// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2013
 * David Feng <fenghua@phytium.com.cn>
 *
 * (C) Copyright 2016
 * Alexander Graf <agraf@suse.de>
 */

#include <common.h>
#include <cpu_func.h>
#include <hang.h>
#include <log.h>
#include <asm/cache.h>
#include <asm/global_data.h>
#include <asm/system.h>
#include <asm/armv8/mmu.h>

DECLARE_GLOBAL_DATA_PTR;

#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)

/*
 *  With 4k page granule, a virtual address is split into 4 lookup parts
 *  spanning 9 bits each:
 *
 *    _______________________________________________
 *   |       |       |       |       |       |       |
 *   |   0   |  Lv0  |  Lv1  |  Lv2  |  Lv3  |  off  |
 *   |_______|_______|_______|_______|_______|_______|
 *     63-48   47-39   38-30   29-21   20-12   11-00
 *
 *             mask        page size
 *
 *    Lv0: FF8000000000       --
 *    Lv1:   7FC0000000       1G
 *    Lv2:     3FE00000       2M
 *    Lv3:       1FF000       4K
 *    off:          FFF
 */

u64 get_tcr(int el, u64 *pips, u64 *pva_bits)
{
        u64 max_addr = 0;
        u64 ips, va_bits;
        u64 tcr;
        int i;

        /* Find the largest address we need to support */
        for (i = 0; mem_map[i].size || mem_map[i].attrs; i++)
                max_addr = max(max_addr, mem_map[i].virt + mem_map[i].size);

        /* Calculate the maximum physical (and thus virtual) address */
        if (max_addr > (1ULL << 44)) {
                ips = 5;
                va_bits = 48;
        } else  if (max_addr > (1ULL << 42)) {
                ips = 4;
                va_bits = 44;
        } else  if (max_addr > (1ULL << 40)) {
                ips = 3;
                va_bits = 42;
        } else  if (max_addr > (1ULL << 36)) {
                ips = 2;
                va_bits = 40;
        } else  if (max_addr > (1ULL << 32)) {
                ips = 1;
                va_bits = 36;
        } else {
                ips = 0;
                va_bits = 32;
        }

        if (el == 1) {
                tcr = TCR_EL1_RSVD | (ips << 32) | TCR_EPD1_DISABLE;
        } else if (el == 2) {
                tcr = TCR_EL2_RSVD | (ips << 16);
        } else {
                tcr = TCR_EL3_RSVD | (ips << 16);
        }

        /* PTWs cacheable, inner/outer WBWA and inner shareable */
        tcr |= TCR_TG0_4K | TCR_SHARED_INNER | TCR_ORGN_WBWA | TCR_IRGN_WBWA;
        tcr |= TCR_T0SZ(va_bits);

        if (pips)
                *pips = ips;
        if (pva_bits)
                *pva_bits = va_bits;

        return tcr;
}

#define MAX_PTE_ENTRIES 512

static int pte_type(u64 *pte)
{
        return *pte & PTE_TYPE_MASK;
}

/* Returns the LSB number for a PTE on level <level> */
static int level2shift(int level)
{
        /* Page is 12 bits wide, every level translates 9 bits */
        return (12 + 9 * (3 - level));
}

static u64 *find_pte(u64 addr, int level)
{
        int start_level = 0;
        u64 *pte;
        u64 idx;
        u64 va_bits;
        int i;

        debug("addr=%llx level=%d\n", addr, level);

        get_tcr(0, NULL, &va_bits);
        if (va_bits < 39)
                start_level = 1;

        if (level < start_level)
                return NULL;

        /* Walk through all page table levels to find our PTE */
        pte = (u64*)gd->arch.tlb_addr;
        for (i = start_level; i < 4; i++) {
                idx = (addr >> level2shift(i)) & 0x1FF;
                pte += idx;
                debug("idx=%llx PTE %p at level %d: %llx\n", idx, pte, i, *pte);

                /* Found it */
                if (i == level)
                        return pte;
                /* PTE is no table (either invalid or block), can't traverse */
                if (pte_type(pte) != PTE_TYPE_TABLE)
                        return NULL;
                /* Off to the next level */
                pte = (u64*)(*pte & 0x0000fffffffff000ULL);
        }

        /* Should never reach here */
        return NULL;
}

/* Returns and creates a new full table (512 entries) */
static u64 *create_table(void)
{
        u64 *new_table = (u64*)gd->arch.tlb_fillptr;
        u64 pt_len = MAX_PTE_ENTRIES * sizeof(u64);

