arch/hexagon/mm/init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Memory subsystem initialization for Hexagon
   4  *
   5  * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/mm.h>
  10 #include <linux/memblock.h>
  11 #include <asm/atomic.h>
  12 #include <linux/highmem.h>
  13 #include <asm/tlb.h>
  14 #include <asm/sections.h>
  15 #include <asm/setup.h>
  16 #include <asm/vm_mmu.h>
  17
  18 /*
  19  * Define a startpg just past the end of the kernel image and a lastpg
  20  * that corresponds to the end of real or simulated platform memory.
  21  */
  22 #define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
  23
  24 unsigned long bootmem_lastpg;   /*  Should be set by platform code  */
  25 unsigned long __phys_offset;    /*  physical kernel offset >> 12  */
  26
  27 /*  Set as variable to limit PMD copies  */
  28 int max_kernel_seg = 0x303;
  29
  30 /*  indicate pfn's of high memory  */
  31 unsigned long highstart_pfn, highend_pfn;
  32
  33 /* Default cache attribute for newly created page tables */
  34 unsigned long _dflt_cache_att = CACHEDEF;
  35
  36 /*
  37  * The current "generation" of kernel map, which should not roll
  38  * over until Hell freezes over.  Actual bound in years needs to be
  39  * calculated to confirm.
  40  */
  41 DEFINE_SPINLOCK(kmap_gen_lock);
  42
  43 /*  checkpatch says don't init this to 0.  */
  44 unsigned long long kmap_generation;
  45
  46 /*
  47  * mem_init - initializes memory
  48  *
  49  * Frees up bootmem
  50  * Fixes up more stuff for HIGHMEM
  51  * Calculates and displays memory available/used
  52  */
  53 void __init mem_init(void)
  54 {
  55         /*  No idea where this is actually declared.  Seems to evade LXR.  */
  56         memblock_free_all();
  57
  58         /*
  59          *  To-Do:  someone somewhere should wipe out the bootmem map
  60          *  after we're done?
  61          */
  62
  63         /*
  64          * This can be moved to some more virtual-memory-specific
  65          * initialization hook at some point.  Set the init_mm
  66          * descriptors "context" value to point to the initial
  67          * kernel segment table's physical address.
  68          */
  69         init_mm.context.ptbase = __pa(init_mm.pgd);
  70 }
  71
  72 void sync_icache_dcache(pte_t pte)
  73 {
  74         unsigned long addr;
  75         struct page *page;
  76
  77         page = pte_page(pte);
  78         addr = (unsigned long) page_address(page);
  79
  80         __vmcache_idsync(addr, PAGE_SIZE);
  81 }
  82
  83 /*
  84  * In order to set up page allocator "nodes",
  85  * somebody has to call free_area_init() for UMA.
  86  *
  87  * In this mode, we only have one pg_data_t
  88  * structure: contig_mem_data.
  89  */
  90 static void __init paging_init(void)
  91 {
  92         unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
  93
  94         /*
  95          *  This is not particularly well documented anywhere, but
  96          *  give ZONE_NORMAL all the memory, including the big holes
  97          *  left by the kernel+bootmem_map which are already left as reserved
  98          *  in the bootmem_map; free_area_init should see those bits and
  99          *  adjust accordingly.
 100          */
 101
 102         max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
 103
 104         free_area_init(max_zone_pfn);  /*  sets up the zonelists and mem_map  */
 105
 106         /*
 107          * Start of high memory area.  Will probably need something more
 108          * fancy if we...  get more fancy.
 109          */
 110         high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT);
 111 }
 112
 113 #ifndef DMA_RESERVE
 114 #define DMA_RESERVE             (4)
 115 #endif
 116
 117 #define DMA_CHUNKSIZE           (1<<22)
 118 #define DMA_RESERVED_BYTES      (DMA_RESERVE * DMA_CHUNKSIZE)
 119
 120 /*
 121  * Pick out the memory size.  We look for mem=size,
 122  * where size is "size[KkMm]"
 123  */
 124 static int __init early_mem(char *p)
 125 {
 126         unsigned long size;
 127         char *endp;
 128
 129         size = memparse(p, &endp);
 130
 131         bootmem_lastpg = PFN_DOWN(size);
 132
 133         return 0;
 134 }
 135 early_param("mem", early_mem);
 136
 137 size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22);
 138
 139 void __init setup_arch_memory(void)
 140 {
 141         /*  XXX Todo: this probably should be cleaned up  */
 142         u32 *segtable = (u32 *) &swapper_pg_dir[0];
 143         u32 *segtable_end;
 144
 145         /*
 146          * Set up boot memory allocator
 147          *
 148          * The Gorman book also talks about these functions.
 149          * This needs to change for highmem setups.
