1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   * Common prep/pmac/chrp boot and setup code.
4   */
5  
6  #include <linux/module.h>
7  #include <linux/string.h>
8  #include <linux/sched.h>
9  #include <linux/init.h>
10  #include <linux/kernel.h>
11  #include <linux/reboot.h>
12  #include <linux/delay.h>
13  #include <linux/initrd.h>
14  #include <linux/tty.h>
15  #include <linux/seq_file.h>
16  #include <linux/root_dev.h>
17  #include <linux/cpu.h>
18  #include <linux/console.h>
19  #include <linux/memblock.h>
20  #include <linux/export.h>
21  #include <linux/nvram.h>
22  #include <linux/pgtable.h>
23  
24  #include <asm/io.h>
25  #include <asm/prom.h>
26  #include <asm/processor.h>
27  #include <asm/setup.h>
28  #include <asm/smp.h>
29  #include <asm/elf.h>
30  #include <asm/cputable.h>
31  #include <asm/bootx.h>
32  #include <asm/btext.h>
33  #include <asm/machdep.h>
34  #include <linux/uaccess.h>
35  #include <asm/pmac_feature.h>
36  #include <asm/sections.h>
37  #include <asm/nvram.h>
38  #include <asm/xmon.h>
39  #include <asm/time.h>
40  #include <asm/serial.h>
41  #include <asm/udbg.h>
42  #include <asm/code-patching.h>
43  #include <asm/cpu_has_feature.h>
44  #include <asm/asm-prototypes.h>
45  #include <asm/kdump.h>
46  #include <asm/feature-fixups.h>
47  #include <asm/early_ioremap.h>
48  
49  #include "setup.h"
50  
51  #define DBG(fmt...)
52  
53  extern void bootx_init(unsigned long r4, unsigned long phys);
54  
55  int boot_cpuid_phys;
56  EXPORT_SYMBOL_GPL(boot_cpuid_phys);
57  
58  int smp_hw_index[NR_CPUS];
59  EXPORT_SYMBOL(smp_hw_index);
60  
61  unsigned int DMA_MODE_READ;
62  unsigned int DMA_MODE_WRITE;
63  
64  EXPORT_SYMBOL(DMA_MODE_READ);
65  EXPORT_SYMBOL(DMA_MODE_WRITE);
66  
67  /*
68   * This is run before start_kernel(), the kernel has been relocated
69   * and we are running with enough of the MMU enabled to have our
70   * proper kernel virtual addresses
71   *
72   * We do the initial parsing of the flat device-tree and prepares
73   * for the MMU to be fully initialized.
74   */
machine_init(u64 dt_ptr)75  notrace void __init machine_init(u64 dt_ptr)
76  {
77  	u32 *addr = (u32 *)patch_site_addr(&patch__memset_nocache);
78  	struct ppc_inst insn;
79  
80  	/* Configure static keys first, now that we're relocated. */
81  	setup_feature_keys();
82  
83  	early_ioremap_init();
84  
85  	/* Enable early debugging if any specified (see udbg.h) */
86  	udbg_early_init();
87  
88  	patch_instruction_site(&patch__memcpy_nocache, ppc_inst(PPC_RAW_NOP()));
89  
90  	create_cond_branch(&insn, addr, branch_target(addr), 0x820000);
91  	patch_instruction(addr, insn);	/* replace b by bne cr0 */
92  
93  	/* Do some early initialization based on the flat device tree */
94  	early_init_devtree(__va(dt_ptr));
95  
96  	early_init_mmu();
97  
98  	setup_kdump_trampoline();
99  }
100  
101  /* Checks "l2cr=xxxx" command-line option */
ppc_setup_l2cr(char * str)102  static int __init ppc_setup_l2cr(char *str)
103  {
104  	if (cpu_has_feature(CPU_FTR_L2CR)) {
105  		unsigned long val = simple_strtoul(str, NULL, 0);
106  		printk(KERN_INFO "l2cr set to %lx\n", val);
107  		_set_L2CR(0);		/* force invalidate by disable cache */
108  		_set_L2CR(val);		/* and enable it */
109  	}
110  	return 1;
111  }
