xref: /kernel/linux/linux-5.10/arch/sparc/mm/init_32.c (revision 8c2ecf20)
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/vaddrs.h>
33#include <asm/setup.h>
34#include <asm/tlb.h>
35#include <asm/prom.h>
36#include <asm/leon.h>
37
38#include "mm_32.h"
39
40unsigned long *sparc_valid_addr_bitmap;
41EXPORT_SYMBOL(sparc_valid_addr_bitmap);
42
43unsigned long phys_base;
44EXPORT_SYMBOL(phys_base);
45
46unsigned long pfn_base;
47EXPORT_SYMBOL(pfn_base);
48
49struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
50
51/* Initial ramdisk setup */
52extern unsigned int sparc_ramdisk_image;
53extern unsigned int sparc_ramdisk_size;
54
55unsigned long highstart_pfn, highend_pfn;
56
57unsigned long last_valid_pfn;
58
59unsigned long calc_highpages(void)
60{
61	int i;
62	int nr = 0;
63
64	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
65		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
66		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
67
68		if (end_pfn <= max_low_pfn)
69			continue;
70
71		if (start_pfn < max_low_pfn)
72			start_pfn = max_low_pfn;
73
74		nr += end_pfn - start_pfn;
75	}
76
77	return nr;
78}
79
80static unsigned long calc_max_low_pfn(void)
81{
82	int i;
83	unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
84	unsigned long curr_pfn, last_pfn;
85
86	last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
87	for (i = 1; sp_banks[i].num_bytes != 0; i++) {
88		curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
89
90		if (curr_pfn >= tmp) {
91			if (last_pfn < tmp)
92				tmp = last_pfn;
93			break;
94		}
95
96		last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
97	}
98
99	return tmp;
100}
101
102static void __init find_ramdisk(unsigned long end_of_phys_memory)
103{
104#ifdef CONFIG_BLK_DEV_INITRD
105	unsigned long size;
106
107	/* Now have to check initial ramdisk, so that it won't pass
108	 * the end of memory
109	 */
110	if (sparc_ramdisk_image) {
111		if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
112			sparc_ramdisk_image -= KERNBASE;
113		initrd_start = sparc_ramdisk_image + phys_base;
114		initrd_end = initrd_start + sparc_ramdisk_size;
115		if (initrd_end > end_of_phys_memory) {
116			printk(KERN_CRIT "initrd extends beyond end of memory "
117			       "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
118			       initrd_end, end_of_phys_memory);
119			initrd_start = 0;
120		} else {
121			/* Reserve the initrd image area. */
122			size = initrd_end - initrd_start;
123			memblock_reserve(initrd_start, size);
124
125			initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
126			initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
127		}
128	}
129#endif
130}
131
132unsigned long __init bootmem_init(unsigned long *pages_avail)
133{
134	unsigned long start_pfn, bytes_avail, size;
135	unsigned long end_of_phys_memory = 0;
136	unsigned long high_pages = 0;
137	int i;
138
139	memblock_set_bottom_up(true);
140	memblock_allow_resize();
141
142	bytes_avail = 0UL;
143	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
144		end_of_phys_memory = sp_banks[i].base_addr +
145			sp_banks[i].num_bytes;
146		bytes_avail += sp_banks[i].num_bytes;
147		if (cmdline_memory_size) {
148			if (bytes_avail > cmdline_memory_size) {
149				unsigned long slack = bytes_avail - cmdline_memory_size;
150
151				bytes_avail -= slack;
152				end_of_phys_memory -= slack;
153
154				sp_banks[i].num_bytes -= slack;
155				if (sp_banks[i].num_bytes == 0) {
156					sp_banks[i].base_addr = 0xdeadbeef;
157				} else {
158					memblock_add(sp_banks[i].base_addr,
159						     sp_banks[i].num_bytes);
160					sp_banks[i+1].num_bytes = 0;
161					sp_banks[i+1].base_addr = 0xdeadbeef;
162				}
163				break;
164			}
165		}
166		memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
167	}
168
169	/* Start with page aligned address of last symbol in kernel
170	 * image.
