xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision ccb01374)
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 
21 #include <asm/io.h>
22 #include <asm/prom.h>
23 #include <asm/processor.h>
24 #include <asm/pgtable.h>
25 #include <asm/setup.h>
26 #include <asm/smp.h>
27 #include <asm/elf.h>
28 #include <asm/cputable.h>
29 #include <asm/bootx.h>
30 #include <asm/btext.h>
31 #include <asm/machdep.h>
32 #include <linux/uaccess.h>
33 #include <asm/pmac_feature.h>
34 #include <asm/sections.h>
35 #include <asm/nvram.h>
36 #include <asm/xmon.h>
37 #include <asm/time.h>
38 #include <asm/serial.h>
39 #include <asm/udbg.h>
40 #include <asm/code-patching.h>
41 #include <asm/cpu_has_feature.h>
42 #include <asm/asm-prototypes.h>
43 #include <asm/kdump.h>
44 #include <asm/feature-fixups.h>
45 
46 #include "setup.h"
47 
48 #define DBG(fmt...)
49 
50 extern void bootx_init(unsigned long r4, unsigned long phys);
51 
52 int boot_cpuid_phys;
53 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
54 
55 int smp_hw_index[NR_CPUS];
56 EXPORT_SYMBOL(smp_hw_index);
57 
58 unsigned long ISA_DMA_THRESHOLD;
59 unsigned int DMA_MODE_READ;
60 unsigned int DMA_MODE_WRITE;
61 
62 EXPORT_SYMBOL(DMA_MODE_READ);
63 EXPORT_SYMBOL(DMA_MODE_WRITE);
64 
65 /*
66  * We're called here very early in the boot.
67  *
68  * Note that the kernel may be running at an address which is different
69  * from the address that it was linked at, so we must use RELOC/PTRRELOC
70  * to access static data (including strings).  -- paulus
71  */
72 notrace unsigned long __init early_init(unsigned long dt_ptr)
73 {
74 	unsigned long offset = reloc_offset();
75 
76 	/* First zero the BSS -- use memset_io, some platforms don't have
77 	 * caches on yet */
78 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
79 			__bss_stop - __bss_start);
80 
81 	/*
82 	 * Identify the CPU type and fix up code sections
83 	 * that depend on which cpu we have.
84 	 */
85 	identify_cpu(offset, mfspr(SPRN_PVR));
86 
87 	apply_feature_fixups();
88 
89 	return KERNELBASE + offset;
90 }
91 
92 
93 /*
94  * This is run before start_kernel(), the kernel has been relocated
95  * and we are running with enough of the MMU enabled to have our
96  * proper kernel virtual addresses
97  *
98  * We do the initial parsing of the flat device-tree and prepares
99  * for the MMU to be fully initialized.
100  */
101 notrace void __init machine_init(u64 dt_ptr)
102 {
103 	unsigned int *addr = (unsigned int *)patch_site_addr(&patch__memset_nocache);
104 	unsigned long insn;
105 
106 	/* Configure static keys first, now that we're relocated. */
107 	setup_feature_keys();
108 
109 	/* Enable early debugging if any specified (see udbg.h) */
110 	udbg_early_init();
111 
112 	patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);
113 
114 	insn = create_cond_branch(addr, branch_target(addr), 0x820000);
115 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
116 
117 	/* Do some early initialization based on the flat device tree */
118 	early_init_devtree(__va(dt_ptr));
119 
120 	early_init_mmu();
121 
122 	setup_kdump_trampoline();
123 }
124 
125 /* Checks "l2cr=xxxx" command-line option */
126 static int __init ppc_setup_l2cr(char *str)
127 {
128 	if (cpu_has_feature(CPU_FTR_L2CR)) {
129 		unsigned long val = simple_strtoul(str, NULL, 0);
130 		printk(KERN_INFO "l2cr set to %lx\n", val);
131 		_set_L2CR(0);		/* force invalidate by disable cache */
132 		_set_L2CR(val);		/* and enable it */
133 	}
134 	return 1;
135 }
136 __setup("l2cr=", ppc_setup_l2cr);
137 
138 /* Checks "l3cr=xxxx" command-line option */
