xref: /openbmc/linux/drivers/xen/efi.c (revision 9a87ffc99ec8eb8d35eed7c4f816d75f5cc9662e)

// 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;
	}
}