1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support 4 * E500 Book E processors. 5 * 6 * Copyright 2004,2010 Freescale Semiconductor, Inc. 7 * 8 * This file contains the routines for initializing the MMU 9 * on the 4xx series of chips. 10 * -- paulus 11 * 12 * Derived from arch/ppc/mm/init.c: 13 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 14 * 15 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 16 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 17 * Copyright (C) 1996 Paul Mackerras 18 * 19 * Derived from "arch/i386/mm/init.c" 20 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 21 */ 22 23 #include <linux/signal.h> 24 #include <linux/sched.h> 25 #include <linux/kernel.h> 26 #include <linux/errno.h> 27 #include <linux/string.h> 28 #include <linux/types.h> 29 #include <linux/ptrace.h> 30 #include <linux/mman.h> 31 #include <linux/mm.h> 32 #include <linux/swap.h> 33 #include <linux/stddef.h> 34 #include <linux/vmalloc.h> 35 #include <linux/init.h> 36 #include <linux/delay.h> 37 #include <linux/highmem.h> 38 #include <linux/memblock.h> 39 #include <linux/of_fdt.h> 40 41 #include <asm/io.h> 42 #include <asm/mmu_context.h> 43 #include <asm/mmu.h> 44 #include <linux/uaccess.h> 45 #include <asm/smp.h> 46 #include <asm/machdep.h> 47 #include <asm/setup.h> 48 #include <asm/paca.h> 49 50 #include <mm/mmu_decl.h> 51 52 unsigned int tlbcam_index; 53 54 struct tlbcam TLBCAM[NUM_TLBCAMS]; 55 56 static struct { 57 unsigned long start; 58 unsigned long limit; 59 phys_addr_t phys; 60 } tlbcam_addrs[NUM_TLBCAMS]; 61 62 #ifdef CONFIG_PPC_85xx 63 /* 64 * Return PA for this VA if it is mapped by a CAM, or 0 65 */ 66 phys_addr_t v_block_mapped(unsigned long va) 67 { 68 int b; 69 for (b = 0; b < tlbcam_index; ++b) 70 if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit) 71 return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start); 72 return 0; 73 } 74 75 /* 76 * Return VA for a given PA or 0 if not mapped 77 */ 78 unsigned long p_block_mapped(phys_addr_t pa) 79 { 80 int b; 81 for (b = 0; b < tlbcam_index; ++b) 82 if (pa >= tlbcam_addrs[b].phys 83 && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start) 84 +tlbcam_addrs[b].phys) 85 return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys); 86 return 0; 87 } 88 #endif 89 90 /* 91 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked; 92 * in particular size must be a power of 4 between 4k and the max supported by 93 * an implementation; max may further be limited by what can be represented in 94 * an unsigned long (for example, 32-bit implementations cannot support a 4GB 95 * size). 96 */ 97 static void settlbcam(int index, unsigned long virt, phys_addr_t phys, 98 unsigned long size, unsigned long flags, unsigned int pid) 99 { 100 unsigned int tsize; 101 102 tsize = __ilog2(size) - 10; 103 104 #if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) 105 if ((flags & _PAGE_NO_CACHE) == 0) 106 flags |= _PAGE_COHERENT; 107 #endif 108 109 TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1); 110 TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid); 111 TLBCAM[index].MAS2 = virt & PAGE_MASK; 112 113 TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0; 114 TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0; 115 TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0; 116 TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0; 117 TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0; 118 119 TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SR; 120 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_SW : 0; 121 if (mmu_has_feature(MMU_FTR_BIG_PHYS)) 122 TLBCAM[index].MAS7 = (u64)phys >> 32; 123 124 /* Below is unlikely -- only for large user pages or similar */ 125 if (pte_user(__pte(flags))) { 126 TLBCAM[index].MAS3 |= MAS3_UR; 127 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_UX : 0; 128 TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_UW : 0; 129 } else { 130 TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_SX : 0; 131 } 132 133 tlbcam_addrs[index].start = virt; 134 tlbcam_addrs[index].limit = virt + size - 1; 135 tlbcam_addrs[index].phys = phys; 136 } 137 138 static unsigned long calc_cam_sz(unsigned long ram, unsigned long virt, 139 phys_addr_t phys) 140 { 141 unsigned int camsize = __ilog2(ram); 142 unsigned int align = __ffs(virt | phys); 143 unsigned long max_cam; 144 145 if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) { 146 /* Convert (4^max) kB to (2^max) bytes */ 147 max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10; 148 camsize &= ~1U; 149 align &= ~1U; 150 } else { 151 /* Convert (2^max) kB to (2^max) bytes */ 152 max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10; 153 } 154 155 if (camsize > align) 156 camsize = align; 157 if (camsize > max_cam) 158 camsize = max_cam; 159 160 return 1UL << camsize; 161 } 162 163 static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt, 164 unsigned long ram, int max_cam_idx, 165 bool dryrun, bool init) 166 { 167 int i; 168 unsigned long amount_mapped = 0; 169 unsigned long boundary; 170 171 if (strict_kernel_rwx_enabled()) 172 boundary = (unsigned long)(_sinittext - _stext); 173 else 174 boundary = ram; 175 176 /* Calculate CAM values */ 177 for (i = 0; boundary && i < max_cam_idx; i++) { 178 unsigned long cam_sz; 179 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL_ROX; 