/*
 * arch/xtensa/mm/init.c
 *
 * Derived from MIPS, PPC.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 * Copyright (C) 2014 - 2016 Cadence Design Systems Inc.
 *
 * Chris Zankel <chris@zankel.net>
 * Joe Taylor   <joe@tensilica.com, joetylr@yahoo.com>
 * Marc Gauthier
 * Kevin Chea
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/mm.h>
#include <linux/of_fdt.h>
#include <linux/dma-contiguous.h>

#include <asm/bootparam.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/sysmem.h>

/*
 * Initialize the bootmem system and give it all low memory we have available.
 */

void __init bootmem_init(void)
{
        /* Reserve all memory below PHYS_OFFSET, as memory
         * accounting doesn't work for pages below that address.
         *
         * If PHYS_OFFSET is zero reserve page at address 0:
         * successfull allocations should never return NULL.
         */
        memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1);

        early_init_fdt_scan_reserved_mem();

        if (!memblock_phys_mem_size())
                panic("No memory found!\n");

        min_low_pfn = PFN_UP(memblock_start_of_DRAM());
        min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET));
        max_pfn = PFN_DOWN(memblock_end_of_DRAM());
        max_low_pfn = min(max_pfn, MAX_LOW_PFN);

        early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
                      (phys_addr_t)max_low_pfn << PAGE_SHIFT);

        memblock_set_current_limit(PFN_PHYS(max_low_pfn));
        dma_contiguous_reserve(PFN_PHYS(max_low_pfn));

        memblock_dump_all();
}


void __init zones_init(void)
{
        /* All pages are DMA-able, so we put them all in the DMA zone. */
        unsigned long zones_size[MAX_NR_ZONES] = {
                [ZONE_NORMAL] = max_low_pfn - ARCH_PFN_OFFSET,
#ifdef CONFIG_HIGHMEM
                [ZONE_HIGHMEM] = max_pfn - max_low_pfn,
#endif
        };
        free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
}

#ifdef CONFIG_HIGHMEM
static void __init free_area_high(unsigned long pfn, unsigned long end)
{
        for (; pfn < end; pfn++)
                free_highmem_page(pfn_to_page(pfn));
}

static void __init free_highpages(void)
{
        unsigned long max_low = max_low_pfn;
        struct memblock_region *mem, *res;

        reset_all_zones_managed_pages();
        /* set highmem page free */
        for_each_memblock(memory, mem) {
                unsigned long start = memblock_region_memory_base_pfn(mem);
                unsigned long end = memblock_region_memory_end_pfn(mem);

                /* Ignore complete lowmem entries */
                if (end <= max_low)
                        continue;

                if (memblock_is_nomap(mem))
                        continue;

                /* Truncate partial highmem entries */
                if (start < max_low)
                        start = max_low;

                /* Find and exclude any reserved regions */
                for_each_memblock(reserved, res) {
                        unsigned long res_start, res_end;

                        res_start = memblock_region_reserved_base_pfn(res);
                        res_end = memblock_region_reserved_end_pfn(res);

                        if (res_end < start)
                                continue;
                        if (res_start < start)
                                res_start = start;
                        if (res_start > end)
                                res_start = end;
                        if (res_end > end)
                                res_end = end;
                        if (res_start != start)
                                free_area_high(start, res_start);
                        start = res_end;
                        if (start == end)
                                break;
                }

                /* And now free anything which remains */
                if (start < end)
                        free_area_high(start, end);
        }
}
#else
static void __init free_highpages(void)
{
}
#endif

/*
 * Initialize memory pages.
 */

void __init mem_init(void)
{
        free_highpages();

        max_mapnr = max_pfn - ARCH_PFN_OFFSET;
        high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);

        memblock_free_all();

        mem_init_print_info(NULL);
        pr_info("virtual kernel memory layout:\n"
#ifdef CONFIG_KASAN
                "    kasan   : 0x%08lx - 0x%08lx  (%5lu MB)\n"
#endif
#ifdef CONFIG_MMU
                "    vmalloc : 0x%08lx - 0x%08lx  (%5lu MB)\n"
#endif
#ifdef CONFIG_HIGHMEM
                "    pkmap   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
                "    fixmap  : 0x%08lx - 0x%08lx  (%5lu kB)\n"
#endif
                "    lowmem  : 0x%08lx - 0x%08lx  (%5lu MB)\n"
                "    .text   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
                "    .rodata : 0x%08lx - 0x%08lx  (%5lu kB)\n"
                "    .data   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
                "    .init   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
                "    .bss    : 0x%08lx - 0x%08lx  (%5lu kB)\n",
#ifdef CONFIG_KASAN
                KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE,
                KASAN_SHADOW_SIZE >> 20,
#endif
#ifdef CONFIG_MMU
                VMALLOC_START, VMALLOC_END,
                (VMALLOC_END - VMALLOC_START) >> 20,
#ifdef CONFIG_HIGHMEM
                PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
                (LAST_PKMAP*PAGE_SIZE) >> 10,
                FIXADDR_START, FIXADDR_TOP,
                (FIXADDR_TOP - FIXADDR_START) >> 10,
#endif
                PAGE_OFFSET, PAGE_OFFSET +
                (max_low_pfn - min_low_pfn) * PAGE_SIZE,
#else
                min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
#endif
                ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20,
                (unsigned long)_text, (unsigned long)_etext,
                (unsigned long)(_etext - _text) >> 10,
                (unsigned long)__start_rodata, (unsigned long)__end_rodata,
                (unsigned long)(__end_rodata - __start_rodata) >> 10,
                (unsigned long)_sdata, (unsigned long)_edata,
                (unsigned long)(_edata - _sdata) >> 10,
                (unsigned long)__init_begin, (unsigned long)__init_end,
                (unsigned long)(__init_end - __init_begin) >> 10,
                (unsigned long)__bss_start, (unsigned long)__bss_stop,
                (unsigned long)(__bss_stop - __bss_start) >> 10);
}

static void __init parse_memmap_one(char *p)
{
        char *oldp;
        unsigned long start_at, mem_size;

        if (!p)
                return;

        oldp = p;
        mem_size = memparse(p, &p);
        if (p == oldp)
                return;

        switch (*p) {
        case '@':
                start_at = memparse(p + 1, &p);
                memblock_add(start_at, mem_size);
                break;

        case '$':
                start_at = memparse(p + 1, &p);
                memblock_reserve(start_at, mem_size);
                break;

        case 0:
                memblock_reserve(mem_size, -mem_size);
                break;

        default:
                pr_warn("Unrecognized memmap syntax: %s\n", p);
                break;
        }
}

static int __init parse_memmap_opt(char *str)
{
        while (str) {
                char *k = strchr(str, ',');

                if (k)
                        *k++ = 0;

                parse_memmap_one(str);
                str = k;
        }

        return 0;
}
early_param("memmap", parse_memmap_opt);