1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * include/linux/node.h - generic node definition
4  *
5  * This is mainly for topological representation. We define the
6  * basic 'struct node' here, which can be embedded in per-arch
7  * definitions of processors.
8  *
9  * Basic handling of the devices is done in drivers/base/node.c
10  * and system devices are handled in drivers/base/sys.c.
11  *
12  * Nodes are exported via driverfs in the class/node/devices/
13  * directory.
14  */
15 #ifndef _LINUX_NODE_H_
16 #define _LINUX_NODE_H_
17 
18 #include <linux/device.h>
19 #include <linux/cpumask.h>
20 #include <linux/list.h>
21 #include <linux/workqueue.h>
22 
23 /**
24  * struct node_hmem_attrs - heterogeneous memory performance attributes
25  *
26  * @read_bandwidth:	Read bandwidth in MB/s
27  * @write_bandwidth:	Write bandwidth in MB/s
28  * @read_latency:	Read latency in nanoseconds
29  * @write_latency:	Write latency in nanoseconds
30  */
31 struct node_hmem_attrs {
32 	unsigned int read_bandwidth;
33 	unsigned int write_bandwidth;
34 	unsigned int read_latency;
35 	unsigned int write_latency;
36 };
37 
38 enum cache_indexing {
39 	NODE_CACHE_DIRECT_MAP,
40 	NODE_CACHE_INDEXED,
41 	NODE_CACHE_OTHER,
42 };
43 
44 enum cache_write_policy {
45 	NODE_CACHE_WRITE_BACK,
46 	NODE_CACHE_WRITE_THROUGH,
47 	NODE_CACHE_WRITE_OTHER,
48 };
49 
50 /**
51  * struct node_cache_attrs - system memory caching attributes
52  *
53  * @indexing:		The ways memory blocks may be placed in cache
54  * @write_policy:	Write back or write through policy
55  * @size:		Total size of cache in bytes
56  * @line_size:		Number of bytes fetched on a cache miss
57  * @level:		The cache hierarchy level
58  */
59 struct node_cache_attrs {
60 	enum cache_indexing indexing;
61 	enum cache_write_policy write_policy;
62 	u64 size;
63 	u16 line_size;
64 	u8 level;
65 };
66 
67 #ifdef CONFIG_HMEM_REPORTING
68 void node_add_cache(unsigned int nid, struct node_cache_attrs *cache_attrs);
69 void node_set_perf_attrs(unsigned int nid, struct node_hmem_attrs *hmem_attrs,
70 			 unsigned access);
71 #else
node_add_cache(unsigned int nid,struct node_cache_attrs * cache_attrs)72 static inline void node_add_cache(unsigned int nid,
73 				  struct node_cache_attrs *cache_attrs)
74 {
75 }
76 
node_set_perf_attrs(unsigned int nid,struct node_hmem_attrs * hmem_attrs,unsigned access)77 static inline void node_set_perf_attrs(unsigned int nid,
78 				       struct node_hmem_attrs *hmem_attrs,
79 				       unsigned access)
80 {
81 }
82 #endif
83 
84 struct node {
85 	struct device	dev;
86 	struct list_head access_list;
87 
88 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_HUGETLBFS)
89 	struct work_struct	node_work;
90 #endif
91 #ifdef CONFIG_HMEM_REPORTING
92 	struct list_head cache_attrs;
93 	struct device *cache_dev;
94 #endif
95 };
96 
97 struct memory_block;
98 extern struct node *node_devices[];
99 typedef  void (*node_registration_func_t)(struct node *);
100 
101 #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_NUMA)
102 void link_mem_sections(int nid, unsigned long start_pfn,
103 		       unsigned long end_pfn,
104 		       enum meminit_context context);
105 #else
link_mem_sections(int nid,unsigned long start_pfn,unsigned long end_pfn,enum meminit_context context)106 static inline void link_mem_sections(int nid, unsigned long start_pfn,
107 				     unsigned long end_pfn,
108 				     enum meminit_context context)
109 {
110 }
111 #endif
112 
113 extern void unregister_node(struct node *node);
114 #ifdef CONFIG_NUMA
115 /* Core of the node registration - only memory hotplug should use this */
116 extern int __register_one_node(int nid);
117 
118 /* Registers an online node */
register_one_node(int nid)119 static inline int register_one_node(int nid)
120 {
121 	int error = 0;
122 
123 	if (node_online(nid)) {
124 		struct pglist_data *pgdat = NODE_DATA(nid);
125 		unsigned long start_pfn = pgdat->node_start_pfn;
126 		unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
127 
128 		error = __register_one_node(nid);
129 		if (error)
130 			return error;
131 		/* link memory sections under this node */
132 		link_mem_sections(nid, start_pfn, end_pfn, MEMINIT_EARLY);
133 	}
134 
135 	return error;
136 }
137 
138 extern void unregister_one_node(int nid);
139 extern int register_cpu_under_node(unsigned int cpu, unsigned int nid);
140 extern int unregister_cpu_under_node(unsigned int cpu, unsigned int nid);
141 extern void unregister_memory_block_under_nodes(struct memory_block *mem_blk);
142 
143 extern int register_memory_node_under_compute_node(unsigned int mem_nid,
144 						   unsigned int cpu_nid,
145 						   unsigned access);
146 
147 #ifdef CONFIG_HUGETLBFS
148 extern void register_hugetlbfs_with_node(node_registration_func_t doregister,
149 					 node_registration_func_t unregister);
150 #endif
151 #else
__register_one_node(int nid)152 static inline int __register_one_node(int nid)
153 {
154 	return 0;
155 }
register_one_node(int nid)156 static inline int register_one_node(int nid)
157 {
158 	return 0;
159 }
unregister_one_node(int nid)160 static inline int unregister_one_node(int nid)
161 {
162 	return 0;
163 }
register_cpu_under_node(unsigned int cpu,unsigned int nid)164 static inline int register_cpu_under_node(unsigned int cpu, unsigned int nid)
165 {
166 	return 0;
167 }
unregister_cpu_under_node(unsigned int cpu,unsigned int nid)168 static inline int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
169 {
170 	return 0;
171 }
unregister_memory_block_under_nodes(struct memory_block * mem_blk)172 static inline void unregister_memory_block_under_nodes(struct memory_block *mem_blk)
173 {
174 }
175 
register_hugetlbfs_with_node(node_registration_func_t reg,node_registration_func_t unreg)176 static inline void register_hugetlbfs_with_node(node_registration_func_t reg,
177 						node_registration_func_t unreg)
178 {
179 }
180 #endif
181 
182 #define to_node(device) container_of(device, struct node, dev)
183 
184 #endif /* _LINUX_NODE_H_ */
185