Add 'discard' request handling
[linux-2.6.git] / arch / sparc / mm / init.c
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
27 #include <asm/system.h>
28 #include <asm/vac-ops.h>
29 #include <asm/page.h>
30 #include <asm/pgtable.h>
31 #include <asm/vaddrs.h>
32 #include <asm/pgalloc.h>        /* bug in asm-generic/tlb.h: check_pgt_cache */
33 #include <asm/tlb.h>
34 #include <asm/prom.h>
35
36 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
37
38 unsigned long *sparc_valid_addr_bitmap;
39
40 unsigned long phys_base;
41 unsigned long pfn_base;
42
43 unsigned long page_kernel;
44
45 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
46 unsigned long sparc_unmapped_base;
47
48 struct pgtable_cache_struct pgt_quicklists;
49
50 /* References to section boundaries */
51 extern char __init_begin, __init_end, _start, _end, etext , edata;
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 pte_t *kmap_pte;
60 pgprot_t kmap_prot;
61
62 #define kmap_get_fixmap_pte(vaddr) \
63         pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
64
65 void __init kmap_init(void)
66 {
67         /* cache the first kmap pte */
68         kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
69         kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
70 }
71
72 void show_mem(void)
73 {
74         printk("Mem-info:\n");
75         show_free_areas();
76         printk("Free swap:       %6ldkB\n",
77                nr_swap_pages << (PAGE_SHIFT-10));
78         printk("%ld pages of RAM\n", totalram_pages);
79         printk("%ld free pages\n", nr_free_pages());
80 #if 0 /* undefined pgtable_cache_size, pgd_cache_size */
81         printk("%ld pages in page table cache\n",pgtable_cache_size);
82 #ifndef CONFIG_SMP
83         if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
84                 printk("%ld entries in page dir cache\n",pgd_cache_size);
85 #endif  
86 #endif
87 }
88
89 void __init sparc_context_init(int numctx)
90 {
91         int ctx;
92
93         ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);
94
95         for(ctx = 0; ctx < numctx; ctx++) {
96                 struct ctx_list *clist;
97
98                 clist = (ctx_list_pool + ctx);
99                 clist->ctx_number = ctx;
100                 clist->ctx_mm = NULL;
101         }
102         ctx_free.next = ctx_free.prev = &ctx_free;
103         ctx_used.next = ctx_used.prev = &ctx_used;
104         for(ctx = 0; ctx < numctx; ctx++)
105                 add_to_free_ctxlist(ctx_list_pool + ctx);
106 }
107
108 extern unsigned long cmdline_memory_size;
109 unsigned long last_valid_pfn;
110
111 unsigned long calc_highpages(void)
112 {
113         int i;
114         int nr = 0;
115
116         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
117                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
118                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
119
120                 if (end_pfn <= max_low_pfn)
121                         continue;
122
123                 if (start_pfn < max_low_pfn)
124                         start_pfn = max_low_pfn;
125
126                 nr += end_pfn - start_pfn;
127         }
128
129         return nr;
130 }
131
132 static unsigned long calc_max_low_pfn(void)
133 {
134         int i;
135         unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
136         unsigned long curr_pfn, last_pfn;
137
138         last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
139         for (i = 1; sp_banks[i].num_bytes != 0; i++) {
140                 curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
141
142                 if (curr_pfn >= tmp) {
143                         if (last_pfn < tmp)
144                                 tmp = last_pfn;
145                         break;
146                 }
147
148                 last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
149         }
150
151         return tmp;
152 }
153
154 unsigned long __init bootmem_init(unsigned long *pages_avail)
155 {
156         unsigned long bootmap_size, start_pfn;
157         unsigned long end_of_phys_memory = 0UL;
158         unsigned long bootmap_pfn, bytes_avail, size;
159         int i;
160
161         bytes_avail = 0UL;
162         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
163                 end_of_phys_memory = sp_banks[i].base_addr +
164                         sp_banks[i].num_bytes;
165                 bytes_avail += sp_banks[i].num_bytes;
166                 if (cmdline_memory_size) {
167                         if (bytes_avail > cmdline_memory_size) {
168                                 unsigned long slack = bytes_avail - cmdline_memory_size;
169
170                                 bytes_avail -= slack;
171                                 end_of_phys_memory -= slack;
172
173                                 sp_banks[i].num_bytes -= slack;
174                                 if (sp_banks[i].num_bytes == 0) {
175                                         sp_banks[i].base_addr = 0xdeadbeef;
176                                 } else {
177                                         sp_banks[i+1].num_bytes = 0;
178                                         sp_banks[i+1].base_addr = 0xdeadbeef;
179                                 }
180                                 break;
181                         }
182                 }
183         }
184
185         /* Start with page aligned address of last symbol in kernel
186          * image.  
