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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _MEMREGION_H_
3#define _MEMREGION_H_
4#include <linux/types.h>
5#include <linux/errno.h>
6#include <linux/bug.h>
7
8struct memregion_info {
9 int target_node;
10};
11
12#ifdef CONFIG_MEMREGION
13int memregion_alloc(gfp_t gfp);
14void memregion_free(int id);
15#else
16static inline int memregion_alloc(gfp_t gfp)
17{
18 return -ENOMEM;
19}
20static inline void memregion_free(int id)
21{
22}
23#endif
24
25/**
26 * cpu_cache_invalidate_memregion - drop any CPU cached data for
27 * memregions described by @res_desc
28 * @res_desc: one of the IORES_DESC_* types
29 *
30 * Perform cache maintenance after a memory event / operation that
31 * changes the contents of physical memory in a cache-incoherent manner.
32 * For example, device memory technologies like NVDIMM and CXL have
33 * device secure erase, and dynamic region provision that can replace
34 * the memory mapped to a given physical address.
35 *
36 * Limit the functionality to architectures that have an efficient way
37 * to writeback and invalidate potentially terabytes of address space at
38 * once. Note that this routine may or may not write back any dirty
39 * contents while performing the invalidation. It is only exported for
40 * the explicit usage of the NVDIMM and CXL modules in the 'DEVMEM'
41 * symbol namespace on bare platforms.
42 *
43 * Returns 0 on success or negative error code on a failure to perform
44 * the cache maintenance.
45 */
46#ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION
47int cpu_cache_invalidate_memregion(int res_desc);
48bool cpu_cache_has_invalidate_memregion(void);
49#else
50static inline bool cpu_cache_has_invalidate_memregion(void)
51{
52 return false;
53}
54
55static inline int cpu_cache_invalidate_memregion(int res_desc)
56{
57 WARN_ON_ONCE("CPU cache invalidation required");
58 return -ENXIO;
59}
60#endif
61#endif /* _MEMREGION_H_ */