LXR linux/arch/powerpc/mm/nohash/fsl

   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
  40#include <asm/pgalloc.h>
  41#include <asm/prom.h>
  42#include <asm/io.h>
  43#include <asm/mmu_context.h>
  44#include <asm/pgtable.h>
  45#include <asm/mmu.h>
  46#include <linux/uaccess.h>
  47#include <asm/smp.h>
  48#include <asm/machdep.h>
  49#include <asm/setup.h>
  50#include <asm/paca.h>
  51
  52#include <mm/mmu_decl.h>
  53
  54unsigned int tlbcam_index;
  55
  56#define NUM_TLBCAMS     (64)
  57struct tlbcam TLBCAM[NUM_TLBCAMS];
  58
  59struct tlbcamrange {
  60        unsigned long start;
  61        unsigned long limit;
  62        phys_addr_t phys;
  63} tlbcam_addrs[NUM_TLBCAMS];
  64
  65unsigned long tlbcam_sz(int idx)
  66{
  67        return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
  68}
  69
  70#ifdef CONFIG_FSL_BOOKE
  71/*
  72 * Return PA for this VA if it is mapped by a CAM, or 0
  73 */
  74phys_addr_t v_block_mapped(unsigned long va)
  75{
  76        int b;
  77        for (b = 0; b < tlbcam_index; ++b)
  78                if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
  79                        return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
  80        return 0;
  81}
  82
  83/*
  84 * Return VA for a given PA or 0 if not mapped
  85 */
  86unsigned long p_block_mapped(phys_addr_t pa)
  87{
  88        int b;
  89        for (b = 0; b < tlbcam_index; ++b)
  90                if (pa >= tlbcam_addrs[b].phys
  91                        && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
  92                              +tlbcam_addrs[b].phys)
  93                        return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
  94        return 0;
  95}
  96#endif
  97
  98/*
  99 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
 100 * in particular size must be a power of 4 between 4k and the max supported by
 101 * an implementation; max may further be limited by what can be represented in
 102 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
 103 * size).
 104 */
 105static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
 106                unsigned long size, unsigned long flags, unsigned int pid)
 107{
 108        unsigned int tsize;
 109
 110        tsize = __ilog2(size) - 10;
 111
 112#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
 113        if ((flags & _PAGE_NO_CACHE) == 0)
 114                flags |= _PAGE_COHERENT;
 115#endif
 116
 117        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
 118        TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
 119        TLBCAM[index].MAS2 = virt & PAGE_MASK;
 120
 121        TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
 122        TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
 123        TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
 124        TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
 125        TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;
 126
 127        TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SX | MAS3_SR;
 128        TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_SW : 0);
 129        if (mmu_has_feature(MMU_FTR_BIG_PHYS))
 130                TLBCAM[index].MAS7 = (u64)phys >> 32;
 131
 132        /* Below is unlikely -- only for large user pages or similar */
 133        if (pte_user(__pte(flags))) {
 134           TLBCAM[index].MAS3 |= MAS3_UX | MAS3_UR;
 135           TLBCAM[index].MAS3 |= ((flags & _PAGE_RW) ? MAS3_UW : 0);
 136        }
 137
 138        tlbcam_addrs[index].start = virt;
 139        tlbcam_addrs[index].limit = virt + size - 1;
 140        tlbcam_addrs[index].phys = phys;
 141}
 142
 143unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 144                          phys_addr_t phys)
 145{
 146        unsigned int camsize = __ilog2(ram);
 147        unsigned int align = __ffs(virt | phys);
 148        unsigned long max_cam;
 149
 150        if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
 151                /* Convert (4^max) kB to (2^max) bytes */
 152                max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
 153                camsize &= ~1U;
 154                align &= ~1U;
 155        } else {
 156                /* Convert (2^max) kB to (2^max) bytes */
 157                max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
 158        }
 159
 160        if (camsize > align)
 161                camsize = align;
 162        if (camsize > max_cam)
 163                camsize = max_cam;
 164
 165        return 1UL << camsize;
 166}
 167
 168static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
 169                                        unsigned long ram, int max_cam_idx,
 170                                        bool dryrun)
 171{
 172        int i;
 173        unsigned long amount_mapped = 0;
 174
 175        /* Calculate CAM values */
 176        for (i = 0; ram && i < max_cam_idx; i++) {
 177                unsigned long cam_sz;
 178
 179                cam_sz = calc_cam_sz(ram, virt, phys);
