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