xref: /openbmc/linux/arch/sparc/mm/init_32.c (revision a2818ee4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/sparc/mm/init.c
4  *
5  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
6  *  Copyright (C) 1995 Eddie C. Dost (ecd@skynet.be)
7  *  Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
8  *  Copyright (C) 2000 Anton Blanchard (anton@samba.org)
9  */
10 
11 #include <linux/module.h>
12 #include <linux/signal.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/ptrace.h>
19 #include <linux/mman.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/initrd.h>
23 #include <linux/init.h>
24 #include <linux/highmem.h>
25 #include <linux/memblock.h>
26 #include <linux/pagemap.h>
27 #include <linux/poison.h>
28 #include <linux/gfp.h>
29 
30 #include <asm/sections.h>
31 #include <asm/page.h>
32 #include <asm/pgtable.h>
33 #include <asm/vaddrs.h>
34 #include <asm/pgalloc.h>	/* bug in asm-generic/tlb.h: check_pgt_cache */
35 #include <asm/setup.h>
36 #include <asm/tlb.h>
37 #include <asm/prom.h>
38 #include <asm/leon.h>
39 
40 #include "mm_32.h"
41 
42 unsigned long *sparc_valid_addr_bitmap;
43 EXPORT_SYMBOL(sparc_valid_addr_bitmap);
44 
45 unsigned long phys_base;
46 EXPORT_SYMBOL(phys_base);
47 
48 unsigned long pfn_base;
49 EXPORT_SYMBOL(pfn_base);
50 
51 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
52 
53 /* Initial ramdisk setup */
54 extern unsigned int sparc_ramdisk_image;
55 extern unsigned int sparc_ramdisk_size;
56 
57 unsigned long highstart_pfn, highend_pfn;
58 
59 unsigned long last_valid_pfn;
60 
61 unsigned long calc_highpages(void)
62 {
63 	int i;
64 	int nr = 0;
65 
66 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
67 		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
68 		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
69 
70 		if (end_pfn <= max_low_pfn)
71 			continue;
72 
73 		if (start_pfn < max_low_pfn)
74 			start_pfn = max_low_pfn;
75 
76 		nr += end_pfn - start_pfn;
77 	}
78 
79 	return nr;
80 }
81 
82 static unsigned long calc_max_low_pfn(void)
83 {
84 	int i;
85 	unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
86 	unsigned long curr_pfn, last_pfn;
87 
88 	last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
89 	for (i = 1; sp_banks[i].num_bytes != 0; i++) {
90 		curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
91 
92 		if (curr_pfn >= tmp) {
93 			if (last_pfn < tmp)
94 				tmp = last_pfn;
95 			break;
96 		}
97 
98 		last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
99 	}
100 
101 	return tmp;
102 }
103 
104 static void __init find_ramdisk(unsigned long end_of_phys_memory)
105 {
106 #ifdef CONFIG_BLK_DEV_INITRD
107 	unsigned long size;
108 
109 	/* Now have to check initial ramdisk, so that it won't pass
110 	 * the end of memory
111 	 */
112 	if (sparc_ramdisk_image) {
113 		if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
114 			sparc_ramdisk_image -= KERNBASE;
115 		initrd_start = sparc_ramdisk_image + phys_base;
116 		initrd_end = initrd_start + sparc_ramdisk_size;
117 		if (initrd_end > end_of_phys_memory) {
118 			printk(KERN_CRIT "initrd extends beyond end of memory "
119 			       "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
120 			       initrd_end, end_of_phys_memory);
121 			initrd_start = 0;
122 		} else {
123 			/* Reserve the initrd image area. */
124 			size = initrd_end - initrd_start;
125 			memblock_reserve(initrd_start, size);
126 
127 			initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
128 			initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
129 		}
130 	}
131 #endif
132 }
133 
134 unsigned long __init bootmem_init(unsigned long *pages_avail)
135 {
136 	unsigned long start_pfn, bytes_avail, size;
137 	unsigned long end_of_phys_memory = 0;
138 	unsigned long high_pages = 0;
139 	int i;
140 
141 	memblock_set_bottom_up(true);
142 	memblock_allow_resize();
143 
144 	bytes_avail = 0UL;
145 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
146 		end_of_phys_memory = sp_banks[i].base_addr +
147 			sp_banks[i].num_bytes;
148 		bytes_avail += sp_banks[i].num_bytes;
149 		if (cmdline_memory_size) {
150 			if (bytes_avail > cmdline_memory_size) {
151 				unsigned long slack = bytes_avail - cmdline_memory_size;
152 
153 				bytes_avail -= slack;
154 				end_of_phys_memory -= slack;
155 
156 				sp_banks[i].num_bytes -= slack;
157 				if (sp_banks[i].num_bytes == 0) {
158 					sp_banks[i].base_addr = 0xdeadbeef;
159 				} else {
160 					memblock_add(sp_banks[i].base_addr,
161 						     sp_banks[i].num_bytes);
162 					sp_banks[i+1].num_bytes = 0;
163 					sp_banks[i+1].base_addr = 0xdeadbeef;
164 				}
165 				break;
166 			}
167 		}
168 		memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
169 	}
170 
171 	/* Start with page aligned address of last symbol in kernel
172 	 * image.