 150          */
 151
 152         /*  Prior to this, bootmem_lastpg is actually mem size  */
 153         bootmem_lastpg += ARCH_PFN_OFFSET;
 154
 155         /* Memory size needs to be a multiple of 16M */
 156         bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
 157                 ~((BIG_KERNEL_PAGE_SIZE) - 1));
 158
 159         memblock_add(PHYS_OFFSET,
 160                      (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
 161
 162         /* Reserve kernel text/data/bss */
 163         memblock_reserve(PHYS_OFFSET,
 164                          (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT);
 165         /*
 166          * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
 167          * memory allocation
 168          */
 169         max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
 170         min_low_pfn = ARCH_PFN_OFFSET;
 171         memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES);
 172
 173         printk(KERN_INFO "bootmem_startpg:  0x%08lx\n", bootmem_startpg);
 174         printk(KERN_INFO "bootmem_lastpg:  0x%08lx\n", bootmem_lastpg);
 175         printk(KERN_INFO "min_low_pfn:  0x%08lx\n", min_low_pfn);
 176         printk(KERN_INFO "max_low_pfn:  0x%08lx\n", max_low_pfn);
 177
 178         /*
 179          * The default VM page tables (will be) populated with
 180          * VA=PA+PAGE_OFFSET mapping.  We go in and invalidate entries
 181          * higher than what we have memory for.
 182          */
 183
 184         /*  this is pointer arithmetic; each entry covers 4MB  */
 185         segtable = segtable + (PAGE_OFFSET >> 22);
 186
 187         /*  this actually only goes to the end of the first gig  */
 188         segtable_end = segtable + (1<<(30-22));
 189
 190         /*
 191          * Move forward to the start of empty pages; take into account
 192          * phys_offset shift.
 193          */
 194
 195         segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
 196         {
 197                 int i;
 198
 199                 for (i = 1 ; i <= DMA_RESERVE ; i++)
 200                         segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
 201                                 | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
 202                                 | __HEXAGON_C_UNC << 6
 203                                 | __HVM_PDE_S_4MB);
 204         }
 205
 206         printk(KERN_INFO "clearing segtable from %p to %p\n", segtable,
 207                 segtable_end);
 208         while (segtable < (segtable_end-8))
 209                 *(segtable++) = __HVM_PDE_S_INVALID;
 210         /* stop the pointer at the device I/O 4MB page  */
 211
 212         printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n",
 213                 segtable);
 214
 215 #if 0
 216         /*  Other half of the early device table from vm_init_segtable. */
 217         printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n",
 218                 (unsigned long) _K_init_devicetable-PAGE_OFFSET);
 219         *segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) |
 220                 __HVM_PDE_S_4KB;
 221         printk(KERN_INFO "*segtable = 0x%08x\n", *segtable);
 222 #endif
 223
 224         /*
 225          *  The bootmem allocator seemingly just lives to feed memory
 226          *  to the paging system
 227          */
 228         printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE);
 229         paging_init();  /*  See Gorman Book, 2.3  */
 230
 231         /*
 232          *  At this point, the page allocator is kind of initialized, but
 233          *  apparently no pages are available (just like with the bootmem
 234          *  allocator), and need to be freed themselves via mem_init(),
 235          *  which is called by start_kernel() later on in the process
 236          */
 237 }
 238
 239 static const pgprot_t protection_map[16] = {
 240         [VM_NONE]                                       = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 241                                                                    CACHEDEF),
 242         [VM_READ]                                       = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 243                                                                    _PAGE_READ | CACHEDEF),
 244         [VM_WRITE]                                      = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 245                                                                    CACHEDEF),
 246         [VM_WRITE | VM_READ]                            = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 247                                                                    _PAGE_READ | CACHEDEF),
 248         [VM_EXEC]                                       = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 249                                                                    _PAGE_EXECUTE | CACHEDEF),
 250         [VM_EXEC | VM_READ]                             = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 251                                                                    _PAGE_EXECUTE | _PAGE_READ |
 252                                                                    CACHEDEF),
 253         [VM_EXEC | VM_WRITE]                            = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 254                                                                    _PAGE_EXECUTE | CACHEDEF),
 255         [VM_EXEC | VM_WRITE | VM_READ]                  = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 256                                                                    _PAGE_EXECUTE | _PAGE_READ |
 257                                                                    CACHEDEF),
 258         [VM_SHARED]                                     = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 259                                                                    CACHEDEF),
 260         [VM_SHARED | VM_READ]                           = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 261                                                                    _PAGE_READ | CACHEDEF),
 262         [VM_SHARED | VM_WRITE]                          = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 263                                                                    _PAGE_WRITE | CACHEDEF),
 264         [VM_SHARED | VM_WRITE | VM_READ]                = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 265                                                                    _PAGE_READ | _PAGE_WRITE |
 266                                                                    CACHEDEF),
 267         [VM_SHARED | VM_EXEC]                           = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 268                                                                    _PAGE_EXECUTE | CACHEDEF),
 269         [VM_SHARED | VM_EXEC | VM_READ]                 = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 270                                                                    _PAGE_EXECUTE | _PAGE_READ |
 271                                                                    CACHEDEF),
 272         [VM_SHARED | VM_EXEC | VM_WRITE]                = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 273                                                                    _PAGE_EXECUTE | _PAGE_WRITE |
 274                                                                    CACHEDEF),
 275         [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = __pgprot(_PAGE_PRESENT | _PAGE_USER |
 276                                                                    _PAGE_READ | _PAGE_EXECUTE |
 277                                                                    _PAGE_WRITE | CACHEDEF)
 278 };
 279 DECLARE_VM_GET_PAGE_PROT