// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Modifications by Kumar Gala (galak@kernel.crashing.org) to support
 * E500 Book E processors.
 *
 * Copyright 2004,2010 Freescale Semiconductor, Inc.
 *
 * This file contains the routines for initializing the MMU
 * on the 4xx series of chips.
 *  -- paulus
 *
 *  Derived from arch/ppc/mm/init.c:
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 */

#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/of_fdt.h>

#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/mmu.h>
#include <linux/uaccess.h>
#include <asm/smp.h>
#include <asm/machdep.h>
#include <asm/setup.h>
#include <asm/paca.h>

#include <mm/mmu_decl.h>

unsigned int tlbcam_index;

struct tlbcam TLBCAM[NUM_TLBCAMS];

static struct {
        unsigned long start;
        unsigned long limit;
        phys_addr_t phys;
} tlbcam_addrs[NUM_TLBCAMS];

#ifdef CONFIG_PPC_85xx
/*
 * Return PA for this VA if it is mapped by a CAM, or 0
 */
phys_addr_t v_block_mapped(unsigned long va)
{
        int b;
        for (b = 0; b < tlbcam_index; ++b)
                if (va >= tlbcam_addrs[b].start && va < tlbcam_addrs[b].limit)
                        return tlbcam_addrs[b].phys + (va - tlbcam_addrs[b].start);
        return 0;
}

/*
 * Return VA for a given PA or 0 if not mapped
 */
unsigned long p_block_mapped(phys_addr_t pa)
{
        int b;
        for (b = 0; b < tlbcam_index; ++b)
                if (pa >= tlbcam_addrs[b].phys
                        && pa < (tlbcam_addrs[b].limit-tlbcam_addrs[b].start)
                              +tlbcam_addrs[b].phys)
                        return tlbcam_addrs[b].start+(pa-tlbcam_addrs[b].phys);
        return 0;
}
#endif

/*
 * Set up a variable-size TLB entry (tlbcam). The parameters are not checked;
 * in particular size must be a power of 4 between 4k and the max supported by
 * an implementation; max may further be limited by what can be represented in
 * an unsigned long (for example, 32-bit implementations cannot support a 4GB
 * size).
 */
static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
                unsigned long size, unsigned long flags, unsigned int pid)
{
        unsigned int tsize;

        tsize = __ilog2(size) - 10;

#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
        if ((flags & _PAGE_NO_CACHE) == 0)
                flags |= _PAGE_COHERENT;
#endif

        TLBCAM[index].MAS0 = MAS0_TLBSEL(1) | MAS0_ESEL(index) | MAS0_NV(index+1);
        TLBCAM[index].MAS1 = MAS1_VALID | MAS1_IPROT | MAS1_TSIZE(tsize) | MAS1_TID(pid);
        TLBCAM[index].MAS2 = virt & PAGE_MASK;

        TLBCAM[index].MAS2 |= (flags & _PAGE_WRITETHRU) ? MAS2_W : 0;
        TLBCAM[index].MAS2 |= (flags & _PAGE_NO_CACHE) ? MAS2_I : 0;
        TLBCAM[index].MAS2 |= (flags & _PAGE_COHERENT) ? MAS2_M : 0;
        TLBCAM[index].MAS2 |= (flags & _PAGE_GUARDED) ? MAS2_G : 0;
        TLBCAM[index].MAS2 |= (flags & _PAGE_ENDIAN) ? MAS2_E : 0;

        TLBCAM[index].MAS3 = (phys & MAS3_RPN) | MAS3_SR;
        TLBCAM[index].MAS3 |= (flags & _PAGE_WRITE) ? MAS3_SW : 0;
        if (mmu_has_feature(MMU_FTR_BIG_PHYS))
                TLBCAM[index].MAS7 = (u64)phys >> 32;

