xref: /linux/drivers/dax/dax-private.h (revision 563cb0b1e736853cfc78956b9de362d2aae74887)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright(c) 2016 Intel Corporation. All rights reserved.
4  */
5 #ifndef __DAX_PRIVATE_H__
6 #define __DAX_PRIVATE_H__
7 
8 #include <linux/device.h>
9 #include <linux/cdev.h>
10 #include <linux/idr.h>
11 
12 /* private routines between core files */
13 struct dax_device;
14 struct dax_device *inode_dax(struct inode *inode);
15 struct inode *dax_inode(struct dax_device *dax_dev);
16 int dax_bus_init(void);
17 void dax_bus_exit(void);
18 
19 /**
20  * struct dax_region - mapping infrastructure for dax devices
21  * @id: kernel-wide unique region for a memory range
22  * @target_node: effective numa node if this memory range is onlined
23  * @kref: to pin while other agents have a need to do lookups
24  * @dev: parent device backing this region
25  * @align: allocation and mapping alignment for child dax devices
26  * @ida: instance id allocator
27  * @res: resource tree to track instance allocations
28  * @seed: allow userspace to find the first unbound seed device
29  * @youngest: allow userspace to find the most recently created device
30  */
31 struct dax_region {
32 	int id;
33 	int target_node;
34 	struct kref kref;
35 	struct device *dev;
36 	unsigned int align;
37 	struct ida ida;
38 	struct resource res;
39 	struct device *seed;
40 	struct device *youngest;
41 };
42 
43 /**
44  * struct dax_mapping - device to display mapping range attributes
45  * @dev: device representing this range
46  * @range_id: index within dev_dax ranges array
47  * @id: ida of this mapping
48  */
49 struct dax_mapping {
50 	struct device dev;
51 	int range_id;
52 	int id;
53 };
54 
55 /**
56  * struct dev_dax_range - tuple represenging a range of memory used by dev_dax
57  * @pgoff: page offset
58  * @range: resource-span
59  * @mapping: reference to the dax_mapping for this range
60  */
61 struct dev_dax_range {
62 	unsigned long pgoff;
63 	struct range range;
64 	struct dax_mapping *mapping;
65 };
66 
67 /**
68  * struct dev_dax - instance data for a subdivision of a dax region, and
69  * data while the device is activated in the driver.
70  * @region - parent region
71  * @dax_dev - core dax functionality
72  * @target_node: effective numa node if dev_dax memory range is onlined
73  * @dyn_id: is this a dynamic or statically created instance
74  * @id: ida allocated id when the dax_region is not static
75  * @ida: mapping id allocator
76  * @dev - device core
77  * @pgmap - pgmap for memmap setup / lifetime (driver owned)
78  * @nr_range: size of @ranges
79  * @ranges: range tuples of memory used
80  */
81 struct dev_dax {
82 	struct dax_region *region;
83 	struct dax_device *dax_dev;
84 	unsigned int align;
85 	int target_node;
86 	bool dyn_id;
87 	int id;
88 	struct ida ida;
89 	struct device dev;
90 	struct dev_pagemap *pgmap;
91 	bool memmap_on_memory;
92 	int nr_range;
93 	struct dev_dax_range *ranges;
94 };
95 
96 /*
97  * While run_dax() is potentially a generic operation that could be
98  * defined in include/linux/dax.h we don't want to grow any users
99  * outside of drivers/dax/
100  */
101 void run_dax(struct dax_device *dax_dev);
102 
to_dev_dax(struct device * dev)103 static inline struct dev_dax *to_dev_dax(struct device *dev)
104 {
105 	return container_of(dev, struct dev_dax, dev);
106 }
107 
to_dax_mapping(struct device * dev)108 static inline struct dax_mapping *to_dax_mapping(struct device *dev)
109 {
110 	return container_of(dev, struct dax_mapping, dev);
111 }
112 
113 phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff, unsigned long size);
114 
115 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
dax_align_valid(unsigned long align)116 static inline bool dax_align_valid(unsigned long align)
117 {
118 	if (align == PUD_SIZE && IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
119 		return true;
120 	if (align == PMD_SIZE && has_transparent_hugepage())
121 		return true;
122 	if (align == PAGE_SIZE)
123 		return true;
124 	return false;
125 }
126 #else
dax_align_valid(unsigned long align)127 static inline bool dax_align_valid(unsigned long align)
128 {
129 	return align == PAGE_SIZE;
130 }
131 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
132 #endif
133