171	 */
172	start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
173
174	/* Now shift down to get the real physical page frame number. */
175	start_pfn >>= PAGE_SHIFT;
176
177	max_pfn = end_of_phys_memory >> PAGE_SHIFT;
178
179	max_low_pfn = max_pfn;
180	highstart_pfn = highend_pfn = max_pfn;
181
182	if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
183		highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
184		max_low_pfn = calc_max_low_pfn();
185		high_pages = calc_highpages();
186		printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
187		    high_pages >> (20 - PAGE_SHIFT));
188	}
189
190	find_ramdisk(end_of_phys_memory);
191
192	/* Reserve the kernel text/data/bss. */
193	size = (start_pfn << PAGE_SHIFT) - phys_base;
194	memblock_reserve(phys_base, size);
195	memblock_add(phys_base, size);
196
197	size = memblock_phys_mem_size() - memblock_reserved_size();
198	*pages_avail = (size >> PAGE_SHIFT) - high_pages;
199
200	/* Only allow low memory to be allocated via memblock allocation */
201	memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
202
203	return max_pfn;
204}
205
206/*
207 * paging_init() sets up the page tables: We call the MMU specific
208 * init routine based upon the Sun model type on the Sparc.
209 *
210 */
211void __init paging_init(void)
212{
213	srmmu_paging_init();
214	prom_build_devicetree();
215	of_fill_in_cpu_data();
216	device_scan();
217}
218
219static void __init taint_real_pages(void)
220{
221	int i;
222
223	for (i = 0; sp_banks[i].num_bytes; i++) {
224		unsigned long start, end;
225
226		start = sp_banks[i].base_addr;
227		end = start + sp_banks[i].num_bytes;
228
229		while (start < end) {
230			set_bit(start >> 20, sparc_valid_addr_bitmap);
231			start += PAGE_SIZE;
232		}
233	}
234}
235
236static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
237{
238	unsigned long tmp;
239
240#ifdef CONFIG_DEBUG_HIGHMEM
241	printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
242#endif
243
244	for (tmp = start_pfn; tmp < end_pfn; tmp++)
245		free_highmem_page(pfn_to_page(tmp));
246}
247
248void __init mem_init(void)
249{
250	int i;
251
252	if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
253		prom_printf("BUG: fixmap and pkmap areas overlap\n");
254		prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
255		       PKMAP_BASE,
256		       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
257		       FIXADDR_START);
258		prom_printf("Please mail sparclinux@vger.kernel.org.\n");
259		prom_halt();
260	}
261
262
263	/* Saves us work later. */
264	memset((void *)empty_zero_page, 0, PAGE_SIZE);
265
266	i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
267	i += 1;
268	sparc_valid_addr_bitmap = (unsigned long *)
269		memblock_alloc(i << 2, SMP_CACHE_BYTES);
270
271	if (sparc_valid_addr_bitmap == NULL) {
272		prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
273		prom_halt();
274	}
275	memset(sparc_valid_addr_bitmap, 0, i << 2);
276
277	taint_real_pages();
278
279	max_mapnr = last_valid_pfn - pfn_base;
280	high_memory = __va(max_low_pfn << PAGE_SHIFT);
281	memblock_free_all();
282
283	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
284		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
285		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
286
287		if (end_pfn <= highstart_pfn)
288			continue;
289
290		if (start_pfn < highstart_pfn)
291			start_pfn = highstart_pfn;
292
293		map_high_region(start_pfn, end_pfn);
294	}
295
296	mem_init_print_info(NULL);
297}
298
299void sparc_flush_page_to_ram(struct page *page)
300{
301	unsigned long vaddr = (unsigned long)page_address(page);
302
303	if (vaddr)
304		__flush_page_to_ram(vaddr);
305}
306EXPORT_SYMBOL(sparc_flush_page_to_ram);
307