xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 828ff2ad)
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(ISA_DMA_THRESHOLD);
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 *)((unsigned long)&patch__memset_nocache +
105 					       patch__memset_nocache);
106 	unsigned long insn;
107 
108 	/* Configure static keys first, now that we're relocated. */
109 	setup_feature_keys();
110 
111 	/* Enable early debugging if any specified (see udbg.h) */
112 	udbg_early_init();
113 
114 	patch_instruction_site(&patch__memcpy_nocache, PPC_INST_NOP);
115 
116 	insn = create_cond_branch(addr, branch_target(addr), 0x820000);
117 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
118 
119 	/* Do some early initialization based on the flat device tree */
120 	early_init_devtree(__va(dt_ptr));
121 
122 	early_init_mmu();
123 
124 	setup_kdump_trampoline();
125 }
126 
127 /* Checks "l2cr=xxxx" command-line option */
128 static int __init ppc_setup_l2cr(char *str)
129 {
130 	if (cpu_has_feature(CPU_FTR_L2CR)) {
131 		unsigned long val = simple_strtoul(str, NULL, 0);
132 		printk(KERN_INFO "l2cr set to %lx\n", val);
133 		_set_L2CR(0);		/* force invalidate by disable cache */
134 		_set_L2CR(val);		/* and enable it */
135 	}
136 	return 1;
137 }
138 __setup("l2cr=", ppc_setup_l2cr);
139 
140 /* Checks "l3cr=xxxx" command-line option */
141 static int __init ppc_setup_l3cr(char *str)
142 {
143 	if (cpu_has_feature(CPU_FTR_L3CR)) {
144 		unsigned long val = simple_strtoul(str, NULL, 0);
145 		printk(KERN_INFO "l3cr set to %lx\n", val);
146 		_set_L3CR(val);		/* and enable it */
147 	}
148 	return 1;
149 }
150 __setup("l3cr=", ppc_setup_l3cr);
151 
152 #ifdef CONFIG_GENERIC_NVRAM
153 
154 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
155 unsigned char nvram_read_byte(int addr)
156 {
157 	if (ppc_md.nvram_read_val)
158 		return ppc_md.nvram_read_val(addr);
159 	return 0xff;
160 }
161 EXPORT_SYMBOL(nvram_read_byte);
162 
163 void nvram_write_byte(unsigned char val, int addr)
164 {
165 	if (ppc_md.nvram_write_val)
166 		ppc_md.nvram_write_val(addr, val);
167 }
168 EXPORT_SYMBOL(nvram_write_byte);
169 
170 ssize_t nvram_get_size(void)
171 {
172 	if (ppc_md.nvram_size)
173 		return ppc_md.nvram_size();
174 	return -1;
175 }
176 EXPORT_SYMBOL(nvram_get_size);
177 
178 void nvram_sync(void)
179 {
180 	if (ppc_md.nvram_sync)
181 		ppc_md.nvram_sync();
182 }
183 EXPORT_SYMBOL(nvram_sync);
184 
185 #endif /* CONFIG_NVRAM */
186 
187 static int __init ppc_init(void)
188 {
189 	/* clear the progress line */
190 	if (ppc_md.progress)
191 		ppc_md.progress("             ", 0xffff);
192 
193 	/* call platform init */
194 	if (ppc_md.init != NULL) {
195 		ppc_md.init();
196 	}
197 	return 0;
198 }
199 arch_initcall(ppc_init);
200 
201 void __init irqstack_early_init(void)
202 {
203 	unsigned int i;
204 
205 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
206 	 * as the memblock is limited to lowmem by default */
207 	for_each_possible_cpu(i) {
208 		softirq_ctx[i] = (struct thread_info *)
209 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
210 		hardirq_ctx[i] = (struct thread_info *)
211 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
212 	}
213 }
214 
215 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
216 void __init exc_lvl_early_init(void)
217 {
218 	unsigned int i, hw_cpu;
219 
220 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
221 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
222 	for_each_possible_cpu(i) {
223 #ifdef CONFIG_SMP
224 		hw_cpu = get_hard_smp_processor_id(i);
225 #else
226 		hw_cpu = 0;
227 #endif
228 
229 		critirq_ctx[hw_cpu] = (struct thread_info *)
230 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
231 #ifdef CONFIG_BOOKE
232 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
233 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
234 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
235 			__va(memblock_phys_alloc(THREAD_SIZE, THREAD_SIZE));
236 #endif
237 	}
238 }
239 #endif
240 
241 void __init setup_power_save(void)
242 {
243 #ifdef CONFIG_6xx
244 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
245 	    cpu_has_feature(CPU_FTR_CAN_NAP))
246 		ppc_md.power_save = ppc6xx_idle;
247 #endif
248 
249 #ifdef CONFIG_E500
250 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
251 	    cpu_has_feature(CPU_FTR_CAN_NAP))
252 		ppc_md.power_save = e500_idle;
253 #endif
254 }
255 
256 __init void initialize_cache_info(void)
257 {
258 	/*
259 	 * Set cache line size based on type of cpu as a default.
260 	 * Systems with OF can look in the properties on the cpu node(s)
261 	 * for a possibly more accurate value.
262 	 */
263 	dcache_bsize = cur_cpu_spec->dcache_bsize;
264 	icache_bsize = cur_cpu_spec->icache_bsize;
265 	ucache_bsize = 0;
266 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
267 		ucache_bsize = icache_bsize = dcache_bsize;
268 }
269