xref: /openbmc/linux/arch/powerpc/kernel/setup_32.c (revision 7e6f7d24)
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 
44 #define DBG(fmt...)
45 
46 extern void bootx_init(unsigned long r4, unsigned long phys);
47 
48 int boot_cpuid_phys;
49 EXPORT_SYMBOL_GPL(boot_cpuid_phys);
50 
51 int smp_hw_index[NR_CPUS];
52 EXPORT_SYMBOL(smp_hw_index);
53 
54 unsigned long ISA_DMA_THRESHOLD;
55 unsigned int DMA_MODE_READ;
56 unsigned int DMA_MODE_WRITE;
57 
58 EXPORT_SYMBOL(ISA_DMA_THRESHOLD);
59 EXPORT_SYMBOL(DMA_MODE_READ);
60 EXPORT_SYMBOL(DMA_MODE_WRITE);
61 
62 /*
63  * We're called here very early in the boot.
64  *
65  * Note that the kernel may be running at an address which is different
66  * from the address that it was linked at, so we must use RELOC/PTRRELOC
67  * to access static data (including strings).  -- paulus
68  */
69 notrace unsigned long __init early_init(unsigned long dt_ptr)
70 {
71 	unsigned long offset = reloc_offset();
72 
73 	/* First zero the BSS -- use memset_io, some platforms don't have
74 	 * caches on yet */
75 	memset_io((void __iomem *)PTRRELOC(&__bss_start), 0,
76 			__bss_stop - __bss_start);
77 
78 	/*
79 	 * Identify the CPU type and fix up code sections
80 	 * that depend on which cpu we have.
81 	 */
82 	identify_cpu(offset, mfspr(SPRN_PVR));
83 
84 	apply_feature_fixups();
85 
86 	return KERNELBASE + offset;
87 }
88 
89 
90 /*
91  * This is run before start_kernel(), the kernel has been relocated
92  * and we are running with enough of the MMU enabled to have our
93  * proper kernel virtual addresses
94  *
95  * We do the initial parsing of the flat device-tree and prepares
96  * for the MMU to be fully initialized.
97  */
98 extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
99 
100 notrace void __init machine_init(u64 dt_ptr)
101 {
102 	unsigned int *addr = &memset_nocache_branch;
103 	unsigned long insn;
104 
105 	/* Configure static keys first, now that we're relocated. */
106 	setup_feature_keys();
107 
108 	/* Enable early debugging if any specified (see udbg.h) */
109 	udbg_early_init();
110 
111 	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
112 
113 	insn = create_cond_branch(addr, branch_target(addr), 0x820000);
114 	patch_instruction(addr, insn);	/* replace b by bne cr0 */
115 
116 	/* Do some early initialization based on the flat device tree */
117 	early_init_devtree(__va(dt_ptr));
118 
119 	early_init_mmu();
120 
121 	setup_kdump_trampoline();
122 }
123 
124 /* Checks "l2cr=xxxx" command-line option */
125 static int __init ppc_setup_l2cr(char *str)
126 {
127 	if (cpu_has_feature(CPU_FTR_L2CR)) {
128 		unsigned long val = simple_strtoul(str, NULL, 0);
129 		printk(KERN_INFO "l2cr set to %lx\n", val);
130 		_set_L2CR(0);		/* force invalidate by disable cache */
131 		_set_L2CR(val);		/* and enable it */
132 	}
133 	return 1;
134 }
135 __setup("l2cr=", ppc_setup_l2cr);
136 
137 /* Checks "l3cr=xxxx" command-line option */
138 static int __init ppc_setup_l3cr(char *str)
139 {
140 	if (cpu_has_feature(CPU_FTR_L3CR)) {
141 		unsigned long val = simple_strtoul(str, NULL, 0);
142 		printk(KERN_INFO "l3cr set to %lx\n", val);
143 		_set_L3CR(val);		/* and enable it */
144 	}
145 	return 1;
146 }
147 __setup("l3cr=", ppc_setup_l3cr);
