xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 884caada)
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 
23 #include <asm/io.h>
24 #include <asm/prom.h>
25 #include <asm/processor.h>
26 #include <asm/pgtable.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 
48 #include "setup.h"
49 
50 #define DBG(fmt...)
51 
52 extern void bootx_init(unsigned long r4, unsigned long phys);
53 
54 int boot_cpuid_phys;
55 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
56 
57 int smp_hw_index[NR_CPUS];
58 EXPORT_SYMBOL(smp_hw_index);
59 
60 unsigned long ISA_DMA_THRESHOLD;
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 	unsigned int *addr = (unsigned int *)patch_site_addr(&patch__memset_nocache);
78 	unsigned long insn;
79 
80 	/* Configure static keys first, now that we're relocated. */
81 	setup_feature_keys();
82 
83 	/* Enable early debugging if any specified (see udbg.h) */
84 	udbg_early_init();
85 
86 	patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);
87 
88 	insn = create_cond_branch(addr, branch_target(addr), 0x820000);
89 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
90 
91 	/* Do some early initialization based on the flat device tree */
92 	early_init_devtree(__va(dt_ptr));
93 
94 	early_init_mmu();
95 
96 	setup_kdump_trampoline();
97 }
98 
99 /* Checks "l2cr=xxxx" command-line option */
100 static int __init ppc_setup_l2cr(char *str)
101 {
102 	if (cpu_has_feature(CPU_FTR_L2CR)) {
103 		unsigned long val = simple_strtoul(str, NULL, 0);
104 		printk(KERN_INFO "l2cr set to %lx\n", val);
105 		_set_L2CR(0);		/* force invalidate by disable cache */
106 		_set_L2CR(val);		/* and enable it */
107 	}
108 	return 1;
109 }
110 __setup("l2cr=", ppc_setup_l2cr);
111 
112 /* Checks "l3cr=xxxx" command-line option */
113 static int __init ppc_setup_l3cr(char *str)
114 {
115 	if (cpu_has_feature(CPU_FTR_L3CR)) {
116 		unsigned long val = simple_strtoul(str, NULL, 0);
117 		printk(KERN_INFO "l3cr set to %lx\n", val);
118 		_set_L3CR(val);		/* and enable it */
119 	}
120 	return 1;
121 }
122 __setup("l3cr=", ppc_setup_l3cr);
123 
124 static int __init ppc_init(void)
125 {
126 	/* clear the progress line */
127 	if (ppc_md.progress)
128 		ppc_md.progress("             ", 0xffff);
129 
130 	/* call platform init */
131 	if (ppc_md.init != NULL) {
132 		ppc_md.init();
133 	}
134 	return 0;
135 }
136 arch_initcall(ppc_init);
137 
138 static void *__init alloc_stack(void)
139 {
140 	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
141 
142 	if (!ptr)
143 		panic("cannot allocate %d bytes for stack at %pS\n",
144 		      THREAD_SIZE, (void *)_RET_IP_);
145 
146 	return ptr;
147 }
148 
149 void __init irqstack_early_init(void)
150 {
151 	unsigned int i;
152 
153 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
154 	 * as the memblock is limited to lowmem by default */
155 	for_each_possible_cpu(i) {
156 		softirq_ctx[i] = alloc_stack();
157 		hardirq_ctx[i] = alloc_stack();
158 	}
159 }
160 
161 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
162 void __init exc_lvl_early_init(void)
163 {
164 	unsigned int i, hw_cpu;
165 
166 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
167 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
168 	for_each_possible_cpu(i) {
169 #ifdef CONFIG_SMP
170 		hw_cpu = get_hard_smp_processor_id(i);
171 #else
172 		hw_cpu = 0;
173 #endif
174 
175 		critirq_ctx[hw_cpu] = alloc_stack();
176 #ifdef CONFIG_BOOKE
177 		dbgirq_ctx[hw_cpu] = alloc_stack();
178 		mcheckirq_ctx[hw_cpu] = alloc_stack();
179 #endif
180 	}
181 }
182 #endif
183 
184 void __init setup_power_save(void)
185 {
186 #ifdef CONFIG_PPC_BOOK3S_32
187 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
188 	    cpu_has_feature(CPU_FTR_CAN_NAP))
189 		ppc_md.power_save = ppc6xx_idle;
190 #endif
191 
192 #ifdef CONFIG_E500
193 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
194 	    cpu_has_feature(CPU_FTR_CAN_NAP))
195 		ppc_md.power_save = e500_idle;
196 #endif
197 }
198 
199 __init void initialize_cache_info(void)
200 {
201 	/*
202 	 * Set cache line size based on type of cpu as a default.
203 	 * Systems with OF can look in the properties on the cpu node(s)
204 	 * for a possibly more accurate value.
205 	 */
206 	dcache_bsize = cur_cpu_spec->dcache_bsize;
207 	icache_bsize = cur_cpu_spec->icache_bsize;
208 	ucache_bsize = 0;
209 	if (IS_ENABLED(CONFIG_PPC_BOOK3S_601) || IS_ENABLED(CONFIG_E200))
210 		ucache_bsize = icache_bsize = dcache_bsize;
211 }
212