        /* Below is unlikely -- only for large user pages or similar */
        if (!is_kernel_addr(virt)) {
                TLBCAM[index].MAS3 |= MAS3_UR;
                TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_UX : 0;
                TLBCAM[index].MAS3 |= (flags & _PAGE_WRITE) ? MAS3_UW : 0;
        } else {
                TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_SX : 0;
        }

        tlbcam_addrs[index].start = virt;
        tlbcam_addrs[index].limit = virt + size - 1;
        tlbcam_addrs[index].phys = phys;
}

static unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
                                 phys_addr_t phys)
{
        unsigned int camsize = __ilog2(ram);
        unsigned int align = __ffs(virt | phys);
        unsigned long max_cam;

        if ((mfspr(SPRN_MMUCFG) & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
                /* Convert (4^max) kB to (2^max) bytes */
                max_cam = ((mfspr(SPRN_TLB1CFG) >> 16) & 0xf) * 2 + 10;
                camsize &= ~1U;
                align &= ~1U;
        } else {
                /* Convert (2^max) kB to (2^max) bytes */
                max_cam = __ilog2(mfspr(SPRN_TLB1PS)) + 10;
        }

        if (camsize > align)
                camsize = align;
        if (camsize > max_cam)
                camsize = max_cam;

        return 1UL << camsize;
}

static unsigned long map_mem_in_cams_addr(phys_addr_t phys, unsigned long virt,
                                        unsigned long ram, int max_cam_idx,
                                        bool dryrun, bool init)
{
        int i;
        unsigned long amount_mapped = 0;
        unsigned long boundary;

        if (strict_kernel_rwx_enabled())
                boundary = (unsigned long)(_sinittext - _stext);
        else
                boundary = ram;

        /* Calculate CAM values */
        for (i = 0; boundary && i < max_cam_idx; i++) {
                unsigned long cam_sz;
                pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL_ROX;

                cam_sz = calc_cam_sz(boundary, virt, phys);
                if (!dryrun)
                        settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);

                boundary -= cam_sz;
                amount_mapped += cam_sz;
                virt += cam_sz;
                phys += cam_sz;
        }
        for (ram -= amount_mapped; ram && i < max_cam_idx; i++) {
                unsigned long cam_sz;
                pgprot_t prot = init ? PAGE_KERNEL_X : PAGE_KERNEL;

                cam_sz = calc_cam_sz(ram, virt, phys);
                if (!dryrun)
                        settlbcam(i, virt, phys, cam_sz, pgprot_val(prot), 0);

                ram -= cam_sz;
                amount_mapped += cam_sz;
                virt += cam_sz;
                phys += cam_sz;
        }

        if (dryrun)
                return amount_mapped;

        if (init) {
                loadcam_multi(0, i, max_cam_idx);
                tlbcam_index = i;
        } else {
                loadcam_multi(0, i, 0);
                WARN_ON(i > tlbcam_index);
        }

#ifdef CONFIG_PPC64
        get_paca()->tcd.esel_next = i;
        get_paca()->tcd.esel_max = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
        get_paca()->tcd.esel_first = i;
#endif

        return amount_mapped;
}

unsigned long map_mem_in_cams(unsigned long ram, int max_cam_idx, bool dryrun, bool init)
{
        unsigned long virt = PAGE_OFFSET;
        phys_addr_t phys = memstart_addr;

        return map_mem_in_cams_addr(phys, virt, ram, max_cam_idx, dryrun, init);
}

#ifdef CONFIG_PPC32

#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
#endif

unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
{
        return tlbcam_addrs[tlbcam_index - 1].limit - PAGE_OFFSET + 1;
}

void flush_instruction_cache(void)
{
        unsigned long tmp;

        tmp = mfspr(SPRN_L1CSR1);
        tmp |= L1CSR1_ICFI | L1CSR1_ICLFR;
        mtspr(SPRN_L1CSR1, tmp);
        isync();
}

