xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 3213486f)
1 /*
2  * Common prep/pmac/chrp boot and setup code.
3  */
4 
5 #include <linux/module.h>
6 #include <linux/string.h>
7 #include <linux/sched.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/reboot.h>
11 #include <linux/delay.h>
12 #include <linux/initrd.h>
13 #include <linux/tty.h>
14 #include <linux/seq_file.h>
15 #include <linux/root_dev.h>
16 #include <linux/cpu.h>
17 #include <linux/console.h>
18 #include <linux/memblock.h>
19 #include <linux/export.h>
20 #include <linux/nvram.h>
21 
22 #include <asm/io.h>
23 #include <asm/prom.h>
24 #include <asm/processor.h>
25 #include <asm/pgtable.h>
26 #include <asm/setup.h>
27 #include <asm/smp.h>
28 #include <asm/elf.h>
29 #include <asm/cputable.h>
30 #include <asm/bootx.h>
31 #include <asm/btext.h>
32 #include <asm/machdep.h>
33 #include <linux/uaccess.h>
34 #include <asm/pmac_feature.h>
35 #include <asm/sections.h>
36 #include <asm/nvram.h>
37 #include <asm/xmon.h>
38 #include <asm/time.h>
39 #include <asm/serial.h>
40 #include <asm/udbg.h>
41 #include <asm/code-patching.h>
42 #include <asm/cpu_has_feature.h>
43 #include <asm/asm-prototypes.h>
44 #include <asm/kdump.h>
45 #include <asm/feature-fixups.h>
46 
47 #include "setup.h"
48 
49 #define DBG(fmt...)
50 
51 extern void bootx_init(unsigned long r4, unsigned long phys);
52 
53 int boot_cpuid_phys;
54 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
55 
56 int smp_hw_index[NR_CPUS];
57 EXPORT_SYMBOL(smp_hw_index);
58 
59 unsigned long ISA_DMA_THRESHOLD;
60 unsigned int DMA_MODE_READ;
61 unsigned int DMA_MODE_WRITE;
62 
63 EXPORT_SYMBOL(DMA_MODE_READ);
64 EXPORT_SYMBOL(DMA_MODE_WRITE);
65 
66 /*
67  * We're called here very early in the boot.
68  *
69  * Note that the kernel may be running at an address which is different
70  * from the address that it was linked at, so we must use RELOC/PTRRELOC
71  * to access static data (including strings).  -- paulus
72  */
73 notrace unsigned long __init early_init(unsigned long dt_ptr)
74 {
75 	unsigned long offset = reloc_offset();
76 
77 	/* First zero the BSS -- use memset_io, some platforms don't have
78 	 * caches on yet */
79 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
80 			__bss_stop - __bss_start);
81 
82 	/*
83 	 * Identify the CPU type and fix up code sections
84 	 * that depend on which cpu we have.
85 	 */
86 	identify_cpu(offset, mfspr(SPRN_PVR));
87 
88 	apply_feature_fixups();
89 
90 	return KERNELBASE + offset;
91 }
92 
93 
94 /*
95  * This is run before start_kernel(), the kernel has been relocated
96  * and we are running with enough of the MMU enabled to have our
97  * proper kernel virtual addresses
98  *
99  * We do the initial parsing of the flat device-tree and prepares
100  * for the MMU to be fully initialized.
