// SPDX-License-Identifier: GPL-2.0
/*
 * x86_64 specific EFI support functions
 * Based on Extensible Firmware Interface Specification version 1.0
 *
 * Copyright (C) 2005-2008 Intel Co.
 *      Fenghua Yu <fenghua.yu@intel.com>
 *      Bibo Mao <bibo.mao@intel.com>
 *      Chandramouli Narayanan <mouli@linux.intel.com>
 *      Huang Ying <ying.huang@intel.com>
 *
 * Code to convert EFI to E820 map has been implemented in elilo bootloader
 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
 * is setup appropriately for EFI runtime code.
 * - mouli 06/14/2007.
 *
 */

#define pr_fmt(fmt) "efi: " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/memblock.h>
#include <linux/ioport.h>
#include <linux/mc146818rtc.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/ucs2_string.h>
#include <linux/mem_encrypt.h>
#include <linux/sched/task.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/e820/api.h>
#include <asm/tlbflush.h>
#include <asm/proto.h>
#include <asm/efi.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/realmode.h>
#include <asm/time.h>
#include <asm/pgalloc.h>
#include <asm/sev.h>

/*
 * We allocate runtime services regions top-down, starting from -4G, i.e.
 * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
 */
static u64 efi_va = EFI_VA_START;
static struct mm_struct *efi_prev_mm;

/*
 * We need our own copy of the higher levels of the page tables
 * because we want to avoid inserting EFI region mappings (EFI_VA_END
 * to EFI_VA_START) into the standard kernel page tables. Everything
 * else can be shared, see efi_sync_low_kernel_mappings().
 *
 * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the
 * allocation.
 */
int __init efi_alloc_page_tables(void)
{
        pgd_t *pgd, *efi_pgd;
        p4d_t *p4d;
        pud_t *pud;
        gfp_t gfp_mask;

        gfp_mask = GFP_KERNEL | __GFP_ZERO;
        efi_pgd = (pgd_t *)__get_free_pages(gfp_mask, PGD_ALLOCATION_ORDER);
        if (!efi_pgd)
                goto fail;

        pgd = efi_pgd + pgd_index(EFI_VA_END);
        p4d = p4d_alloc(&init_mm, pgd, EFI_VA_END);
        if (!p4d)
                goto free_pgd;

        pud = pud_alloc(&init_mm, p4d, EFI_VA_END);
        if (!pud)
                goto free_p4d;

        efi_mm.pgd = efi_pgd;
        mm_init_cpumask(&efi_mm);
        init_new_context(NULL, &efi_mm);

        return 0;

free_p4d:
        if (pgtable_l5_enabled())
                free_page((unsigned long)pgd_page_vaddr(*pgd));
free_pgd:
        free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
fail:
        return -ENOMEM;
}

/*
 * Add low kernel mappings for passing arguments to EFI functions.
 */
void efi_sync_low_kernel_mappings(void)
{
        unsigned num_entries;
        pgd_t *pgd_k, *pgd_efi;
        p4d_t *p4d_k, *p4d_efi;
        pud_t *pud_k, *pud_efi;
        pgd_t *efi_pgd = efi_mm.pgd;

        pgd_efi = efi_pgd + pgd_index(PAGE_OFFSET);
        pgd_k = pgd_offset_k(PAGE_OFFSET);

        num_entries = pgd_index(EFI_VA_END) - pgd_index(PAGE_OFFSET);
        memcpy(pgd_efi, pgd_k, sizeof(pgd_t) * num_entries);

        pgd_efi = efi_pgd + pgd_index(EFI_VA_END);
        pgd_k = pgd_offset_k(EFI_VA_END);
        p4d_efi = p4d_offset(pgd_efi, 0);
        p4d_k = p4d_offset(pgd_k, 0);

        num_entries = p4d_index(EFI_VA_END);
        memcpy(p4d_efi, p4d_k, sizeof(p4d_t) * num_entries);

