// SPDX-License-Identifier: GPL-2.0

#include <linux/export.h>
#include <linux/mm.h>
#include <asm/pgtable.h>
#include <asm/mem_encrypt.h>

static pgprot_t protection_map[16] __ro_after_init = {
        [VM_NONE]                                       = PAGE_NONE,
        [VM_READ]                                       = PAGE_READONLY,
        [VM_WRITE]                                      = PAGE_COPY,
        [VM_WRITE | VM_READ]                            = PAGE_COPY,
        [VM_EXEC]                                       = PAGE_READONLY_EXEC,
        [VM_EXEC | VM_READ]                             = PAGE_READONLY_EXEC,
        [VM_EXEC | VM_WRITE]                            = PAGE_COPY_EXEC,
        [VM_EXEC | VM_WRITE | VM_READ]                  = PAGE_COPY_EXEC,
        [VM_SHARED]                                     = PAGE_NONE,
        [VM_SHARED | VM_READ]                           = PAGE_READONLY,
        [VM_SHARED | VM_WRITE]                          = PAGE_SHARED,
        [VM_SHARED | VM_WRITE | VM_READ]                = PAGE_SHARED,
        [VM_SHARED | VM_EXEC]                           = PAGE_READONLY_EXEC,
        [VM_SHARED | VM_EXEC | VM_READ]                 = PAGE_READONLY_EXEC,
        [VM_SHARED | VM_EXEC | VM_WRITE]                = PAGE_SHARED_EXEC,
        [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ]      = PAGE_SHARED_EXEC
};

void add_encrypt_protection_map(void)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(protection_map); i++)
                protection_map[i] = pgprot_encrypted(protection_map[i]);
}

pgprot_t vm_get_page_prot(vm_flags_t vm_flags)
{
        unsigned long val = pgprot_val(protection_map[vm_flags &
                                      (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
        /*
         * Take the 4 protection key bits out of the vma->vm_flags value and
         * turn them in to the bits that we can put in to a pte.
         *
         * Only override these if Protection Keys are available (which is only
         * on 64-bit).
         */
        if (vm_flags & VM_PKEY_BIT0)
                val |= _PAGE_PKEY_BIT0;
        if (vm_flags & VM_PKEY_BIT1)
                val |= _PAGE_PKEY_BIT1;
        if (vm_flags & VM_PKEY_BIT2)
                val |= _PAGE_PKEY_BIT2;
        if (vm_flags & VM_PKEY_BIT3)
                val |= _PAGE_PKEY_BIT3;
#endif

        val = __sme_set(val);
        if (val & _PAGE_PRESENT)
                val &= __supported_pte_mask;
        return __pgprot(val);
}
EXPORT_SYMBOL(vm_get_page_prot);