arch/powerpc/mm/mem.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  PowerPC version
   4  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   5  *
   6  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
   7  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   8  *    Copyright (C) 1996 Paul Mackerras
   9  *  PPC44x/36-bit changes by Matt Porter (mporter@mvista.com)
  10  *
  11  *  Derived from "arch/i386/mm/init.c"
  12  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  13  */
  14
  15 #include <linux/memblock.h>
  16 #include <linux/highmem.h>
  17 #include <linux/suspend.h>
  18 #include <linux/dma-direct.h>
  19 #include <linux/execmem.h>
  20 #include <linux/vmalloc.h>
  21
  22 #include <asm/swiotlb.h>
  23 #include <asm/machdep.h>
  24 #include <asm/rtas.h>
  25 #include <asm/kasan.h>
  26 #include <asm/svm.h>
  27 #include <asm/mmzone.h>
  28 #include <asm/ftrace.h>
  29 #include <asm/text-patching.h>
  30 #include <asm/setup.h>
  31 #include <asm/fixmap.h>
  32
  33 #include <mm/mmu_decl.h>
  34
  35 unsigned long long memory_limit __initdata;
  36
  37 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  38 EXPORT_SYMBOL(empty_zero_page);
  39
  40 pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size,
  41                                 pgprot_t vma_prot)
  42 {
  43         if (ppc_md.phys_mem_access_prot)
  44                 return ppc_md.phys_mem_access_prot(pfn, size, vma_prot);
  45
  46         if (!page_is_ram(pfn))
  47                 vma_prot = pgprot_noncached(vma_prot);
  48
  49         return vma_prot;
  50 }
  51 EXPORT_SYMBOL(__phys_mem_access_prot);
  52
  53 #ifdef CONFIG_MEMORY_HOTPLUG
  54 static DEFINE_MUTEX(linear_mapping_mutex);
  55
  56 #ifdef CONFIG_NUMA
  57 int memory_add_physaddr_to_nid(u64 start)
  58 {
  59         return hot_add_scn_to_nid(start);
  60 }
  61 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
  62 #endif
  63
  64 int __weak create_section_mapping(unsigned long start, unsigned long end,
  65                                   int nid, pgprot_t prot)
  66 {
  67         return -ENODEV;
  68 }
  69
  70 int __weak remove_section_mapping(unsigned long start, unsigned long end)
  71 {
  72         return -ENODEV;
  73 }
  74
  75 int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
  76                                      struct mhp_params *params)
  77 {
  78         int rc;
  79
  80         start = (unsigned long)__va(start);
  81         mutex_lock(&linear_mapping_mutex);
  82         rc = create_section_mapping(start, start + size, nid,
  83                                     params->pgprot);
  84         mutex_unlock(&linear_mapping_mutex);
  85         if (rc) {
  86                 pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
  87                         start, start + size, rc);
  88                 return -EFAULT;
  89         }
  90         return 0;
  91 }
  92
  93 void __ref arch_remove_linear_mapping(u64 start, u64 size)
  94 {
  95         int ret;
  96
  97         /* Remove htab bolted mappings for this section of memory */
  98         start = (unsigned long)__va(start);
  99
 100         mutex_lock(&linear_mapping_mutex);
 101         ret = remove_section_mapping(start, start + size);
 102         mutex_unlock(&linear_mapping_mutex);
 103         if (ret)
 104                 pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
 105                         start, start + size, ret);
 106
 107         /* Ensure all vmalloc mappings are flushed in case they also
 108          * hit that section of memory
 109          */
 110         vm_unmap_aliases();
 111 }
 112
 113 /*
 114  * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
 115  * updating.
