xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 726bd223)
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 
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  * We're called here very early in the boot.
63  *
64  * Note that the kernel may be running at an address which is different
65  * from the address that it was linked at, so we must use RELOC/PTRRELOC
66  * to access static data (including strings).  -- paulus
67  */
68 notrace unsigned long __init early_init(unsigned long dt_ptr)
69 {
70 	unsigned long offset = reloc_offset();
71 
72 	/* First zero the BSS -- use memset_io, some platforms don't have
73 	 * caches on yet */
74 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
75 			__bss_stop - __bss_start);
76 
77 	/*
78 	 * Identify the CPU type and fix up code sections
79 	 * that depend on which cpu we have.
80 	 */
81 	identify_cpu(offset, mfspr(SPRN_PVR));
82 
83 	apply_feature_fixups();
84 
85 	return KERNELBASE + offset;
86 }
87 
88 
89 /*
90  * This is run before start_kernel(), the kernel has been relocated
91  * and we are running with enough of the MMU enabled to have our
92  * proper kernel virtual addresses
93  *
94  * We do the initial parsing of the flat device-tree and prepares
95  * for the MMU to be fully initialized.
96  */
97 extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
98 
99 notrace void __init machine_init(u64 dt_ptr)
100 {
101 	/* Configure static keys first, now that we're relocated. */
102 	setup_feature_keys();
103 
104 	/* Enable early debugging if any specified (see udbg.h) */
105 	udbg_early_init();
106 
107 	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
108 	patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
109 
110 	/* Do some early initialization based on the flat device tree */
111 	early_init_devtree(__va(dt_ptr));
112 
113 	early_init_mmu();
114 
115 	setup_kdump_trampoline();
116 }
117 
118 /* Checks "l2cr=xxxx" command-line option */
119 int __init ppc_setup_l2cr(char *str)
120 {
121 	if (cpu_has_feature(CPU_FTR_L2CR)) {
122 		unsigned long val = simple_strtoul(str, NULL, 0);
123 		printk(KERN_INFO "l2cr set to %lx\n", val);
124 		_set_L2CR(0);		/* force invalidate by disable cache */
125 		_set_L2CR(val);		/* and enable it */
126 	}
127 	return 1;
128 }
129 __setup("l2cr=", ppc_setup_l2cr);
130 
131 /* Checks "l3cr=xxxx" command-line option */
132 int __init ppc_setup_l3cr(char *str)
133 {
134 	if (cpu_has_feature(CPU_FTR_L3CR)) {
135 		unsigned long val = simple_strtoul(str, NULL, 0);
136 		printk(KERN_INFO "l3cr set to %lx\n", val);
137 		_set_L3CR(val);		/* and enable it */
138 	}
139 	return 1;
140 }
141 __setup("l3cr=", ppc_setup_l3cr);
142 
143 #ifdef CONFIG_GENERIC_NVRAM
144 
145 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
146 unsigned char nvram_read_byte(int addr)
147 {
148 	if (ppc_md.nvram_read_val)
149 		return ppc_md.nvram_read_val(addr);
150 	return 0xff;
151 }
152 EXPORT_SYMBOL(nvram_read_byte);
153 
154 void nvram_write_byte(unsigned char val, int addr)
155 {
156 	if (ppc_md.nvram_write_val)
157 		ppc_md.nvram_write_val(addr, val);
158 }
159 EXPORT_SYMBOL(nvram_write_byte);
160 
161 ssize_t nvram_get_size(void)
162 {
163 	if (ppc_md.nvram_size)
164 		return ppc_md.nvram_size();
165 	return -1;
166 }
167 EXPORT_SYMBOL(nvram_get_size);
168 
169 void nvram_sync(void)
170 {
171 	if (ppc_md.nvram_sync)
172 		ppc_md.nvram_sync();
173 }
174 EXPORT_SYMBOL(nvram_sync);
175 
176 #endif /* CONFIG_NVRAM */
177 
178 int __init ppc_init(void)
179 {
180 	/* clear the progress line */
181 	if (ppc_md.progress)
182 		ppc_md.progress("             ", 0xffff);
183 
184 	/* call platform init */
185 	if (ppc_md.init != NULL) {
186 		ppc_md.init();
187 	}
188 	return 0;
189 }
190 
191 arch_initcall(ppc_init);
192 
193 void __init irqstack_early_init(void)
194 {
195 	unsigned int i;
196 
197 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
198 	 * as the memblock is limited to lowmem by default */
199 	for_each_possible_cpu(i) {
200 		softirq_ctx[i] = (struct thread_info *)
201 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
202 		hardirq_ctx[i] = (struct thread_info *)
203 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
204 	}
205 }
206 
207 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
208 void __init exc_lvl_early_init(void)
209 {
210 	unsigned int i, hw_cpu;
211 
212 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
213 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
214 	for_each_possible_cpu(i) {
215 #ifdef CONFIG_SMP
216 		hw_cpu = get_hard_smp_processor_id(i);
217 #else
218 		hw_cpu = 0;
219 #endif
220 
221 		critirq_ctx[hw_cpu] = (struct thread_info *)
222 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
223 #ifdef CONFIG_BOOKE
224 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
225 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
226 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
227 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
228 #endif
229 	}
230 }
231 #endif
232 
233 void __init setup_power_save(void)
234 {
235 #ifdef CONFIG_6xx
236 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
237 	    cpu_has_feature(CPU_FTR_CAN_NAP))
238 		ppc_md.power_save = ppc6xx_idle;
239 #endif
240 
241 #ifdef CONFIG_E500
242 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
243 	    cpu_has_feature(CPU_FTR_CAN_NAP))
244 		ppc_md.power_save = e500_idle;
245 #endif
246 }
247 
248 __init void initialize_cache_info(void)
249 {
250 	/*
251 	 * Set cache line size based on type of cpu as a default.
252 	 * Systems with OF can look in the properties on the cpu node(s)
253 	 * for a possibly more accurate value.
254 	 */
255 	dcache_bsize = cur_cpu_spec->dcache_bsize;
256 	icache_bsize = cur_cpu_spec->icache_bsize;
257 	ucache_bsize = 0;
258 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
259 		ucache_bsize = icache_bsize = dcache_bsize;
260 }
261