+
+/*
+ * Memory allocation
+ */
+void *
+kalloc(size_t sz)
+{
+    void *tmp;
+
+    if (!is_init) {
+        return NULL;
+    }
+
+    spinlock_acquire(&lock);
+    tmp = tlsf_malloc(tlsf_ctx, sz);
+    spinlock_release(&lock);
+    return tmp;
+}
+
+/*
+ * Memory deallocation
+ */
+void
+kfree(void *ptr)
+{
+    spinlock_acquire(&lock);
+    tlsf_free(tlsf_ctx, ptr);
+    spinlock_release(&lock);
+}
+
+void
+__kalloc_init(void)
+{
+    /* Don't do it twice */
+    if (is_init) {
+        return;
+    }
+
+    pool = vm_alloc_frame(KALLOC_POOL_PAGES);
+    if (pool == 0) {
+        panic("__kalloc_init: could not create pool\n");
+    }
+
+    pool_va = PHYS_TO_VIRT(pool);
+    tlsf_ctx = tlsf_create_with_pool(pool_va, KALLOC_POOL_SZ);
+    is_init = true;
+}