xref: /linux/arch/powerpc/kernel/setup_32.c (revision dee81e9886748594babac67c14b0f720148e255d)
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 <asm/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 
43 #define DBG(fmt...)
44 
45 extern void bootx_init(unsigned long r4, unsigned long phys);
46 
47 int boot_cpuid_phys;
48 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
49 
50 int smp_hw_index[NR_CPUS];
51 EXPORT_SYMBOL(smp_hw_index);
52 
53 unsigned long ISA_DMA_THRESHOLD;
54 unsigned int DMA_MODE_READ;
55 unsigned int DMA_MODE_WRITE;
56 
57 EXPORT_SYMBOL(ISA_DMA_THRESHOLD);
58 EXPORT_SYMBOL(DMA_MODE_READ);
59 EXPORT_SYMBOL(DMA_MODE_WRITE);
60 
61 /*
62  * These are used in binfmt_elf.c to put aux entries on the stack
63  * for each elf executable being started.
64  */
65 int dcache_bsize;
66 int icache_bsize;
67 int ucache_bsize;
68 
69 /*
70  * We're called here very early in the boot.
71  *
72  * Note that the kernel may be running at an address which is different
73  * from the address that it was linked at, so we must use RELOC/PTRRELOC
74  * to access static data (including strings).  -- paulus
75  */
76 notrace unsigned long __init early_init(unsigned long dt_ptr)
77 {
78 	unsigned long offset = reloc_offset();
79 
80 	/* First zero the BSS -- use memset_io, some platforms don't have
81 	 * caches on yet */
82 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
83 			__bss_stop - __bss_start);
84 
85 	/*
86 	 * Identify the CPU type and fix up code sections
87 	 * that depend on which cpu we have.
88 	 */
89 	identify_cpu(offset, mfspr(SPRN_PVR));
90 
91 	apply_feature_fixups();
92 
93 	return KERNELBASE + offset;
94 }
95 
96 
97 /*
98  * This is run before start_kernel(), the kernel has been relocated
99  * and we are running with enough of the MMU enabled to have our
100  * proper kernel virtual addresses
101  *
102  * Find out what kind of machine we're on and save any data we need
103  * from the early boot process (devtree is copied on pmac by prom_init()).
104  * This is called very early on the boot process, after a minimal
105  * MMU environment has been set up but before MMU_init is called.
106  */
107 extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
108 
109 notrace void __init machine_init(u64 dt_ptr)
110 {
111 	/* Enable early debugging if any specified (see udbg.h) */
112 	udbg_early_init();
113 
114 	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
115 	patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
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 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 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 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 
198 arch_initcall(ppc_init);
199 
200 void __init irqstack_early_init(void)
201 {
202 	unsigned int i;
203 
204 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
205 	 * as the memblock is limited to lowmem by default */
206 	for_each_possible_cpu(i) {
207 		softirq_ctx[i] = (struct thread_info *)
208 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
209 		hardirq_ctx[i] = (struct thread_info *)
210 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
211 	}
212 }
213 
214 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
215 void __init exc_lvl_early_init(void)
216 {
217 	unsigned int i, hw_cpu;
218 
219 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
220 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
221 	for_each_possible_cpu(i) {
222 #ifdef CONFIG_SMP
223 		hw_cpu = get_hard_smp_processor_id(i);
224 #else
225 		hw_cpu = 0;
226 #endif
227 
228 		critirq_ctx[hw_cpu] = (struct thread_info *)
229 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
230 #ifdef CONFIG_BOOKE
231 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
232 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
233 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
234 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
235 #endif
236 	}
237 }
238 #endif
239 
240 void __init setup_power_save(void)
241 {
242 #ifdef CONFIG_6xx
243 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
244 	    cpu_has_feature(CPU_FTR_CAN_NAP))
245 		ppc_md.power_save = ppc6xx_idle;
246 #endif
247 
248 #ifdef CONFIG_E500
249 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
250 	    cpu_has_feature(CPU_FTR_CAN_NAP))
251 		ppc_md.power_save = e500_idle;
252 #endif
253 }
254 
255 __init void initialize_cache_info(void)
256 {
257 	/*
258 	 * Set cache line size based on type of cpu as a default.
259 	 * Systems with OF can look in the properties on the cpu node(s)
260 	 * for a possibly more accurate value.
261 	 */
262 	dcache_bsize = cur_cpu_spec->dcache_bsize;
263 	icache_bsize = cur_cpu_spec->icache_bsize;
264 	ucache_bsize = 0;
265 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
266 		ucache_bsize = icache_bsize = dcache_bsize;
267 }
268