        /*
         * We share all the PUD entries apart from those that map the
         * EFI regions. Copy around them.
         */
        BUILD_BUG_ON((EFI_VA_START & ~PUD_MASK) != 0);
        BUILD_BUG_ON((EFI_VA_END & ~PUD_MASK) != 0);

        p4d_efi = p4d_offset(pgd_efi, EFI_VA_END);
        p4d_k = p4d_offset(pgd_k, EFI_VA_END);
        pud_efi = pud_offset(p4d_efi, 0);
        pud_k = pud_offset(p4d_k, 0);

        num_entries = pud_index(EFI_VA_END);
        memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);

        pud_efi = pud_offset(p4d_efi, EFI_VA_START);
        pud_k = pud_offset(p4d_k, EFI_VA_START);

        num_entries = PTRS_PER_PUD - pud_index(EFI_VA_START);
        memcpy(pud_efi, pud_k, sizeof(pud_t) * num_entries);
}

/*
 * Wrapper for slow_virt_to_phys() that handles NULL addresses.
 */
static inline phys_addr_t
virt_to_phys_or_null_size(void *va, unsigned long size)
{
        phys_addr_t pa;

        if (!va)
                return 0;

        if (virt_addr_valid(va))
                return virt_to_phys(va);

        pa = slow_virt_to_phys(va);

        /* check if the object crosses a page boundary */
        if (WARN_ON((pa ^ (pa + size - 1)) & PAGE_MASK))
                return 0;

        return pa;
}

#define virt_to_phys_or_null(addr)                              \
        virt_to_phys_or_null_size((addr), sizeof(*(addr)))

int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
        unsigned long pfn, text, pf, rodata;
        struct page *page;
        unsigned npages;
        pgd_t *pgd = efi_mm.pgd;

        /*
         * It can happen that the physical address of new_memmap lands in memory
         * which is not mapped in the EFI page table. Therefore we need to go
         * and ident-map those pages containing the map before calling
         * phys_efi_set_virtual_address_map().
         */
        pfn = pa_memmap >> PAGE_SHIFT;
        pf = _PAGE_NX | _PAGE_RW | _PAGE_ENC;
        if (kernel_map_pages_in_pgd(pgd, pfn, pa_memmap, num_pages, pf)) {
                pr_err("Error ident-mapping new memmap (0x%lx)!\n", pa_memmap);
                return 1;
        }

        /*
         * Certain firmware versions are way too sentimental and still believe
         * they are exclusive and unquestionable owners of the first physical page,
         * even though they explicitly mark it as EFI_CONVENTIONAL_MEMORY
         * (but then write-access it later during SetVirtualAddressMap()).
         *
         * Create a 1:1 mapping for this page, to avoid triple faults during early
         * boot with such firmware. We are free to hand this page to the BIOS,
         * as trim_bios_range() will reserve the first page and isolate it away
         * from memory allocators anyway.
         */
        if (kernel_map_pages_in_pgd(pgd, 0x0, 0x0, 1, pf)) {
                pr_err("Failed to create 1:1 mapping for the first page!\n");
                return 1;
        }

        /*
         * When SEV-ES is active, the GHCB as set by the kernel will be used
         * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
         */
        if (sev_es_efi_map_ghcbs(pgd)) {
                pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
                return 1;
        }

        /*
         * When making calls to the firmware everything needs to be 1:1
         * mapped and addressable with 32-bit pointers. Map the kernel
         * text and allocate a new stack because we can't rely on the
         * stack pointer being < 4GB.
         */
        if (!efi_is_mixed())
                return 0;

        page = alloc_page(GFP_KERNEL|__GFP_DMA32);
        if (!page) {
                pr_err("Unable to allocate EFI runtime stack < 4GB\n");
                return 1;
        }

        efi_mixed_mode_stack_pa = page_to_phys(page + 1); /* stack grows down */

        npages = (_etext - _text) >> PAGE_SHIFT;
        text = __pa(_text);
        pfn = text >> PAGE_SHIFT;

        pf = _PAGE_ENC;
        if (kernel_map_pages_in_pgd(pgd, pfn, text, npages, pf)) {
                pr_err("Failed to map kernel text 1:1\n");
                return 1;
        }

        npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
        rodata = __pa(__start_rodata);
        pfn = rodata >> PAGE_SHIFT;

        pf = _PAGE_NX | _PAGE_ENC;
        if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
                pr_err("Failed to map kernel rodata 1:1\n");
                return 1;
        }

        return 0;
}

static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
        unsigned long flags = _PAGE_RW;
        unsigned long pfn;
        pgd_t *pgd = efi_mm.pgd;

