// SPDX-License-Identifier: GPL-2.0
#include <linux/memblock.h>
#include <linux/mmdebug.h>
#include <linux/export.h>
#include <linux/mm.h>

#include <asm/page.h>
#include <linux/vmalloc.h>

#include "physaddr.h"

#ifdef CONFIG_X86_64

#ifdef CONFIG_DEBUG_VIRTUAL
unsigned long __phys_addr(unsigned long x)
{
        unsigned long y = x - __START_KERNEL_map;

        /* use the carry flag to determine if x was < __START_KERNEL_map */
        if (unlikely(x > y)) {
                x = y + phys_base;

                VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);
        } else {
                x = y + (__START_KERNEL_map - PAGE_OFFSET);

                /* carry flag will be set if starting x was >= PAGE_OFFSET */
                VIRTUAL_BUG_ON((x > y) || !phys_addr_valid(x));
        }

        return x;
}
EXPORT_SYMBOL(__phys_addr);
#endif

bool __virt_addr_valid(unsigned long x)
{
        unsigned long y = x - __START_KERNEL_map;

        /* use the carry flag to determine if x was < __START_KERNEL_map */
        if (unlikely(x > y)) {
                x = y + phys_base;

                if (y >= KERNEL_IMAGE_SIZE)
                        return false;
        } else {
                x = y + (__START_KERNEL_map - PAGE_OFFSET);

                /* carry flag will be set if starting x was >= PAGE_OFFSET */
                if ((x > y) || !phys_addr_valid(x))
                        return false;
        }

        return pfn_valid(x >> PAGE_SHIFT);
}
EXPORT_SYMBOL(__virt_addr_valid);

#else

#ifdef CONFIG_DEBUG_VIRTUAL
unsigned long __phys_addr(unsigned long x)
{
        unsigned long phys_addr = x - PAGE_OFFSET;
        /* VMALLOC_* aren't constants  */
        VIRTUAL_BUG_ON(x < PAGE_OFFSET);
        VIRTUAL_BUG_ON(__vmalloc_start_set && is_vmalloc_addr((void *) x));
        /* max_low_pfn is set early, but not _that_ early */
        if (max_low_pfn) {
                VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
                BUG_ON(slow_virt_to_phys((void *)x) != phys_addr);
        }
        return phys_addr;
}
EXPORT_SYMBOL(__phys_addr);
#endif

bool __virt_addr_valid(unsigned long x)
{
        if (x < PAGE_OFFSET)
                return false;
        if (__vmalloc_start_set && is_vmalloc_addr((void *) x))
                return false;
        if (x >= FIXADDR_START)
                return false;
        return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
}
EXPORT_SYMBOL(__virt_addr_valid);

#endif  /* CONFIG_X86_64 */