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