        /*
         * EFI_RUNTIME_SERVICES_CODE regions typically cover PE/COFF
         * executable images in memory that consist of both R-X and
         * RW- sections, so we cannot apply read-only or non-exec
         * permissions just yet. However, modern EFI systems provide
         * a memory attributes table that describes those sections
         * with the appropriate restricted permissions, which are
         * applied in efi_runtime_update_mappings() below. All other
         * regions can be mapped non-executable at this point, with
         * the exception of boot services code regions, but those will
         * be unmapped again entirely in efi_free_boot_services().
         */
        if (md->type != EFI_BOOT_SERVICES_CODE &&
            md->type != EFI_RUNTIME_SERVICES_CODE)
                flags |= _PAGE_NX;

        if (!(md->attribute & EFI_MEMORY_WB))
                flags |= _PAGE_PCD;

        if (sev_active() && md->type != EFI_MEMORY_MAPPED_IO)
                flags |= _PAGE_ENC;

        pfn = md->phys_addr >> PAGE_SHIFT;
        if (kernel_map_pages_in_pgd(pgd, pfn, va, md->num_pages, flags))
                pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
                           md->phys_addr, va);
}

void __init efi_map_region(efi_memory_desc_t *md)
{
        unsigned long size = md->num_pages << PAGE_SHIFT;
        u64 pa = md->phys_addr;

        /*
         * Make sure the 1:1 mappings are present as a catch-all for b0rked
         * firmware which doesn't update all internal pointers after switching
         * to virtual mode and would otherwise crap on us.
         */
        __map_region(md, md->phys_addr);

        /*
         * Enforce the 1:1 mapping as the default virtual address when
         * booting in EFI mixed mode, because even though we may be
         * running a 64-bit kernel, the firmware may only be 32-bit.
         */
        if (efi_is_mixed()) {
                md->virt_addr = md->phys_addr;
                return;
        }

        efi_va -= size;

        /* Is PA 2M-aligned? */
        if (!(pa & (PMD_SIZE - 1))) {
                efi_va &= PMD_MASK;
        } else {
                u64 pa_offset = pa & (PMD_SIZE - 1);
                u64 prev_va = efi_va;

                /* get us the same offset within this 2M page */
                efi_va = (efi_va & PMD_MASK) + pa_offset;

                if (efi_va > prev_va)
                        efi_va -= PMD_SIZE;
        }

        if (efi_va < EFI_VA_END) {
                pr_warn(FW_WARN "VA address range overflow!\n");
                return;
        }

        /* Do the VA map */
        __map_region(md, efi_va);
        md->virt_addr = efi_va;
}

/*
 * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
 * md->virt_addr is the original virtual address which had been mapped in kexec
 * 1st kernel.
 */
void __init efi_map_region_fixed(efi_memory_desc_t *md)
{
        __map_region(md, md->phys_addr);
        __map_region(md, md->virt_addr);
}

void __init parse_efi_setup(u64 phys_addr, u32 data_len)
{
        efi_setup = phys_addr + sizeof(struct setup_data);
}

static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf)
{
        unsigned long pfn;
        pgd_t *pgd = efi_mm.pgd;
        int err1, err2;

        /* Update the 1:1 mapping */
        pfn = md->phys_addr >> PAGE_SHIFT;
        err1 = kernel_map_pages_in_pgd(pgd, pfn, md->phys_addr, md->num_pages, pf);
        if (err1) {
                pr_err("Error while updating 1:1 mapping PA 0x%llx -> VA 0x%llx!\n",
                           md->phys_addr, md->virt_addr);
        }

        err2 = kernel_map_pages_in_pgd(pgd, pfn, md->virt_addr, md->num_pages, pf);
        if (err2) {
                pr_err("Error while updating VA mapping PA 0x%llx -> VA 0x%llx!\n",
                           md->phys_addr, md->virt_addr);
        }

        return err1 || err2;
}

static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md)
{
        unsigned long pf = 0;

        if (md->attribute & EFI_MEMORY_XP)
                pf |= _PAGE_NX;

        if (!(md->attribute & EFI_MEMORY_RO))
                pf |= _PAGE_RW;

        if (sev_active())
                pf |= _PAGE_ENC;

        return efi_update_mappings(md, pf);
}

void __init efi_runtime_update_mappings(void)
{
        efi_memory_desc_t *md;

