1 files changed, 71 insertions, 0 deletions
diff --git a/include/linux/memregion.h b/include/linux/memregion.h
new file mode 100644
index 000000000000..a55f62cc5266
--- /dev/null
+++ b/include/linux/memregion.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _MEMREGION_H_
+#define _MEMREGION_H_
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/range.h>
+#include <linux/bug.h>
+
+struct memregion_info {
+	int target_node;
+	struct range range;
+};
+
+#ifdef CONFIG_MEMREGION
+int memregion_alloc(gfp_t gfp);
+void memregion_free(int id);
+#else
+static inline int memregion_alloc(gfp_t gfp)
+{
+	return -ENOMEM;
+}
+static inline void memregion_free(int id)
+{
+}
+#endif
+
+/**
+ * cpu_cache_invalidate_memregion - drop any CPU cached data for
+ *     memregion
+ * @start: start physical address of the target memory region.
+ * @len: length of the target memory region. -1 for all the regions of
+ *       the target type.
+ *
+ * Perform cache maintenance after a memory event / operation that
+ * changes the contents of physical memory in a cache-incoherent manner.
+ * For example, device memory technologies like NVDIMM and CXL have
+ * device secure erase, and dynamic region provision that can replace
+ * the memory mapped to a given physical address.
+ *
+ * Limit the functionality to architectures that have an efficient way
+ * to writeback and invalidate potentially terabytes of address space at
+ * once.  Note that this routine may or may not write back any dirty
+ * contents while performing the invalidation. It is only exported for
+ * the explicit usage of the NVDIMM and CXL modules in the 'DEVMEM'
+ * symbol namespace on bare platforms.
+ *
+ * Returns 0 on success or negative error code on a failure to perform
+ * the cache maintenance.
+ */
+#ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
+int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len);
+bool cpu_cache_has_invalidate_memregion(void);
+#else
+static inline bool cpu_cache_has_invalidate_memregion(void)
+{
+	return false;
+}
+
+static inline int cpu_cache_invalidate_memregion(phys_addr_t start, size_t len)
+{
+	WARN_ON_ONCE("CPU cache invalidation required");
+	return -ENXIO;
+}
+#endif
+
+static inline int cpu_cache_invalidate_all(void)
+{
+	return cpu_cache_invalidate_memregion(0, -1);
+}
+
+#endif /* _MEMREGION_H_ */