linux/arch/sparc/mm/init_32.c
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   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
  40unsigned long *sparc_valid_addr_bitmap;
  41EXPORT_SYMBOL(sparc_valid_addr_bitmap);
  42
  43unsigned long phys_base;
  44EXPORT_SYMBOL(phys_base);
  45
  46unsigned long pfn_base;
  47EXPORT_SYMBOL(pfn_base);
  48
  49struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  50
  51/* Initial ramdisk setup */
  52extern unsigned int sparc_ramdisk_image;
  53extern unsigned int sparc_ramdisk_size;
  54
  55unsigned long highstart_pfn, highend_pfn;
  56
  57unsigned long last_valid_pfn;
  58
  59unsigned 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
  80static 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
 102static 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
 132unsigned 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 */
 211void __init paging_init(void)
 212{
 213        srmmu_paging_init();
 214        prom_build_devicetree();
 215        of_fill_in_cpu_data();
 216        device_scan();
 217}
 218
 219static 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
 236static 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
 248void __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
 297void 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}
 304EXPORT_SYMBOL(sparc_flush_page_to_ram);
 305
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