[linux-2.6-block.git] / include / linux / memory-tiers.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MEMORY_TIERS_H
#define _LINUX_MEMORY_TIERS_H

#include <linux/types.h>
#include <linux/nodemask.h>
#include <linux/kref.h>
#include <linux/mmzone.h>
/*
 * Each tier cover a abstrace distance chunk size of 128
 */
#define MEMTIER_CHUNK_BITS	7
#define MEMTIER_CHUNK_SIZE	(1 << MEMTIER_CHUNK_BITS)
/*
 * Smaller abstract distance values imply faster (higher) memory tiers. Offset
 * the DRAM adistance so that we can accommodate devices with a slightly lower
 * adistance value (slightly faster) than default DRAM adistance to be part of
 * the same memory tier.
 */
#define MEMTIER_ADISTANCE_DRAM	((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))

struct memory_tier;
struct memory_dev_type {
	/* list of memory types that are part of same tier as this type */
	struct list_head tier_sibiling;
	/* abstract distance for this specific memory type */
	int adistance;
	/* Nodes of same abstract distance */
	nodemask_t nodes;
	struct kref kref;
};

#ifdef CONFIG_NUMA
extern bool numa_demotion_enabled;
struct memory_dev_type *alloc_memory_type(int adistance);
void destroy_memory_type(struct memory_dev_type *memtype);
void init_node_memory_type(int node, struct memory_dev_type *default_type);
void clear_node_memory_type(int node, struct memory_dev_type *memtype);
#ifdef CONFIG_MIGRATION
int next_demotion_node(int node);
void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
bool node_is_toptier(int node);
#else
static inline int next_demotion_node(int node)
{
	return NUMA_NO_NODE;
}

static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
	*targets = NODE_MASK_NONE;
}

static inline bool node_is_toptier(int node)
{
	return true;
}
#endif

#else

#define numa_demotion_enabled	false
/*
 * CONFIG_NUMA implementation returns non NULL error.
 */
static inline struct memory_dev_type *alloc_memory_type(int adistance)
{
	return NULL;
}

static inline void destroy_memory_type(struct memory_dev_type *memtype)
{

}

static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
{

}

static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
{

}

static inline int next_demotion_node(int node)
{
	return NUMA_NO_NODE;
}

static inline void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets)
{
	*targets = NODE_MASK_NONE;
}

static inline bool node_is_toptier(int node)
{
	return true;
}
#endif	/* CONFIG_NUMA */
#endif  /* _LINUX_MEMORY_TIERS_H */
Commit	Line	Data
992bf775 AK	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _LINUX_MEMORY_TIERS_H
	3	#define _LINUX_MEMORY_TIERS_H
	4
7b88bda3 AK	5	#include <linux/types.h>
	6	#include <linux/nodemask.h>
	7	#include <linux/kref.h>
32008027	8	#include <linux/mmzone.h>
992bf775 AK	9	/*
	10	* Each tier cover a abstrace distance chunk size of 128
	11	*/
	12	#define MEMTIER_CHUNK_BITS 7
	13	#define MEMTIER_CHUNK_SIZE (1 << MEMTIER_CHUNK_BITS)
	14	/*
	15	* Smaller abstract distance values imply faster (higher) memory tiers. Offset
	16	* the DRAM adistance so that we can accommodate devices with a slightly lower
	17	* adistance value (slightly faster) than default DRAM adistance to be part of
	18	* the same memory tier.
	19	*/
	20	#define MEMTIER_ADISTANCE_DRAM ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1))
	21
7b88bda3 AK	22	struct memory_tier;
	23	struct memory_dev_type {
	24	/* list of memory types that are part of same tier as this type */
	25	struct list_head tier_sibiling;
	26	/* abstract distance for this specific memory type */
	27	int adistance;
	28	/* Nodes of same abstract distance */
	29	nodemask_t nodes;
	30	struct kref kref;
7b88bda3 AK	31	};
7b88bda3 AK	32
91952440	33	#ifdef CONFIG_NUMA
91952440	34	extern bool numa_demotion_enabled;
7b88bda3 AK	35	struct memory_dev_type *alloc_memory_type(int adistance);
	36	void destroy_memory_type(struct memory_dev_type *memtype);
	37	void init_node_memory_type(int node, struct memory_dev_type *default_type);
	38	void clear_node_memory_type(int node, struct memory_dev_type *memtype);
6c542ab7 AK	39	#ifdef CONFIG_MIGRATION
6c542ab7 AK	40	int next_demotion_node(int node);
32008027	41	void node_get_allowed_targets(pg_data_t pgdat, nodemask_t targets);
467b171a	42	bool node_is_toptier(int node);
6c542ab7 AK	43	#else
	44	static inline int next_demotion_node(int node)
	45	{
	46	return NUMA_NO_NODE;
	47	}
32008027 JG	48
	49	static inline void node_get_allowed_targets(pg_data_t pgdat, nodemask_t targets)
	50	{
	51	*targets = NODE_MASK_NONE;
	52	}
467b171a AK	53
	54	static inline bool node_is_toptier(int node)
	55	{
	56	return true;
	57	}
6c542ab7	58	#endif
91952440 AK	59
	60	#else
	61
	62	#define numa_demotion_enabled false
7b88bda3 AK	63	/*
	64	* CONFIG_NUMA implementation returns non NULL error.
	65	*/
	66	static inline struct memory_dev_type *alloc_memory_type(int adistance)
	67	{
	68	return NULL;
	69	}
	70
	71	static inline void destroy_memory_type(struct memory_dev_type *memtype)
	72	{
	73
	74	}
	75
	76	static inline void init_node_memory_type(int node, struct memory_dev_type *default_type)
	77	{
	78
	79	}
	80
	81	static inline void clear_node_memory_type(int node, struct memory_dev_type *memtype)
	82	{
	83
	84	}
6c542ab7 AK	85
	86	static inline int next_demotion_node(int node)
	87	{
	88	return NUMA_NO_NODE;
	89	}
32008027 JG	90
	91	static inline void node_get_allowed_targets(pg_data_t pgdat, nodemask_t targets)
	92	{
	93	*targets = NODE_MASK_NONE;
	94	}
467b171a AK	95
	96	static inline bool node_is_toptier(int node)
	97	{
	98	return true;
	99	}
91952440	100	#endif /* CONFIG_NUMA */
992bf775	101	#endif /* _LINUX_MEMORY_TIERS_H */