xref: /kvm-unit-tests/lib/riscv/setup.c (revision ad435a714fb07cd4bfd5af479b177e245ec48c56)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Initialize machine setup information and I/O.
4  *
5  * Copyright (C) 2023, Ventana Micro Systems Inc., Andrew Jones <ajones@ventanamicro.com>
6  */
7 #include <libcflat.h>
8 #include <alloc.h>
9 #include <alloc_page.h>
10 #include <alloc_phys.h>
11 #include <argv.h>
12 #include <cpumask.h>
13 #include <devicetree.h>
14 #include <memregions.h>
15 #include <on-cpus.h>
16 #include <asm/csr.h>
17 #include <asm/mmu.h>
18 #include <asm/page.h>
19 #include <asm/processor.h>
20 #include <asm/setup.h>
21 
22 #define VA_BASE			((phys_addr_t)3 * SZ_1G)
23 
24 #define MAX_DT_MEM_REGIONS	16
25 #define NR_MEM_REGIONS		(MAX_DT_MEM_REGIONS + 16)
26 
27 char *initrd;
28 u32 initrd_size;
29 
30 struct thread_info cpus[NR_CPUS];
31 int nr_cpus;
32 
33 static struct mem_region riscv_mem_regions[NR_MEM_REGIONS + 1];
34 
35 int hartid_to_cpu(unsigned long hartid)
36 {
37 	int cpu;
38 
39 	for_each_present_cpu(cpu)
40 		if (cpus[cpu].hartid == hartid)
41 			return cpu;
42 	return -1;
43 }
44 
45 static void cpu_set_fdt(int fdtnode __unused, u64 regval, void *info __unused)
46 {
47 	int cpu = nr_cpus++;
48 
49 	assert_msg(cpu < NR_CPUS, "Number cpus exceeds maximum supported (%d).", NR_CPUS);
50 
51 	cpus[cpu].cpu = cpu;
52 	cpus[cpu].hartid = regval;
53 	set_cpu_present(cpu, true);
54 }
55 
56 static void cpu_init_acpi(void)
57 {
58 	assert_msg(false, "ACPI not available");
59 }
60 
61 static void cpu_init(void)
62 {
63 	int ret;
64 
65 	nr_cpus = 0;
66 	if (dt_available()) {
67 		ret = dt_for_each_cpu_node(cpu_set_fdt, NULL);
68 		assert(ret == 0);
69 	} else {
70 		cpu_init_acpi();
71 	}
72 
73 	set_cpu_online(hartid_to_cpu(csr_read(CSR_SSCRATCH)), true);
74 	cpu0_calls_idle = true;
75 }
76 
77 extern unsigned long _etext;
78 
79 static void mem_init(phys_addr_t freemem_start)
80 {
81 	struct mem_region *freemem, *code, *data;
82 	phys_addr_t freemem_end, base, top;
83 
84 	memregions_init(riscv_mem_regions, NR_MEM_REGIONS);
85 	memregions_add_dt_regions(MAX_DT_MEM_REGIONS);
86 
87 	/* Split the region with the code into two regions; code and data */
88 	memregions_split((unsigned long)&_etext, &code, &data);
89 	assert(code);
90 	code->flags |= MR_F_CODE;
91 
92 	freemem = memregions_find(freemem_start);
93 	assert(freemem && !(freemem->flags & (MR_F_IO | MR_F_CODE)));
94 
95 	freemem_end = freemem->end & PAGE_MASK;
96 
97 	/*
98 	 * The assert below is mostly checking that the free memory doesn't
99 	 * start in the 3G-4G range, which is reserved for virtual addresses,
100 	 * but it also confirms that there is some free memory (the amount
101 	 * is arbitrarily selected, but should be sufficient for a unit test)
102 	 *
103 	 * TODO: Allow the VA range to shrink and move.
104 	 */
105 	if (freemem_end > VA_BASE)
106 		freemem_end = VA_BASE;
107 	assert(freemem_end - freemem_start >= SZ_1M * 16);
108 
109 	/*
110 	 * TODO: Remove the need for this phys allocator dance, since, as we
111 	 * can see with the assert, we could have gone straight to the page
112 	 * allocator.
113 	 */
114 	phys_alloc_init(freemem_start, freemem_end - freemem_start);
115 	phys_alloc_set_minimum_alignment(PAGE_SIZE);
116 	phys_alloc_get_unused(&base, &top);
117 	assert(base == freemem_start && top == freemem_end);
118 
119 	page_alloc_init_area(0, freemem_start >> PAGE_SHIFT, freemem_end >> PAGE_SHIFT);
120 	page_alloc_ops_enable();
121 }
122 
123 static void banner(void)
124 {
125 	puts("\n");
126 	puts("##########################################################################\n");
127 	puts("#    kvm-unit-tests\n");
128 	puts("##########################################################################\n");
129 	puts("\n");
130 }
131 
132 void setup(const void *fdt, phys_addr_t freemem_start)
133 {
134 	void *freemem;
135 	const char *bootargs, *tmp;
136 	u32 fdt_size;
137 	int ret;
138 
139 	assert(sizeof(long) == 8 || freemem_start < VA_BASE);
140 	freemem = (void *)(unsigned long)freemem_start;
141 
142 	/* Move the FDT to the base of free memory */
143 	fdt_size = fdt_totalsize(fdt);
144 	ret = fdt_move(fdt, freemem, fdt_size);
145 	assert(ret == 0);
146 	ret = dt_init(freemem);
147 	assert(ret == 0);
148 	freemem += fdt_size;
149 
150 	/* Move the initrd to the top of the FDT */
151 	ret = dt_get_initrd(&tmp, &initrd_size);
152 	assert(ret == 0 || ret == -FDT_ERR_NOTFOUND);
153 	if (ret == 0) {
154 		initrd = freemem;
155 		memmove(initrd, tmp, initrd_size);
156 		freemem += initrd_size;
157 	}
158 
159 	mem_init(PAGE_ALIGN((unsigned long)freemem));
160 	cpu_init();
161 	thread_info_init();
162 	io_init();
163 
164 	ret = dt_get_bootargs(&bootargs);
165 	assert(ret == 0 || ret == -FDT_ERR_NOTFOUND);
166 	setup_args_progname(bootargs);
167 
168 	if (initrd) {
169 		/* environ is currently the only file in the initrd */
170 		char *env = malloc(initrd_size);
171 		memcpy(env, initrd, initrd_size);
172 		setup_env(env, initrd_size);
173 	}
174 
175 	setup_mmu();
176 
177 	banner();
178 }
179