        /*
         * Use the EFI Memory Attribute Table for mapping permissions if it
         * exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
         */
        if (efi_enabled(EFI_MEM_ATTR)) {
                efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
                return;
        }

        /*
         * EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
         * EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
         * permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
         * published by the firmware. Even if we find a buggy implementation of
         * EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
         * EFI_PROPERTIES_TABLE, because of the same reason.
         */

        if (!efi_enabled(EFI_NX_PE_DATA))
                return;

        for_each_efi_memory_desc(md) {
                unsigned long pf = 0;

                if (!(md->attribute & EFI_MEMORY_RUNTIME))
                        continue;

                if (!(md->attribute & EFI_MEMORY_WB))
                        pf |= _PAGE_PCD;

                if ((md->attribute & EFI_MEMORY_XP) ||
                        (md->type == EFI_RUNTIME_SERVICES_DATA))
                        pf |= _PAGE_NX;

                if (!(md->attribute & EFI_MEMORY_RO) &&
                        (md->type != EFI_RUNTIME_SERVICES_CODE))
                        pf |= _PAGE_RW;

                if (sev_active())
                        pf |= _PAGE_ENC;

                efi_update_mappings(md, pf);
        }
}

void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
        ptdump_walk_pgd_level(NULL, &efi_mm);
#endif
}

/*
 * Makes the calling thread switch to/from efi_mm context. Can be used
 * in a kernel thread and user context. Preemption needs to remain disabled
 * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm
 * can not change under us.
 * It should be ensured that there are no concurrent calls to this function.
 */
void efi_enter_mm(void)
{
        efi_prev_mm = current->active_mm;
        current->active_mm = &efi_mm;
        switch_mm(efi_prev_mm, &efi_mm, NULL);
}

void efi_leave_mm(void)
{
        current->active_mm = efi_prev_mm;
        switch_mm(&efi_mm, efi_prev_mm, NULL);
}

static DEFINE_SPINLOCK(efi_runtime_lock);

/*
 * DS and ES contain user values.  We need to save them.
 * The 32-bit EFI code needs a valid DS, ES, and SS.  There's no
 * need to save the old SS: __KERNEL_DS is always acceptable.
 */
#define __efi_thunk(func, ...)                                          \
({                                                                      \
        unsigned short __ds, __es;                                      \
        efi_status_t ____s;                                             \
                                                                        \
        savesegment(ds, __ds);                                          \
        savesegment(es, __es);                                          \
                                                                        \
        loadsegment(ss, __KERNEL_DS);                                   \
        loadsegment(ds, __KERNEL_DS);                                   \
        loadsegment(es, __KERNEL_DS);                                   \
                                                                        \
        ____s = efi64_thunk(efi.runtime->mixed_mode.func, __VA_ARGS__); \
                                                                        \
        loadsegment(ds, __ds);                                          \
        loadsegment(es, __es);                                          \
                                                                        \
        ____s ^= (____s & BIT(31)) | (____s & BIT_ULL(31)) << 32;       \
        ____s;                                                          \
})

/*
 * Switch to the EFI page tables early so that we can access the 1:1
 * runtime services mappings which are not mapped in any other page
 * tables.
 *
 * Also, disable interrupts because the IDT points to 64-bit handlers,
 * which aren't going to function correctly when we switch to 32-bit.
 */
#define efi_thunk(func...)                                              \
({                                                                      \
        efi_status_t __s;                                               \
                                                                        \
        arch_efi_call_virt_setup();                                     \
                                                                        \
        __s = __efi_thunk(func);                                        \
                                                                        \
        arch_efi_call_virt_teardown();                                  \
                                                                        \
        __s;                                                            \
})

static efi_status_t __init __no_sanitize_address
efi_thunk_set_virtual_address_map(unsigned long memory_map_size,
                                  unsigned long descriptor_size,
                                  u32 descriptor_version,
                                  efi_memory_desc_t *virtual_map)
{
        efi_status_t status;
        unsigned long flags;

