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
  20 #include <asm/machdep.h>
  21 #include <asm/rtas.h>
  22 #include <asm/kasan.h>
  23 #include <asm/svm.h>
  24 #include <asm/mmzone.h>
  25
  26 #include <mm/mmu_decl.h>
  27
  28 unsigned long long memory_limit;
  29 bool init_mem_is_free;
  30
  31 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
  32 EXPORT_SYMBOL(empty_zero_page);
  33
  34 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  35                               unsigned long size, pgprot_t vma_prot)
  36 {
  37         if (ppc_md.phys_mem_access_prot)
  38                 return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
  39
  40         if (!page_is_ram(pfn))
  41                 vma_prot = pgprot_noncached(vma_prot);
  42
  43         return vma_prot;
  44 }
  45 EXPORT_SYMBOL(phys_mem_access_prot);
  46
  47 #ifdef CONFIG_MEMORY_HOTPLUG
  48 static DEFINE_MUTEX(linear_mapping_mutex);
  49
  50 #ifdef CONFIG_NUMA
  51 int memory_add_physaddr_to_nid(u64 start)
  52 {
  53         return hot_add_scn_to_nid(start);
  54 }
  55 #endif
  56
  57 int __weak create_section_mapping(unsigned long start, unsigned long end,
  58                                   int nid, pgprot_t prot)
  59 {
  60         return -ENODEV;
  61 }
  62
  63 int __weak remove_section_mapping(unsigned long start, unsigned long end)
  64 {
  65         return -ENODEV;
  66 }
  67
  68 int __ref arch_create_linear_mapping(int nid, u64 start, u64 size,
  69                                      struct mhp_params *params)
  70 {
  71         int rc;
  72
  73         start = (unsigned long)__va(start);
  74         mutex_lock(&linear_mapping_mutex);
  75         rc = create_section_mapping(start, start + size, nid,
  76                                     params->pgprot);
  77         mutex_unlock(&linear_mapping_mutex);
  78         if (rc) {
  79                 pr_warn("Unable to create linear mapping for 0x%llx..0x%llx: %d\n",
  80                         start, start + size, rc);
  81                 return -EFAULT;
  82         }
  83         return 0;
  84 }
  85
  86 void __ref arch_remove_linear_mapping(u64 start, u64 size)
  87 {
  88         int ret;
  89
  90         /* Remove htab bolted mappings for this section of memory */
  91         start = (unsigned long)__va(start);
  92
  93         mutex_lock(&linear_mapping_mutex);
  94         ret = remove_section_mapping(start, start + size);
  95         mutex_unlock(&linear_mapping_mutex);
  96         if (ret)
  97                 pr_warn("Unable to remove linear mapping for 0x%llx..0x%llx: %d\n",
  98                         start, start + size, ret);
  99
 100         /* Ensure all vmalloc mappings are flushed in case they also
 101          * hit that section of memory
 102          */
 103         vm_unmap_aliases();
 104 }
 105
 106 int __ref arch_add_memory(int nid, u64 start, u64 size,
 107                           struct mhp_params *params)
 108 {
 109         unsigned long start_pfn = start >> PAGE_SHIFT;
 110         unsigned long nr_pages = size >> PAGE_SHIFT;
 111         int rc;
 112
 113         rc = arch_create_linear_mapping(nid, start, size, params);
 114         if (rc)
 115                 return rc;
 116         rc = __add_pages(nid, start_pfn, nr_pages, params);
 117         if (rc)
 118                 arch_remove_linear_mapping(start, size);
 119         return rc;
 120 }
 121
 122 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
 123 {
 124         unsigned long start_pfn = start >> PAGE_SHIFT;
 125         unsigned long nr_pages = size >> PAGE_SHIFT;
 126
 127         __remove_pages(start_pfn, nr_pages, altmap);
 128         arch_remove_linear_mapping(start, size);
 129 }
 130 #endif
 131
 132 #ifndef CONFIG_NUMA
 133 void __init mem_topology_setup(void)
 134 {
 135         max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
 136         min_low_pfn = MEMORY_START >> PAGE_SHIFT;
 137 #ifdef CONFIG_HIGHMEM
 138         max_low_pfn = lowmem_end_addr >> PAGE_SHIFT;
 139 #endif
 140
 141         /* Place all memblock_regions in the same node and merge contiguous
 142          * memblock_regions
 143          */
 144         memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
 145 }
 146
 147 void __init initmem_init(void)
 148 {
 149         sparse_init();
 150 }
 151
 152 /* mark pages that don't exist as nosave */
 153 static int __init mark_nonram_nosave(void)
 154 {
 155         unsigned long spfn, epfn, prev = 0;
 156         int i;
 157
 158         for_each_mem_pfn_range(i, MAX_NUMNODES, &spfn, &epfn, NULL) {
 159                 if (prev && prev < spfn)
 160                         register_nosave_region(prev, spfn);
 161
 162                 prev = epfn;
 163         }
 164
 165         return 0;
 166 }
 167 #else /* CONFIG_NUMA */
 168 static int __init mark_nonram_nosave(void)
 169 {
 170         return 0;
 171 }
 172 #endif
 173
 174 /*
 175  * Zones usage:
 176  *
 177  * We setup ZONE_DMA to be 31-bits on all platforms and ZONE_NORMAL to be
 178  * everything else. GFP_DMA32 page allocations automatically fall back to
 179  * ZONE_DMA.