139 static int __init ppc_setup_l3cr(char *str)
140 {
141 	if (cpu_has_feature(CPU_FTR_L3CR)) {
142 		unsigned long val = simple_strtoul(str, NULL, 0);
143 		printk(KERN_INFO "l3cr set to %lx\n", val);
144 		_set_L3CR(val);		/* and enable it */
145 	}
146 	return 1;
147 }
148 __setup("l3cr=", ppc_setup_l3cr);
149 
150 #ifdef CONFIG_GENERIC_NVRAM
151 
152 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
153 unsigned char nvram_read_byte(int addr)
154 {
155 	if (ppc_md.nvram_read_val)
156 		return ppc_md.nvram_read_val(addr);
157 	return 0xff;
158 }
159 EXPORT_SYMBOL(nvram_read_byte);
160 
161 void nvram_write_byte(unsigned char val, int addr)
162 {
163 	if (ppc_md.nvram_write_val)
164 		ppc_md.nvram_write_val(addr, val);
165 }
166 EXPORT_SYMBOL(nvram_write_byte);
167 
168 ssize_t nvram_get_size(void)
169 {
170 	if (ppc_md.nvram_size)
171 		return ppc_md.nvram_size();
172 	return -1;
173 }
174 EXPORT_SYMBOL(nvram_get_size);
175 
176 void nvram_sync(void)
177 {
178 	if (ppc_md.nvram_sync)
179 		ppc_md.nvram_sync();
180 }
181 EXPORT_SYMBOL(nvram_sync);
182 
183 #endif /* CONFIG_NVRAM */
184 
185 static int __init ppc_init(void)
186 {
187 	/* clear the progress line */
188 	if (ppc_md.progress)
189 		ppc_md.progress("             ", 0xffff);
190 
191 	/* call platform init */
192 	if (ppc_md.init != NULL) {
193 		ppc_md.init();
194 	}
195 	return 0;
196 }
197 arch_initcall(ppc_init);
198 
199 void __init irqstack_early_init(void)
200 {
201 	unsigned int i;
202 
203 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
204 	 * as the memblock is limited to lowmem by default */
205 	for_each_possible_cpu(i) {
206 		softirq_ctx[i] = (struct thread_info *)
207 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
208 		hardirq_ctx[i] = (struct thread_info *)
209 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
210 	}
211 }
212 
213 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
214 void __init exc_lvl_early_init(void)
215 {
216 	unsigned int i, hw_cpu;
217 
218 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
219 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
220 	for_each_possible_cpu(i) {
221 #ifdef CONFIG_SMP
222 		hw_cpu = get_hard_smp_processor_id(i);
223 #else
224 		hw_cpu = 0;
225 #endif
226 
227 		critirq_ctx[hw_cpu] = (struct thread_info *)
228 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
229 #ifdef CONFIG_BOOKE
230 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
231 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
232 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
233 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
234 #endif
235 	}
236 }
237 #endif
238 
239 void __init setup_power_save(void)
240 {
241 #ifdef CONFIG_PPC_BOOK3S_32
242 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
243 	    cpu_has_feature(CPU_FTR_CAN_NAP))
244 		ppc_md.power_save = ppc6xx_idle;
245 #endif
246 
247 #ifdef CONFIG_E500
248 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
249 	    cpu_has_feature(CPU_FTR_CAN_NAP))
250 		ppc_md.power_save = e500_idle;
251 #endif
252 }
253 
254 __init void initialize_cache_info(void)
255 {
256 	/*
257 	 * Set cache line size based on type of cpu as a default.
258 	 * Systems with OF can look in the properties on the cpu node(s)
259 	 * for a possibly more accurate value.
260 	 */
261 	dcache_bsize = cur_cpu_spec->dcache_bsize;
262 	icache_bsize = cur_cpu_spec->icache_bsize;
263 	ucache_bsize = 0;
264 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
265 		ucache_bsize = icache_bsize = dcache_bsize;
266 }
267