1 /* 2 * Memory subsystem initialization for Hexagon 3 * 4 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 and 8 * only version 2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 * 02110-1301, USA. 19 */ 20 21 #include <linux/init.h> 22 #include <linux/mm.h> 23 #include <linux/memblock.h> 24 #include <asm/atomic.h> 25 #include <linux/highmem.h> 26 #include <asm/tlb.h> 27 #include <asm/sections.h> 28 #include <asm/vm_mmu.h> 29 30 /* 31 * Define a startpg just past the end of the kernel image and a lastpg 32 * that corresponds to the end of real or simulated platform memory. 33 */ 34 #define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET)) 35 36 unsigned long bootmem_lastpg; /* Should be set by platform code */ 37 unsigned long __phys_offset; /* physical kernel offset >> 12 */ 38 39 /* Set as variable to limit PMD copies */ 40 int max_kernel_seg = 0x303; 41 42 /* indicate pfn's of high memory */ 43 unsigned long highstart_pfn, highend_pfn; 44 45 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); 46 47 /* Default cache attribute for newly created page tables */ 48 unsigned long _dflt_cache_att = CACHEDEF; 49 50 /* 51 * The current "generation" of kernel map, which should not roll 52 * over until Hell freezes over. Actual bound in years needs to be 53 * calculated to confirm. 54 */ 55 DEFINE_SPINLOCK(kmap_gen_lock); 56 57 /* checkpatch says don't init this to 0. */ 58 unsigned long long kmap_generation; 59 60 /* 61 * mem_init - initializes memory 62 * 63 * Frees up bootmem 64 * Fixes up more stuff for HIGHMEM 65 * Calculates and displays memory available/used 66 */ 67 void __init mem_init(void) 68 { 69 /* No idea where this is actually declared. Seems to evade LXR. */ 70 memblock_free_all(); 71 mem_init_print_info(NULL); 72 73 /* 74 * To-Do: someone somewhere should wipe out the bootmem map 75 * after we're done? 76 */ 77 78 /* 79 * This can be moved to some more virtual-memory-specific 80 * initialization hook at some point. Set the init_mm 81 * descriptors "context" value to point to the initial 82 * kernel segment table's physical address. 83 */ 84 init_mm.context.ptbase = __pa(init_mm.pgd); 85 } 86 87 /* 88 * free_initmem - frees memory used by stuff declared with __init 89 * 90 * Todo: free pages between __init_begin and __init_end; possibly 91 * some devtree related stuff as well. 92 */ 93 void __ref free_initmem(void) 94 { 95 } 96 97 /* 98 * free_initrd_mem - frees... initrd memory. 99 * @start - start of init memory 100 * @end - end of init memory 101 * 102 * Apparently has to be passed the address of the initrd memory. 103 * 104 * Wrapped by #ifdef CONFIG_BLKDEV_INITRD 105 */ 106 void free_initrd_mem(unsigned long start, unsigned long end) 107 { 108 } 109 110 void sync_icache_dcache(pte_t pte) 111 { 112 unsigned long addr; 113 struct page *page; 114 115 page = pte_page(pte); 116 addr = (unsigned long) page_address(page); 117 118 __vmcache_idsync(addr, PAGE_SIZE); 119 } 120 121 /* 122 * In order to set up page allocator "nodes", 123 * somebody has to call free_area_init() for UMA. 124 * 125 * In this mode, we only have one pg_data_t 126 * structure: contig_mem_data. 127 */ 128 void __init paging_init(void) 129 { 130 unsigned long zones_sizes[MAX_NR_ZONES] = {0, }; 131 132 /* 133 * This is not particularly well documented anywhere, but 134 * give ZONE_NORMAL all the memory, including the big holes 135 * left by the kernel+bootmem_map which are already left as reserved 136 * in the bootmem_map; free_area_init should see those bits and 137 * adjust accordingly. 138 */ 139 140 zones_sizes[ZONE_NORMAL] = max_low_pfn; 141 142 free_area_init(zones_sizes); /* sets up the zonelists and mem_map */ 143 144 /* 145 * Start of high memory area. Will probably need something more 146 * fancy if we... get more fancy. 