/*
 * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 */
void __init MMU_init_hw(void)
{
        flush_instruction_cache();
}

static unsigned long __init tlbcam_sz(int idx)
{
        return tlbcam_addrs[idx].limit - tlbcam_addrs[idx].start + 1;
}

void __init adjust_total_lowmem(void)
{
        unsigned long ram;
        int i;

        /* adjust lowmem size to __max_low_memory */
        ram = min((phys_addr_t)__max_low_memory, (phys_addr_t)total_lowmem);

        i = switch_to_as1();
        __max_low_memory = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, false, true);
        restore_to_as0(i, 0, NULL, 1);

        pr_info("Memory CAM mapping: ");
        for (i = 0; i < tlbcam_index - 1; i++)
                pr_cont("%lu/", tlbcam_sz(i) >> 20);
        pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
                (unsigned int)((total_lowmem - __max_low_memory) >> 20));

        memblock_set_current_limit(memstart_addr + __max_low_memory);
}

#ifdef CONFIG_STRICT_KERNEL_RWX
int mmu_mark_rodata_ro(void)
{
        unsigned long remapped;

        remapped = map_mem_in_cams(__max_low_memory, CONFIG_LOWMEM_CAM_NUM, false, false);

        if (WARN_ON(__max_low_memory != remapped))
                return -EINVAL;

        return 0;
}
#endif

int mmu_mark_initmem_nx(void)
{
        /* Everything is done in mmu_mark_rodata_ro() */
        return 0;
}

void setup_initial_memory_limit(phys_addr_t first_memblock_base,
                                phys_addr_t first_memblock_size)
{
        phys_addr_t limit = first_memblock_base + first_memblock_size;

        /* 64M mapped initially according to head_fsl_booke.S */
        memblock_set_current_limit(min_t(u64, limit, 0x04000000));
}

#ifdef CONFIG_RELOCATABLE
int __initdata is_second_reloc;
notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
{
        unsigned long base = kernstart_virt_addr;
        phys_addr_t size;

        kernstart_addr = start;
        if (is_second_reloc) {
                virt_phys_offset = PAGE_OFFSET - memstart_addr;
                kaslr_late_init();
                return;
        }

        /*
         * Relocatable kernel support based on processing of dynamic
         * relocation entries. Before we get the real memstart_addr,
         * We will compute the virt_phys_offset like this:
         * virt_phys_offset = stext.run - kernstart_addr
         *
         * stext.run = (KERNELBASE & ~0x3ffffff) +
         *                              (kernstart_addr & 0x3ffffff)
         * When we relocate, we have :
         *
         *      (kernstart_addr & 0x3ffffff) = (stext.run & 0x3ffffff)
         *
         * hence:
         *  virt_phys_offset = (KERNELBASE & ~0x3ffffff) -
         *                              (kernstart_addr & ~0x3ffffff)
         *
         */
        start &= ~0x3ffffff;
        base &= ~0x3ffffff;
        virt_phys_offset = base - start;
        early_get_first_memblock_info(__va(dt_ptr), &size);
        /*
         * We now get the memstart_addr, then we should check if this
         * address is the same as what the PAGE_OFFSET map to now. If
         * not we have to change the map of PAGE_OFFSET to memstart_addr
         * and do a second relocation.
         */
        if (start != memstart_addr) {
                int n;
                long offset = start - memstart_addr;

                is_second_reloc = 1;
                n = switch_to_as1();
                /* map a 64M area for the second relocation */
                if (memstart_addr > start)
                        map_mem_in_cams(0x4000000, CONFIG_LOWMEM_CAM_NUM,
                                        false, true);
                else
                        map_mem_in_cams_addr(start, PAGE_OFFSET + offset,
                                        0x4000000, CONFIG_LOWMEM_CAM_NUM,
                                        false, true);
                restore_to_as0(n, offset, __va(dt_ptr), 1);
                /* We should never reach here */
                panic("Relocation error");
        }

        kaslr_early_init(__va(dt_ptr), size);
}
#endif
#endif