187          */
188         start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
189
190         /* Now shift down to get the real physical page frame number. */
191         start_pfn >>= PAGE_SHIFT;
192
193         bootmap_pfn = start_pfn;
194
195         max_pfn = end_of_phys_memory >> PAGE_SHIFT;
196
197         max_low_pfn = max_pfn;
198         highstart_pfn = highend_pfn = max_pfn;
199
200         if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
201                 highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
202                 max_low_pfn = calc_max_low_pfn();
203                 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
204                     calc_highpages() >> (20 - PAGE_SHIFT));
205         }
206
207 #ifdef CONFIG_BLK_DEV_INITRD
208         /* Now have to check initial ramdisk, so that bootmap does not overwrite it */
209         if (sparc_ramdisk_image) {
210                 if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
211                         sparc_ramdisk_image -= KERNBASE;
212                 initrd_start = sparc_ramdisk_image + phys_base;
213                 initrd_end = initrd_start + sparc_ramdisk_size;
214                 if (initrd_end > end_of_phys_memory) {
215                         printk(KERN_CRIT "initrd extends beyond end of memory "
216                                          "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
217                                initrd_end, end_of_phys_memory);
218                         initrd_start = 0;
219                 }
220                 if (initrd_start) {
221                         if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
222                             initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
223                                 bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
224                 }
225         }
226 #endif  
227         /* Initialize the boot-time allocator. */
228         bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
229                                          max_low_pfn);
230
231         /* Now register the available physical memory with the
232          * allocator.
233          */
234         *pages_avail = 0;
235         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
236                 unsigned long curr_pfn, last_pfn;
237
238                 curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
239                 if (curr_pfn >= max_low_pfn)
240                         break;
241
242                 last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
243                 if (last_pfn > max_low_pfn)
244                         last_pfn = max_low_pfn;
245
246                 /*
247                  * .. finally, did all the rounding and playing
248                  * around just make the area go away?
249                  */
250                 if (last_pfn <= curr_pfn)
251                         continue;
252
253                 size = (last_pfn - curr_pfn) << PAGE_SHIFT;
254                 *pages_avail += last_pfn - curr_pfn;
255
256                 free_bootmem(sp_banks[i].base_addr, size);
257         }
258
259 #ifdef CONFIG_BLK_DEV_INITRD
260         if (initrd_start) {
261                 /* Reserve the initrd image area. */
262                 size = initrd_end - initrd_start;
263                 reserve_bootmem(initrd_start, size, BOOTMEM_DEFAULT);
264                 *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
265
266                 initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
267                 initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;            
268         }
269 #endif
270         /* Reserve the kernel text/data/bss. */
271         size = (start_pfn << PAGE_SHIFT) - phys_base;
272         reserve_bootmem(phys_base, size, BOOTMEM_DEFAULT);
273         *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
274
275         /* Reserve the bootmem map.   We do not account for it
276          * in pages_avail because we will release that memory
277          * in free_all_bootmem.
278          */
279         size = bootmap_size;
280         reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
281         *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;
282
283         return max_pfn;
284 }
285
286 /*
287  * check_pgt_cache
288  *
289  * This is called at the end of unmapping of VMA (zap_page_range),
290  * to rescan the page cache for architecture specific things,
291  * presumably something like sun4/sun4c PMEGs. Most architectures
292  * define check_pgt_cache empty.
293  *
294  * We simply copy the 2.4 implementation for now.
295  */
296 static int pgt_cache_water[2] = { 25, 50 };
297
298 void check_pgt_cache(void)
299 {
300         do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
301 }
302
303 /*
304  * paging_init() sets up the page tables: We call the MMU specific
305  * init routine based upon the Sun model type on the Sparc.