 180  *
 181  * By using 31-bit unconditionally, we can exploit zone_dma_bits to inform the
 182  * generic DMA mapping code.  32-bit only devices (if not handled by an IOMMU
 183  * anyway) will take a first dip into ZONE_NORMAL and get otherwise served by
 184  * ZONE_DMA.
 185  */
 186 static unsigned long max_zone_pfns[MAX_NR_ZONES];
 187
 188 /*
 189  * paging_init() sets up the page tables - in fact we've already done this.
 190  */
 191 void __init paging_init(void)
 192 {
 193         unsigned long long total_ram = memblock_phys_mem_size();
 194         phys_addr_t top_of_ram = memblock_end_of_DRAM();
 195
 196 #ifdef CONFIG_HIGHMEM
 197         unsigned long v = __fix_to_virt(FIX_KMAP_END);
 198         unsigned long end = __fix_to_virt(FIX_KMAP_BEGIN);
 199
 200         for (; v < end; v += PAGE_SIZE)
 201                 map_kernel_page(v, 0, __pgprot(0)); /* XXX gross */
 202
 203         map_kernel_page(PKMAP_BASE, 0, __pgprot(0));    /* XXX gross */
 204         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 205 #endif /* CONFIG_HIGHMEM */
 206
 207         printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
 208                (unsigned long long)top_of_ram, total_ram);
 209         printk(KERN_DEBUG "Memory hole size: %ldMB\n",
 210                (long int)((top_of_ram - total_ram) >> 20));
 211
 212         /*
 213          * Allow 30-bit DMA for very limited Broadcom wifi chips on many
 214          * powerbooks.
 215          */
 216         if (IS_ENABLED(CONFIG_PPC32))
 217                 zone_dma_bits = 30;
 218         else
 219                 zone_dma_bits = 31;
 220
 221 #ifdef CONFIG_ZONE_DMA
 222         max_zone_pfns[ZONE_DMA] = min(max_low_pfn,
 223                                       1UL << (zone_dma_bits - PAGE_SHIFT));
 224 #endif
 225         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 226 #ifdef CONFIG_HIGHMEM
 227         max_zone_pfns[ZONE_HIGHMEM] = max_pfn;
 228 #endif
 229
 230         free_area_init(max_zone_pfns);
 231
 232         mark_nonram_nosave();
 233 }
 234
 235 void __init mem_init(void)
 236 {
 237         /*
 238          * book3s is limited to 16 page sizes due to encoding this in
 239          * a 4-bit field for slices.
 240          */
 241         BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 242
 243 #ifdef CONFIG_SWIOTLB
 244         /*
 245          * Some platforms (e.g. 85xx) limit DMA-able memory way below
 246          * 4G. We force memblock to bottom-up mode to ensure that the
 247          * memory allocated in swiotlb_init() is DMA-able.
 248          * As it's the last memblock allocation, no need to reset it
 249          * back to to-down.
