/*
 * Procedures for maintaining information about logical memory blocks.
 *
 * Peter Bergner, IBM Corp.     June 2001.
 * Copyright (C) 2001 Peter Bergner.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <lmb.h>

#define LMB_ALLOC_ANYWHERE      0

void lmb_dump_all(struct lmb *lmb)
{
#ifdef DEBUG
        unsigned long i;

        debug("lmb_dump_all:\n");
        debug("    memory.cnt              = 0x%lx\n", lmb->memory.cnt);
        debug("    memory.size             = 0x%llx\n",
              (unsigned long long)lmb->memory.size);
        for (i=0; i < lmb->memory.cnt ;i++) {
                debug("    memory.reg[0x%lx].base   = 0x%llx\n", i,
                        (long long unsigned)lmb->memory.region[i].base);
                debug("            .size   = 0x%llx\n",
                        (long long unsigned)lmb->memory.region[i].size);
        }

        debug("\n    reserved.cnt          = 0x%lx\n",
                lmb->reserved.cnt);
        debug("    reserved.size           = 0x%llx\n",
                (long long unsigned)lmb->reserved.size);
        for (i=0; i < lmb->reserved.cnt ;i++) {
                debug("    reserved.reg[0x%lx].base = 0x%llx\n", i,
                        (long long unsigned)lmb->reserved.region[i].base);
                debug("              .size = 0x%llx\n",
                        (long long unsigned)lmb->reserved.region[i].size);
        }
#endif /* DEBUG */
}

static long lmb_addrs_overlap(phys_addr_t base1,
                phys_size_t size1, phys_addr_t base2, phys_size_t size2)
{
        return ((base1 < (base2+size2)) && (base2 < (base1+size1)));
}

static long lmb_addrs_adjacent(phys_addr_t base1, phys_size_t size1,
                phys_addr_t base2, phys_size_t size2)
{
        if (base2 == base1 + size1)
                return 1;
        else if (base1 == base2 + size2)
                return -1;

        return 0;
}

static long lmb_regions_adjacent(struct lmb_region *rgn,
                unsigned long r1, unsigned long r2)
{
        phys_addr_t base1 = rgn->region[r1].base;
        phys_size_t size1 = rgn->region[r1].size;
        phys_addr_t base2 = rgn->region[r2].base;
        phys_size_t size2 = rgn->region[r2].size;

        return lmb_addrs_adjacent(base1, size1, base2, size2);
}

static void lmb_remove_region(struct lmb_region *rgn, unsigned long r)
{
        unsigned long i;

        for (i = r; i < rgn->cnt - 1; i++) {
                rgn->region[i].base = rgn->region[i + 1].base;
                rgn->region[i].size = rgn->region[i + 1].size;
        }
        rgn->cnt--;
}

/* Assumption: base addr of region 1 < base addr of region 2 */
static void lmb_coalesce_regions(struct lmb_region *rgn,
                unsigned long r1, unsigned long r2)
{
        rgn->region[r1].size += rgn->region[r2].size;
        lmb_remove_region(rgn, r2);
}

void lmb_init(struct lmb *lmb)
{
        /* Create a dummy zero size LMB which will get coalesced away later.
         * This simplifies the lmb_add() code below...
         */
        lmb->memory.region[0].base = 0;
        lmb->memory.region[0].size = 0;
        lmb->memory.cnt = 1;
        lmb->memory.size = 0;

        /* Ditto. */
        lmb->reserved.region[0].base = 0;
        lmb->reserved.region[0].size = 0;
        lmb->reserved.cnt = 1;
        lmb->reserved.size = 0;
}

/* This routine called with relocation disabled. */
static long lmb_add_region(struct lmb_region *rgn, phys_addr_t base, phys_size_t size)
{
        unsigned long coalesced = 0;
        long adjacent, i;

        if ((rgn->cnt == 1) && (rgn->region[0].size == 0)) {
                rgn->region[0].base = base;
                rgn->region[0].size = size;
                return 0;
        }

        /* First try and coalesce this LMB with another. */
        for (i=0; i < rgn->cnt; i++) {
                phys_addr_t rgnbase = rgn->region[i].base;
                phys_size_t rgnsize = rgn->region[i].size;

                if ((rgnbase == base) && (rgnsize == size))
                        /* Already have this region, so we're done */
                        return 0;

                adjacent = lmb_addrs_adjacent(base,size,rgnbase,rgnsize);
                if ( adjacent > 0 ) {
                        rgn->region[i].base -= size;
                        rgn->region[i].size += size;
                        coalesced++;
                        break;
                }
                else if ( adjacent < 0 ) {
                        rgn->region[i].size += size;
                        coalesced++;
                        break;
                }
        }

        if ((i < rgn->cnt-1) && lmb_regions_adjacent(rgn, i, i+1) ) {
                lmb_coalesce_regions(rgn, i, i+1);
                coalesced++;
        }

        if (coalesced)
                return coalesced;
        if (rgn->cnt >= MAX_LMB_REGIONS)
                return -1;

