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/bootmem.h>
  26 #include <linux/memblock.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/poison.h>
  29 #include <linux/gfp.h>
  30
  31 #include <asm/sections.h>
  32 #include <asm/page.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/vaddrs.h>
  35 #include <asm/pgalloc.h>        /* bug in asm-generic/tlb.h: check_pgt_cache */
  36 #include <asm/setup.h>
  37 #include <asm/tlb.h>
  38 #include <asm/prom.h>
  39 #include <asm/leon.h>
  40
  41 #include "mm_32.h"
  42
  43 unsigned long *sparc_valid_addr_bitmap;
  44 EXPORT_SYMBOL(sparc_valid_addr_bitmap);
  45
  46 unsigned long phys_base;
  47 EXPORT_SYMBOL(phys_base);
  48
  49 unsigned long pfn_base;
  50 EXPORT_SYMBOL(pfn_base);
  51
  52 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  53
  54 /* Initial ramdisk setup */
  55 extern unsigned int sparc_ramdisk_image;
  56 extern unsigned int sparc_ramdisk_size;
  57
  58 unsigned long highstart_pfn, highend_pfn;
  59
  60 unsigned long last_valid_pfn;
  61
  62 unsigned long calc_highpages(void)
  63 {
  64         int i;
  65         int nr = 0;
  66
  67         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
  68                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
  69                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
  70
  71                 if (end_pfn <= max_low_pfn)
  72                         continue;
  73
  74                 if (start_pfn < max_low_pfn)
  75                         start_pfn = max_low_pfn;
  76
  77                 nr += end_pfn - start_pfn;
  78         }
  79
  80         return nr;
  81 }
  82
  83 static unsigned long calc_max_low_pfn(void)
  84 {
  85         int i;
  86         unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
  87         unsigned long curr_pfn, last_pfn;
  88
  89         last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
  90         for (i = 1; sp_banks[i].num_bytes != 0; i++) {
  91                 curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
  92
  93                 if (curr_pfn >= tmp) {
  94                         if (last_pfn < tmp)
  95                                 tmp = last_pfn;
  96                         break;
  97                 }
  98
  99                 last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 100         }
 101
 102         return tmp;
 103 }
 104
 105 static void __init find_ramdisk(unsigned long end_of_phys_memory)
 106 {
 107 #ifdef CONFIG_BLK_DEV_INITRD
 108         unsigned long size;
 109
 110         /* Now have to check initial ramdisk, so that it won't pass
 111          * the end of memory
 112          */
 113         if (sparc_ramdisk_image) {
 114                 if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
 115                         sparc_ramdisk_image -= KERNBASE;
 116                 initrd_start = sparc_ramdisk_image + phys_base;
 117                 initrd_end = initrd_start + sparc_ramdisk_size;
 118                 if (initrd_end > end_of_phys_memory) {
 119                         printk(KERN_CRIT "initrd extends beyond end of memory "
 120                                "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
 121                                initrd_end, end_of_phys_memory);
 122                         initrd_start = 0;
 123                 } else {
 124                         /* Reserve the initrd image area. */
 125                         size = initrd_end - initrd_start;
 126                         memblock_reserve(initrd_start, size);
 127
 128                         initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
 129                         initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
 130                 }
 131         }
 132 #endif
 133 }
 134
 135 unsigned long __init bootmem_init(unsigned long *pages_avail)
 136 {
 137         unsigned long start_pfn, bytes_avail, size;
 138         unsigned long end_of_phys_memory = 0;
 139         unsigned long high_pages = 0;
 140         int i;
 141
 142         memblock_set_bottom_up(true);
 143         memblock_allow_resize();
 144
 145         bytes_avail = 0UL;
 146         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 147                 end_of_phys_memory = sp_banks[i].base_addr +
 148                         sp_banks[i].num_bytes;
 149                 bytes_avail += sp_banks[i].num_bytes;
 150                 if (cmdline_memory_size) {
 151                         if (bytes_avail > cmdline_memory_size) {
 152                                 unsigned long slack = bytes_avail - cmdline_memory_size;
 153
 154                                 bytes_avail -= slack;
 155                                 end_of_phys_memory -= slack;
 156
 157                                 sp_banks[i].num_bytes -= slack;
 158                                 if (sp_banks[i].num_bytes == 0) {
 159                                         sp_banks[i].base_addr = 0xdeadbeef;
 160                                 } else {
 161                                         memblock_add(sp_banks[i].base_addr,
 162                                                      sp_banks[i].num_bytes);
 163                                         sp_banks[i+1].num_bytes = 0;
 164                                         sp_banks[i+1].base_addr = 0xdeadbeef;
 165                                 }
 166                                 break;
 167                         }
 168                 }
 169                 memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
 170         }
 171
 172         /* Start with page aligned address of last symbol in kernel
 173          * image.