        /* Allocate MAX_PTE_ENTRIES pte entries */
        gd->arch.tlb_fillptr += pt_len;

        if (gd->arch.tlb_fillptr - gd->arch.tlb_addr > gd->arch.tlb_size)
                panic("Insufficient RAM for page table: 0x%lx > 0x%lx. "
                      "Please increase the size in get_page_table_size()",
                        gd->arch.tlb_fillptr - gd->arch.tlb_addr,
                        gd->arch.tlb_size);

        /* Mark all entries as invalid */
        memset(new_table, 0, pt_len);

        return new_table;
}

static void set_pte_table(u64 *pte, u64 *table)
{
        /* Point *pte to the new table */
        debug("Setting %p to addr=%p\n", pte, table);
        *pte = PTE_TYPE_TABLE | (ulong)table;
}

/* Splits a block PTE into table with subpages spanning the old block */
static void split_block(u64 *pte, int level)
{
        u64 old_pte = *pte;
        u64 *new_table;
        u64 i = 0;
        /* level describes the parent level, we need the child ones */
        int levelshift = level2shift(level + 1);

        if (pte_type(pte) != PTE_TYPE_BLOCK)
                panic("PTE %p (%llx) is not a block. Some driver code wants to "
                      "modify dcache settings for an range not covered in "
                      "mem_map.", pte, old_pte);

        new_table = create_table();
        debug("Splitting pte %p (%llx) into %p\n", pte, old_pte, new_table);

        for (i = 0; i < MAX_PTE_ENTRIES; i++) {
                new_table[i] = old_pte | (i << levelshift);

                /* Level 3 block PTEs have the table type */
                if ((level + 1) == 3)
                        new_table[i] |= PTE_TYPE_TABLE;

                debug("Setting new_table[%lld] = %llx\n", i, new_table[i]);
        }

        /* Set the new table into effect */
        set_pte_table(pte, new_table);
}

/* Add one mm_region map entry to the page tables */
static void add_map(struct mm_region *map)
{
        u64 *pte;
        u64 virt = map->virt;
        u64 phys = map->phys;
        u64 size = map->size;
        u64 attrs = map->attrs | PTE_TYPE_BLOCK | PTE_BLOCK_AF;
        u64 blocksize;
        int level;
        u64 *new_table;

        while (size) {
                pte = find_pte(virt, 0);
                if (pte && (pte_type(pte) == PTE_TYPE_FAULT)) {
                        debug("Creating table for virt 0x%llx\n", virt);
                        new_table = create_table();
                        set_pte_table(pte, new_table);
                }

                for (level = 1; level < 4; level++) {
                        pte = find_pte(virt, level);
                        if (!pte)
                                panic("pte not found\n");

                        blocksize = 1ULL << level2shift(level);
                        debug("Checking if pte fits for virt=%llx size=%llx blocksize=%llx\n",
                              virt, size, blocksize);
                        if (size >= blocksize && !(virt & (blocksize - 1))) {
                                /* Page fits, create block PTE */
                                debug("Setting PTE %p to block virt=%llx\n",
                                      pte, virt);
                                if (level == 3)
                                        *pte = phys | attrs | PTE_TYPE_PAGE;
                                else
                                        *pte = phys | attrs;
                                virt += blocksize;
                                phys += blocksize;
                                size -= blocksize;
                                break;
                        } else if (pte_type(pte) == PTE_TYPE_FAULT) {
                                /* Page doesn't fit, create subpages */
                                debug("Creating subtable for virt 0x%llx blksize=%llx\n",
                                      virt, blocksize);
                                new_table = create_table();
                                set_pte_table(pte, new_table);
                        } else if (pte_type(pte) == PTE_TYPE_BLOCK) {
                                debug("Split block into subtable for virt 0x%llx blksize=0x%llx\n",
                                      virt, blocksize);
                                split_block(pte, level);
                        }
                }
        }
}

enum pte_type {
        PTE_INVAL,
        PTE_BLOCK,
        PTE_LEVEL,
};