 116  */
 117 static void update_end_of_memory_vars(u64 start, u64 size)
 118 {
 119         unsigned long end_pfn = PFN_UP(start + size);
 120
 121         if (end_pfn > max_pfn) {
 122                 max_pfn = end_pfn;
 123                 max_low_pfn = end_pfn;
 124                 high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
 125         }
 126 }
 127
 128 int __ref add_pages(int nid, unsigned long start_pfn, unsigned long nr_pages,
 129                     struct mhp_params *params)
 130 {
 131         int ret;
 132
 133         ret = __add_pages(nid, start_pfn, nr_pages, params);
 134         if (ret)
 135                 return ret;
 136
 137         /* update max_pfn, max_low_pfn and high_memory */
 138         update_end_of_memory_vars(start_pfn << PAGE_SHIFT,
 139                                   nr_pages << PAGE_SHIFT);
 140
 141         return ret;
 142 }
 143
 144 int __ref arch_add_memory(int nid, u64 start, u64 size,
 145                           struct mhp_params *params)
 146 {
 147         unsigned long start_pfn = start >> PAGE_SHIFT;
 148         unsigned long nr_pages = size >> PAGE_SHIFT;
 149         int rc;
 150
 151         rc = arch_create_linear_mapping(nid, start, size, params);
 152         if (rc)
 153                 return rc;
 154         rc = add_pages(nid, start_pfn, nr_pages, params);
 155         if (rc)
 156                 arch_remove_linear_mapping(start, size);
 157         return rc;
 158 }
 159
 160 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
 161 {
 162         unsigned long start_pfn = start >> PAGE_SHIFT;
 163         unsigned long nr_pages = size >> PAGE_SHIFT;
 164
 165         __remove_pages(start_pfn, nr_pages, altmap);
 166         arch_remove_linear_mapping(start, size);
 167 }
 168 #endif
 169
 170 #ifndef CONFIG_NUMA
 171 void __init mem_topology_setup(void)
 172 {
 173         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 174         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 175 #ifdef CONFIG_HIGHMEM
 176         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 177 #endif
 178
 179         /* Place all memblock_regions in the same node and merge contiguous
 180          * memblock_regions
 181          */
 182         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 183 }
 184
 185 void __init initmem_init(void)
 186 {
 187         sparse_init();
 188 }
 189
 190 /* mark pages that don't exist as nosave */
 191 static int __init mark_nonram_nosave(void)
 192 {
 193         unsigned long spfn, epfn, prev = 0;
 194         int i;
 195
 196         for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
 197                 if (prev && prev < spfn)
 198                         register_nosave_region(prev, spfn);
 199
 200                 prev = epfn;
 201         }
 202
 203         return 0;
 204 }
 205 #else /* CONFIG_NUMA */
 206 static int __init mark_nonram_nosave(void)
 207 {
 208         return 0;
 209 }
 210 #endif
 211
 212 /*
 213  * Zones usage:
 214  *
 215  * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
 216  * everything else. GFP_DMA32 page allocations automatically fall back to
 217  * ZONE_DMA.
 218  *
 219  * By using 31-bit unconditionally, we can exploit zone_dma_limit to inform the
 220  * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
 221  * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
 222  * ZONE_DMA.
 223  */
 224 static unsigned long max_zone_pfns[MAX_NR_ZONES];
 225
 226 /*
 227  * paging_init() sets up the page tables - in fact we've already done this.
 228  */
 229 void __init paging_init(void)
 230 {
 231         unsigned long long total_ram = memblock_phys_mem_size();
 232         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 233         int zone_dma_bits;
 234
 235 #ifdef CONFIG_HIGHMEM
 236         unsigned long v = __fix_to_virt(FIX_KMAP_END);
 237         unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
 238
 239         for (; v < end; v += PAGE_SIZE)
 240                 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
 241
 242         map_kernel_page(PKMAP_BASE, 0, __pgprot(0));    /* XXX gross */
 243         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 244 #endif /* CONFIG_HIGHMEM */
 245
 246         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 247                (unsigned long long)top_of_ram, total_ram);
 248         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 249                (long int)((top_of_ram - total_ram) >> 20));
 250
 251         /*
 252          * Allow 30-bit DMA for very limited Broadcom wifi chips on many
 253          * powerbooks.
