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1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
4  */
5 
6 #ifndef __FW_CFG__
7 #define __FW_CFG__
8 
9 #include <linux/list.h>
10 
11 enum qemu_fwcfg_items {
12 	FW_CFG_SIGNATURE	= 0x00,
13 	FW_CFG_ID		= 0x01,
14 	FW_CFG_UUID		= 0x02,
15 	FW_CFG_RAM_SIZE		= 0x03,
16 	FW_CFG_NOGRAPHIC	= 0x04,
17 	FW_CFG_NB_CPUS		= 0x05,
18 	FW_CFG_MACHINE_ID	= 0x06,
19 	FW_CFG_KERNEL_ADDR	= 0x07,
20 	FW_CFG_KERNEL_SIZE	= 0x08,
21 	FW_CFG_KERNEL_CMDLINE   = 0x09,
22 	FW_CFG_INITRD_ADDR	= 0x0a,
23 	FW_CFG_INITRD_SIZE	= 0x0b,
24 	FW_CFG_BOOT_DEVICE	= 0x0c,
25 	FW_CFG_NUMA		= 0x0d,
26 	FW_CFG_BOOT_MENU	= 0x0e,
27 	FW_CFG_MAX_CPUS		= 0x0f,
28 	FW_CFG_KERNEL_ENTRY	= 0x10,
29 	FW_CFG_KERNEL_DATA	= 0x11,
30 	FW_CFG_INITRD_DATA	= 0x12,
31 	FW_CFG_CMDLINE_ADDR	= 0x13,
32 	FW_CFG_CMDLINE_SIZE	= 0x14,
33 	FW_CFG_CMDLINE_DATA	= 0x15,
34 	FW_CFG_SETUP_ADDR	= 0x16,
35 	FW_CFG_SETUP_SIZE	= 0x17,
36 	FW_CFG_SETUP_DATA	= 0x18,
37 	FW_CFG_FILE_DIR		= 0x19,
38 	FW_CFG_FILE_FIRST	= 0x20,
39 	FW_CFG_WRITE_CHANNEL	= 0x4000,
40 	FW_CFG_ARCH_LOCAL	= 0x8000,
41 	FW_CFG_INVALID		= 0xffff,
42 };
43 
44 enum {
45 	BIOS_LINKER_LOADER_COMMAND_ALLOCATE	= 0x1,
46 	BIOS_LINKER_LOADER_COMMAND_ADD_POINTER  = 0x2,
47 	BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
48 };
49 
50 enum {
51 	BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1,
52 	BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2,
53 };
54 
55 #define FW_CFG_FILE_SLOTS	0x10
56 #define FW_CFG_MAX_ENTRY	(FW_CFG_FILE_FIRST + FW_CFG_FILE_SLOTS)
57 #define FW_CFG_ENTRY_MASK	 ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
58 
59 #define FW_CFG_MAX_FILE_PATH	56
60 #define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH
61 
62 #define QEMU_FW_CFG_SIGNATURE	(('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
63 
64 #define FW_CFG_DMA_ERROR	(1 << 0)
65 #define FW_CFG_DMA_READ	(1 << 1)
66 #define FW_CFG_DMA_SKIP	(1 << 2)
67 #define FW_CFG_DMA_SELECT	(1 << 3)
68 
69 #define FW_CFG_DMA_ENABLED	(1 << 1)
70 
71 struct fw_cfg_file {
72 	__be32 size;
73 	__be16 select;
74 	__be16 reserved;
75 	char name[FW_CFG_MAX_FILE_PATH];
76 };
77 
78 struct fw_file {
79 	struct fw_cfg_file cfg; /* firmware file information */
80 	unsigned long addr;     /* firmware file in-memory address */
81 	struct list_head list;  /* list node to link to fw_list */
82 };
83 
84 struct fw_cfg_file_iter {
85 	struct list_head *entry; /* structure to iterate file list */
86 };
87 
88 struct fw_cfg_dma_access {
89 	__be32 control;
90 	__be32 length;
91 	__be64 address;
92 };
93 
94 struct fw_cfg_arch_ops {
95 	void (*arch_read_pio)(uint16_t selector, uint32_t size,
96 			void *address);
97 	void (*arch_read_dma)(struct fw_cfg_dma_access *dma);
98 };
99 
100 struct bios_linker_entry {
101 	__le32 command;
102 	union {
103 		/*
104 		 * COMMAND_ALLOCATE - allocate a table from @alloc.file
105 		 * subject to @alloc.align alignment (must be power of 2)
106 		 * and @alloc.zone (can be HIGH or FSEG) requirements.
107 		 *
108 		 * Must appear exactly once for each file, and before
109 		 * this file is referenced by any other command.
110 		 */
111 		struct {
112 			char file[BIOS_LINKER_LOADER_FILESZ];
113 			__le32 align;
114 			uint8_t zone;
115 		} alloc;
116 
117 		/*
118 		 * COMMAND_ADD_POINTER - patch the table (originating from
119 		 * @dest_file) at @pointer.offset, by adding a pointer to the
120 		 * table originating from @src_file. 1,2,4 or 8 byte unsigned
121 		 * addition is used depending on @pointer.size.
122 		 */
123 		struct {
124 			char dest_file[BIOS_LINKER_LOADER_FILESZ];
125 			char src_file[BIOS_LINKER_LOADER_FILESZ];
126 			__le32 offset;
127 			uint8_t size;
128 		} pointer;
129 
130 		/*
131 		 * COMMAND_ADD_CHECKSUM - calculate checksum of the range
132 		 * specified by @cksum_start and @cksum_length fields,
133 		 * and then add the value at @cksum.offset.
134 		 * Checksum simply sums -X for each byte X in the range
135 		 * using 8-bit math.
136 		 */
137 		struct {
138 			char file[BIOS_LINKER_LOADER_FILESZ];
139 			__le32 offset;
140 			__le32 start;
141 			__le32 length;
142 		} cksum;
143 
144 		/* padding */
145 		char pad[124];
146 	};
147 } __packed;
148 
149 /**
150  * Initialize QEMU fw_cfg interface
151  *
152  * @ops: arch specific read operations
153  */
154 void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops);
155 
156 void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address);
157 int qemu_fwcfg_read_firmware_list(void);
158 struct fw_file *qemu_fwcfg_find_file(const char *name);
159 
160 /**
161  * Get system cpu number
162  *
163  * @return:   cpu number in system
164  */
165 int qemu_fwcfg_online_cpus(void);
166 
167 /* helper functions to iterate firmware file list */
168 struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter);
169 struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter);
170 bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter);
171 
172 bool qemu_fwcfg_present(void);
173 bool qemu_fwcfg_dma_present(void);
174 
175 #endif
176