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 280