// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/sparc/mm/leon_m.c
 *
 * Copyright (C) 2004 Konrad Eisele (eiselekd@web.de, konrad@gaisler.com) Gaisler Research
 * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
 * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
 *
 * do srmmu probe in software
 *
 */

#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/asi.h>
#include <asm/leon.h>
#include <asm/tlbflush.h>

#include "mm_32.h"

int leon_flush_during_switch = 1;
static int srmmu_swprobe_trace;

static inline unsigned long leon_get_ctable_ptr(void)
{
        unsigned int retval;

        __asm__ __volatile__("lda [%1] %2, %0\n\t" :
                             "=r" (retval) :
                             "r" (SRMMU_CTXTBL_PTR),
                             "i" (ASI_LEON_MMUREGS));
        return (retval & SRMMU_CTX_PMASK) << 4;
}


unsigned long leon_swprobe(unsigned long vaddr, unsigned long *paddr)
{

        unsigned int ctxtbl;
        unsigned int pgd, pmd, ped;
        unsigned int ptr;
        unsigned int lvl, pte;
        unsigned int ctx;
        unsigned int paddr_calc;

        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe: trace on\n");

        ctxtbl = leon_get_ctable_ptr();
        if (!(ctxtbl)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: leon_get_ctable_ptr returned 0=>0\n");
                return 0;
        }
        if (!_pfn_valid(PFN(ctxtbl))) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO
                               "swprobe: !_pfn_valid(%x)=>0\n",
                               PFN(ctxtbl));
                return 0;
        }

        ctx = srmmu_get_context();
        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe:  --- ctx (%x) ---\n", ctx);

        pgd = LEON_BYPASS_LOAD_PA(ctxtbl + (ctx * 4));

        if (((pgd & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: pgd is entry level 3\n");
                lvl = 3;
                pte = pgd;
                goto ready;
        }
        if (((pgd & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: pgd is invalid => 0\n");
                return 0;
        }

        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe:  --- pgd (%x) ---\n", pgd);

        ptr = (pgd & SRMMU_PTD_PMASK) << 4;
        ptr += ((((vaddr) >> LEON_PGD_SH) & LEON_PGD_M) * 4);
        if (!_pfn_valid(PFN(ptr)))
                return 0;

        pmd = LEON_BYPASS_LOAD_PA(ptr);
        if (((pmd & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: pmd is entry level 2\n");
                lvl = 2;
                pte = pmd;
                goto ready;
        }
        if (((pmd & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: pmd is invalid => 0\n");
                return 0;
        }

        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe:  --- pmd (%x) ---\n", pmd);

        ptr = (pmd & SRMMU_PTD_PMASK) << 4;
        ptr += (((vaddr >> LEON_PMD_SH) & LEON_PMD_M) * 4);
        if (!_pfn_valid(PFN(ptr))) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: !_pfn_valid(%x)=>0\n",
                               PFN(ptr));
                return 0;
        }

        ped = LEON_BYPASS_LOAD_PA(ptr);

        if (((ped & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: ped is entry level 1\n");
                lvl = 1;
                pte = ped;
                goto ready;
        }
        if (((ped & SRMMU_ET_MASK) != SRMMU_ET_PTD)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: ped is invalid => 0\n");
                return 0;
        }

        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe:  --- ped (%x) ---\n", ped);

        ptr = (ped & SRMMU_PTD_PMASK) << 4;
        ptr += (((vaddr >> LEON_PTE_SH) & LEON_PTE_M) * 4);
        if (!_pfn_valid(PFN(ptr)))
                return 0;

        ptr = LEON_BYPASS_LOAD_PA(ptr);
        if (((ptr & SRMMU_ET_MASK) == SRMMU_ET_PTE)) {
                if (srmmu_swprobe_trace)
                        printk(KERN_INFO "swprobe: ptr is entry level 0\n");
                lvl = 0;
                pte = ptr;
                goto ready;
        }
        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe: ptr is invalid => 0\n");
        return 0;

ready:
        switch (lvl) {
        case 0:
                paddr_calc =
                    (vaddr & ~(-1 << LEON_PTE_SH)) | ((pte & ~0xff) << 4);
                break;
        case 1:
                paddr_calc =
                    (vaddr & ~(-1 << LEON_PMD_SH)) | ((pte & ~0xff) << 4);
                break;
        case 2:
                paddr_calc =
                    (vaddr & ~(-1 << LEON_PGD_SH)) | ((pte & ~0xff) << 4);
                break;
        default:
        case 3:
                paddr_calc = vaddr;
                break;
        }
        if (srmmu_swprobe_trace)
                printk(KERN_INFO "swprobe: padde %x\n", paddr_calc);
        if (paddr)
                *paddr = paddr_calc;
        return pte;
}

void leon_flush_icache_all(void)
{
        __asm__ __volatile__(" flush ");        /*iflush*/
}

void leon_flush_dcache_all(void)
{
        __asm__ __volatile__("sta %%g0, [%%g0] %0\n\t" : :
                             "i"(ASI_LEON_DFLUSH) : "memory");
}

void leon_flush_pcache_all(struct vm_area_struct *vma, unsigned long page)
{
        if (vma->vm_flags & VM_EXEC)
                leon_flush_icache_all();
        leon_flush_dcache_all();
}

void leon_flush_cache_all(void)
{
        __asm__ __volatile__(" flush ");        /*iflush*/
        __asm__ __volatile__("sta %%g0, [%%g0] %0\n\t" : :
                             "i"(ASI_LEON_DFLUSH) : "memory");
}

void leon_flush_tlb_all(void)
{
        leon_flush_cache_all();
        __asm__ __volatile__("sta %%g0, [%0] %1\n\t" : : "r"(0x400),
                             "i"(ASI_LEON_MMUFLUSH) : "memory");
}