101  */
102 notrace void __init machine_init(u64 dt_ptr)
103 {
104 	unsigned int *addr = (unsigned int *)patch_site_addr(&patch__memset_nocache);
105 	unsigned long insn;
106 
107 	/* Configure static keys first, now that we're relocated. */
108 	setup_feature_keys();
109 
110 	/* Enable early debugging if any specified (see udbg.h) */
111 	udbg_early_init();
112 
113 	patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);
114 
115 	insn = create_cond_branch(addr, branch_target(addr), 0x820000);
116 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
117 
118 	/* Do some early initialization based on the flat device tree */
119 	early_init_devtree(__va(dt_ptr));
120 
121 	early_init_mmu();
122 
123 	setup_kdump_trampoline();
124 }
125 
126 /* Checks "l2cr=xxxx" command-line option */
127 static int __init ppc_setup_l2cr(char *str)
128 {
129 	if (cpu_has_feature(CPU_FTR_L2CR)) {
130 		unsigned long val = simple_strtoul(str, NULL, 0);
131 		printk(KERN_INFO "l2cr set to %lx\n", val);
132 		_set_L2CR(0);		/* force invalidate by disable cache */
133 		_set_L2CR(val);		/* and enable it */
134 	}
135 	return 1;
136 }
137 __setup("l2cr=", ppc_setup_l2cr);
138 
139 /* Checks "l3cr=xxxx" command-line option */
140 static int __init ppc_setup_l3cr(char *str)
141 {
142 	if (cpu_has_feature(CPU_FTR_L3CR)) {
143 		unsigned long val = simple_strtoul(str, NULL, 0);
144 		printk(KERN_INFO "l3cr set to %lx\n", val);
145 		_set_L3CR(val);		/* and enable it */
146 	}
147 	return 1;
148 }
149 __setup("l3cr=", ppc_setup_l3cr);
150 
151 static int __init ppc_init(void)
152 {
153 	/* clear the progress line */
154 	if (ppc_md.progress)
155 		ppc_md.progress("             ", 0xffff);
156 
157 	/* call platform init */
158 	if (ppc_md.init != NULL) {
159 		ppc_md.init();
160 	}
161 	return 0;
162 }
163 arch_initcall(ppc_init);
164 
165 static void *__init alloc_stack(void)
166 {
167 	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
168 
169 	if (!ptr)
170 		panic("cannot allocate %d bytes for stack at %pS\n",
171 		      THREAD_SIZE, (void *)_RET_IP_);
172 
173 	return ptr;
174 }
175 
176 void __init irqstack_early_init(void)
177 {
178 	unsigned int i;
179 
180 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
181 	 * as the memblock is limited to lowmem by default */
182 	for_each_possible_cpu(i) {
183 		softirq_ctx[i] = alloc_stack();
184 		hardirq_ctx[i] = alloc_stack();
185 	}
186 }
187 
188 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
189 void __init exc_lvl_early_init(void)
190 {
191 	unsigned int i, hw_cpu;
192 
193 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
194 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
195 	for_each_possible_cpu(i) {
196 #ifdef CONFIG_SMP
197 		hw_cpu = get_hard_smp_processor_id(i);
198 #else
199 		hw_cpu = 0;
200 #endif
201 
202 		critirq_ctx[hw_cpu] = alloc_stack();
203 #ifdef CONFIG_BOOKE
204 		dbgirq_ctx[hw_cpu] = alloc_stack();
205 		mcheckirq_ctx[hw_cpu] = alloc_stack();
206 #endif
207 	}
208 }
209 #endif
210 
211 void __init setup_power_save(void)
212 {
213 #ifdef CONFIG_PPC_BOOK3S_32
214 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
215 	    cpu_has_feature(CPU_FTR_CAN_NAP))
216 		ppc_md.power_save = ppc6xx_idle;
217 #endif
218 
219 #ifdef CONFIG_E500
220 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
221 	    cpu_has_feature(CPU_FTR_CAN_NAP))
222 		ppc_md.power_save = e500_idle;
223 #endif
224 }
225 
226 __init void initialize_cache_info(void)
227 {
228 	/*
229 	 * Set cache line size based on type of cpu as a default.
230 	 * Systems with OF can look in the properties on the cpu node(s)
231 	 * for a possibly more accurate value.
232 	 */
233 	dcache_bsize = cur_cpu_spec->dcache_bsize;
234 	icache_bsize = cur_cpu_spec->icache_bsize;
235 	ucache_bsize = 0;
236 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
237 		ucache_bsize = icache_bsize = dcache_bsize;
238 }
239