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