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 void sync_icache_dcache(pte_t pte) 47 { 48 unsigned long addr; 49 struct page *page; 50 51 page = pte_page(pte); 52 addr = (unsigned long) page_address(page); 53 54 __vmcache_idsync(addr, PAGE_SIZE); 55 } 56 57 /* 58 * In order to set up page allocator "nodes", 59 * somebody has to call free_area_init() for UMA. 60 * 61 * In this mode, we only have one pg_data_t 62 * structure: contig_mem_data. 63 */ 64 static void __init paging_init(void) 65 { 66 unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, }; 67 68 /* 69 * This is not particularly well documented anywhere, but 70 * give ZONE_NORMAL all the memory, including the big holes 71 * left by the kernel+bootmem_map which are already left as reserved 72 * in the bootmem_map; free_area_init should see those bits and 73 * adjust accordingly. 74 */ 75 76 max_zone_pfn[ZONE_NORMAL] = max_low_pfn; 77 78 free_area_init(max_zone_pfn); /* sets up the zonelists and mem_map */ 79 80 /* 81 * Set the init_mm descriptors "context" value to point to the 82 * initial kernel segment table's physical address. 83 */ 84 init_mm.context.ptbase = __pa(init_mm.pgd); 85 } 86 87 #ifndef DMA_RESERVE 88 #define DMA_RESERVE (4) 89 #endif 90 91 #define DMA_CHUNKSIZE (1<<22) 92 #define DMA_RESERVED_BYTES (DMA_RESERVE * DMA_CHUNKSIZE) 93 94 /* 95 * Pick out the memory size. We look for mem=size, 96 * where size is "size[KkMm]" 97 */ 98 static int __init early_mem(char *p) 99 { 100 unsigned long size; 101 char *endp; 102 103 size = memparse(p, &endp); 104 105 bootmem_lastpg = PFN_DOWN(size); 106 107 return 0; 108 } 109 early_param("mem", early_mem); 110 111 size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22); 112 113 void __init setup_arch_memory(void) 114 { 115 /* XXX Todo: this probably should be cleaned up */ 116 u32 *segtable = (u32 *) &swapper_pg_dir[0]; 117 u32 *segtable_end; 118 119 /* 120 * Set up boot memory allocator 121 * 122 * The Gorman book also talks about these functions. 123 * This needs to change for highmem setups. 124 */ 125 126 /* Prior to this, bootmem_lastpg is actually mem size */ 127 bootmem_lastpg += ARCH_PFN_OFFSET; 128 129 /* Memory size needs to be a multiple of 16M */ 130 bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) & 131 ~((BIG_KERNEL_PAGE_SIZE) - 1)); 132 133 memblock_add(PHYS_OFFSET, 134 (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); 135 136 /* Reserve kernel text/data/bss */ 137 memblock_reserve(PHYS_OFFSET, 138 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); 139 /* 140 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached) 141 * memory allocation 142 */ 143 max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES); 144 min_low_pfn = ARCH_PFN_OFFSET; 145 memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES); 146 147 printk(KERN_INFO "bootmem_startpg: 0x%08lx\n", bootmem_startpg); 148 printk(KERN_INFO "bootmem_lastpg: 0x%08lx\n", bootmem_lastpg); 149 printk(KERN_INFO "min_low_pfn: 0x%08lx\n", min_low_pfn); 150 printk(KERN_INFO "max_low_pfn: 0x%08lx\n", max_low_pfn); 151 152 /* 153 * The default VM page tables (will be) populated with 154 * VA=PA+PAGE_OFFSET mapping. We go in and invalidate entries 155 * higher than what we have memory for. 156 */ 157 158 /* this is pointer arithmetic; each entry covers 4MB */ 159 segtable = segtable + (PAGE_OFFSET >> 22); 160 161 /* this actually only goes to the end of the first gig */ 162 segtable_end = segtable + (1<<(30-22)); 163 164 /* 165 * Move forward to the start of empty pages; take into account 166 * phys_offset shift. 167 */ 168 169 segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT); 170 { 171 int i; 172 173 for (i = 1 ; i <= DMA_RESERVE ; i++) 174 segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB) 175 | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X 176 | __HEXAGON_C_UNC << 6 177 | __HVM_PDE_S_4MB); 178 } 179 180 printk(KERN_INFO "clearing segtable from %p to %p\n", segtable, 181 segtable_end); 182 while (segtable < (segtable_end-8)) 183 *(segtable++) = __HVM_PDE_S_INVALID; 184 /* stop the pointer at the device I/O 4MB page */ 185 186 printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n", 187 segtable); 188 189 #if 0 190 /* Other half of the early device table from vm_init_segtable. */ 191 printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n", 192 (unsigned long) _K_init_devicetable-PAGE_OFFSET); 193 *segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) | 194 __HVM_PDE_S_4KB; 195 printk(KERN_INFO "*segtable = 0x%08x\n", *segtable); 196 #endif 197 198 /* 199 * The bootmem allocator seemingly just lives to feed memory 200 * to the paging system 201 */ 202 printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE); 203 paging_init(); /* See Gorman Book, 2.3 */ 204 205 /* 206 * At this point, the page allocator is kind of initialized, but 207 * apparently no pages are available (just like with the bootmem 208 * allocator), and need to be freed themselves via mem_init(), 209 * which is called by start_kernel() later on in the process 210 */ 211 } 212 213 static const pgprot_t protection_map[16] = { 214 [VM_NONE] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 215 CACHEDEF), 216 [VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 217 _PAGE_READ | CACHEDEF), 218 [VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 219 CACHEDEF), 220 [VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 221 _PAGE_READ | CACHEDEF), 222 [VM_EXEC] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 223 _PAGE_EXECUTE | CACHEDEF), 224 [VM_EXEC | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 225 _PAGE_EXECUTE | _PAGE_READ | 226 CACHEDEF), 227 [VM_EXEC | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 228 _PAGE_EXECUTE | CACHEDEF), 229 [VM_EXEC | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 230 _PAGE_EXECUTE | _PAGE_READ | 231 CACHEDEF), 232 [VM_SHARED] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 233 CACHEDEF), 234 [VM_SHARED | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 235 _PAGE_READ | CACHEDEF), 236 [VM_SHARED | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 237 _PAGE_WRITE | CACHEDEF), 238 [VM_SHARED | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 239 _PAGE_READ | _PAGE_WRITE | 240 CACHEDEF), 241 [VM_SHARED | VM_EXEC] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 242 _PAGE_EXECUTE | CACHEDEF), 243 [VM_SHARED | VM_EXEC | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 244 _PAGE_EXECUTE | _PAGE_READ | 245 CACHEDEF), 246 [VM_SHARED | VM_EXEC | VM_WRITE] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 247 _PAGE_EXECUTE | _PAGE_WRITE | 248 CACHEDEF), 249 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = __pgprot(_PAGE_PRESENT | _PAGE_USER | 250 _PAGE_READ | _PAGE_EXECUTE | 251 _PAGE_WRITE | CACHEDEF) 252 }; 253 DECLARE_VM_GET_PAGE_PROT 254