1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2015 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #ifndef __CPU_H
8 #define __CPU_H
9 
10 #include <linux/types.h>
11 
12 struct udevice;
13 
14 /**
15  * struct cpu_plat - platform data for a CPU
16  * @cpu_id:	   Platform-specific way of identifying the CPU.
17  * @ucode_version: Microcode version, if CPU_FEAT_UCODE is set
18  * @device_id:     Driver-defined device identifier
19  * @family:        DMTF CPU Family identifier
20  * @id:            DMTF CPU Processor identifier
21  * @timebase_freq: the current frequency at which the cpu timer timebase
22  *		   registers are updated (in Hz)
23  *
24  * This can be accessed with dev_get_parent_plat() for any UCLASS_CPU
25  * device.
26  */
27 struct cpu_plat {
28 	int cpu_id;
29 	int ucode_version;
30 	ulong device_id;
31 	u16 family;
32 	u32 id[2];
33 	u32 timebase_freq;
34 };
35 
36 /* CPU features - mostly just a placeholder for now */
37 enum {
38 	CPU_FEAT_L1_CACHE	= 0,	/* Supports level 1 cache */
39 	CPU_FEAT_MMU		= 1,	/* Supports virtual memory */
40 	CPU_FEAT_UCODE		= 2,	/* Requires/uses microcode */
41 	CPU_FEAT_DEVICE_ID	= 3,	/* Provides a device ID */
42 
43 	CPU_FEAT_COUNT,
44 };
45 
46 /**
47  * struct cpu_info - Information about a CPU
48  *
49  * @cpu_freq:	Current CPU frequency in Hz
50  * @features:	Flags for supported CPU features
51  * @address_width:	Width of the CPU address space in bits (e.g. 32)
52  */
53 struct cpu_info {
54 	ulong cpu_freq;
55 	ulong features;
56 	uint address_width;
57 };
58 
59 struct cpu_ops {
60 	/**
61 	 * get_desc() - Get a description string for a CPU
62 	 *
63 	 * @dev:	Device to check (UCLASS_CPU)
64 	 * @buf:	Buffer to place string
65 	 * @size:	Size of string space
66 	 * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
67 	 */
68 	int (*get_desc)(const struct udevice *dev, char *buf, int size);
69 
70 	/**
71 	 * get_info() - Get information about a CPU
72 	 *
73 	 * @dev:	Device to check (UCLASS_CPU)
74 	 * @info:	Returns CPU info
75 	 * @return 0 if OK, -ve on error
76 	 */
77 	int (*get_info)(const struct udevice *dev, struct cpu_info *info);
78 
79 	/**
80 	 * get_count() - Get number of CPUs
81 	 *
82 	 * @dev:	Device to check (UCLASS_CPU)
83 	 * @return CPU count if OK, -ve on error
84 	 */
85 	int (*get_count)(const struct udevice *dev);
86 
87 	/**
88 	 * get_vendor() - Get vendor name of a CPU
89 	 *
90 	 * @dev:	Device to check (UCLASS_CPU)
91 	 * @buf:	Buffer to place string
92 	 * @size:	Size of string space
93 	 * @return 0 if OK, -ENOSPC if buffer is too small, other -ve on error
94 	 */
95 	int (*get_vendor)(const struct udevice *dev, char *buf, int size);
96 
97 	/**
98 	 * is_current() - Check if the CPU that U-Boot is currently running from
99 	 *
100 	 * @dev:	Device to check (UCLASS_CPU)
101 	 * @return 1 if the CPU that U-Boot is currently running from, 0
102 	 *         if not.
103 	 */
104 	int (*is_current)(struct udevice *dev);
105 
106 	/**
107 	 * release_core() - Relase a CPU core to the given address to run application
108 	 *
109 	 * @dev:	Device to check (UCLASS_CPU)
110 	 * @addr:	Address to relese the CPU core
111 	 * @return 0 if OK, -ve on error
112 	 */
113 	int (*release_core)(const struct udevice *dev, phys_addr_t addr);
114 };
115 
116 #define cpu_get_ops(dev)        ((struct cpu_ops *)(dev)->driver->ops)
117 
118 /**
119  * cpu_get_desc() - Get a description string for a CPU
120  * @dev:	Device to check (UCLASS_CPU)
121  * @buf:	Buffer to place string
122  * @size:	Size of string space
123  *
124  * Return: 0 if OK, -ENOSPC if buffer is too small, other -ve on error
125  */
126 int cpu_get_desc(const struct udevice *dev, char *buf, int size);
127 
128 /**
129  * cpu_get_info() - Get information about a CPU
130  * @dev:	Device to check (UCLASS_CPU)
131  * @info:	Returns CPU info
132  *
133  * Return: 0 if OK, -ve on error
134  */
135 int cpu_get_info(const struct udevice *dev, struct cpu_info *info);
136 
137 /**
138  * cpu_get_count() - Get number of CPUs
139  * @dev:	Device to check (UCLASS_CPU)
140  *
141  * Return: CPU count if OK, -ve on error
142  */
143 int cpu_get_count(const struct udevice *dev);
144 
145 /**
146  * cpu_get_vendor() - Get vendor name of a CPU
147  * @dev:	Device to check (UCLASS_CPU)
148  * @buf:	Buffer to place string
149  * @size:	Size of string space
150  *
151  * Return: 0 if OK, -ENOSPC if buffer is too small, other -ve on error
152  */
153 int cpu_get_vendor(const struct udevice *dev, char *buf, int size);
154 
155 /**
156  * cpu_probe_all() - Probe all available CPUs
157  *
158  * Return: 0 if OK, -ve on error
159  */
160 int cpu_probe_all(void);
161 
162 /**
163  * cpu_is_current() - Check if the CPU that U-Boot is currently running from
164  *
165  * Return: 1 if yes, - 0 if not
166  */
167 int cpu_is_current(struct udevice *cpu);
168 
169 /**
170  * cpu_get_current_dev() - Get CPU udevice for current CPU
171  *
172  * Return: udevice if OK, - NULL on error
173  */
174 struct udevice *cpu_get_current_dev(void);
175 
176 /**
177  * cpu_release_core() - Relase a CPU core to the given address to run application
178  *
179  * @return 0 if OK, -ve on error
180  */
181 int cpu_release_core(const struct udevice *dev, phys_addr_t addr);
182 
183 /**
184  * cpu_phys_address_size() - Get the physical-address size for the CPU
185  *
186  * x86 CPUs have a setting which indicates how many bits of address space are
187  * available on the CPU. This is 32 for older CPUs but newer ones may support 36
188  * or more.
189  *
190  * For non-x86 CPUs the result may simply be 32 for 32-bit CPUS or 64 for 64-bit
191  *
192  * Return: address size (typically 32 or 36)
193  */
194 int cpu_phys_address_size(void);
195 
196 #endif
197