        efi_sync_low_kernel_mappings();
        local_irq_save(flags);

        efi_enter_mm();

        status = __efi_thunk(set_virtual_address_map, memory_map_size,
                             descriptor_size, descriptor_version, virtual_map);

        efi_leave_mm();
        local_irq_restore(flags);

        return status;
}

static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
        return EFI_UNSUPPORTED;
}

static efi_status_t efi_thunk_set_time(efi_time_t *tm)
{
        return EFI_UNSUPPORTED;
}

static efi_status_t
efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
                          efi_time_t *tm)
{
        return EFI_UNSUPPORTED;
}

static efi_status_t
efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
        return EFI_UNSUPPORTED;
}

static unsigned long efi_name_size(efi_char16_t *name)
{
        return ucs2_strsize(name, EFI_VAR_NAME_LEN) + 1;
}

static efi_status_t
efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
                       u32 *attr, unsigned long *data_size, void *data)
{
        u8 buf[24] __aligned(8);
        efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
        efi_status_t status;
        u32 phys_name, phys_vendor, phys_attr;
        u32 phys_data_size, phys_data;
        unsigned long flags;

        spin_lock_irqsave(&efi_runtime_lock, flags);

        *vnd = *vendor;

        phys_data_size = virt_to_phys_or_null(data_size);
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
        phys_attr = virt_to_phys_or_null(attr);
        phys_data = virt_to_phys_or_null_size(data, *data_size);

        if (!phys_name || (data && !phys_data))
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(get_variable, phys_name, phys_vendor,
                                   phys_attr, phys_data_size, phys_data);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        return status;
}

static efi_status_t
efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
                       u32 attr, unsigned long data_size, void *data)
{
        u8 buf[24] __aligned(8);
        efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
        u32 phys_name, phys_vendor, phys_data;
        efi_status_t status;
        unsigned long flags;

        spin_lock_irqsave(&efi_runtime_lock, flags);

        *vnd = *vendor;

        phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_data = virt_to_phys_or_null_size(data, data_size);

        if (!phys_name || (data && !phys_data))
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(set_variable, phys_name, phys_vendor,
                                   attr, data_size, phys_data);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        return status;
}

static efi_status_t
efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
                                   u32 attr, unsigned long data_size,
                                   void *data)
{
        u8 buf[24] __aligned(8);
        efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
        u32 phys_name, phys_vendor, phys_data;
        efi_status_t status;
        unsigned long flags;

        if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
                return EFI_NOT_READY;

        *vnd = *vendor;

        phys_name = virt_to_phys_or_null_size(name, efi_name_size(name));
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_data = virt_to_phys_or_null_size(data, data_size);

        if (!phys_name || (data && !phys_data))
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(set_variable, phys_name, phys_vendor,
                                   attr, data_size, phys_data);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        return status;
}

static efi_status_t
efi_thunk_get_next_variable(unsigned long *name_size,
                            efi_char16_t *name,
                            efi_guid_t *vendor)
{
        u8 buf[24] __aligned(8);
        efi_guid_t *vnd = PTR_ALIGN((efi_guid_t *)buf, sizeof(*vnd));
        efi_status_t status;
        u32 phys_name_size, phys_name, phys_vendor;
        unsigned long flags;

        spin_lock_irqsave(&efi_runtime_lock, flags);

        *vnd = *vendor;

        phys_name_size = virt_to_phys_or_null(name_size);
        phys_vendor = virt_to_phys_or_null(vnd);
        phys_name = virt_to_phys_or_null_size(name, *name_size);

        if (!phys_name)
                status = EFI_INVALID_PARAMETER;
        else
                status = efi_thunk(get_next_variable, phys_name_size,
                                   phys_name, phys_vendor);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        *vendor = *vnd;
        return status;
}

static efi_status_t
efi_thunk_get_next_high_mono_count(u32 *count)
{
        return EFI_UNSUPPORTED;
}

static void
efi_thunk_reset_system(int reset_type, efi_status_t status,
                       unsigned long data_size, efi_char16_t *data)
{
        u32 phys_data;
        unsigned long flags;

        spin_lock_irqsave(&efi_runtime_lock, flags);