148 
149 #ifdef CONFIG_GENERIC_NVRAM
150 
151 /* Generic nvram hooks used by drivers/char/gen_nvram.c */
152 unsigned char nvram_read_byte(int addr)
153 {
154 	if (ppc_md.nvram_read_val)
155 		return ppc_md.nvram_read_val(addr);
156 	return 0xff;
157 }
158 EXPORT_SYMBOL(nvram_read_byte);
159 
160 void nvram_write_byte(unsigned char val, int addr)
161 {
162 	if (ppc_md.nvram_write_val)
163 		ppc_md.nvram_write_val(addr, val);
164 }
165 EXPORT_SYMBOL(nvram_write_byte);
166 
167 ssize_t nvram_get_size(void)
168 {
169 	if (ppc_md.nvram_size)
170 		return ppc_md.nvram_size();
171 	return -1;
172 }
173 EXPORT_SYMBOL(nvram_get_size);
174 
175 void nvram_sync(void)
176 {
177 	if (ppc_md.nvram_sync)
178 		ppc_md.nvram_sync();
179 }
180 EXPORT_SYMBOL(nvram_sync);
181 
182 #endif /* CONFIG_NVRAM */
183 
184 static int __init ppc_init(void)
185 {
186 	/* clear the progress line */
187 	if (ppc_md.progress)
188 		ppc_md.progress("             ", 0xffff);
189 
190 	/* call platform init */
191 	if (ppc_md.init != NULL) {
192 		ppc_md.init();
193 	}
194 	return 0;
195 }
196 arch_initcall(ppc_init);
197 
198 void __init irqstack_early_init(void)
199 {
200 	unsigned int i;
201 
202 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
203 	 * as the memblock is limited to lowmem by default */
204 	for_each_possible_cpu(i) {
205 		softirq_ctx[i] = (struct thread_info *)
206 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
207 		hardirq_ctx[i] = (struct thread_info *)
208 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
209 	}
210 }
211 
212 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
213 void __init exc_lvl_early_init(void)
214 {
215 	unsigned int i, hw_cpu;
216 
217 	/* interrupt stacks must be in lowmem, we get that for free on ppc32
218 	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
219 	for_each_possible_cpu(i) {
220 #ifdef CONFIG_SMP
221 		hw_cpu = get_hard_smp_processor_id(i);
222 #else
223 		hw_cpu = 0;
224 #endif
225 
226 		critirq_ctx[hw_cpu] = (struct thread_info *)
227 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
228 #ifdef CONFIG_BOOKE
229 		dbgirq_ctx[hw_cpu] = (struct thread_info *)
230 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
231 		mcheckirq_ctx[hw_cpu] = (struct thread_info *)
232 			__va(memblock_alloc(THREAD_SIZE, THREAD_SIZE));
233 #endif
234 	}
235 }
236 #endif
237 
238 void __init setup_power_save(void)
239 {
240 #ifdef CONFIG_6xx
241 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
242 	    cpu_has_feature(CPU_FTR_CAN_NAP))
243 		ppc_md.power_save = ppc6xx_idle;
244 #endif
245 
246 #ifdef CONFIG_E500
247 	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
248 	    cpu_has_feature(CPU_FTR_CAN_NAP))
249 		ppc_md.power_save = e500_idle;
250 #endif
251 }
252 
253 __init void initialize_cache_info(void)
254 {
255 	/*
256 	 * Set cache line size based on type of cpu as a default.
257 	 * Systems with OF can look in the properties on the cpu node(s)
258 	 * for a possibly more accurate value.
259 	 */
260 	dcache_bsize = cur_cpu_spec->dcache_bsize;
261 	icache_bsize = cur_cpu_spec->icache_bsize;
262 	ucache_bsize = 0;
263 	if (cpu_has_feature(CPU_FTR_UNIFIED_ID_CACHE))
264 		ucache_bsize = icache_bsize = dcache_bsize;
265 }
266