lib: utils: Add cache flush library

The current RISC-V CMO only defines how to flush a cache block. However,
certain use cases, such as power management, may require flushing the
entire cache. Therefore, a framework is being introduced to allow vendors
to flush the entire cache using their own methods.

Signed-off-by: Nick Hu <[email protected]>
Reviewed-by: Samuel Holland <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Anup Patel <[email protected]>

1 files changed, 69 insertions, 0 deletions

diff --git a/include/sbi_utils/cache/cache.h b/include/sbi_utils/cache/cache.h
new file mode 100644
index 00000000..70d9286f
--- /dev/null
+++ b/include/sbi_utils/cache/cache.h
@@ -0,0 +1,69 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 SiFive Inc.
+ */
+
+#ifndef __CACHE_H__
+#define __CACHE_H__
+
+#include <sbi/sbi_list.h>
+#include <sbi/sbi_types.h>
+
+#define CACHE_NAME_LEN	32
+
+struct cache_device;
+
+struct cache_ops {
+	/** Warm init **/
+	int (*warm_init)(struct cache_device *dev);
+	/** Flush entire cache **/
+	int (*cache_flush_all)(struct cache_device *dev);
+};
+
+struct cache_device {
+	/** Name of the device **/
+	char name[CACHE_NAME_LEN];
+	/** List node for search **/
+	struct sbi_dlist node;
+	/** Point to the next level cache **/
+	struct cache_device *next;
+	/** Cache Management Operations **/
+	struct cache_ops *ops;
+	/** CPU private cache **/
+	bool cpu_private;
+	/** The unique id of this cache device **/
+	u32 id;
+};
+
+/**
+ * Find a registered cache device
+ *
+ * @param id unique ID of the cache device
+ *
+ * @return the cache device or NULL
+ */
+struct cache_device *cache_find(u32 id);
+
+/**
+ * Register a cache device
+ *
+ * cache_device->id must be initialized already and must not change during the life
+ * of the cache_device object.
+ *
+ * @param dev the cache device to register
+ *
+ * @return 0 on success, or a negative error code on failure
+ */
+int cache_add(struct cache_device *dev);
+
+/**
+ * Flush the entire cache
+ *
+ * @param dev the cache to flush
+ *
+ * @return 0 on success, or a negative error code on failure
+ */
+int cache_flush_all(struct cache_device *dev);
+
+#endif