1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2020 Western Digital Corporation or its affiliates
4  *
5  */
6 
7 #define LOG_CATEGORY LOGC_ARCH
8 
9 #include <common.h>
10 #include <fdt_support.h>
11 #include <log.h>
12 #include <mapmem.h>
13 #include <asm/global_data.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 /**
18  * riscv_fdt_copy_resv_mem_node() - Copy reserve memory node entry
19  * @src: Pointer to the source device tree from which reserved memory node
20  *	 needs to be copied.
21  * @dst: Pointer to the destination device tree to which reserved memory node
22  *	 needs to be copied.
23  *
24  * Return: 0 on success or if source doesn't have reserved memory node.
25  *	   Error if copy process failed.
26  */
riscv_fdt_copy_resv_mem_node(const void * src,void * dst)27 int riscv_fdt_copy_resv_mem_node(const void *src, void *dst)
28 {
29 	u32 phandle;
30 	struct fdt_memory pmp_mem;
31 	fdt_addr_t addr;
32 	fdt_size_t size;
33 	int offset, node, err, rmem_offset;
34 	bool nomap = true;
35 	char basename[32] = {0};
36 	int bname_len;
37 	int max_len = sizeof(basename);
38 	const char *name;
39 	char *temp;
40 
41 	offset = fdt_path_offset(src, "/reserved-memory");
42 	if (offset < 0) {
43 		log_debug("No reserved memory region found in source FDT\n");
44 		return 0;
45 	}
46 
47 	/*
48 	 * Extend the FDT by the following estimated size:
49 	 *
50 	 * Each PMP memory region entry occupies 64 bytes.
51 	 * With 16 PMP memory regions we need 64 * 16 = 1024 bytes.
52 	 */
53 	err = fdt_open_into(dst, dst, fdt_totalsize(dst) + 1024);
54 	if (err < 0) {
55 		printf("Device Tree can't be expanded to accommodate new node");
56 		return err;
57 	}
58 
59 	fdt_for_each_subnode(node, src, offset) {
60 		name = fdt_get_name(src, node, NULL);
61 
62 		addr = fdtdec_get_addr_size_auto_parent(src, offset, node,
63 							"reg", 0, &size,
64 							false);
65 		if (addr == FDT_ADDR_T_NONE) {
66 			log_debug("failed to read address/size for %s\n", name);
67 			continue;
68 		}
69 		strncpy(basename, name, max_len);
70 		temp = strchr(basename, '@');
71 		if (temp) {
72 			bname_len = strnlen(basename, max_len) - strnlen(temp,
73 								       max_len);
74 			*(basename + bname_len) = '\0';
75 		}
76 		pmp_mem.start = addr;
77 		pmp_mem.end = addr + size - 1;
78 		err = fdtdec_add_reserved_memory(dst, basename, &pmp_mem,
79 						 &phandle, false);
80 		if (err < 0 && err != -FDT_ERR_EXISTS) {
81 			log_err("failed to add reserved memory: %d\n", err);
82 			return err;
83 		}
84 		if (!fdt_getprop(src, node, "no-map", NULL))
85 			nomap = false;
86 		if (nomap) {
87 			rmem_offset = fdt_node_offset_by_phandle(dst, phandle);
88 			fdt_setprop_empty(dst, rmem_offset, "no-map");
89 		}
90 	}
91 
92 	return 0;
93 }
94 
95 /**
96  * riscv_board_reserved_mem_fixup() - Fix up reserved memory node for a board
97  * @fdt: Pointer to the device tree in which reserved memory node needs to be
98  *	 added.
99  *
100  * In RISC-V, any board needs to copy the reserved memory node from the device
101  * tree provided by the firmware to the device tree used by U-Boot. This is a
102  * common function that individual board fixup functions can invoke.
103  *
104  * Return: 0 on success or error otherwise.
105  */
riscv_board_reserved_mem_fixup(void * fdt)106 int riscv_board_reserved_mem_fixup(void *fdt)
107 {
108 	int err;
109 	void *src_fdt_addr;
110 
111 	src_fdt_addr = map_sysmem(gd->arch.firmware_fdt_addr, 0);
112 
113 	/* avoid the copy if we are using the same device tree */
114 	if (src_fdt_addr == fdt)
115 		return 0;
116 
117 	err = riscv_fdt_copy_resv_mem_node(src_fdt_addr, fdt);
118 	if (err < 0)
119 		return err;
120 
121 	return 0;
122 }
123 
124 #ifdef CONFIG_OF_BOARD_FIXUP
board_fix_fdt(void * fdt)125 int board_fix_fdt(void *fdt)
126 {
127 	int err;
128 
129 	err = riscv_board_reserved_mem_fixup(fdt);
130 	if (err < 0) {
131 		log_err("failed to fixup DT for reserved memory: %d\n", err);
132 		return err;
133 	}
134 
135 	return 0;
136 }
137 #endif
138 
arch_fixup_fdt(void * blob)139 int arch_fixup_fdt(void *blob)
140 {
141 	int err;
142 #ifdef CONFIG_EFI_LOADER
143 	u32 size;
144 	int chosen_offset;
145 
146 	size = fdt_totalsize(blob);
147 	err  = fdt_open_into(blob, blob, size + 32);
148 	if (err < 0) {
149 		log_err("Device Tree can't be expanded to accommodate new node");
150 		return err;
151 	}
152 	chosen_offset = fdt_path_offset(blob, "/chosen");
153 	if (chosen_offset < 0) {
154 		err = fdt_add_subnode(blob, 0, "chosen");
155 		if (err < 0) {
156 			log_err("chosen node cannot be added\n");
157 			return err;
158 		}
159 	}
160 	/* Overwrite the boot-hartid as U-Boot is the last stage BL */
161 	fdt_setprop_u32(blob, chosen_offset, "boot-hartid", gd->arch.boot_hart);
162 #endif
163 
164 	/* Copy the reserved-memory node to the DT used by OS */
165 	err = riscv_fdt_copy_resv_mem_node(gd->fdt_blob, blob);
166 	if (err < 0)
167 		return err;
168 
169 	return 0;
170 }
171