xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 3e26a691)
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/mmu_context.h>
40 #include <asm/epapr_hcalls.h>
41 #include <asm/code-patching.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 
52 unsigned long ISA_DMA_THRESHOLD;
53 unsigned int DMA_MODE_READ;
54 unsigned int DMA_MODE_WRITE;
55 
56 /*
57  * These are used in binfmt_elf.c to put aux entries on the stack
58  * for each elf executable being started.
59  */
60 int dcache_bsize;
61 int icache_bsize;
62 int ucache_bsize;
63 
64 /*
65  * We're called here very early in the boot.  We determine the machine
66  * type and call the appropriate low-level setup functions.
67  *  -- Cort <cort@fsmlabs.com>
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 	struct cpu_spec *spec;
77 
78 	/* First zero the BSS -- use memset_io, some platforms don't have
79 	 * caches on yet */
80 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
81 			__bss_stop - __bss_start);
82 
83 	/*
84 	 * Identify the CPU type and fix up code sections
85 	 * that depend on which cpu we have.
86 	 */
87 	spec = identify_cpu(offset, mfspr(SPRN_PVR));
88 
89 	do_feature_fixups(spec->cpu_features,
90 			  PTRRELOC(&__start___ftr_fixup),
91 			  PTRRELOC(&__stop___ftr_fixup));
92 
93 	do_feature_fixups(spec->mmu_features,
94 			  PTRRELOC(&__start___mmu_ftr_fixup),
95 			  PTRRELOC(&__stop___mmu_ftr_fixup));
96 
97 	do_lwsync_fixups(spec->cpu_features,
98 			 PTRRELOC(&__start___lwsync_fixup),
99 			 PTRRELOC(&__stop___lwsync_fixup));
100 
101 	do_final_fixups();
102 
103 	return KERNELBASE + offset;
104 }
105 
106 
107 /*
108  * Find out what kind of machine we're on and save any data we need
109  * from the early boot process (devtree is copied on pmac by prom_init()).
110  * This is called very early on the boot process, after a minimal
111  * MMU environment has been set up but before MMU_init is called.
112  */
113 extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
114 
115 notrace void __init machine_init(u64 dt_ptr)
116 {
117 	/* Enable early debugging if any specified (see udbg.h) */
118 	udbg_early_init();
119 
120 	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
121 	patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
122 
123 	/* Do some early initialization based on the flat device tree */
124 	early_init_devtree(__va(dt_ptr));
125 
126 	epapr_paravirt_early_init();
127 
128 	early_init_mmu();
129 
130 	probe_machine();
131 
132 	setup_kdump_trampoline();
133 
134 #ifdef CONFIG_6xx
135 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
136 	    cpu_has_feature(CPU_FTR_CAN_NAP))
137 		ppc_md.power_save = ppc6xx_idle;
138 #endif
139 
140 #ifdef CONFIG_E500
141 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
142 	    cpu_has_feature(CPU_FTR_CAN_NAP))
143 		ppc_md.power_save = e500_idle;
144 #endif
145 	if (ppc_md.progress)
146 		ppc_md.progress("id mach(): done", 0x200);
147 }
148 
149 /* Checks "l2cr=xxxx" command-line option */
150 int __init ppc_setup_l2cr(char *str)
151 {
152 	if (cpu_has_feature(CPU_FTR_L2CR)) {
153 		unsigned long val = simple_strtoul(str, NULL, 0);
154 		printk(KERN_INFO "l2cr set to %lx\n", val);
155 		_set_L2CR(0);		/* force invalidate by disable cache */
156 		_set_L2CR(val);		/* and enable it */
157 	}
158 	return 1;
159 }
160 __setup("l2cr=", ppc_setup_l2cr);
161 
162 /* Checks "l3cr=xxxx" command-line option */
163 int __init ppc_setup_l3cr(char *str)
164 {
165 	if (cpu_has_feature(CPU_FTR_L3CR)) {
166 		unsigned long val = simple_strtoul(str, NULL, 0);
167 		printk(KERN_INFO "l3cr set to %lx\n", val);
168 		_set_L3CR(val);		/* and enable it */
169 	}
170 	return 1;
171 }
172 __setup("l3cr=", ppc_setup_l3cr);
173 
174 #ifdef CONFIG_GENERIC_NVRAM
175 
176 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
177 unsigned char nvram_read_byte(int addr)
178 {
179 	if (ppc_md.nvram_read_val)
