1 /*
2  *  linux/arch/sparc/mm/init.c
3  *
4  *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5  *  Copyright (C) 1995 Eddie C. Dost (ecd@skynet.be)
6  *  Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7  *  Copyright (C) 2000 Anton Blanchard (anton@samba.org)
8  */
9 
10 #include <linux/module.h>
11 #include <linux/signal.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 #include <linux/ptrace.h>
18 #include <linux/mman.h>
19 #include <linux/mm.h>
20 #include <linux/swap.h>
21 #include <linux/initrd.h>
22 #include <linux/init.h>
23 #include <linux/highmem.h>
24 #include <linux/bootmem.h>
25 #include <linux/pagemap.h>
26 #include <linux/poison.h>
27 #include <linux/gfp.h>
28 
29 #include <asm/sections.h>
30 #include <asm/vac-ops.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/tlb.h>
36 #include <asm/prom.h>
37 #include <asm/leon.h>
38 
39 unsigned long *sparc_valid_addr_bitmap;
40 EXPORT_SYMBOL(sparc_valid_addr_bitmap);
41 
42 unsigned long phys_base;
43 EXPORT_SYMBOL(phys_base);
44 
45 unsigned long pfn_base;
46 EXPORT_SYMBOL(pfn_base);
47 
48 unsigned long page_kernel;
49 EXPORT_SYMBOL(page_kernel);
50 
51 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
52 unsigned long sparc_unmapped_base;
53 
54 struct pgtable_cache_struct pgt_quicklists;
55 
56 /* Initial ramdisk setup */
57 extern unsigned int sparc_ramdisk_image;
58 extern unsigned int sparc_ramdisk_size;
59 
60 unsigned long highstart_pfn, highend_pfn;
61 
62 pte_t *kmap_pte;
63 pgprot_t kmap_prot;
64 
65 #define kmap_get_fixmap_pte(vaddr) \
66 	pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
67 
kmap_init(void)68 void __init kmap_init(void)
69 {
70 	/* cache the first kmap pte */
71 	kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
72 	kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
73 }
74 
show_mem(unsigned int filter)75 void show_mem(unsigned int filter)
76 {
77 	printk("Mem-info:\n");
78 	show_free_areas(filter);
79 	printk("Free swap:       %6ldkB\n",
80 	       nr_swap_pages << (PAGE_SHIFT-10));
81 	printk("%ld pages of RAM\n", totalram_pages);
82 	printk("%ld free pages\n", nr_free_pages());
83 #if 0 /* undefined pgtable_cache_size, pgd_cache_size */
84 	printk("%ld pages in page table cache\n",pgtable_cache_size);
85 #ifndef CONFIG_SMP
86 	if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
87 		printk("%ld entries in page dir cache\n",pgd_cache_size);
88 #endif
89 #endif
90 }
91 
sparc_context_init(int numctx)92 void __init sparc_context_init(int numctx)
93 {
94 	int ctx;
95 
96 	ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);
97 
98 	for(ctx = 0; ctx < numctx; ctx++) {
99 		struct ctx_list *clist;
100 
101 		clist = (ctx_list_pool + ctx);
102 		clist->ctx_number = ctx;
103 		clist->ctx_mm = NULL;
104 	}
105 	ctx_free.next = ctx_free.prev = &ctx_free;
106 	ctx_used.next = ctx_used.prev = &ctx_used;
107 	for(ctx = 0; ctx < numctx; ctx++)
108 		add_to_free_ctxlist(ctx_list_pool + ctx);
109 }
110 
111 extern unsigned long cmdline_memory_size;
112 unsigned long last_valid_pfn;
113 
calc_highpages(void)114 unsigned long calc_highpages(void)
115 {
116 	int i;
117 	int nr = 0;
118 
119 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
120 		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
121 		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
122 
123 		if (end_pfn <= max_low_pfn)
124 			continue;
125 
126 		if (start_pfn < max_low_pfn)
127 			start_pfn = max_low_pfn;
128 
129 		nr += end_pfn - start_pfn;
130 	}
131 
132 	return nr;
133 }
134 
calc_max_low_pfn(void)135 static unsigned long calc_max_low_pfn(void)
136 {
137 	int i;
138 	unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
139 	unsigned long curr_pfn, last_pfn;
140 
141 	last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
142 	for (i = 1; sp_banks[i].num_bytes != 0; i++) {
143 		curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
144 
145 		if (curr_pfn >= tmp) {
146 			if (last_pfn < tmp)
147 				tmp = last_pfn;
148 			break;
149 		}
150 
151 		last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
152 	}
153 
154 	return tmp;
155 }
156 
bootmem_init(unsigned long * pages_avail)157 unsigned long __init bootmem_init(unsigned long *pages_avail)