306  *
307  */
308 extern void sun4c_paging_init(void);
309 extern void srmmu_paging_init(void);
310 extern void device_scan(void);
311
312 pgprot_t PAGE_SHARED __read_mostly;
313 EXPORT_SYMBOL(PAGE_SHARED);
314
315 void __init paging_init(void)
316 {
317         switch(sparc_cpu_model) {
318         case sun4c:
319         case sun4e:
320         case sun4:
321                 sun4c_paging_init();
322                 sparc_unmapped_base = 0xe0000000;
323                 BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
324                 break;
325         case sun4m:
326         case sun4d:
327                 srmmu_paging_init();
328                 sparc_unmapped_base = 0x50000000;
329                 BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
330                 break;
331         default:
332                 prom_printf("paging_init: Cannot init paging on this Sparc\n");
333                 prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
334                 prom_printf("paging_init: Halting...\n");
335                 prom_halt();
336         };
337
338         /* Initialize the protection map with non-constant, MMU dependent values. */
339         protection_map[0] = PAGE_NONE;
340         protection_map[1] = PAGE_READONLY;
341         protection_map[2] = PAGE_COPY;
342         protection_map[3] = PAGE_COPY;
343         protection_map[4] = PAGE_READONLY;
344         protection_map[5] = PAGE_READONLY;
345         protection_map[6] = PAGE_COPY;
346         protection_map[7] = PAGE_COPY;
347         protection_map[8] = PAGE_NONE;
348         protection_map[9] = PAGE_READONLY;
349         protection_map[10] = PAGE_SHARED;
350         protection_map[11] = PAGE_SHARED;
351         protection_map[12] = PAGE_READONLY;
352         protection_map[13] = PAGE_READONLY;
353         protection_map[14] = PAGE_SHARED;
354         protection_map[15] = PAGE_SHARED;
355         btfixup();
356         prom_build_devicetree();
357         device_scan();
358 }
359
360 static void __init taint_real_pages(void)
361 {
362         int i;
363
364         for (i = 0; sp_banks[i].num_bytes; i++) {
365                 unsigned long start, end;
366
367                 start = sp_banks[i].base_addr;
368                 end = start + sp_banks[i].num_bytes;
369
370                 while (start < end) {
371                         set_bit(start >> 20, sparc_valid_addr_bitmap);
372                         start += PAGE_SIZE;
373                 }
374         }
375 }
376
377 static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
378 {
379         unsigned long tmp;
380
381 #ifdef CONFIG_DEBUG_HIGHMEM
382         printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
383 #endif
384
385         for (tmp = start_pfn; tmp < end_pfn; tmp++) {
386                 struct page *page = pfn_to_page(tmp);
387
388                 ClearPageReserved(page);
389                 init_page_count(page);
390                 __free_page(page);
391                 totalhigh_pages++;
392         }
393 }
394
395 void __init mem_init(void)
396 {
397         int codepages = 0;
398         int datapages = 0;
399         int initpages = 0; 
400         int reservedpages = 0;
401         int i;
402
403         if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
404                 prom_printf("BUG: fixmap and pkmap areas overlap\n");
405                 prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
406                        PKMAP_BASE,
407                        (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
408                        FIXADDR_START);
409                 prom_printf("Please mail sparclinux@vger.kernel.org.\n");
410                 prom_halt();
411         }
412
413
414         /* Saves us work later. */
415         memset((void *)&empty_zero_page, 0, PAGE_SIZE);
416
417         i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
418         i += 1;
419         sparc_valid_addr_bitmap = (unsigned long *)
420                 __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);
421
422         if (sparc_valid_addr_bitmap == NULL) {
423                 prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
424                 prom_halt();
425         }
426         memset(sparc_valid_addr_bitmap, 0, i << 2);
427
428         taint_real_pages();
429
430         max_mapnr = last_valid_pfn - pfn_base;
431         high_memory = __va(max_low_pfn << PAGE_SHIFT);
432
433         totalram_pages = free_all_bootmem();
434
435         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
436                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
437                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
438
439                 num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;
440
441                 if (end_pfn <= highstart_pfn)
442                         continue;
443
444                 if (start_pfn < highstart_pfn)
445                         start_pfn = highstart_pfn;
446
447                 map_high_region(start_pfn, end_pfn);
448         }
449         
450         totalram_pages += totalhigh_pages;
451
452         codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
453         codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
454         datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
455         datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
456         initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
457         initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;
458
459         /* Ignore memory holes for the purpose of counting reserved pages */
460         for (i=0; i < max_low_pfn; i++)
461                 if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
462                     && PageReserved(pfn_to_page(i)))
463                         reservedpages++;
464
465         printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
466                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
467                num_physpages << (PAGE_SHIFT - 10),
468                codepages << (PAGE_SHIFT-10),
469                reservedpages << (PAGE_SHIFT - 10),
470                datapages << (PAGE_SHIFT-10), 
471                initpages << (PAGE_SHIFT-10),
472                totalhigh_pages << (PAGE_SHIFT-10));
473 }
474
475 void free_initmem (void)
476 {
477         unsigned long addr;
478
479         addr = (unsigned long)(&__init_begin);
480         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
481                 struct page *p;
482
483                 p = virt_to_page(addr);
484
485                 ClearPageReserved(p);
486                 init_page_count(p);
487                 __free_page(p);
488                 totalram_pages++;
489                 num_physpages++;
490         }
491         printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
492 }
493
494 #ifdef CONFIG_BLK_DEV_INITRD
495 void free_initrd_mem(unsigned long start, unsigned long end)
496 {
497         if (start < end)
498                 printk (KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
499         for (; start < end; start += PAGE_SIZE) {
500                 struct page *p = virt_to_page(start);
501
502                 ClearPageReserved(p);
503                 init_page_count(p);
504                 __free_page(p);
505                 num_physpages++;
506         }
507 }
508 #endif
509
510 void sparc_flush_page_to_ram(struct page *page)
511 {
512         unsigned long vaddr = (unsigned long)page_address(page);
513
514         if (vaddr)
515                 __flush_page_to_ram(vaddr);
516 }