/*
 * This is a recursively called function to count the number of
 * page tables we need to cover a particular PTE range. If you
 * call this with level = -1 you basically get the full 48 bit
 * coverage.
 */
static int count_required_pts(u64 addr, int level, u64 maxaddr)
{
        int levelshift = level2shift(level);
        u64 levelsize = 1ULL << levelshift;
        u64 levelmask = levelsize - 1;
        u64 levelend = addr + levelsize;
        int r = 0;
        int i;
        enum pte_type pte_type = PTE_INVAL;

        for (i = 0; mem_map[i].size || mem_map[i].attrs; i++) {
                struct mm_region *map = &mem_map[i];
                u64 start = map->virt;
                u64 end = start + map->size;

                /* Check if the PTE would overlap with the map */
                if (max(addr, start) <= min(levelend, end)) {
                        start = max(addr, start);
                        end = min(levelend, end);

                        /* We need a sub-pt for this level */
                        if ((start & levelmask) || (end & levelmask)) {
                                pte_type = PTE_LEVEL;
                                break;
                        }

                        /* Lv0 can not do block PTEs, so do levels here too */
                        if (level <= 0) {
                                pte_type = PTE_LEVEL;
                                break;
                        }

                        /* PTE is active, but fits into a block */
                        pte_type = PTE_BLOCK;
                }
        }

        /*
         * Block PTEs at this level are already covered by the parent page
         * table, so we only need to count sub page tables.
         */
        if (pte_type == PTE_LEVEL) {
                int sublevel = level + 1;
                u64 sublevelsize = 1ULL << level2shift(sublevel);

                /* Account for the new sub page table ... */
                r = 1;

                /* ... and for all child page tables that one might have */
                for (i = 0; i < MAX_PTE_ENTRIES; i++) {
                        r += count_required_pts(addr, sublevel, maxaddr);
                        addr += sublevelsize;

                        if (addr >= maxaddr) {
                                /*
                                 * We reached the end of address space, no need
                                 * to look any further.
                                 */
                                break;
                        }
                }
        }

        return r;
}

/* Returns the estimated required size of all page tables */
__weak u64 get_page_table_size(void)
{
        u64 one_pt = MAX_PTE_ENTRIES * sizeof(u64);
        u64 size = 0;
        u64 va_bits;
        int start_level = 0;

        get_tcr(0, NULL, &va_bits);
        if (va_bits < 39)
                start_level = 1;

        /* Account for all page tables we would need to cover our memory map */
        size = one_pt * count_required_pts(0, start_level - 1, 1ULL << va_bits);

        /*
         * We need to duplicate our page table once to have an emergency pt to
         * resort to when splitting page tables later on
         */
        size *= 2;

        /*
         * We may need to split page tables later on if dcache settings change,
         * so reserve up to 4 (random pick) page tables for that.
         */
        size += one_pt * 4;

        return size;
}

void setup_pgtables(void)
{
        int i;

        if (!gd->arch.tlb_fillptr || !gd->arch.tlb_addr)
                panic("Page table pointer not setup.");

        /*
         * Allocate the first level we're on with invalidate entries.
         * If the starting level is 0 (va_bits >= 39), then this is our
         * Lv0 page table, otherwise it's the entry Lv1 page table.
         */
        create_table();

        /* Now add all MMU table entries one after another to the table */
        for (i = 0; mem_map[i].size || mem_map[i].attrs; i++)
                add_map(&mem_map[i]);
}

static void setup_all_pgtables(void)
{
        u64 tlb_addr = gd->arch.tlb_addr;
        u64 tlb_size = gd->arch.tlb_size;

        /* Reset the fill ptr */
        gd->arch.tlb_fillptr = tlb_addr;

        /* Create normal system page tables */
        setup_pgtables();

        /* Create emergency page tables */
        gd->arch.tlb_size -= (uintptr_t)gd->arch.tlb_fillptr -
                             (uintptr_t)gd->arch.tlb_addr;
        gd->arch.tlb_addr = gd->arch.tlb_fillptr;
        setup_pgtables();
        gd->arch.tlb_emerg = gd->arch.tlb_addr;
        gd->arch.tlb_addr = tlb_addr;
        gd->arch.tlb_size = tlb_size;
}

/* to activate the MMU we need to set up virtual memory */
__weak void mmu_setup(void)
{
        int el;

        /* Set up page tables only once */
        if (!gd->arch.tlb_fillptr)
                setup_all_pgtables();

        el = current_el();
        set_ttbr_tcr_mair(el, gd->arch.tlb_addr, get_tcr(el, NULL, NULL),
                          MEMORY_ATTRIBUTES);