180 181 cam_sz = calc_cam_sz(boundary, virt, phys); 182 if (!dryrun) 183 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0); 184 185 boundary -= cam_sz; 186 amount_mapped += cam_sz; 187 virt += cam_sz; 188 phys += cam_sz; 189 } 190 for (ram -= amount_mapped; ram && i < max_cam_idx; i++) { 191 unsigned long cam_sz; 192 pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL; 193 194 cam_sz = calc_cam_sz(ram, virt, phys); 195 if (!dryrun) 196 settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0); 197 198 ram -= cam_sz; 199 amount_mapped += cam_sz; 200 virt += cam_sz; 201 phys += cam_sz; 202 } 203 204 if (dryrun) 205 return amount_mapped; 206 207 if (init) { 208 loadcam_multi(0, i, max_cam_idx); 209 tlbcam_index = i; 210 } else { 211 loadcam_multi(0, i, 0); 212 WARN_ON(i > tlbcam_index); 213 } 214 215 #ifdef CONFIG_PPC64 216 get_paca()->tcd.esel_next = i; 217 get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY; 218 get_paca()->tcd.esel_first = i; 219 #endif 220 221 return amount_mapped; 222 } 223 224 unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun, bool init) 225 { 226 unsigned long virt = PAGE_OFFSET; 227 phys_addr_t phys = memstart_addr; 228 229 return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun, init); 230 } 231 232 #ifdef CONFIG_PPC32 233 234 #if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS) 235 #error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS" 236 #endif 237 238 unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) 239 { 240 return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1; 241 } 242 243 void flush_instruction_cache(void) 244 { 245 unsigned long tmp; 246 247 tmp = mfspr(SPRN_L1CSR1); 248 tmp |= L1CSR1_ICFI | L1CSR1_ICLFR; 249 mtspr(SPRN_L1CSR1, tmp); 250 isync(); 251 } 252 253 /* 254 * MMU_init_hw does the chip-specific initialization of the MMU hardware. 255 */ 256 void __init MMU_init_hw(void) 257 { 258 flush_instruction_cache(); 259 } 260 261 static unsigned long __init tlbcam_sz(int idx) 262 { 263 return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1; 264 } 265 266 void __init adjust_total_lowmem(void) 267 { 268 unsigned long ram; 269 int i; 270 271 /* adjust lowmem size to __max_low_memory */ 272 ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem); 273 274 i = switch_to_as1(); 275 __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false, true); 276 restore_to_as0(i, 0, NULL, 1); 277 278 pr_info("Memory CAM mapping: "); 279 for (i = 0; i < tlbcam_index - 1; i++) 280 pr_cont("%lu/", tlbcam_sz(i) >> 20); 281 pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20, 282 (unsigned int)((total_lowmem - __max_low_memory) >> 20)); 283 284 memblock_set_current_limit(memstart_addr + __max_low_memory); 285 } 286 287 #ifdef CONFIG_STRICT_KERNEL_RWX 288 void mmu_mark_rodata_ro(void) 289 { 290 unsigned long remapped; 291 292 remapped = map_mem_in_cams(__max_low_memory, CONFIG_LOWMEM_CAM_NUM, false, false); 293 294 WARN_ON(__max_low_memory != remapped); 295 } 296 #endif 297 298 void mmu_mark_initmem_nx(void) 299 { 300 /* Everything is done in mmu_mark_rodata_ro() */ 301 } 302 303 void setup_initial_memory_limit(phys_addr_t first_memblock_base, 304 phys_addr_t first_memblock_size) 305 { 306 phys_addr_t limit = first_memblock_base + first_memblock_size; 307 308 /* 64M mapped initially according to head_fsl_booke.S */ 309 memblock_set_current_limit(min_t(u64, limit, 0x04000000)); 310 } 311 312 #ifdef CONFIG_RELOCATABLE 313 int __initdata is_second_reloc; 314 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) 315 { 316 unsigned long base = kernstart_virt_addr; 317 phys_addr_t size; 318 319 kernstart_addr = start; 320 if (is_second_reloc) { 321 virt_phys_offset = PAGE_OFFSET - memstart_addr; 322 kaslr_late_init(); 323 return; 324 } 325 326 /* 327 * Relocatable kernel support based on processing of dynamic 328 * relocation entries. Before we get the real memstart_addr, 329 * We will compute the virt_phys_offset like this: 330 * virt_phys_offset = stext.run - kernstart_addr 331 * 332 * stext.run = (KERNELBASE & ~0x3ffffff) + 333 * (kernstart_addr & 0x3ffffff) 334 * When we relocate, we have : 335 * 336 * (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff) 337 * 338 * hence: 339 * virt_phys_offset = (KERNELBASE & ~0x3ffffff) - 340 * (kernstart_addr & ~0x3ffffff) 341 * 342 */ 343 start &= ~0x3ffffff; 344 base &= ~0x3ffffff; 345 virt_phys_offset = base - start; 346 early_get_first_memblock_info(__va(dt_ptr), &size); 347 /* 348 * We now get the memstart_addr, then we should check if this 349 * address is the same as what the PAGE_OFFSET map to now. If 350 * not we have to change the map of PAGE_OFFSET to memstart_addr 351 * and do a second relocation. 352 */ 353 if (start != memstart_addr) { 354 int n; 355 long offset = start - memstart_addr; 356 357 is_second_reloc = 1; 358 n = switch_to_as1(); 359 /* map a 64M area for the second relocation */ 360 if (memstart_addr > start) 361 map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM, 362 false, true); 363 else 364 map_mem_in_cams_addr(start, PAGE_OFFSET + offset, 365 0x4000000, CONFIG_LOWMEM_CAM_NUM, 366 false, true); 367 restore_to_as0(n, offset, __va(dt_ptr), 1); 368 /* We should never reach here */ 369 panic("Relocation error"); 370 } 371 372 kaslr_early_init(__va(dt_ptr), size); 373 } 374 #endif 375 #endif 376