 254          */
 255         if (IS_ENABLED(CONFIG_PPC32))
 256                 zone_dma_bits = 30;
 257         else
 258                 zone_dma_bits = 31;
 259
 260         zone_dma_limit = DMA_BIT_MASK(zone_dma_bits);
 261
 262 #ifdef CONFIG_ZONE_DMA
 263         max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
 264                                       1UL << (zone_dma_bits - PAGE_SHIFT));
 265 #endif
 266         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 267 #ifdef CONFIG_HIGHMEM
 268         max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
 269 #endif
 270
 271         free_area_init(max_zone_pfns);
 272
 273         mark_nonram_nosave();
 274 }
 275
 276 void __init mem_init(void)
 277 {
 278         /*
 279          * book3s is limited to 16 page sizes due to encoding this in
 280          * a 4-bit field for slices.
 281          */
 282         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 283
 284 #ifdef CONFIG_SWIOTLB
 285         /*
 286          * Some platforms (e.g. 85xx) limit DMA-able memory way below
 287          * 4G. We force memblock to bottom-up mode to ensure that the
 288          * memory allocated in swiotlb_init() is DMA-able.
 289          * As it's the last memblock allocation, no need to reset it
 290          * back to to-down.
 291          */
 292         memblock_set_bottom_up(true);
 293         swiotlb_init(ppc_swiotlb_enable, ppc_swiotlb_flags);
 294 #endif
 295
 296         kasan_late_init();
 297
 298         memblock_free_all();
 299
 300 #ifdef CONFIG_HIGHMEM
 301         {
 302                 unsigned long pfn, highmem_mapnr;
 303
 304                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 305                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 306                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 307                         struct page *page = pfn_to_page(pfn);
 308                         if (memblock_is_memory(paddr) && !memblock_is_reserved(paddr))
 309                                 free_highmem_page(page);
 310                 }
 311         }
 312 #endif /* CONFIG_HIGHMEM */
 313
 314 #if defined(CONFIG_PPC_E500) && !defined(CONFIG_SMP)
 315         /*
 316          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 317          * functions.... do it here for the non-smp case.
 318          */
 319         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 320                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 321 #endif
 322
 323 #ifdef CONFIG_PPC32
 324         pr_info("Kernel virtual memory layout:\n");
 325 #ifdef CONFIG_KASAN
 326         pr_info("  * 0x%08lx..0x%08lx  : kasan shadow mem\n",
 327                 KASAN_SHADOW_START, KASAN_SHADOW_END);
 328 #endif
 329         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 330 #ifdef CONFIG_HIGHMEM
 331         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 332                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 333 #endif /* CONFIG_HIGHMEM */
 334         if (ioremap_bot != IOREMAP_TOP)
 335                 pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 336                         ioremap_bot, IOREMAP_TOP);
 337         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 338                 VMALLOC_START, VMALLOC_END);
 339 #ifdef MODULES_VADDR
 340         pr_info("  * 0x%08lx..0x%08lx  : modules\n",
 341                 MODULES_VADDR, MODULES_END);
 342 #endif
 343 #endif /* CONFIG_PPC32 */
 344 }
 345
 346 void free_initmem(void)
 347 {
 348         ppc_md.progress = ppc_printk_progress;
 349         mark_initmem_nx();
 350         free_initmem_default(POISON_FREE_INITMEM);
 351         ftrace_free_init_tramp();
 352 }
 353
 354 /*
 355  * System memory should not be in /proc/iomem but various tools expect it
 356  * (eg kdump).
 357  */
 358 static int __init add_system_ram_resources(void)
 359 {
 360         phys_addr_t start, end;
 361         u64 i;
 362
 363         for_each_mem_range(i, &start, &end) {
 364                 struct resource *res;
 365
 366                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 367                 WARN_ON(!res);
 368
 369                 if (res) {
 370                         res->name = "System RAM";
 371                         res->start = start;
 372                         /*
 373                          * In memblock, end points to the first byte after
 374                          * the range while in resourses, end points to the
 375                          * last byte in the range.