        /* enable the mmu */
        set_sctlr(get_sctlr() | CR_M);
}

/*
 * Performs a invalidation of the entire data cache at all levels
 */
void invalidate_dcache_all(void)
{
        __asm_invalidate_dcache_all();
        __asm_invalidate_l3_dcache();
}

/*
 * Performs a clean & invalidation of the entire data cache at all levels.
 * This function needs to be inline to avoid using stack.
 * __asm_flush_l3_dcache return status of timeout
 */
inline void flush_dcache_all(void)
{
        int ret;

        __asm_flush_dcache_all();
        ret = __asm_flush_l3_dcache();
        if (ret)
                debug("flushing dcache returns 0x%x\n", ret);
        else
                debug("flushing dcache successfully.\n");
}

#ifndef CONFIG_SYS_DISABLE_DCACHE_OPS
/*
 * Invalidates range in all levels of D-cache/unified cache
 */
void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
        __asm_invalidate_dcache_range(start, stop);
}

/*
 * Flush range(clean & invalidate) from all levels of D-cache/unified cache
 */
void flush_dcache_range(unsigned long start, unsigned long stop)
{
        __asm_flush_dcache_range(start, stop);
}
#else
void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
}

void flush_dcache_range(unsigned long start, unsigned long stop)
{
}
#endif /* CONFIG_SYS_DISABLE_DCACHE_OPS */

void dcache_enable(void)
{
        /* The data cache is not active unless the mmu is enabled */
        if (!(get_sctlr() & CR_M)) {
                invalidate_dcache_all();
                __asm_invalidate_tlb_all();
                mmu_setup();
        }

        set_sctlr(get_sctlr() | CR_C);
}

void dcache_disable(void)
{
        uint32_t sctlr;

        sctlr = get_sctlr();

        /* if cache isn't enabled no need to disable */
        if (!(sctlr & CR_C))
                return;

        set_sctlr(sctlr & ~(CR_C|CR_M));

        flush_dcache_all();
        __asm_invalidate_tlb_all();
}

int dcache_status(void)
{
        return (get_sctlr() & CR_C) != 0;
}

u64 *__weak arch_get_page_table(void) {
        puts("No page table offset defined\n");

        return NULL;
}

static bool is_aligned(u64 addr, u64 size, u64 align)
{
        return !(addr & (align - 1)) && !(size & (align - 1));
}

/* Use flag to indicate if attrs has more than d-cache attributes */
static u64 set_one_region(u64 start, u64 size, u64 attrs, bool flag, int level)
{
        int levelshift = level2shift(level);
        u64 levelsize = 1ULL << levelshift;
        u64 *pte = find_pte(start, level);

        /* Can we can just modify the current level block PTE? */
        if (is_aligned(start, size, levelsize)) {
                if (flag) {
                        *pte &= ~PMD_ATTRMASK;
                        *pte |= attrs & PMD_ATTRMASK;
                } else {
                        *pte &= ~PMD_ATTRINDX_MASK;
                        *pte |= attrs & PMD_ATTRINDX_MASK;
                }
                debug("Set attrs=%llx pte=%p level=%d\n", attrs, pte, level);

                return levelsize;
        }

        /* Unaligned or doesn't fit, maybe split block into table */
        debug("addr=%llx level=%d pte=%p (%llx)\n", start, level, pte, *pte);

        /* Maybe we need to split the block into a table */
        if (pte_type(pte) == PTE_TYPE_BLOCK)
                split_block(pte, level);

        /* And then double-check it became a table or already is one */
        if (pte_type(pte) != PTE_TYPE_TABLE)
                panic("PTE %p (%llx) for addr=%llx should be a table",
                      pte, *pte, start);

        /* Roll on to the next page table level */
        return 0;
}

void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
                                     enum dcache_option option)
{
        u64 attrs = PMD_ATTRINDX(option >> 2);
        u64 real_start = start;
        u64 real_size = size;

        debug("start=%lx size=%lx\n", (ulong)start, (ulong)size);

        if (!gd->arch.tlb_emerg)
                panic("Emergency page table not setup.");

        /*
         * We can not modify page tables that we're currently running on,
         * so we first need to switch to the "emergency" page tables where
         * we can safely modify our primary page tables and then switch back
         */
        __asm_switch_ttbr(gd->arch.tlb_emerg);