 250          */
 251         memblock_set_bottom_up(true);
 252         if (is_secure_guest())
 253                 svm_swiotlb_init();
 254         else
 255                 swiotlb_init(0);
 256 #endif
 257
 258         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 259         set_max_mapnr(max_pfn);
 260
 261         kasan_late_init();
 262
 263         memblock_free_all();
 264
 265 #ifdef CONFIG_HIGHMEM
 266         {
 267                 unsigned long pfn, highmem_mapnr;
 268
 269                 highmem_mapnr = lowmem_end_addr >> PAGE_SHIFT;
 270                 for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
 271                         phys_addr_t paddr = (phys_addr_t)pfn << PAGE_SHIFT;
 272                         struct page *page = pfn_to_page(pfn);
 273                         if (!memblock_is_reserved(paddr))
 274                                 free_highmem_page(page);
 275                 }
 276         }
 277 #endif /* CONFIG_HIGHMEM */
 278
 279 #if defined(CONFIG_PPC_FSL_BOOK3E) && !defined(CONFIG_SMP)
 280         /*
 281          * If smp is enabled, next_tlbcam_idx is initialized in the cpu up
 282          * functions.... do it here for the non-smp case.
 283          */
 284         per_cpu(next_tlbcam_idx, smp_processor_id()) =
 285                 (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) - 1;
 286 #endif
 287
 288 #ifdef CONFIG_PPC32
 289         pr_info("Kernel virtual memory layout:\n");
 290 #ifdef CONFIG_KASAN
 291         pr_info("  * 0x%08lx..0x%08lx  : kasan shadow mem\n",
 292                 KASAN_SHADOW_START, KASAN_SHADOW_END);
 293 #endif
 294         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 295 #ifdef CONFIG_HIGHMEM
 296         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 297                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 298 #endif /* CONFIG_HIGHMEM */
 299         if (ioremap_bot != IOREMAP_TOP)
 300                 pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 301                         ioremap_bot, IOREMAP_TOP);
 302         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 303                 VMALLOC_START, VMALLOC_END);
 304 #ifdef MODULES_VADDR
 305         pr_info("  * 0x%08lx..0x%08lx  : modules\n",
 306                 MODULES_VADDR, MODULES_END);
 307 #endif
 308 #endif /* CONFIG_PPC32 */
 309 }
 310
 311 void free_initmem(void)
 312 {
 313         ppc_md.progress = ppc_printk_progress;
 314         mark_initmem_nx();
 315         init_mem_is_free = true;
 316         free_initmem_default(POISON_FREE_INITMEM);
 317 }
 318
 319 /*
 320  * System memory should not be in /proc/iomem but various tools expect it
 321  * (eg kdump).
 322  */
 323 static int __init add_system_ram_resources(void)
 324 {
 325         phys_addr_t start, end;
 326         u64 i;
 327
 328         for_each_mem_range(i, &start, &end) {
 329                 struct resource *res;
 330
 331                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 332                 WARN_ON(!res);
 333
 334                 if (res) {
 335                         res->name = "System RAM";
 336                         res->start = start;
 337                         /*
 338                          * In memblock, end points to the first byte after
 339                          * the range while in resourses, end points to the
 340                          * last byte in the range.
 341                          */
 342                         res->end = end - 1;
 343                         res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 344                         WARN_ON(request_resource(&iomem_resource, res) < 0);
 345                 }
 346         }
 347
 348         return 0;
 349 }
 350 subsys_initcall(add_system_ram_resources);
 351
 352 #ifdef CONFIG_STRICT_DEVMEM
 353 /*
 354  * devmem_is_allowed(): check to see if /dev/mem access to a certain address
 355  * is valid. The argument is a physical page number.
 356  *
 357  * Access has to be given to non-kernel-ram areas as well, these contain the
 358  * PCI mmio resources as well as potential bios/acpi data regions.
 359  */
 360 int devmem_is_allowed(unsigned long pfn)
 361 {
 362         if (page_is_rtas_user_buf(pfn))
 363                 return 1;
 364         if (iomem_is_exclusive(PFN_PHYS(pfn)))
 365                 return 0;
 366         if (!page_is_ram(pfn))
 367                 return 1;
 368         return 0;
 369 }
 370 #endif /* CONFIG_STRICT_DEVMEM */
 371
 372 /*
 373  * This is defined in kernel/resource.c but only powerpc needs to export it, for
 374  * the EHEA driver. Drop this when drivers/net/ethernet/ibm/ehea is removed.
 375  */
 376 EXPORT_SYMBOL_GPL(walk_system_ram_range);