112  __setup("l2cr=", ppc_setup_l2cr);
113  
114  /* Checks "l3cr=xxxx" command-line option */
ppc_setup_l3cr(char * str)115  static int __init ppc_setup_l3cr(char *str)
116  {
117  	if (cpu_has_feature(CPU_FTR_L3CR)) {
118  		unsigned long val = simple_strtoul(str, NULL, 0);
119  		printk(KERN_INFO "l3cr set to %lx\n", val);
120  		_set_L3CR(val);		/* and enable it */
121  	}
122  	return 1;
123  }
124  __setup("l3cr=", ppc_setup_l3cr);
125  
ppc_init(void)126  static int __init ppc_init(void)
127  {
128  	/* clear the progress line */
129  	if (ppc_md.progress)
130  		ppc_md.progress("             ", 0xffff);
131  
132  	/* call platform init */
133  	if (ppc_md.init != NULL) {
134  		ppc_md.init();
135  	}
136  	return 0;
137  }
138  arch_initcall(ppc_init);
139  
alloc_stack(void)140  static void *__init alloc_stack(void)
141  {
142  	void *ptr = memblock_alloc(THREAD_SIZE, THREAD_ALIGN);
143  
144  	if (!ptr)
145  		panic("cannot allocate %d bytes for stack at %pS\n",
146  		      THREAD_SIZE, (void *)_RET_IP_);
147  
148  	return ptr;
149  }
150  
irqstack_early_init(void)151  void __init irqstack_early_init(void)
152  {
153  	unsigned int i;
154  
155  	if (IS_ENABLED(CONFIG_VMAP_STACK))
156  		return;
157  
158  	/* interrupt stacks must be in lowmem, we get that for free on ppc32
159  	 * as the memblock is limited to lowmem by default */
160  	for_each_possible_cpu(i) {
161  		softirq_ctx[i] = alloc_stack();
162  		hardirq_ctx[i] = alloc_stack();
163  	}
164  }
165  
166  #ifdef CONFIG_VMAP_STACK
167  void *emergency_ctx[NR_CPUS] __ro_after_init = {[0] = &init_stack};
168  
emergency_stack_init(void)169  void __init emergency_stack_init(void)
170  {
171  	unsigned int i;
172  
173  	for_each_possible_cpu(i)
174  		emergency_ctx[i] = alloc_stack();
175  }
176  #endif
177  
178  #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
exc_lvl_early_init(void)179  void __init exc_lvl_early_init(void)
180  {
181  	unsigned int i, hw_cpu;
182  
183  	/* interrupt stacks must be in lowmem, we get that for free on ppc32
184  	 * as the memblock is limited to lowmem by MEMBLOCK_REAL_LIMIT */
185  	for_each_possible_cpu(i) {
186  #ifdef CONFIG_SMP
187  		hw_cpu = get_hard_smp_processor_id(i);
188  #else
189  		hw_cpu = 0;
190  #endif
191  
192  		critirq_ctx[hw_cpu] = alloc_stack();
193  #ifdef CONFIG_BOOKE
194  		dbgirq_ctx[hw_cpu] = alloc_stack();
195  		mcheckirq_ctx[hw_cpu] = alloc_stack();
196  #endif
197  	}
198  }
199  #endif
200  
setup_power_save(void)201  void __init setup_power_save(void)
202  {
203  #ifdef CONFIG_PPC_BOOK3S_32
204  	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
205  	    cpu_has_feature(CPU_FTR_CAN_NAP))
206  		ppc_md.power_save = ppc6xx_idle;
207  #endif
208  
209  #ifdef CONFIG_E500
210  	if (cpu_has_feature(CPU_FTR_CAN_DOZE) ||
211  	    cpu_has_feature(CPU_FTR_CAN_NAP))
212  		ppc_md.power_save = e500_idle;
213  #endif
214  }
215  
initialize_cache_info(void)216  __init void initialize_cache_info(void)
217  {
218  	/*
219  	 * Set cache line size based on type of cpu as a default.
220  	 * Systems with OF can look in the properties on the cpu node(s)
221  	 * for a possibly more accurate value.
222  	 */
223  	dcache_bsize = cur_cpu_spec->dcache_bsize;
224  	icache_bsize = cur_cpu_spec->icache_bsize;
225  }
226