From 08eeb79db14145d83578025e1f0e7f7af460ee25 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sat, 17 May 2025 21:56:07 -0400
Subject: kernel: acpi: Add uACPI port

See https://github.com/uACPI/uACPI/

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/dev/acpi/uacpi/shareable.c | 71 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 sys/dev/acpi/uacpi/shareable.c

(limited to 'sys/dev/acpi/uacpi/shareable.c')

diff --git a/sys/dev/acpi/uacpi/shareable.c b/sys/dev/acpi/uacpi/shareable.c
new file mode 100644
index 0000000..b42660a
--- /dev/null
+++ b/sys/dev/acpi/uacpi/shareable.c
@@ -0,0 +1,71 @@
+#include <uacpi/internal/shareable.h>
+#include <uacpi/internal/stdlib.h>
+#include <uacpi/platform/atomic.h>
+
+#ifndef UACPI_BAREBONES_MODE
+
+#define BUGGED_REFCOUNT 0xFFFFFFFF
+
+void uacpi_shareable_init(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+    shareable->reference_count = 1;
+}
+
+uacpi_bool uacpi_bugged_shareable(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+
+    if (uacpi_unlikely(shareable->reference_count == 0))
+        uacpi_make_shareable_bugged(shareable);
+
+    return uacpi_atomic_load32(&shareable->reference_count) == BUGGED_REFCOUNT;
+}
+
+void uacpi_make_shareable_bugged(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+    uacpi_atomic_store32(&shareable->reference_count, BUGGED_REFCOUNT);
+}
+
+uacpi_u32 uacpi_shareable_ref(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+
+    if (uacpi_unlikely(uacpi_bugged_shareable(shareable)))
+        return BUGGED_REFCOUNT;
+
+    return uacpi_atomic_inc32(&shareable->reference_count) - 1;
+}
+
+uacpi_u32 uacpi_shareable_unref(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+
+    if (uacpi_unlikely(uacpi_bugged_shareable(shareable)))
+        return BUGGED_REFCOUNT;
+
+    return uacpi_atomic_dec32(&shareable->reference_count) + 1;
+}
+
+void uacpi_shareable_unref_and_delete_if_last(
+    uacpi_handle handle, void (*do_free)(uacpi_handle)
+)
+{
+    if (handle == UACPI_NULL)
+        return;
+
+    if (uacpi_unlikely(uacpi_bugged_shareable(handle)))
+        return;
+
+    if (uacpi_shareable_unref(handle) == 1)
+        do_free(handle);
+}
+
+uacpi_u32 uacpi_shareable_refcount(uacpi_handle handle)
+{
+    struct uacpi_shareable *shareable = handle;
+    return uacpi_atomic_load32(&shareable->reference_count);
+}
+
+#endif // !UACPI_BAREBONES_MODE
-- 
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