173 	 */
174 	start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
175 
176 	/* Now shift down to get the real physical page frame number. */
177 	start_pfn >>= PAGE_SHIFT;
178 
179 	max_pfn = end_of_phys_memory >> PAGE_SHIFT;
180 
181 	max_low_pfn = max_pfn;
182 	highstart_pfn = highend_pfn = max_pfn;
183 
184 	if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
185 		highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
186 		max_low_pfn = calc_max_low_pfn();
187 		high_pages = calc_highpages();
188 		printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
189 		    high_pages >> (20 - PAGE_SHIFT));
190 	}
191 
192 	find_ramdisk(end_of_phys_memory);
193 
194 	/* Reserve the kernel text/data/bss. */
195 	size = (start_pfn << PAGE_SHIFT) - phys_base;
196 	memblock_reserve(phys_base, size);
197 
198 	size = memblock_phys_mem_size() - memblock_reserved_size();
199 	*pages_avail = (size >> PAGE_SHIFT) - high_pages;
200 
201 	return max_pfn;
202 }
203 
204 /*
205  * paging_init() sets up the page tables: We call the MMU specific
206  * init routine based upon the Sun model type on the Sparc.
207  *
208  */
209 void __init paging_init(void)
210 {
211 	srmmu_paging_init();
212 	prom_build_devicetree();
213 	of_fill_in_cpu_data();
214 	device_scan();
215 }
216 
217 static void __init taint_real_pages(void)
218 {
219 	int i;
220 
221 	for (i = 0; sp_banks[i].num_bytes; i++) {
222 		unsigned long start, end;
223 
224 		start = sp_banks[i].base_addr;
225 		end = start + sp_banks[i].num_bytes;
226 
227 		while (start < end) {
228 			set_bit(start >> 20, sparc_valid_addr_bitmap);
229 			start += PAGE_SIZE;
230 		}
231 	}
232 }
233 
234 static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
235 {
236 	unsigned long tmp;
237 
238 #ifdef CONFIG_DEBUG_HIGHMEM
239 	printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
240 #endif
241 
242 	for (tmp = start_pfn; tmp < end_pfn; tmp++)
243 		free_highmem_page(pfn_to_page(tmp));
244 }
245 
246 void __init mem_init(void)
247 {
248 	int i;
249 
250 	if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
251 		prom_printf("BUG: fixmap and pkmap areas overlap\n");
252 		prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
253 		       PKMAP_BASE,
254 		       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
255 		       FIXADDR_START);
256 		prom_printf("Please mail sparclinux@vger.kernel.org.\n");
257 		prom_halt();
258 	}
259 
260 
261 	/* Saves us work later. */
262 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
263 
264 	i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
265 	i += 1;
266 	sparc_valid_addr_bitmap = (unsigned long *)
267 		memblock_alloc_from(i << 2, SMP_CACHE_BYTES, 0UL);
268 
269 	if (sparc_valid_addr_bitmap == NULL) {
270 		prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
271 		prom_halt();
272 	}
273 	memset(sparc_valid_addr_bitmap, 0, i << 2);
274 
275 	taint_real_pages();
276 
277 	max_mapnr = last_valid_pfn - pfn_base;
278 	high_memory = __va(max_low_pfn << PAGE_SHIFT);
279 	memblock_free_all();
280 
281 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
282 		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
283 		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
284 
285 		if (end_pfn <= highstart_pfn)
286 			continue;
287 
288 		if (start_pfn < highstart_pfn)
289 			start_pfn = highstart_pfn;
290 
291 		map_high_region(start_pfn, end_pfn);
292 	}
293 
294 	mem_init_print_info(NULL);
295 }
296 
297 void free_initmem (void)
298 {
299 	free_initmem_default(POISON_FREE_INITMEM);
300 }
301 
302 #ifdef CONFIG_BLK_DEV_INITRD
303 void free_initrd_mem(unsigned long start, unsigned long end)
304 {
305 	free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
306 			   "initrd");
307 }
308 #endif
309 
310 void sparc_flush_page_to_ram(struct page *page)
311 {
312 	unsigned long vaddr = (unsigned long)page_address(page);
313 
314 	if (vaddr)
315 		__flush_page_to_ram(vaddr);
316 }
317 EXPORT_SYMBOL(sparc_flush_page_to_ram);
318