180 		return ppc_md.nvram_read_val(addr);
181 	return 0xff;
182 }
183 EXPORT_SYMBOL(nvram_read_byte);
184 
185 void nvram_write_byte(unsigned char val, int addr)
186 {
187 	if (ppc_md.nvram_write_val)
188 		ppc_md.nvram_write_val(addr, val);
189 }
190 EXPORT_SYMBOL(nvram_write_byte);
191 
192 ssize_t nvram_get_size(void)
193 {
194 	if (ppc_md.nvram_size)
195 		return ppc_md.nvram_size();
196 	return -1;
197 }
198 EXPORT_SYMBOL(nvram_get_size);
199 
200 void nvram_sync(void)
201 {
202 	if (ppc_md.nvram_sync)
203 		ppc_md.nvram_sync();
204 }
205 EXPORT_SYMBOL(nvram_sync);
206 
207 #endif /* CONFIG_NVRAM */
208 
209 int __init ppc_init(void)
210 {
211 	/* clear the progress line */
212 	if (ppc_md.progress)
213 		ppc_md.progress("             ", 0xffff);
214 
215 	/* call platform init */
216 	if (ppc_md.init != NULL) {
217 		ppc_md.init();
218 	}
219 	return 0;
220 }
221 
222 arch_initcall(ppc_init);
223 
224 static void __init irqstack_early_init(void)
225 {
226 	unsigned int i;
227 
228 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
229 	 * as the memblock is limited to lowmem by default */
230 	for_each_possible_cpu(i) {
231 		softirq_ctx[i] = (struct thread_info *)
232 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
233 		hardirq_ctx[i] = (struct thread_info *)
234 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
235 	}
236 }
237 
238 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
239 static void __init exc_lvl_early_init(void)
240 {
241 	unsigned int i, hw_cpu;
242 
243 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
244 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
245 	for_each_possible_cpu(i) {
246 #ifdef CONFIG_SMP
247 		hw_cpu = get_hard_smp_processor_id(i);
248 #else
249 		hw_cpu = 0;
250 #endif
251 
252 		critirq_ctx[hw_cpu] = (struct thread_info *)
253 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
254 #ifdef CONFIG_BOOKE
255 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
256 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
257 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
258 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
259 #endif
260 	}
261 }
262 #else
263 #define exc_lvl_early_init()
264 #endif
265 
266 /* Warning, IO base is not yet inited */
267 void __init setup_arch(char **cmdline_p)
268 {
269 	*cmdline_p = boot_command_line;
270 
271 	/* so udelay does something sensible, assume <= 1000 bogomips */
272 	loops_per_jiffy = 500000000 / HZ;
273 
274 	unflatten_device_tree();
275 	check_for_initrd();
276 
277 	if (ppc_md.init_early)
278 		ppc_md.init_early();
279 
280 	find_legacy_serial_ports();
281 
282 	smp_setup_cpu_maps();
283 
284 	/* Register early console */
285 	register_early_udbg_console();
286 
287 	xmon_setup();
288 
289 	/*
290 	 * Set cache line size based on type of cpu as a default.
291 	 * Systems with OF can look in the properties on the cpu node(s)
292 	 * for a possibly more accurate value.
293 	 */
294 	dcache_bsize = cur_cpu_spec->dcache_bsize;
295 	icache_bsize = cur_cpu_spec->icache_bsize;
296 	ucache_bsize = 0;
297 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
298 		ucache_bsize = icache_bsize = dcache_bsize;
299 
300 	if (ppc_md.panic)
301 		setup_panic();
302 
303 	init_mm.start_code = (unsigned long)_stext;
304 	init_mm.end_code = (unsigned long) _etext;
305 	init_mm.end_data = (unsigned long) _edata;
306 	init_mm.brk = klimit;
307 
308 	exc_lvl_early_init();
309 
310 	irqstack_early_init();
311 
312 	initmem_init();
313 	if ( ppc_md.progress ) ppc_md.progress("setup_arch: initmem", 0x3eab);
314 
315 #ifdef CONFIG_DUMMY_CONSOLE
316 	conswitchp = &dummy_con;
317 #endif
318 
319 	if (ppc_md.setup_arch)
320 		ppc_md.setup_arch();
321 	if ( ppc_md.progress ) ppc_md.progress("arch: exit", 0x3eab);
322 
323 	paging_init();
324 
325 	/* Initialize the MMU context management stuff */
326 	mmu_context_init();
327 }
328