 174          */
 175         start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
 176
 177         /* Now shift down to get the real physical page frame number. */
 178         start_pfn >>= PAGE_SHIFT;
 179
 180         max_pfn = end_of_phys_memory >> PAGE_SHIFT;
 181
 182         max_low_pfn = max_pfn;
 183         highstart_pfn = highend_pfn = max_pfn;
 184
 185         if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
 186                 highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 187                 max_low_pfn = calc_max_low_pfn();
 188                 high_pages = calc_highpages();
 189                 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 190                     high_pages >> (20 - PAGE_SHIFT));
 191         }
 192
 193         find_ramdisk(end_of_phys_memory);
 194
 195         /* Reserve the kernel text/data/bss. */
 196         size = (start_pfn << PAGE_SHIFT) - phys_base;
 197         memblock_reserve(phys_base, size);
 198
 199         size = memblock_phys_mem_size() - memblock_reserved_size();
 200         *pages_avail = (size >> PAGE_SHIFT) - high_pages;
 201
 202         /* Only allow low memory to be allocated via memblock allocation */
 203         memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
 204
 205         return max_pfn;
 206 }
 207
 208 /*
 209  * paging_init() sets up the page tables: We call the MMU specific
 210  * init routine based upon the Sun model type on the Sparc.
 211  *
 212  */
 213 void __init paging_init(void)
 214 {
 215         srmmu_paging_init();
 216         prom_build_devicetree();
 217         of_fill_in_cpu_data();
 218         device_scan();
 219 }
 220
 221 static void __init taint_real_pages(void)
 222 {
 223         int i;
 224
 225         for (i = 0; sp_banks[i].num_bytes; i++) {
 226                 unsigned long start, end;
 227
 228                 start = sp_banks[i].base_addr;
 229                 end = start + sp_banks[i].num_bytes;
 230
 231                 while (start < end) {
 232                         set_bit(start >> 20, sparc_valid_addr_bitmap);
 233                         start += PAGE_SIZE;
 234                 }
 235         }
 236 }
 237
 238 static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
 239 {
 240         unsigned long tmp;
 241
 242 #ifdef CONFIG_DEBUG_HIGHMEM
 243         printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
 244 #endif
 245
 246         for (tmp = start_pfn; tmp < end_pfn; tmp++)
 247                 free_highmem_page(pfn_to_page(tmp));
 248 }
 249
 250 void __init mem_init(void)
 251 {
 252         int i;
 253
 254         if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 255                 prom_printf("BUG: fixmap and pkmap areas overlap\n");
 256                 prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
 257                        PKMAP_BASE,
 258                        (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
 259                        FIXADDR_START);
 260                 prom_printf("Please mail sparclinux@vger.kernel.org.\n");
 261                 prom_halt();
 262         }
 263
 264
 265         /* Saves us work later. */
 266         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 267
 268         i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
 269         i += 1;
 270         sparc_valid_addr_bitmap = (unsigned long *)
 271                 __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);
 272
 273         if (sparc_valid_addr_bitmap == NULL) {
 274                 prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
 275                 prom_halt();
 276         }
 277         memset(sparc_valid_addr_bitmap, 0, i << 2);
 278
 279         taint_real_pages();
 280
 281         max_mapnr = last_valid_pfn - pfn_base;
 282         high_memory = __va(max_low_pfn << PAGE_SHIFT);
 283         free_all_bootmem();
 284
 285         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 286                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 287                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 288
 289                 if (end_pfn <= highstart_pfn)
 290                         continue;
 291
 292                 if (start_pfn < highstart_pfn)
 293                         start_pfn = highstart_pfn;
 294
 295                 map_high_region(start_pfn, end_pfn);
 296         }
 297
 298         mem_init_print_info(NULL);
 299 }
 300
 301 void free_initmem (void)
 302 {
 303         free_initmem_default(POISON_FREE_INITMEM);
 304 }
 305
 306 #ifdef CONFIG_BLK_DEV_INITRD
 307 void free_initrd_mem(unsigned long start, unsigned long end)
 308 {
 309         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 310                            "initrd");
 311 }
 312 #endif
 313
 314 void sparc_flush_page_to_ram(struct page *page)
 315 {
 316         unsigned long vaddr = (unsigned long)page_address(page);
 317
 318         if (vaddr)
 319                 __flush_page_to_ram(vaddr);
 320 }
 321 EXPORT_SYMBOL(sparc_flush_page_to_ram);