158 {
159 	unsigned long bootmap_size, start_pfn;
160 	unsigned long end_of_phys_memory = 0UL;
161 	unsigned long bootmap_pfn, bytes_avail, size;
162 	int i;
163 
164 	bytes_avail = 0UL;
165 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
166 		end_of_phys_memory = sp_banks[i].base_addr +
167 			sp_banks[i].num_bytes;
168 		bytes_avail += sp_banks[i].num_bytes;
169 		if (cmdline_memory_size) {
170 			if (bytes_avail > cmdline_memory_size) {
171 				unsigned long slack = bytes_avail - cmdline_memory_size;
172 
173 				bytes_avail -= slack;
174 				end_of_phys_memory -= slack;
175 
176 				sp_banks[i].num_bytes -= slack;
177 				if (sp_banks[i].num_bytes == 0) {
178 					sp_banks[i].base_addr = 0xdeadbeef;
179 				} else {
180 					sp_banks[i+1].num_bytes = 0;
181 					sp_banks[i+1].base_addr = 0xdeadbeef;
182 				}
183 				break;
184 			}
185 		}
186 	}
187 
188 	/* Start with page aligned address of last symbol in kernel
189 	 * image.
190 	 */
191 	start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
192 
193 	/* Now shift down to get the real physical page frame number. */
194 	start_pfn >>= PAGE_SHIFT;
195 
196 	bootmap_pfn = start_pfn;
197 
198 	max_pfn = end_of_phys_memory >> PAGE_SHIFT;
199 
200 	max_low_pfn = max_pfn;
201 	highstart_pfn = highend_pfn = max_pfn;
202 
203 	if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
204 		highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
205 		max_low_pfn = calc_max_low_pfn();
206 		printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
207 		    calc_highpages() >> (20 - PAGE_SHIFT));
208 	}
209 
210 #ifdef CONFIG_BLK_DEV_INITRD
211 	/* Now have to check initial ramdisk, so that bootmap does not overwrite it */
212 	if (sparc_ramdisk_image) {
213 		if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
214 			sparc_ramdisk_image -= KERNBASE;
215 		initrd_start = sparc_ramdisk_image + phys_base;
216 		initrd_end = initrd_start + sparc_ramdisk_size;
217 		if (initrd_end > end_of_phys_memory) {
218 			printk(KERN_CRIT "initrd extends beyond end of memory "
219 		                 	 "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
220 			       initrd_end, end_of_phys_memory);
221 			initrd_start = 0;
222 		}
223 		if (initrd_start) {
224 			if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
225 			    initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
226 				bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
227 		}
228 	}
229 #endif
230 	/* Initialize the boot-time allocator. */
231 	bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
232 					 max_low_pfn);
233 
234 	/* Now register the available physical memory with the
235 	 * allocator.
236 	 */
237 	*pages_avail = 0;
238 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
239 		unsigned long curr_pfn, last_pfn;
240 
241 		curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
242 		if (curr_pfn >= max_low_pfn)
243 			break;
244 
245 		last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
246 		if (last_pfn > max_low_pfn)
247 			last_pfn = max_low_pfn;
248 
249 		/*
250 		 * .. finally, did all the rounding and playing
251 		 * around just make the area go away?
252 		 */
253 		if (last_pfn <= curr_pfn)
254 			continue;
255 
256 		size = (last_pfn - curr_pfn) << PAGE_SHIFT;
257 		*pages_avail += last_pfn - curr_pfn;
258 
259 		free_bootmem(sp_banks[i].base_addr, size);
260 	}
261 
262 #ifdef CONFIG_BLK_DEV_INITRD
263 	if (initrd_start) {
264 		/* Reserve the initrd image area. */
265 		size = initrd_end - initrd_start;
266 		reserve_bootmem(initrd_start, size, BOOTMEM_DEFAULT);
267 		*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
268 
269 		initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
270 		initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
271 	}
272 #endif
273 	/* Reserve the kernel text/data/bss. */
274 	size = (start_pfn << PAGE_SHIFT) - phys_base;
275 	reserve_bootmem(phys_base, size, BOOTMEM_DEFAULT);
276 	*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
277 
278 	/* Reserve the bootmem map.   We do not account for it
279 	 * in pages_avail because we will release that memory
280 	 * in free_all_bootmem.
