// SPDX-License-Identifier: GPL-2.0-only
/*
 * EFI support for Xen.
 *
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 * Copyright (C) 1999-2002 Hewlett-Packard Co.
 *      David Mosberger-Tang <davidm@hpl.hp.com>
 *      Stephane Eranian <eranian@hpl.hp.com>
 * 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>
 * Copyright (C) 2011 Novell Co.
 *      Jan Beulich <JBeulich@suse.com>
 * Copyright (C) 2011-2012 Oracle Co.
 *      Liang Tang <liang.tang@oracle.com>
 * Copyright (c) 2014 Oracle Co., Daniel Kiper
 */

#include <linux/bug.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/string.h>

#include <xen/interface/xen.h>
#include <xen/interface/platform.h>
#include <xen/page.h>
#include <xen/xen.h>
#include <xen/xen-ops.h>

#include <asm/page.h>

#include <asm/xen/hypercall.h>

#define INIT_EFI_OP(name) \
        {.cmd = XENPF_efi_runtime_call, \
         .u.efi_runtime_call.function = XEN_EFI_##name, \
         .u.efi_runtime_call.misc = 0}

#define efi_data(op)    (op.u.efi_runtime_call)

static efi_status_t xen_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
        struct xen_platform_op op = INIT_EFI_OP(get_time);

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        if (tm) {
                BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_time.time));
                memcpy(tm, &efi_data(op).u.get_time.time, sizeof(*tm));
        }

        if (tc) {
                tc->resolution = efi_data(op).u.get_time.resolution;
                tc->accuracy = efi_data(op).u.get_time.accuracy;
                tc->sets_to_zero = !!(efi_data(op).misc &
                                      XEN_EFI_GET_TIME_SET_CLEARS_NS);
        }

        return efi_data(op).status;
}

static efi_status_t xen_efi_set_time(efi_time_t *tm)
{
        struct xen_platform_op op = INIT_EFI_OP(set_time);

        BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_time));
        memcpy(&efi_data(op).u.set_time, tm, sizeof(*tm));

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        return efi_data(op).status;
}

static efi_status_t xen_efi_get_wakeup_time(efi_bool_t *enabled,
                                            efi_bool_t *pending,
                                            efi_time_t *tm)
{
        struct xen_platform_op op = INIT_EFI_OP(get_wakeup_time);

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        if (tm) {
                BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.get_wakeup_time));
                memcpy(tm, &efi_data(op).u.get_wakeup_time, sizeof(*tm));
        }

        if (enabled)
                *enabled = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_ENABLED);

        if (pending)
                *pending = !!(efi_data(op).misc & XEN_EFI_GET_WAKEUP_TIME_PENDING);

        return efi_data(op).status;
}

static efi_status_t xen_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
        struct xen_platform_op op = INIT_EFI_OP(set_wakeup_time);

        BUILD_BUG_ON(sizeof(*tm) != sizeof(efi_data(op).u.set_wakeup_time));
        if (enabled)
                efi_data(op).misc = XEN_EFI_SET_WAKEUP_TIME_ENABLE;
        if (tm)
                memcpy(&efi_data(op).u.set_wakeup_time, tm, sizeof(*tm));
        else
                efi_data(op).misc |= XEN_EFI_SET_WAKEUP_TIME_ENABLE_ONLY;

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        return efi_data(op).status;
}

static efi_status_t xen_efi_get_variable(efi_char16_t *name, efi_guid_t *vendor,
                                         u32 *attr, unsigned long *data_size,
                                         void *data)
{
        struct xen_platform_op op = INIT_EFI_OP(get_variable);

        set_xen_guest_handle(efi_data(op).u.get_variable.name, name);
        BUILD_BUG_ON(sizeof(*vendor) !=
                     sizeof(efi_data(op).u.get_variable.vendor_guid));
        memcpy(&efi_data(op).u.get_variable.vendor_guid, vendor, sizeof(*vendor));
        efi_data(op).u.get_variable.size = *data_size;
        set_xen_guest_handle(efi_data(op).u.get_variable.data, data);

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        *data_size = efi_data(op).u.get_variable.size;
        if (attr)
                *attr = efi_data(op).misc;

        return efi_data(op).status;
}

static efi_status_t xen_efi_get_next_variable(unsigned long *name_size,
                                              efi_char16_t *name,
                                              efi_guid_t *vendor)
{
        struct xen_platform_op op = INIT_EFI_OP(get_next_variable_name);

        efi_data(op).u.get_next_variable_name.size = *name_size;
        set_xen_guest_handle(efi_data(op).u.get_next_variable_name.name, name);
        BUILD_BUG_ON(sizeof(*vendor) !=
                     sizeof(efi_data(op).u.get_next_variable_name.vendor_guid));
        memcpy(&efi_data(op).u.get_next_variable_name.vendor_guid, vendor,
               sizeof(*vendor));

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        *name_size = efi_data(op).u.get_next_variable_name.size;
        memcpy(vendor, &efi_data(op).u.get_next_variable_name.vendor_guid,
               sizeof(*vendor));

        return efi_data(op).status;
}

static efi_status_t xen_efi_set_variable(efi_char16_t *name, efi_guid_t *vendor,
                                         u32 attr, unsigned long data_size,
                                         void *data)
{
        struct xen_platform_op op = INIT_EFI_OP(set_variable);

        set_xen_guest_handle(efi_data(op).u.set_variable.name, name);
        efi_data(op).misc = attr;
        BUILD_BUG_ON(sizeof(*vendor) !=
                     sizeof(efi_data(op).u.set_variable.vendor_guid));
        memcpy(&efi_data(op).u.set_variable.vendor_guid, vendor, sizeof(*vendor));
        efi_data(op).u.set_variable.size = data_size;
        set_xen_guest_handle(efi_data(op).u.set_variable.data, data);