        phys_data = virt_to_phys_or_null_size(data, data_size);

        efi_thunk(reset_system, reset_type, status, data_size, phys_data);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);
}

static efi_status_t
efi_thunk_update_capsule(efi_capsule_header_t **capsules,
                         unsigned long count, unsigned long sg_list)
{
        /*
         * To properly support this function we would need to repackage
         * 'capsules' because the firmware doesn't understand 64-bit
         * pointers.
         */
        return EFI_UNSUPPORTED;
}

static efi_status_t
efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
                              u64 *remaining_space,
                              u64 *max_variable_size)
{
        efi_status_t status;
        u32 phys_storage, phys_remaining, phys_max;
        unsigned long flags;

        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;

        spin_lock_irqsave(&efi_runtime_lock, flags);

        phys_storage = virt_to_phys_or_null(storage_space);
        phys_remaining = virt_to_phys_or_null(remaining_space);
        phys_max = virt_to_phys_or_null(max_variable_size);

        status = efi_thunk(query_variable_info, attr, phys_storage,
                           phys_remaining, phys_max);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        return status;
}

static efi_status_t
efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space,
                                          u64 *remaining_space,
                                          u64 *max_variable_size)
{
        efi_status_t status;
        u32 phys_storage, phys_remaining, phys_max;
        unsigned long flags;

        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;

        if (!spin_trylock_irqsave(&efi_runtime_lock, flags))
                return EFI_NOT_READY;

        phys_storage = virt_to_phys_or_null(storage_space);
        phys_remaining = virt_to_phys_or_null(remaining_space);
        phys_max = virt_to_phys_or_null(max_variable_size);

        status = efi_thunk(query_variable_info, attr, phys_storage,
                           phys_remaining, phys_max);

        spin_unlock_irqrestore(&efi_runtime_lock, flags);

        return status;
}

static efi_status_t
efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
                             unsigned long count, u64 *max_size,
                             int *reset_type)
{
        /*
         * To properly support this function we would need to repackage
         * 'capsules' because the firmware doesn't understand 64-bit
         * pointers.
         */
        return EFI_UNSUPPORTED;
}

void __init efi_thunk_runtime_setup(void)
{
        if (!IS_ENABLED(CONFIG_EFI_MIXED))
                return;

        efi.get_time = efi_thunk_get_time;
        efi.set_time = efi_thunk_set_time;
        efi.get_wakeup_time = efi_thunk_get_wakeup_time;
        efi.set_wakeup_time = efi_thunk_set_wakeup_time;
        efi.get_variable = efi_thunk_get_variable;
        efi.get_next_variable = efi_thunk_get_next_variable;
        efi.set_variable = efi_thunk_set_variable;
        efi.set_variable_nonblocking = efi_thunk_set_variable_nonblocking;
        efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
        efi.reset_system = efi_thunk_reset_system;
        efi.query_variable_info = efi_thunk_query_variable_info;
        efi.query_variable_info_nonblocking = efi_thunk_query_variable_info_nonblocking;
        efi.update_capsule = efi_thunk_update_capsule;
        efi.query_capsule_caps = efi_thunk_query_capsule_caps;
}

efi_status_t __init __no_sanitize_address
efi_set_virtual_address_map(unsigned long memory_map_size,
                            unsigned long descriptor_size,
                            u32 descriptor_version,
                            efi_memory_desc_t *virtual_map,
                            unsigned long systab_phys)
{
        const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
        efi_status_t status;
        unsigned long flags;

        if (efi_is_mixed())
                return efi_thunk_set_virtual_address_map(memory_map_size,
                                                         descriptor_size,
                                                         descriptor_version,
                                                         virtual_map);
        efi_enter_mm();

        efi_fpu_begin();

        /* Disable interrupts around EFI calls: */
        local_irq_save(flags);
        status = efi_call(efi.runtime->set_virtual_address_map,
                          memory_map_size, descriptor_size,
                          descriptor_version, virtual_map);
        local_irq_restore(flags);

        efi_fpu_end();

        /* grab the virtually remapped EFI runtime services table pointer */
        efi.runtime = READ_ONCE(systab->runtime);

        efi_leave_mm();

        return status;
}