arch/sparc/mm/init_32.c

   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(i << 2, SMP_CACHE_BYTES);
 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);