147 */ 148 high_memory = (void *)((bootmem_lastpg + 1) << PAGE_SHIFT); 149 } 150 151 #ifndef DMA_RESERVE 152 #define DMA_RESERVE (4) 153 #endif 154 155 #define DMA_CHUNKSIZE (1<<22) 156 #define DMA_RESERVED_BYTES (DMA_RESERVE * DMA_CHUNKSIZE) 157 158 /* 159 * Pick out the memory size. We look for mem=size, 160 * where size is "size[KkMm]" 161 */ 162 static int __init early_mem(char *p) 163 { 164 unsigned long size; 165 char *endp; 166 167 size = memparse(p, &endp); 168 169 bootmem_lastpg = PFN_DOWN(size); 170 171 return 0; 172 } 173 early_param("mem", early_mem); 174 175 size_t hexagon_coherent_pool_size = (size_t) (DMA_RESERVE << 22); 176 177 void __init setup_arch_memory(void) 178 { 179 /* XXX Todo: this probably should be cleaned up */ 180 u32 *segtable = (u32 *) &swapper_pg_dir[0]; 181 u32 *segtable_end; 182 183 /* 184 * Set up boot memory allocator 185 * 186 * The Gorman book also talks about these functions. 187 * This needs to change for highmem setups. 188 */ 189 190 /* Prior to this, bootmem_lastpg is actually mem size */ 191 bootmem_lastpg += ARCH_PFN_OFFSET; 192 193 /* Memory size needs to be a multiple of 16M */ 194 bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) & 195 ~((BIG_KERNEL_PAGE_SIZE) - 1)); 196 197 memblock_add(PHYS_OFFSET, 198 (bootmem_lastpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); 199 200 /* Reserve kernel text/data/bss */ 201 memblock_reserve(PHYS_OFFSET, 202 (bootmem_startpg - ARCH_PFN_OFFSET) << PAGE_SHIFT); 203 /* 204 * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached) 205 * memory allocation 206 */ 207 max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES); 208 min_low_pfn = ARCH_PFN_OFFSET; 209 memblock_reserve(PFN_PHYS(max_low_pfn), DMA_RESERVED_BYTES); 210 211 printk(KERN_INFO "bootmem_startpg: 0x%08lx\n", bootmem_startpg); 212 printk(KERN_INFO "bootmem_lastpg: 0x%08lx\n", bootmem_lastpg); 213 printk(KERN_INFO "min_low_pfn: 0x%08lx\n", min_low_pfn); 214 printk(KERN_INFO "max_low_pfn: 0x%08lx\n", max_low_pfn); 215 216 /* 217 * The default VM page tables (will be) populated with 218 * VA=PA+PAGE_OFFSET mapping. We go in and invalidate entries 219 * higher than what we have memory for. 220 */ 221 222 /* this is pointer arithmetic; each entry covers 4MB */ 223 segtable = segtable + (PAGE_OFFSET >> 22); 224 225 /* this actually only goes to the end of the first gig */ 226 segtable_end = segtable + (1<<(30-22)); 227 228 /* 229 * Move forward to the start of empty pages; take into account 230 * phys_offset shift. 231 */ 232 233 segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT); 234 { 235 int i; 236 237 for (i = 1 ; i <= DMA_RESERVE ; i++) 238 segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB) 239 | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X 240 | __HEXAGON_C_UNC << 6 241 | __HVM_PDE_S_4MB); 242 } 243 244 printk(KERN_INFO "clearing segtable from %p to %p\n", segtable, 245 segtable_end); 246 while (segtable < (segtable_end-8)) 247 *(segtable++) = __HVM_PDE_S_INVALID; 248 /* stop the pointer at the device I/O 4MB page */ 249 250 printk(KERN_INFO "segtable = %p (should be equal to _K_io_map)\n", 251 segtable); 252 253 #if 0 254 /* Other half of the early device table from vm_init_segtable. */ 255 printk(KERN_INFO "&_K_init_devicetable = 0x%08x\n", 256 (unsigned long) _K_init_devicetable-PAGE_OFFSET); 257 *segtable = ((u32) (unsigned long) _K_init_devicetable-PAGE_OFFSET) | 258 __HVM_PDE_S_4KB; 259 printk(KERN_INFO "*segtable = 0x%08x\n", *segtable); 260 #endif 261 262 /* 263 * The bootmem allocator seemingly just lives to feed memory 264 * to the paging system 265 */ 266 printk(KERN_INFO "PAGE_SIZE=%lu\n", PAGE_SIZE); 267 paging_init(); /* See Gorman Book, 2.3 */ 268 269 /* 270 * At this point, the page allocator is kind of initialized, but 271 * apparently no pages are available (just like with the bootmem 272 * allocator), and need to be freed themselves via mem_init(), 273 * which is called by start_kernel() later on in the process 274 */ 275 } 276