xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 79e790ff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Common prep/pmac/chrp boot and setup code.
4  */
5 
6 #include <linux/module.h>
7 #include <linux/string.h>
8 #include <linux/sched.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/reboot.h>
12 #include <linux/delay.h>
13 #include <linux/initrd.h>
14 #include <linux/tty.h>
15 #include <linux/seq_file.h>
16 #include <linux/root_dev.h>
17 #include <linux/cpu.h>
18 #include <linux/console.h>
19 #include <linux/memblock.h>
20 #include <linux/export.h>
21 #include <linux/nvram.h>
22 #include <linux/pgtable.h>
23 
24 #include <asm/io.h>
25 #include <asm/prom.h>
26 #include <asm/processor.h>
27 #include <asm/setup.h>
28 #include <asm/smp.h>
29 #include <asm/elf.h>
30 #include <asm/cputable.h>
31 #include <asm/bootx.h>
32 #include <asm/btext.h>
33 #include <asm/machdep.h>
34 #include <linux/uaccess.h>
35 #include <asm/pmac_feature.h>
36 #include <asm/sections.h>
37 #include <asm/nvram.h>
38 #include <asm/xmon.h>
39 #include <asm/time.h>
40 #include <asm/serial.h>
41 #include <asm/udbg.h>
42 #include <asm/code-patching.h>
43 #include <asm/cpu_has_feature.h>
44 #include <asm/asm-prototypes.h>
45 #include <asm/kdump.h>
46 #include <asm/feature-fixups.h>
47 #include <asm/early_ioremap.h>
48 
49 #include "setup.h"
50 
51 #define DBG(fmt...)
52 
53 extern void bootx_init(unsigned long r4, unsigned long phys);
54 
55 int boot_cpuid_phys;
56 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
57 
58 int smp_hw_index[NR_CPUS];
59 EXPORT_SYMBOL(smp_hw_index);
60 
61 unsigned int DMA_MODE_READ;
62 unsigned int DMA_MODE_WRITE;
63 
64 EXPORT_SYMBOL(DMA_MODE_READ);
65 EXPORT_SYMBOL(DMA_MODE_WRITE);
66 
67 /*
68  * This is run before start_kernel(), the kernel has been relocated
69  * and we are running with enough of the MMU enabled to have our
70  * proper kernel virtual addresses
71  *
72  * We do the initial parsing of the flat device-tree and prepares
73  * for the MMU to be fully initialized.
74  */
75 notrace void __init machine_init(u64 dt_ptr)
76 {
77 	struct ppc_inst *addr = (struct ppc_inst *)patch_site_addr(&patch__memset_nocache);
78 	struct ppc_inst insn;
79 
80 	/* Configure static keys first, now that we're relocated. */
81 	setup_feature_keys();
82 
83 	early_ioremap_init();
84 
85 	/* Enable early debugging if any specified (see udbg.h) */
86 	udbg_early_init();
87 
88 	patch_instruction_site(&patch__memcpy_nocache, ppc_inst(PPC_INST_NOP));
89 
90 	create_cond_branch(&insn, addr, branch_target(addr), 0x820000);
91 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
92 
93 	/* Do some early initialization based on the flat device tree */
94 	early_init_devtree(__va(dt_ptr));
95 
96 	early_init_mmu();
97 
98 	setup_kdump_trampoline();
99 }
100 
101 /* Checks "l2cr=xxxx" command-line option */
102 static int __init ppc_setup_l2cr(char *str)
103 {
104 	if (cpu_has_feature(CPU_FTR_L2CR)) {
105 		unsigned long val = simple_strtoul(str, NULL, 0);
106 		printk(KERN_INFO "l2cr set to %lx\n", val);
107 		_set_L2CR(0);		/* force invalidate by disable cache */
108 		_set_L2CR(val);		/* and enable it */
109 	}
110 	return 1;
111 }
112 __setup("l2cr=", ppc_setup_l2cr);
113 
114 /* Checks "l3cr=xxxx" command-line option */
115 static int __init ppc_setup_l3cr(char *str)
116 {
117 	if (cpu_has_feature(CPU_FTR_L3CR)) {
118 		unsigned long val = simple_strtoul(str, NULL, 0);
119 		printk(KERN_INFO "l3cr set to %lx\n", val);
120 		_set_L3CR(val);		/* and enable it */
121 	}
122 	return 1;
123 }
124 __setup("l3cr=", ppc_setup_l3cr);
125 
126 static int __init ppc_init(void)
127 {
128 	/* clear the progress line */
129 	if (ppc_md.progress)
130 		ppc_md.progress("             ", 0xffff);
131 
132 	/* call platform init */
133 	if (ppc_md.init != NULL) {
134 		ppc_md.init();
135 	}
136 	return 0;
137 }
138 arch_initcall(ppc_init);
139 
140 static void *__init alloc_stack(void)
141 {
142 	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_ALIGN);
143 
144 	if (!ptr)
145 		panic("cannot allocate %d bytes for stack at %pS\n",
146 		      THREAD_SIZE, (void *)_RET_IP_);
147 
148 	return ptr;
149 }
150 
151 void __init irqstack_early_init(void)
152 {
153 	unsigned int i;
154 
155 	if (IS_ENABLED(CONFIG_VMAP_STACK))
156 		return;
157 
158 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
159 	 * as the memblock is limited to lowmem by default */
160 	for_each_possible_cpu(i) {
161 		softirq_ctx[i] = alloc_stack();
162 		hardirq_ctx[i] = alloc_stack();
163 	}
164 }
165 
166 #ifdef CONFIG_VMAP_STACK
167 void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
168 
169 void __init emergency_stack_init(void)
170 {
171 	unsigned int i;
172 
173 	for_each_possible_cpu(i)
174 		emergency_ctx[i] = alloc_stack();
175 }
176 #endif
177 
178 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
179 void __init exc_lvl_early_init(void)
180 {
181 	unsigned int i, hw_cpu;
182 
183 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
184 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
185 	for_each_possible_cpu(i) {
186 #ifdef CONFIG_SMP
187 		hw_cpu = get_hard_smp_processor_id(i);
188 #else
189 		hw_cpu = 0;
190 #endif
191 
192 		critirq_ctx[hw_cpu] = alloc_stack();
193 #ifdef CONFIG_BOOKE
194 		dbgirq_ctx[hw_cpu] = alloc_stack();
195 		mcheckirq_ctx[hw_cpu] = alloc_stack();
196 #endif
197 	}
198 }
199 #endif
200 
201 void __init setup_power_save(void)
202 {
203 #ifdef CONFIG_PPC_BOOK3S_32
204 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
205 	    cpu_has_feature(CPU_FTR_CAN_NAP))
206 		ppc_md.power_save = ppc6xx_idle;
207 #endif
208 
209 #ifdef CONFIG_E500
210 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
211 	    cpu_has_feature(CPU_FTR_CAN_NAP))
212 		ppc_md.power_save = e500_idle;
213 #endif
214 }
215 
216 __init void initialize_cache_info(void)
217 {
218 	/*
219 	 * Set cache line size based on type of cpu as a default.
220 	 * Systems with OF can look in the properties on the cpu node(s)
221 	 * for a possibly more accurate value.
222 	 */
223 	dcache_bsize = cur_cpu_spec->dcache_bsize;
224 	icache_bsize = cur_cpu_spec->icache_bsize;
225 }
226