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/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
  40 unsigned long *sparc_valid_addr_bitmap;
  41 EXPORT_SYMBOL(sparc_valid_addr_bitmap);
  42
  43 unsigned long phys_base;
  44 EXPORT_SYMBOL(phys_base);
  45
  46 unsigned long pfn_base;
  47 EXPORT_SYMBOL(pfn_base);
  48
  49 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  50
  51 /* Initial ramdisk setup */
  52 extern unsigned int sparc_ramdisk_image;
  53 extern unsigned int sparc_ramdisk_size;
  54
  55 unsigned long highstart_pfn, highend_pfn;
  56
  57 unsigned long last_valid_pfn;
  58
  59 unsigned 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
  80 static 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
 102 static 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
 132 unsigned 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  */
 211 void __init paging_init(void)
 212 {
 213         srmmu_paging_init();
 214         prom_build_devicetree();
 215         of_fill_in_cpu_data();
 216         device_scan();
 217 }
 218
 219 static 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
 236 static 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
 248 void __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
 297 void sparc_flush_page_to_ram(struct page *page)
 298 {
 299         unsigned long vaddr = (unsigned long)page_address(page);
 300
 301         if (vaddr)
 302                 __flush_page_to_ram(vaddr);
 303 }
 304 EXPORT_SYMBOL(sparc_flush_page_to_ram);