281 	 */
282 	size = bootmap_size;
283 	reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
284 	*pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
285 
286 	return max_pfn;
287 }
288 
289 /*
290  * check_pgt_cache
291  *
292  * This is called at the end of unmapping of VMA (zap_page_range),
293  * to rescan the page cache for architecture specific things,
294  * presumably something like sun4/sun4c PMEGs. Most architectures
295  * define check_pgt_cache empty.
296  *
297  * We simply copy the 2.4 implementation for now.
298  */
299 static int pgt_cache_water[2] = { 25, 50 };
300 
check_pgt_cache(void)301 void check_pgt_cache(void)
302 {
303 	do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
304 }
305 
306 /*
307  * paging_init() sets up the page tables: We call the MMU specific
308  * init routine based upon the Sun model type on the Sparc.
309  *
310  */
311 extern void sun4c_paging_init(void);
312 extern void srmmu_paging_init(void);
313 extern void device_scan(void);
314 
315 pgprot_t PAGE_SHARED __read_mostly;
316 EXPORT_SYMBOL(PAGE_SHARED);
317 
paging_init(void)318 void __init paging_init(void)
319 {
320 	switch(sparc_cpu_model) {
321 	case sun4c:
322 	case sun4e:
323 	case sun4:
324 		sun4c_paging_init();
325 		sparc_unmapped_base = 0xe0000000;
326 		BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
327 		break;
328 	case sparc_leon:
329 		leon_init();
330 		/* fall through */
331 	case sun4m:
332 	case sun4d:
333 		srmmu_paging_init();
334 		sparc_unmapped_base = 0x50000000;
335 		BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
336 		break;
337 	default:
338 		prom_printf("paging_init: Cannot init paging on this Sparc\n");
339 		prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
340 		prom_printf("paging_init: Halting...\n");
341 		prom_halt();
342 	}
343 
344 	/* Initialize the protection map with non-constant, MMU dependent values. */
345 	protection_map[0] = PAGE_NONE;
346 	protection_map[1] = PAGE_READONLY;
347 	protection_map[2] = PAGE_COPY;
348 	protection_map[3] = PAGE_COPY;
349 	protection_map[4] = PAGE_READONLY;
350 	protection_map[5] = PAGE_READONLY;
351 	protection_map[6] = PAGE_COPY;
352 	protection_map[7] = PAGE_COPY;
353 	protection_map[8] = PAGE_NONE;
354 	protection_map[9] = PAGE_READONLY;
355 	protection_map[10] = PAGE_SHARED;
356 	protection_map[11] = PAGE_SHARED;
357 	protection_map[12] = PAGE_READONLY;
358 	protection_map[13] = PAGE_READONLY;
359 	protection_map[14] = PAGE_SHARED;
360 	protection_map[15] = PAGE_SHARED;
361 	btfixup();
362 	prom_build_devicetree();
363 	of_fill_in_cpu_data();
364 	device_scan();
365 }
366 
taint_real_pages(void)367 static void __init taint_real_pages(void)
368 {
369 	int i;
370 
371 	for (i = 0; sp_banks[i].num_bytes; i++) {
372 		unsigned long start, end;
373 
374 		start = sp_banks[i].base_addr;
375 		end = start + sp_banks[i].num_bytes;
376 
377 		while (start < end) {
378 			set_bit(start >> 20, sparc_valid_addr_bitmap);
379 			start += PAGE_SIZE;
380 		}
381 	}
382 }
383 
map_high_region(unsigned long start_pfn,unsigned long end_pfn)384 static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
385 {
386 	unsigned long tmp;
387 
388 #ifdef CONFIG_DEBUG_HIGHMEM
389 	printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
390 #endif
391 
392 	for (tmp = start_pfn; tmp < end_pfn; tmp++) {
393 		struct page *page = pfn_to_page(tmp);
394 
395 		ClearPageReserved(page);
396 		init_page_count(page);
397 		__free_page(page);
398 		totalhigh_pages++;
399 	}
400 }
401 
mem_init(void)402 void __init mem_init(void)
403 {
404 	int codepages = 0;
405 	int datapages = 0;
406 	int initpages = 0;
407 	int reservedpages = 0;
408 	int i;
409 
410 	if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
411 		prom_printf("BUG: fixmap and pkmap areas overlap\n");
412 		prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