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        return efi_data(op).status;
}

static efi_status_t xen_efi_query_variable_info(u32 attr, u64 *storage_space,
                                                u64 *remaining_space,
                                                u64 *max_variable_size)
{
        struct xen_platform_op op = INIT_EFI_OP(query_variable_info);

        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;

        efi_data(op).u.query_variable_info.attr = attr;

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        *storage_space = efi_data(op).u.query_variable_info.max_store_size;
        *remaining_space = efi_data(op).u.query_variable_info.remain_store_size;
        *max_variable_size = efi_data(op).u.query_variable_info.max_size;

        return efi_data(op).status;
}

static efi_status_t xen_efi_get_next_high_mono_count(u32 *count)
{
        struct xen_platform_op op = INIT_EFI_OP(get_next_high_monotonic_count);

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        *count = efi_data(op).misc;

        return efi_data(op).status;
}

static efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules,
                                unsigned long count, unsigned long sg_list)
{
        struct xen_platform_op op = INIT_EFI_OP(update_capsule);

        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;

        set_xen_guest_handle(efi_data(op).u.update_capsule.capsule_header_array,
                             capsules);
        efi_data(op).u.update_capsule.capsule_count = count;
        efi_data(op).u.update_capsule.sg_list = sg_list;

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        return efi_data(op).status;
}

static efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules,
                        unsigned long count, u64 *max_size, int *reset_type)
{
        struct xen_platform_op op = INIT_EFI_OP(query_capsule_capabilities);

        if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
                return EFI_UNSUPPORTED;

        set_xen_guest_handle(efi_data(op).u.query_capsule_capabilities.capsule_header_array,
                                        capsules);
        efi_data(op).u.query_capsule_capabilities.capsule_count = count;

        if (HYPERVISOR_platform_op(&op) < 0)
                return EFI_UNSUPPORTED;

        *max_size = efi_data(op).u.query_capsule_capabilities.max_capsule_size;
        *reset_type = efi_data(op).u.query_capsule_capabilities.reset_type;

        return efi_data(op).status;
}

static void xen_efi_reset_system(int reset_type, efi_status_t status,
                                 unsigned long data_size, efi_char16_t *data)
{
        switch (reset_type) {
        case EFI_RESET_COLD:
        case EFI_RESET_WARM:
                xen_reboot(SHUTDOWN_reboot);
                break;
        case EFI_RESET_SHUTDOWN:
                xen_reboot(SHUTDOWN_poweroff);
                break;
        default:
                BUG();
        }
}

/*
 * Set XEN EFI runtime services function pointers. Other fields of struct efi,
 * e.g. efi.systab, will be set like normal EFI.
 */
void __init xen_efi_runtime_setup(void)
{
        efi.get_time                    = xen_efi_get_time;
        efi.set_time                    = xen_efi_set_time;
        efi.get_wakeup_time             = xen_efi_get_wakeup_time;
        efi.set_wakeup_time             = xen_efi_set_wakeup_time;
        efi.get_variable                = xen_efi_get_variable;
        efi.get_next_variable           = xen_efi_get_next_variable;
        efi.set_variable                = xen_efi_set_variable;
        efi.set_variable_nonblocking    = xen_efi_set_variable;
        efi.query_variable_info         = xen_efi_query_variable_info;
        efi.query_variable_info_nonblocking = xen_efi_query_variable_info;
        efi.update_capsule              = xen_efi_update_capsule;
        efi.query_capsule_caps          = xen_efi_query_capsule_caps;
        efi.get_next_high_mono_count    = xen_efi_get_next_high_mono_count;
        efi.reset_system                = xen_efi_reset_system;
}

int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md)
{
        static_assert(XEN_PAGE_SHIFT == EFI_PAGE_SHIFT,
                      "Mismatch between EFI_PAGE_SHIFT and XEN_PAGE_SHIFT");
        struct xen_platform_op op;
        union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
        int rc;

        if (!efi_enabled(EFI_PARAVIRT) || efi_enabled(EFI_MEMMAP))
                return __efi_mem_desc_lookup(phys_addr, out_md);
        phys_addr &= ~(u64)(EFI_PAGE_SIZE - 1);
        op = (struct xen_platform_op) {
                .cmd = XENPF_firmware_info,
                .u.firmware_info = {
                        .type = XEN_FW_EFI_INFO,
                        .index = XEN_FW_EFI_MEM_INFO,
                        .u.efi_info.mem.addr = phys_addr,
                        .u.efi_info.mem.size = U64_MAX - phys_addr,
                },
        };

        rc = HYPERVISOR_platform_op(&op);
        if (rc) {
                pr_warn("Failed to lookup header 0x%llx in Xen memory map: error %d\n",
                        phys_addr, rc);
        }

        out_md->phys_addr       = info->mem.addr;
        out_md->num_pages       = info->mem.size >> EFI_PAGE_SHIFT;
        out_md->type            = info->mem.type;
        out_md->attribute       = info->mem.attr;

        return 0;
}

bool __init xen_efi_config_table_is_usable(const efi_guid_t *guid,
                                           unsigned long table)
{
        efi_memory_desc_t md;
        int rc;

        if (!efi_enabled(EFI_PARAVIRT))
                return true;

        rc = efi_mem_desc_lookup(table, &md);
        if (rc)
                return false;

        switch (md.type) {
        case EFI_RUNTIME_SERVICES_CODE:
        case EFI_RUNTIME_SERVICES_DATA:
        case EFI_ACPI_RECLAIM_MEMORY:
        case EFI_ACPI_MEMORY_NVS:
        case EFI_RESERVED_TYPE:
                return true;
        default:
                return false;
        }
}