/* get all cache regs */
void leon3_getCacheRegs(struct leon3_cacheregs *regs)
{
        unsigned long ccr, iccr, dccr;

        if (!regs)
                return;
        /* Get Cache regs from "Cache ASI" address 0x0, 0x8 and 0xC */
        __asm__ __volatile__("lda [%%g0] %3, %0\n\t"
                             "mov 0x08, %%g1\n\t"
                             "lda [%%g1] %3, %1\n\t"
                             "mov 0x0c, %%g1\n\t"
                             "lda [%%g1] %3, %2\n\t"
                             : "=r"(ccr), "=r"(iccr), "=r"(dccr)
                               /* output */
                             : "i"(ASI_LEON_CACHEREGS)  /* input */
                             : "g1"     /* clobber list */
            );
        regs->ccr = ccr;
        regs->iccr = iccr;
        regs->dccr = dccr;
}

/* Due to virtual cache we need to check cache configuration if
 * it is possible to skip flushing in some cases.
 *
 * Leon2 and Leon3 differ in their way of telling cache information
 *
 */
int __init leon_flush_needed(void)
{
        int flush_needed = -1;
        unsigned int ssize, sets;
        char *setStr[4] =
            { "direct mapped", "2-way associative", "3-way associative",
                "4-way associative"
        };
        /* leon 3 */
        struct leon3_cacheregs cregs;
        leon3_getCacheRegs(&cregs);
        sets = (cregs.dccr & LEON3_XCCR_SETS_MASK) >> 24;
        /* (ssize=>realsize) 0=>1k, 1=>2k, 2=>4k, 3=>8k ... */
        ssize = 1 << ((cregs.dccr & LEON3_XCCR_SSIZE_MASK) >> 20);

        printk(KERN_INFO "CACHE: %s cache, set size %dk\n",
               sets > 3 ? "unknown" : setStr[sets], ssize);
        if ((ssize <= (PAGE_SIZE / 1024)) && (sets == 0)) {
                /* Set Size <= Page size  ==>
                   flush on every context switch not needed. */
                flush_needed = 0;
                printk(KERN_INFO "CACHE: not flushing on every context switch\n");
        }
        return flush_needed;
}

void leon_switch_mm(void)
{
        flush_tlb_mm((void *)0);
        if (leon_flush_during_switch)
                leon_flush_cache_all();
}

static void leon_flush_cache_mm(struct mm_struct *mm)
{
        leon_flush_cache_all();
}

static void leon_flush_cache_page(struct vm_area_struct *vma, unsigned long page)
{
        leon_flush_pcache_all(vma, page);
}

static void leon_flush_cache_range(struct vm_area_struct *vma,
                                   unsigned long start,
                                   unsigned long end)
{
        leon_flush_cache_all();
}

static void leon_flush_tlb_mm(struct mm_struct *mm)
{
        leon_flush_tlb_all();
}

static void leon_flush_tlb_page(struct vm_area_struct *vma,
                                unsigned long page)
{
        leon_flush_tlb_all();
}

static void leon_flush_tlb_range(struct vm_area_struct *vma,
                                 unsigned long start,
                                 unsigned long end)
{
        leon_flush_tlb_all();
}

static void leon_flush_page_to_ram(unsigned long page)
{
        leon_flush_cache_all();
}

static void leon_flush_sig_insns(struct mm_struct *mm, unsigned long page)
{
        leon_flush_cache_all();
}

static void leon_flush_page_for_dma(unsigned long page)
{
        leon_flush_dcache_all();
}

void __init poke_leonsparc(void)
{
}

static const struct sparc32_cachetlb_ops leon_ops = {
        .cache_all      = leon_flush_cache_all,
        .cache_mm       = leon_flush_cache_mm,
        .cache_page     = leon_flush_cache_page,
        .cache_range    = leon_flush_cache_range,
        .tlb_all        = leon_flush_tlb_all,
        .tlb_mm         = leon_flush_tlb_mm,
        .tlb_page       = leon_flush_tlb_page,
        .tlb_range      = leon_flush_tlb_range,
        .page_to_ram    = leon_flush_page_to_ram,
        .sig_insns      = leon_flush_sig_insns,
        .page_for_dma   = leon_flush_page_for_dma,
};

void __init init_leon(void)
{
        srmmu_name = "LEON";
        sparc32_cachetlb_ops = &leon_ops;
        poke_srmmu = poke_leonsparc;

        leon_flush_during_switch = leon_flush_needed();
}