413 		       PKMAP_BASE,
414 		       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
415 		       FIXADDR_START);
416 		prom_printf("Please mail sparclinux@vger.kernel.org.\n");
417 		prom_halt();
418 	}
419 
420 
421 	/* Saves us work later. */
422 	memset((void *)&empty_zero_page, 0, PAGE_SIZE);
423 
424 	i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
425 	i += 1;
426 	sparc_valid_addr_bitmap = (unsigned long *)
427 		__alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);
428 
429 	if (sparc_valid_addr_bitmap == NULL) {
430 		prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
431 		prom_halt();
432 	}
433 	memset(sparc_valid_addr_bitmap, 0, i << 2);
434 
435 	taint_real_pages();
436 
437 	max_mapnr = last_valid_pfn - pfn_base;
438 	high_memory = __va(max_low_pfn << PAGE_SHIFT);
439 
440 	totalram_pages = free_all_bootmem();
441 
442 	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
443 		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
444 		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
445 
446 		num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;
447 
448 		if (end_pfn <= highstart_pfn)
449 			continue;
450 
451 		if (start_pfn < highstart_pfn)
452 			start_pfn = highstart_pfn;
453 
454 		map_high_region(start_pfn, end_pfn);
455 	}
456 
457 	totalram_pages += totalhigh_pages;
458 
459 	codepages = (((unsigned long) &_etext) - ((unsigned long)&_start));
460 	codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
461 	datapages = (((unsigned long) &_edata) - ((unsigned long)&_etext));
462 	datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
463 	initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
464 	initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;
465 
466 	/* Ignore memory holes for the purpose of counting reserved pages */
467 	for (i=0; i < max_low_pfn; i++)
468 		if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
469 		    && PageReserved(pfn_to_page(i)))
470 			reservedpages++;
471 
472 	printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
473 	       nr_free_pages() << (PAGE_SHIFT-10),
474 	       num_physpages << (PAGE_SHIFT - 10),
475 	       codepages << (PAGE_SHIFT-10),
476 	       reservedpages << (PAGE_SHIFT - 10),
477 	       datapages << (PAGE_SHIFT-10),
478 	       initpages << (PAGE_SHIFT-10),
479 	       totalhigh_pages << (PAGE_SHIFT-10));
480 }
481 
free_initmem(void)482 void free_initmem (void)
483 {
484 	unsigned long addr;
485 	unsigned long freed;
486 
487 	addr = (unsigned long)(&__init_begin);
488 	freed = (unsigned long)(&__init_end) - addr;
489 	for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
490 		struct page *p;
491 
492 		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
493 		p = virt_to_page(addr);
494 
495 		ClearPageReserved(p);
496 		init_page_count(p);
497 		__free_page(p);
498 		totalram_pages++;
499 		num_physpages++;
500 	}
501 	printk(KERN_INFO "Freeing unused kernel memory: %ldk freed\n",
502 		freed >> 10);
503 }
504 
505 #ifdef CONFIG_BLK_DEV_INITRD
free_initrd_mem(unsigned long start,unsigned long end)506 void free_initrd_mem(unsigned long start, unsigned long end)
507 {
508 	if (start < end)
509 		printk(KERN_INFO "Freeing initrd memory: %ldk freed\n",
510 			(end - start) >> 10);
511 	for (; start < end; start += PAGE_SIZE) {
512 		struct page *p;
513 
514 		memset((void *)start, POISON_FREE_INITMEM, PAGE_SIZE);
515 		p = virt_to_page(start);
516 
517 		ClearPageReserved(p);
518 		init_page_count(p);
519 		__free_page(p);
520 		totalram_pages++;
521 		num_physpages++;
522 	}
523 }
524 #endif
525 
sparc_flush_page_to_ram(struct page * page)526 void sparc_flush_page_to_ram(struct page *page)
527 {
528 	unsigned long vaddr = (unsigned long)page_address(page);
529 
530 	if (vaddr)
531 		__flush_page_to_ram(vaddr);
532 }
533 EXPORT_SYMBOL(sparc_flush_page_to_ram);
534