xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 293d5b43)
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 
20 #include <asm/io.h>
21 #include <asm/prom.h>
22 #include <asm/processor.h>
23 #include <asm/pgtable.h>
24 #include <asm/setup.h>
25 #include <asm/smp.h>
26 #include <asm/elf.h>
27 #include <asm/cputable.h>
28 #include <asm/bootx.h>
29 #include <asm/btext.h>
30 #include <asm/machdep.h>
31 #include <asm/uaccess.h>
32 #include <asm/pmac_feature.h>
33 #include <asm/sections.h>
34 #include <asm/nvram.h>
35 #include <asm/xmon.h>
36 #include <asm/time.h>
37 #include <asm/serial.h>
38 #include <asm/udbg.h>
39 #include <asm/code-patching.h>
40 #include <asm/cpu_has_feature.h>
41 
42 #define DBG(fmt...)
43 
44 extern void bootx_init(unsigned long r4, unsigned long phys);
45 
46 int boot_cpuid_phys;
47 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
48 
49 int smp_hw_index[NR_CPUS];
50 
51 unsigned long ISA_DMA_THRESHOLD;
52 unsigned int DMA_MODE_READ;
53 unsigned int DMA_MODE_WRITE;
54 
55 /*
56  * These are used in binfmt_elf.c to put aux entries on the stack
57  * for each elf executable being started.
58  */
59 int dcache_bsize;
60 int icache_bsize;
61 int ucache_bsize;
62 
63 /*
64  * We're called here very early in the boot.
65  *
66  * Note that the kernel may be running at an address which is different
67  * from the address that it was linked at, so we must use RELOC/PTRRELOC
68  * to access static data (including strings).  -- paulus
69  */
70 notrace unsigned long __init early_init(unsigned long dt_ptr)
71 {
72 	unsigned long offset = reloc_offset();
73 
74 	/* First zero the BSS -- use memset_io, some platforms don't have
75 	 * caches on yet */
76 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
77 			__bss_stop - __bss_start);
78 
79 	/*
80 	 * Identify the CPU type and fix up code sections
81 	 * that depend on which cpu we have.
82 	 */
83 	identify_cpu(offset, mfspr(SPRN_PVR));
84 
85 	apply_feature_fixups();
86 
87 	return KERNELBASE + offset;
88 }
89 
90 
91 /*
92  * This is run before start_kernel(), the kernel has been relocated
93  * and we are running with enough of the MMU enabled to have our
94  * proper kernel virtual addresses
95  *
96  * We do the initial parsing of the flat device-tree and prepares
97  * for the MMU to be fully initialized.
98  */
99 extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
100 
101 notrace void __init machine_init(u64 dt_ptr)
102 {
103 	/* Configure static keys first, now that we're relocated. */
104 	setup_feature_keys();
105 
106 	/* Enable early debugging if any specified (see udbg.h) */
107 	udbg_early_init();
108 
109 	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
110 	patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
111 
112 	/* Do some early initialization based on the flat device tree */
113 	early_init_devtree(__va(dt_ptr));
114 
115 	early_init_mmu();
116 
117 	setup_kdump_trampoline();
118 }
119 
120 /* Checks "l2cr=xxxx" command-line option */
121 int __init ppc_setup_l2cr(char *str)
122 {
123 	if (cpu_has_feature(CPU_FTR_L2CR)) {
124 		unsigned long val = simple_strtoul(str, NULL, 0);
125 		printk(KERN_INFO "l2cr set to %lx\n", val);
126 		_set_L2CR(0);		/* force invalidate by disable cache */
127 		_set_L2CR(val);		/* and enable it */
128 	}
129 	return 1;
130 }
131 __setup("l2cr=", ppc_setup_l2cr);
132 
133 /* Checks "l3cr=xxxx" command-line option */
134 int __init ppc_setup_l3cr(char *str)
135 {
136 	if (cpu_has_feature(CPU_FTR_L3CR)) {
137 		unsigned long val = simple_strtoul(str, NULL, 0);
138 		printk(KERN_INFO "l3cr set to %lx\n", val);
139 		_set_L3CR(val);		/* and enable it */
140 	}
141 	return 1;
142 }
143 __setup("l3cr=", ppc_setup_l3cr);
144 
145 #ifdef CONFIG_GENERIC_NVRAM
146 
147 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
148 unsigned char nvram_read_byte(int addr)
149 {
150 	if (ppc_md.nvram_read_val)
151 		return ppc_md.nvram_read_val(addr);
152 	return 0xff;
153 }
154 EXPORT_SYMBOL(nvram_read_byte);
155 
156 void nvram_write_byte(unsigned char val, int addr)
157 {
158 	if (ppc_md.nvram_write_val)
159 		ppc_md.nvram_write_val(addr, val);
160 }
161 EXPORT_SYMBOL(nvram_write_byte);
162 
163 ssize_t nvram_get_size(void)
164 {
165 	if (ppc_md.nvram_size)
166 		return ppc_md.nvram_size();
167 	return -1;
168 }
169 EXPORT_SYMBOL(nvram_get_size);
170 
171 void nvram_sync(void)
172 {
173 	if (ppc_md.nvram_sync)
174 		ppc_md.nvram_sync();
175 }
176 EXPORT_SYMBOL(nvram_sync);
177 
178 #endif /* CONFIG_NVRAM */
179 
180 int __init ppc_init(void)
181 {
182 	/* clear the progress line */
183 	if (ppc_md.progress)
184 		ppc_md.progress("             ", 0xffff);
185 
186 	/* call platform init */
187 	if (ppc_md.init != NULL) {
188 		ppc_md.init();
189 	}
190 	return 0;
191 }
192 
193 arch_initcall(ppc_init);
194 
195 void __init irqstack_early_init(void)
196 {
197 	unsigned int i;
198 
199 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
200 	 * as the memblock is limited to lowmem by default */
201 	for_each_possible_cpu(i) {
202 		softirq_ctx[i] = (struct thread_info *)
203 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
204 		hardirq_ctx[i] = (struct thread_info *)
205 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
206 	}
207 }
208 
209 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
210 void __init exc_lvl_early_init(void)
211 {
212 	unsigned int i, hw_cpu;
213 
214 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
215 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
216 	for_each_possible_cpu(i) {
217 #ifdef CONFIG_SMP
218 		hw_cpu = get_hard_smp_processor_id(i);
219 #else
220 		hw_cpu = 0;
221 #endif
222 
223 		critirq_ctx[hw_cpu] = (struct thread_info *)
224 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
225 #ifdef CONFIG_BOOKE
226 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
227 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
228 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
229 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
230 #endif
231 	}
232 }
233 #endif
234 
235 void __init setup_power_save(void)
236 {
237 #ifdef CONFIG_6xx
238 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
239 	    cpu_has_feature(CPU_FTR_CAN_NAP))
240 		ppc_md.power_save = ppc6xx_idle;
241 #endif
242 
243 #ifdef CONFIG_E500
244 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
245 	    cpu_has_feature(CPU_FTR_CAN_NAP))
246 		ppc_md.power_save = e500_idle;
247 #endif
248 }
249 
250 __init void initialize_cache_info(void)
251 {
252 	/*
253 	 * Set cache line size based on type of cpu as a default.
254 	 * Systems with OF can look in the properties on the cpu node(s)
255 	 * for a possibly more accurate value.
256 	 */
257 	dcache_bsize = cur_cpu_spec->dcache_bsize;
258 	icache_bsize = cur_cpu_spec->icache_bsize;
259 	ucache_bsize = 0;
260 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
261 		ucache_bsize = icache_bsize = dcache_bsize;
262 }
263