arch/riscv/mm/init.c

   1 /*
   2  * Copyright (C) 2012 Regents of the University of California
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful,
   9  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  *   GNU General Public License for more details.
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/mm.h>
  16 #include <linux/memblock.h>
  17 #include <linux/initrd.h>
  18 #include <linux/swap.h>
  19 #include <linux/sizes.h>
  20 #include <linux/of_fdt.h>
  21
  22 #include <asm/fixmap.h>
  23 #include <asm/tlbflush.h>
  24 #include <asm/sections.h>
  25 #include <asm/pgtable.h>
  26 #include <asm/io.h>
  27
  28 static void __init zone_sizes_init(void)
  29 {
  30         unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
  31
  32 #ifdef CONFIG_ZONE_DMA32
  33         max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
  34                         (unsigned long) PFN_PHYS(max_low_pfn)));
  35 #endif
  36         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  37
  38         free_area_init_nodes(max_zone_pfns);
  39 }
  40
  41 void setup_zero_page(void)
  42 {
  43         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  44 }
  45
  46 void __init paging_init(void)
  47 {
  48         setup_zero_page();
  49         local_flush_tlb_all();
  50         zone_sizes_init();
  51 }
  52
  53 void __init mem_init(void)
  54 {
  55 #ifdef CONFIG_FLATMEM
  56         BUG_ON(!mem_map);
  57 #endif /* CONFIG_FLATMEM */
  58
  59         high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
  60         memblock_free_all();
  61
  62         mem_init_print_info(NULL);
  63 }
  64
  65 void free_initmem(void)
  66 {
  67         free_initmem_default(0);
  68 }
  69
  70 #ifdef CONFIG_BLK_DEV_INITRD
  71 static void __init setup_initrd(void)
  72 {
  73         unsigned long size;
  74
  75         if (initrd_start >= initrd_end) {
  76                 pr_info("initrd not found or empty");
  77                 goto disable;
  78         }
  79         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  80                 pr_err("initrd extends beyond end of memory");
  81                 goto disable;
  82         }
  83
  84         size = initrd_end - initrd_start;
  85         memblock_reserve(__pa(initrd_start), size);
  86         initrd_below_start_ok = 1;
  87
  88         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
  89                 (void *)(initrd_start), size);
  90         return;
  91 disable:
  92         pr_cont(" - disabling initrd\n");
  93         initrd_start = 0;
  94         initrd_end = 0;
  95 }
  96
  97 void __init free_initrd_mem(unsigned long start, unsigned long end)
  98 {
  99         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 100 }
 101 #endif /* CONFIG_BLK_DEV_INITRD */
 102
 103 void __init setup_bootmem(void)
 104 {
 105         struct memblock_region *reg;
 106         phys_addr_t mem_size = 0;
 107
 108         /* Find the memory region containing the kernel */
 109         for_each_memblock(memory, reg) {
 110                 phys_addr_t vmlinux_end = __pa(_end);
 111                 phys_addr_t end = reg->base + reg->size;
 112
 113                 if (reg->base <= vmlinux_end && vmlinux_end <= end) {
 114                         /*
 115                          * Reserve from the start of the region to the end of
 116                          * the kernel
 117                          */
 118                         memblock_reserve(reg->base, vmlinux_end - reg->base);
 119                         mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);
 120                 }
 121         }
 122         BUG_ON(mem_size == 0);
 123
 124         set_max_mapnr(PFN_DOWN(mem_size));
 125         max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
 126
 127 #ifdef CONFIG_BLK_DEV_INITRD
 128         setup_initrd();
 129 #endif /* CONFIG_BLK_DEV_INITRD */
 130
 131         early_init_fdt_reserve_self();
 132         early_init_fdt_scan_reserved_mem();
 133         memblock_allow_resize();
 134         memblock_dump_all();
 135
 136         for_each_memblock(memory, reg) {
 137                 unsigned long start_pfn = memblock_region_memory_base_pfn(reg);
 138                 unsigned long end_pfn = memblock_region_memory_end_pfn(reg);
 139
 140                 memblock_set_node(PFN_PHYS(start_pfn),
 141                                   PFN_PHYS(end_pfn - start_pfn),
 142                                   &memblock.memory, 0);
 143         }
 144 }
 145
 146 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 147 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 148
 149 #ifndef __PAGETABLE_PMD_FOLDED
 150 #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT)
 151 pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss;
 152 pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 153 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
 154 #endif
 155
 156 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
 157
 158 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 159 {
 160         unsigned long addr = __fix_to_virt(idx);
 161         pte_t *ptep;
 162
 163         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 164
 165         ptep = &fixmap_pte[pte_index(addr)];
 166
 167         if (pgprot_val(prot)) {
 168                 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
 169         } else {
 170                 pte_clear(&init_mm, addr, ptep);
 171                 local_flush_tlb_page(addr);
 172         }
 173 }
 174
 175 asmlinkage void __init setup_vm(void)
 176 {
 177         extern char _start;
 178         uintptr_t i;
 179         uintptr_t pa = (uintptr_t) &_start;
 180         pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC);
 181
 182         va_pa_offset = PAGE_OFFSET - pa;
 183         pfn_base = PFN_DOWN(pa);
 184
 185         /* Sanity check alignment and size */
 186         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 187         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
 188
 189 #ifndef __PAGETABLE_PMD_FOLDED
 190         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 191                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
 192                         __pgprot(_PAGE_TABLE));
 193         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
 194
 195         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 196                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 197
 198                 swapper_pg_dir[o] =
 199                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
 200                                 __pgprot(_PAGE_TABLE));
 201         }
 202         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
 203                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
 204
 205         swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 206                 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
 207                                 __pgprot(_PAGE_TABLE));
 208         fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
 209                 pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
 210                                 __pgprot(_PAGE_TABLE));
 211 #else
 212         trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 213                 pfn_pgd(PFN_DOWN(pa), prot);
 214
 215         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
 216                 size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
 217
 218                 swapper_pg_dir[o] =
 219                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
 220         }
 221
 222         swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
 223                 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
 224                                 __pgprot(_PAGE_TABLE));
 225 #endif
 226 }