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 static unsigned long *sparc_valid_addr_bitmap;
  41
  42 unsigned long phys_base;
  43 EXPORT_SYMBOL(phys_base);
  44
  45 unsigned long pfn_base;
  46 EXPORT_SYMBOL(pfn_base);
  47
  48 struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
  49
  50 /* Initial ramdisk setup */
  51 extern unsigned int sparc_ramdisk_image;
  52 extern unsigned int sparc_ramdisk_size;
  53
  54 unsigned long highstart_pfn, highend_pfn;
  55
  56 unsigned long last_valid_pfn;
  57
  58 unsigned long calc_highpages(void)
  59 {
  60         int i;
  61         int nr = 0;
  62
  63         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
  64                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
  65                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
  66
  67                 if (end_pfn <= max_low_pfn)
  68                         continue;
  69
  70                 if (start_pfn < max_low_pfn)
  71                         start_pfn = max_low_pfn;
  72
  73                 nr += end_pfn - start_pfn;
  74         }
  75
  76         return nr;
  77 }
  78
  79 static unsigned long calc_max_low_pfn(void)
  80 {
  81         int i;
  82         unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
  83         unsigned long curr_pfn, last_pfn;
  84
  85         last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
  86         for (i = 1; sp_banks[i].num_bytes != 0; i++) {
  87                 curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
  88
  89                 if (curr_pfn >= tmp) {
  90                         if (last_pfn < tmp)
  91                                 tmp = last_pfn;
  92                         break;
  93                 }
  94
  95                 last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
  96         }
  97
  98         return tmp;
  99 }
 100
 101 static void __init find_ramdisk(unsigned long end_of_phys_memory)
 102 {
 103 #ifdef CONFIG_BLK_DEV_INITRD
 104         unsigned long size;
 105
 106         /* Now have to check initial ramdisk, so that it won't pass
 107          * the end of memory
 108          */
 109         if (sparc_ramdisk_image) {
 110                 if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
 111                         sparc_ramdisk_image -= KERNBASE;
 112                 initrd_start = sparc_ramdisk_image + phys_base;
 113                 initrd_end = initrd_start + sparc_ramdisk_size;
 114                 if (initrd_end > end_of_phys_memory) {
 115                         printk(KERN_CRIT "initrd extends beyond end of memory "
 116                                "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
 117                                initrd_end, end_of_phys_memory);
 118                         initrd_start = 0;
 119                 } else {
 120                         /* Reserve the initrd image area. */
 121                         size = initrd_end - initrd_start;
 122                         memblock_reserve(initrd_start, size);
 123
 124                         initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
 125                         initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;
 126                 }
 127         }
 128 #endif
 129 }
 130
 131 unsigned long __init bootmem_init(unsigned long *pages_avail)
 132 {
 133         unsigned long start_pfn, bytes_avail, size;
 134         unsigned long end_of_phys_memory = 0;
 135         unsigned long high_pages = 0;
 136         int i;
 137
 138         memblock_set_bottom_up(true);
 139         memblock_allow_resize();
 140
 141         bytes_avail = 0UL;
 142         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 143                 end_of_phys_memory = sp_banks[i].base_addr +
 144                         sp_banks[i].num_bytes;
 145                 bytes_avail += sp_banks[i].num_bytes;
 146                 if (cmdline_memory_size) {
 147                         if (bytes_avail > cmdline_memory_size) {
 148                                 unsigned long slack = bytes_avail - cmdline_memory_size;
 149
 150                                 bytes_avail -= slack;
 151                                 end_of_phys_memory -= slack;
 152
 153                                 sp_banks[i].num_bytes -= slack;
 154                                 if (sp_banks[i].num_bytes == 0) {
 155                                         sp_banks[i].base_addr = 0xdeadbeef;
 156                                 } else {
 157                                         memblock_add(sp_banks[i].base_addr,
 158                                                      sp_banks[i].num_bytes);
 159                                         sp_banks[i+1].num_bytes = 0;
 160                                         sp_banks[i+1].base_addr = 0xdeadbeef;
 161                                 }
 162                                 break;
 163                         }
 164                 }
 165                 memblock_add(sp_banks[i].base_addr, sp_banks[i].num_bytes);
 166         }
 167
 168         /* Start with page aligned address of last symbol in kernel
 169          * image.
 170          */
 171         start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));
 172
 173         /* Now shift down to get the real physical page frame number. */
 174         start_pfn >>= PAGE_SHIFT;
 175
 176         max_pfn = end_of_phys_memory >> PAGE_SHIFT;
 177
 178         max_low_pfn = max_pfn;
 179         highstart_pfn = highend_pfn = max_pfn;
 180
 181         if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
 182                 highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
 183                 max_low_pfn = calc_max_low_pfn();
 184                 high_pages = calc_highpages();
 185                 printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
 186                     high_pages >> (20 - PAGE_SHIFT));
 187         }
 188
 189         find_ramdisk(end_of_phys_memory);
 190
 191         /* Reserve the kernel text/data/bss. */
 192         size = (start_pfn << PAGE_SHIFT) - phys_base;
 193         memblock_reserve(phys_base, size);
 194         memblock_add(phys_base, size);
 195
 196         size = memblock_phys_mem_size() - memblock_reserved_size();
 197         *pages_avail = (size >> PAGE_SHIFT) - high_pages;
 198
 199         /* Only allow low memory to be allocated via memblock allocation */
 200         memblock_set_current_limit(max_low_pfn << PAGE_SHIFT);
 201
 202         return max_pfn;
 203 }
 204
 205 /*
 206  * paging_init() sets up the page tables: We call the MMU specific
 207  * init routine based upon the Sun model type on the Sparc.