 180                if (!dryrun)
 181                        settlbcam(i, virt, phys, cam_sz,
 182                                  pgprot_val(PAGE_KERNEL_X), 0);
 183
 184                ram -= cam_sz;
 185                amount_mapped += cam_sz;
 186                virt += cam_sz;
 187                phys += cam_sz;
 188        }
 189
 190        if (dryrun)
 191                return amount_mapped;
 192
 193        loadcam_multi(0, i, max_cam_idx);
 194        tlbcam_index = i;
 195
 196#ifdef CONFIG_PPC64
 197        get_paca()->tcd.esel_next = i;
 198        get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
 199        get_paca()->tcd.esel_first = i;
 200#endif
 201
 202        return amount_mapped;
 203}
 204
 205unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun)
 206{
 207        unsigned long virt = PAGE_OFFSET;
 208        phys_addr_t phys = memstart_addr;
 209
 210        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun);
 211}
 212
 213#ifdef CONFIG_PPC32
 214
 215#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
 216#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
 217#endif
 218
 219unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
 220{
 221        return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
 222}
 223
 224/*
 225 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 226 */
 227void __init MMU_init_hw(void)
 228{
 229        flush_instruction_cache();
 230}
 231
 232void __init adjust_total_lowmem(void)
 233{
 234        unsigned long ram;
 235        int i;
 236
 237        /* adjust lowmem size to __max_low_memory */
 238        ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);
 239
 240        i = switch_to_as1();
 241        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false);
 242        restore_to_as0(i, 0, 0, 1);
 243
 244        pr_info("Memory CAM mapping: ");
 245        for (i = 0; i < tlbcam_index - 1; i++)
 246                pr_cont("%lu/", tlbcam_sz(i) >> 20);
 247        pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
 248                (unsigned int)((total_lowmem - __max_low_memory) >> 20));
 249
 250        memblock_set_current_limit(memstart_addr + __max_low_memory);
 251}
 252
 253void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 254                                phys_addr_t first_memblock_size)
 255{
 256        phys_addr_t limit = first_memblock_base + first_memblock_size;
 257
 258        /* 64M mapped initially according to head_fsl_booke.S */
 259        memblock_set_current_limit(min_t(u64, limit, 0x04000000));
 260}
 261
 262#ifdef CONFIG_RELOCATABLE
 263int __initdata is_second_reloc;
 264notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 265{
 266        unsigned long base = KERNELBASE;
 267
 268        kernstart_addr = start;
 269        if (is_second_reloc) {
 270                virt_phys_offset = PAGE_OFFSET - memstart_addr;
 271                return;
 272        }
 273
 274        /*
 275         * Relocatable kernel support based on processing of dynamic
 276         * relocation entries. Before we get the real memstart_addr,
 277         * We will compute the virt_phys_offset like this:
 278         * virt_phys_offset = stext.run - kernstart_addr
 279         *
 280         * stext.run = (KERNELBASE & ~0x3ffffff) +
 281         *                              (kernstart_addr & 0x3ffffff)
 282         * When we relocate, we have :
 283         *
 284         *      (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
 285         *
 286         * hence:
 287         *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
 288         *                              (kernstart_addr & ~0x3ffffff)
 289         *
 290         */
 291        start &= ~0x3ffffff;
 292        base &= ~0x3ffffff;
 293        virt_phys_offset = base - start;
 294        early_get_first_memblock_info(__va(dt_ptr), NULL);
 295        /*
 296         * We now get the memstart_addr, then we should check if this
 297         * address is the same as what the PAGE_OFFSET map to now. If
 298         * not we have to change the map of PAGE_OFFSET to memstart_addr
 299         * and do a second relocation.
 300         */
 301        if (start != memstart_addr) {
 302                int n;
 303                long offset = start - memstart_addr;
 304
 305                is_second_reloc = 1;
 306                n = switch_to_as1();
 307                /* map a 64M area for the second relocation */
 308                if (memstart_addr > start)
 309                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
 310                                        false);
 311                else
 312                        map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
 313                                        0x4000000, CONFIG_LOWMEM_CAM_NUM,
 314                                        false);
 315                restore_to_as0(n, offset, __va(dt_ptr), 1);
 316                /* We should never reach here */
 317                panic("Relocation error");
 318        }
 319}
 320#endif
 321#endif
 322