        /* Couldn't coalesce the LMB, so add it to the sorted table. */
        for (i = rgn->cnt-1; i >= 0; i--) {
                if (base < rgn->region[i].base) {
                        rgn->region[i+1].base = rgn->region[i].base;
                        rgn->region[i+1].size = rgn->region[i].size;
                } else {
                        rgn->region[i+1].base = base;
                        rgn->region[i+1].size = size;
                        break;
                }
        }

        if (base < rgn->region[0].base) {
                rgn->region[0].base = base;
                rgn->region[0].size = size;
        }

        rgn->cnt++;

        return 0;
}

/* This routine may be called with relocation disabled. */
long lmb_add(struct lmb *lmb, phys_addr_t base, phys_size_t size)
{
        struct lmb_region *_rgn = &(lmb->memory);

        return lmb_add_region(_rgn, base, size);
}

long lmb_free(struct lmb *lmb, phys_addr_t base, phys_size_t size)
{
        struct lmb_region *rgn = &(lmb->reserved);
        phys_addr_t rgnbegin, rgnend;
        phys_addr_t end = base + size;
        int i;

        rgnbegin = rgnend = 0; /* supress gcc warnings */

        /* Find the region where (base, size) belongs to */
        for (i=0; i < rgn->cnt; i++) {
                rgnbegin = rgn->region[i].base;
                rgnend = rgnbegin + rgn->region[i].size;

                if ((rgnbegin <= base) && (end <= rgnend))
                        break;
        }

        /* Didn't find the region */
        if (i == rgn->cnt)
                return -1;

        /* Check to see if we are removing entire region */
        if ((rgnbegin == base) && (rgnend == end)) {
                lmb_remove_region(rgn, i);
                return 0;
        }

        /* Check to see if region is matching at the front */
        if (rgnbegin == base) {
                rgn->region[i].base = end;
                rgn->region[i].size -= size;
                return 0;
        }

        /* Check to see if the region is matching at the end */
        if (rgnend == end) {
                rgn->region[i].size -= size;
                return 0;
        }

        /*
         * We need to split the entry -  adjust the current one to the
         * beginging of the hole and add the region after hole.
         */
        rgn->region[i].size = base - rgn->region[i].base;
        return lmb_add_region(rgn, end, rgnend - end);
}

long lmb_reserve(struct lmb *lmb, phys_addr_t base, phys_size_t size)
{
        struct lmb_region *_rgn = &(lmb->reserved);

        return lmb_add_region(_rgn, base, size);
}

static long lmb_overlaps_region(struct lmb_region *rgn, phys_addr_t base,
                                phys_size_t size)
{
        unsigned long i;

        for (i=0; i < rgn->cnt; i++) {
                phys_addr_t rgnbase = rgn->region[i].base;
                phys_size_t rgnsize = rgn->region[i].size;
                if ( lmb_addrs_overlap(base,size,rgnbase,rgnsize) ) {
                        break;
                }
        }

        return (i < rgn->cnt) ? i : -1;
}

phys_addr_t lmb_alloc(struct lmb *lmb, phys_size_t size, ulong align)
{
        return lmb_alloc_base(lmb, size, align, LMB_ALLOC_ANYWHERE);
}

phys_addr_t lmb_alloc_base(struct lmb *lmb, phys_size_t size, ulong align, phys_addr_t max_addr)
{
        phys_addr_t alloc;

        alloc = __lmb_alloc_base(lmb, size, align, max_addr);

        if (alloc == 0)
                printf("ERROR: Failed to allocate 0x%lx bytes below 0x%lx.\n",
                      (ulong)size, (ulong)max_addr);

        return alloc;
}

static phys_addr_t lmb_align_down(phys_addr_t addr, phys_size_t size)
{
        return addr & ~(size - 1);
}

static phys_addr_t lmb_align_up(phys_addr_t addr, ulong size)
{
        return (addr + (size - 1)) & ~(size - 1);
}

phys_addr_t __lmb_alloc_base(struct lmb *lmb, phys_size_t size, ulong align, phys_addr_t max_addr)
{
        long i, j;
        phys_addr_t base = 0;
        phys_addr_t res_base;

        for (i = lmb->memory.cnt-1; i >= 0; i--) {
                phys_addr_t lmbbase = lmb->memory.region[i].base;
                phys_size_t lmbsize = lmb->memory.region[i].size;

                if (lmbsize < size)
                        continue;
                if (max_addr == LMB_ALLOC_ANYWHERE)
                        base = lmb_align_down(lmbbase + lmbsize - size, align);
                else if (lmbbase < max_addr) {
                        base = lmbbase + lmbsize;
                        if (base < lmbbase)
                                base = -1;
                        base = min(base, max_addr);
                        base = lmb_align_down(base - size, align);
                } else
                        continue;

                while (base && lmbbase <= base) {
                        j = lmb_overlaps_region(&lmb->reserved, base, size);
                        if (j < 0) {
                                /* This area isn't reserved, take it */
                                if (lmb_add_region(&lmb->reserved, base,
                                                        lmb_align_up(size,
                                                                align)) < 0)
                                        return 0;
                                return base;
                        }
                        res_base = lmb->reserved.region[j].base;
                        if (res_base < size)
                                break;
                        base = lmb_align_down(res_base - size, align);
                }
        }
        return 0;
}

int lmb_is_reserved(struct lmb *lmb, phys_addr_t addr)
{
        int i;

        for (i = 0; i < lmb->reserved.cnt; i++) {
                phys_addr_t upper = lmb->reserved.region[i].base +
                        lmb->reserved.region[i].size - 1;
                if ((addr >= lmb->reserved.region[i].base) && (addr <= upper))
                        return 1;
        }
        return 0;
}

__weak void board_lmb_reserve(struct lmb *lmb)
{
        /* please define platform specific board_lmb_reserve() */
}

__weak void arch_lmb_reserve(struct lmb *lmb)
{
        /* please define platform specific arch_lmb_reserve() */
}