 376                          */
 377                         res->end = end - 1;
 378                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 379                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 380                 }
 381         }
 382
 383         return 0;
 384 }
 385 subsys_initcall(add_system_ram_resources);
 386
 387 #ifdef CONFIG_STRICT_DEVMEM
 388 /*
 389  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 390  * is valid. The argument is a physical page number.
 391  *
 392  * Access has to be given to non-kernel-ram areas as well, these contain the
 393  * PCI mmio resources as well as potential bios/acpi data regions.
 394  */
 395 int devmem_is_allowed(unsigned long pfn)
 396 {
 397         if (page_is_rtas_user_buf(pfn))
 398                 return 1;
 399         if (iomem_is_exclusive(PFN_PHYS(pfn)))
 400                 return 0;
 401         if (!page_is_ram(pfn))
 402                 return 1;
 403         return 0;
 404 }
 405 #endif /* CONFIG_STRICT_DEVMEM */
 406
 407 /*
 408  * This is defined in kernel/resource.c but only powerpc needs to export it, for
 409  * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
 410  */
 411 EXPORT_SYMBOL_GPL(walk_system_ram_range);
 412
 413 #ifdef CONFIG_EXECMEM
 414 static struct execmem_info execmem_info __ro_after_init;
 415
 416 #if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC_BOOK3S_603)
 417 static void prealloc_execmem_pgtable(void)
 418 {
 419         unsigned long va;
 420
 421         for (va = ALIGN_DOWN(MODULES_VADDR, PGDIR_SIZE); va < MODULES_END; va += PGDIR_SIZE)
 422                 pte_alloc_kernel(pmd_off_k(va), va);
 423 }
 424 #else
 425 static void prealloc_execmem_pgtable(void) { }
 426 #endif
 427
 428 struct execmem_info __init *execmem_arch_setup(void)
 429 {
 430         pgprot_t kprobes_prot = strict_module_rwx_enabled() ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
 431         pgprot_t prot = strict_module_rwx_enabled() ? PAGE_KERNEL : PAGE_KERNEL_EXEC;
 432         unsigned long fallback_start = 0, fallback_end = 0;
 433         unsigned long start, end;
 434
 435         /*
 436          * BOOK3S_32 and 8xx define MODULES_VADDR for text allocations and
 437          * allow allocating data in the entire vmalloc space
 438          */
 439 #ifdef MODULES_VADDR
 440         unsigned long limit = (unsigned long)_etext - SZ_32M;
 441
 442         BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
 443
 444         /* First try within 32M limit from _etext to avoid branch trampolines */
 445         if (MODULES_VADDR < PAGE_OFFSET && MODULES_END > limit) {
 446                 start = limit;
 447                 fallback_start = MODULES_VADDR;
 448                 fallback_end = MODULES_END;
 449         } else {
 450                 start = MODULES_VADDR;
 451         }
 452
 453         end = MODULES_END;
 454 #else
 455         start = VMALLOC_START;
 456         end = VMALLOC_END;
 457 #endif
 458
 459         prealloc_execmem_pgtable();
 460
 461         execmem_info = (struct execmem_info){
 462                 .ranges = {
 463                         [EXECMEM_DEFAULT] = {
 464                                 .start  = start,
 465                                 .end    = end,
 466                                 .pgprot = prot,
 467                                 .alignment = 1,
 468                                 .fallback_start = fallback_start,
 469                                 .fallback_end   = fallback_end,
 470                         },
 471                         [EXECMEM_KPROBES] = {
 472                                 .start  = VMALLOC_START,
 473                                 .end    = VMALLOC_END,
 474                                 .pgprot = kprobes_prot,
 475                                 .alignment = 1,
 476                         },
 477                         [EXECMEM_MODULE_DATA] = {
 478                                 .start  = VMALLOC_START,
 479                                 .end    = VMALLOC_END,
 480                                 .pgprot = PAGE_KERNEL,
 481                                 .alignment = 1,
 482                         },
 483                 },
 484         };
 485
 486         return &execmem_info;
 487 }
 488 #endif /* CONFIG_EXECMEM */