        /*
         * Loop through the address range until we find a page granule that fits
         * our alignment constraints, then set it to the new cache attributes
         */
        while (size > 0) {
                int level;
                u64 r;

                for (level = 1; level < 4; level++) {
                        /* Set d-cache attributes only */
                        r = set_one_region(start, size, attrs, false, level);
                        if (r) {
                                /* PTE successfully replaced */
                                size -= r;
                                start += r;
                                break;
                        }
                }

        }

        /* We're done modifying page tables, switch back to our primary ones */
        __asm_switch_ttbr(gd->arch.tlb_addr);

        /*
         * Make sure there's nothing stale in dcache for a region that might
         * have caches off now
         */
        flush_dcache_range(real_start, real_start + real_size);
}

/*
 * Modify MMU table for a region with updated PXN/UXN/Memory type/valid bits.
 * The procecess is break-before-make. The target region will be marked as
 * invalid during the process of changing.
 */
void mmu_change_region_attr(phys_addr_t addr, size_t siz, u64 attrs)
{
        int level;
        u64 r, size, start;

        start = addr;
        size = siz;
        /*
         * Loop through the address range until we find a page granule that fits
         * our alignment constraints, then set it to "invalid".
         */
        while (size > 0) {
                for (level = 1; level < 4; level++) {
                        /* Set PTE to fault */
                        r = set_one_region(start, size, PTE_TYPE_FAULT, true,
                                           level);
                        if (r) {
                                /* PTE successfully invalidated */
                                size -= r;
                                start += r;
                                break;
                        }
                }
        }

        flush_dcache_range(gd->arch.tlb_addr,
                           gd->arch.tlb_addr + gd->arch.tlb_size);
        __asm_invalidate_tlb_all();

        /*
         * Loop through the address range until we find a page granule that fits
         * our alignment constraints, then set it to the new cache attributes
         */
        start = addr;
        size = siz;
        while (size > 0) {
                for (level = 1; level < 4; level++) {
                        /* Set PTE to new attributes */
                        r = set_one_region(start, size, attrs, true, level);
                        if (r) {
                                /* PTE successfully updated */
                                size -= r;
                                start += r;
                                break;
                        }
                }
        }
        flush_dcache_range(gd->arch.tlb_addr,
                           gd->arch.tlb_addr + gd->arch.tlb_size);
        __asm_invalidate_tlb_all();
}

#else   /* !CONFIG_IS_ENABLED(SYS_DCACHE_OFF) */

/*
 * For SPL builds, we may want to not have dcache enabled. Any real U-Boot
 * running however really wants to have dcache and the MMU active. Check that
 * everything is sane and give the developer a hint if it isn't.
 */
#ifndef CONFIG_SPL_BUILD
#error Please describe your MMU layout in CONFIG_SYS_MEM_MAP and enable dcache.
#endif

void invalidate_dcache_all(void)
{
}

void flush_dcache_all(void)
{
}

void dcache_enable(void)
{
}

void dcache_disable(void)
{
}

int dcache_status(void)
{
        return 0;
}

void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
                                     enum dcache_option option)
{
}

#endif  /* !CONFIG_IS_ENABLED(SYS_DCACHE_OFF) */

#if !CONFIG_IS_ENABLED(SYS_ICACHE_OFF)

void icache_enable(void)
{
        invalidate_icache_all();
        set_sctlr(get_sctlr() | CR_I);
}

void icache_disable(void)
{
        set_sctlr(get_sctlr() & ~CR_I);
}

int icache_status(void)
{
        return (get_sctlr() & CR_I) != 0;
}

int mmu_status(void)
{
        return (get_sctlr() & CR_M) != 0;
}

void invalidate_icache_all(void)
{
        __asm_invalidate_icache_all();
        __asm_invalidate_l3_icache();
}

#else   /* !CONFIG_IS_ENABLED(SYS_ICACHE_OFF) */

void icache_enable(void)
{
}

void icache_disable(void)
{
}

int icache_status(void)
{
        return 0;
}

int mmu_status(void)
{
        return 0;
}

void invalidate_icache_all(void)
{
}

#endif  /* !CONFIG_IS_ENABLED(SYS_ICACHE_OFF) */

/*
 * Enable dCache & iCache, whether cache is actually enabled
 * depend on CONFIG_SYS_DCACHE_OFF and CONFIG_SYS_ICACHE_OFF
 */
void __weak enable_caches(void)
{
        icache_enable();
        dcache_enable();
}