 208  *
 209  */
 210 void __init paging_init(void)
 211 {
 212         srmmu_paging_init();
 213         prom_build_devicetree();
 214         of_fill_in_cpu_data();
 215         device_scan();
 216 }
 217
 218 static void __init taint_real_pages(void)
 219 {
 220         int i;
 221
 222         for (i = 0; sp_banks[i].num_bytes; i++) {
 223                 unsigned long start, end;
 224
 225                 start = sp_banks[i].base_addr;
 226                 end = start + sp_banks[i].num_bytes;
 227
 228                 while (start < end) {
 229                         set_bit(start >> 20, sparc_valid_addr_bitmap);
 230                         start += PAGE_SIZE;
 231                 }
 232         }
 233 }
 234
 235 static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
 236 {
 237         unsigned long tmp;
 238
 239 #ifdef CONFIG_DEBUG_HIGHMEM
 240         printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
 241 #endif
 242
 243         for (tmp = start_pfn; tmp < end_pfn; tmp++)
 244                 free_highmem_page(pfn_to_page(tmp));
 245 }
 246
 247 void __init mem_init(void)
 248 {
 249         int i;
 250
 251         if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
 252                 prom_printf("BUG: fixmap and pkmap areas overlap\n");
 253                 prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
 254                        PKMAP_BASE,
 255                        (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
 256                        FIXADDR_START);
 257                 prom_printf("Please mail sparclinux@vger.kernel.org.\n");
 258                 prom_halt();
 259         }
 260
 261
 262         /* Saves us work later. */
 263         memset((void *)empty_zero_page, 0, PAGE_SIZE);
 264
 265         i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
 266         i += 1;
 267         sparc_valid_addr_bitmap = (unsigned long *)
 268                 memblock_alloc(i << 2, SMP_CACHE_BYTES);
 269
 270         if (sparc_valid_addr_bitmap == NULL) {
 271                 prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
 272                 prom_halt();
 273         }
 274         memset(sparc_valid_addr_bitmap, 0, i << 2);
 275
 276         taint_real_pages();
 277
 278         max_mapnr = last_valid_pfn - pfn_base;
 279         high_memory = __va(max_low_pfn << PAGE_SHIFT);
 280         memblock_free_all();
 281
 282         for (i = 0; sp_banks[i].num_bytes != 0; i++) {
 283                 unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
 284                 unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
 285
 286                 if (end_pfn <= highstart_pfn)
 287                         continue;
 288
 289                 if (start_pfn < highstart_pfn)
 290                         start_pfn = highstart_pfn;
 291
 292                 map_high_region(start_pfn, end_pfn);
 293         }
 294 }
 295
 296 void sparc_flush_page_to_ram(struct page *page)
 297 {
 298         unsigned long vaddr = (unsigned long)page_address(page);
 299
 300         __flush_page_to_ram(vaddr);
 301 }
 302 EXPORT_SYMBOL(sparc_flush_page_to_ram);
 303
 304 void sparc_flush_folio_to_ram(struct folio *folio)
 305 {
 306         unsigned long vaddr = (unsigned long)folio_address(folio);
 307         unsigned int i, nr = folio_nr_pages(folio);
 308
 309         for (i = 0; i < nr; i++)
 310                 __flush_page_to_ram(vaddr + i * PAGE_SIZE);
 311 }
 312 EXPORT_SYMBOL(sparc_flush_folio_to_ram);
 313
 314 static const pgprot_t protection_map[16] = {
 315         [VM_NONE]                                       = PAGE_NONE,
 316         [VM_READ]                                       = PAGE_READONLY,
 317         [VM_WRITE]                                      = PAGE_COPY,
 318         [VM_WRITE | VM_READ]                            = PAGE_COPY,
 319         [VM_EXEC]                                       = PAGE_READONLY,
 320         [VM_EXEC | VM_READ]                             = PAGE_READONLY,
 321         [VM_EXEC | VM_WRITE]                            = PAGE_COPY,
 322         [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_COPY,
 323         [VM_SHARED]                                     = PAGE_NONE,
 324         [VM_SHARED | VM_READ]                           = PAGE_READONLY,
 325         [VM_SHARED | VM_WRITE]                          = PAGE_SHARED,
 326         [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_SHARED,
 327         [VM_SHARED | VM_EXEC]                           = PAGE_READONLY,
 328         [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_READONLY,
 329         [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_SHARED,
 330         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_SHARED
 331 };
 332 DECLARE_VM_GET_PAGE_PROT