1/*
  2 * Copyright (c) 2014 Oracle Co., Daniel Kiper
  3 *
  4 * This program is free software; you can redistribute it and/or modify
  5 * it under the terms of the GNU General Public License as published by
  6 * the Free Software Foundation; either version 2 of the License, or
  7 * (at your option) any later version.
  8 *
  9 * This program is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12 * GNU General Public License for more details.
 13 *
 14 * You should have received a copy of the GNU General Public License along
 15 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 16 */
 17
 18#include <linux/bitops.h>
 19#include <linux/efi.h>
 20#include <linux/init.h>
 21#include <linux/string.h>
 22
 23#include <xen/xen.h>
 24#include <xen/xen-ops.h>
 25#include <xen/interface/platform.h>
 26
 27#include <asm/page.h>
 28#include <asm/setup.h>
 29#include <asm/xen/hypercall.h>
 30
 31static efi_char16_t vendor[100] __initdata;
 32
 33static efi_system_table_t efi_systab_xen __initdata = {
 34	.hdr = {
 35		.signature	= EFI_SYSTEM_TABLE_SIGNATURE,
 36		.revision	= 0, /* Initialized later. */
 37		.headersize	= 0, /* Ignored by Linux Kernel. */
 38		.crc32		= 0, /* Ignored by Linux Kernel. */
 39		.reserved	= 0
 40	},
 41	.fw_vendor	= EFI_INVALID_TABLE_ADDR, /* Initialized later. */
 42	.fw_revision	= 0,			  /* Initialized later. */
 43	.con_in_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 44	.con_in		= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 45	.con_out_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 46	.con_out	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 47	.stderr_handle	= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 48	.stderr		= EFI_INVALID_TABLE_ADDR, /* Not used under Xen. */
 49	.runtime	= (efi_runtime_services_t *)EFI_INVALID_TABLE_ADDR,
 50						  /* Not used under Xen. */
 51	.boottime	= (efi_boot_services_t *)EFI_INVALID_TABLE_ADDR,
 52						  /* Not used under Xen. */
 53	.nr_tables	= 0,			  /* Initialized later. */
 54	.tables		= EFI_INVALID_TABLE_ADDR  /* Initialized later. */
 55};
 56
 57static efi_system_table_t __init *xen_efi_probe(void)
 58{
 59	struct xen_platform_op op = {
 60		.cmd = XENPF_firmware_info,
 61		.u.firmware_info = {
 62			.type = XEN_FW_EFI_INFO,
 63			.index = XEN_FW_EFI_CONFIG_TABLE
 64		}
 65	};
 66	union xenpf_efi_info *info = &op.u.firmware_info.u.efi_info;
 67
 68	if (!xen_initial_domain() || HYPERVISOR_platform_op(&op) < 0)
 69		return NULL;
 70
 71	/* Here we know that Xen runs on EFI platform. */
 72
 73	efi.get_time                 = xen_efi_get_time;
 74	efi.set_time                 = xen_efi_set_time;
 75	efi.get_wakeup_time          = xen_efi_get_wakeup_time;
 76	efi.set_wakeup_time          = xen_efi_set_wakeup_time;
 77	efi.get_variable             = xen_efi_get_variable;
 78	efi.get_next_variable        = xen_efi_get_next_variable;
 79	efi.set_variable             = xen_efi_set_variable;
 80	efi.query_variable_info      = xen_efi_query_variable_info;
 81	efi.update_capsule           = xen_efi_update_capsule;
 82	efi.query_capsule_caps       = xen_efi_query_capsule_caps;
 83	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
 84	efi.reset_system             = xen_efi_reset_system;
 85
 86	efi_systab_xen.tables = info->cfg.addr;
 87	efi_systab_xen.nr_tables = info->cfg.nent;
 88
 89	op.cmd = XENPF_firmware_info;
 90	op.u.firmware_info.type = XEN_FW_EFI_INFO;
 91	op.u.firmware_info.index = XEN_FW_EFI_VENDOR;
 92	info->vendor.bufsz = sizeof(vendor);
 93	set_xen_guest_handle(info->vendor.name, vendor);
 94
 95	if (HYPERVISOR_platform_op(&op) == 0) {
 96		efi_systab_xen.fw_vendor = __pa_symbol(vendor);
 97		efi_systab_xen.fw_revision = info->vendor.revision;
 98	} else
 99		efi_systab_xen.fw_vendor = __pa_symbol(L"UNKNOWN");
100
101	op.cmd = XENPF_firmware_info;
102	op.u.firmware_info.type = XEN_FW_EFI_INFO;
103	op.u.firmware_info.index = XEN_FW_EFI_VERSION;
104
105	if (HYPERVISOR_platform_op(&op) == 0)
106		efi_systab_xen.hdr.revision = info->version;
107
108	op.cmd = XENPF_firmware_info;
109	op.u.firmware_info.type = XEN_FW_EFI_INFO;
110	op.u.firmware_info.index = XEN_FW_EFI_RT_VERSION;
111
112	if (HYPERVISOR_platform_op(&op) == 0)
113		efi.runtime_version = info->version;
114
115	return &efi_systab_xen;
116}
117
118void __init xen_efi_init(void)
119{
120	efi_system_table_t *efi_systab_xen;
121
122	efi_systab_xen = xen_efi_probe();
123
124	if (efi_systab_xen == NULL)
125		return;
126
127	strncpy((char *)&boot_params.efi_info.efi_loader_signature, "Xen",
128			sizeof(boot_params.efi_info.efi_loader_signature));
129	boot_params.efi_info.efi_systab = (__u32)__pa(efi_systab_xen);
130	boot_params.efi_info.efi_systab_hi = (__u32)(__pa(efi_systab_xen) >> 32);
131
132	set_bit(EFI_BOOT, &efi.flags);
133	set_bit(EFI_PARAVIRT, &efi.flags);
134	set_bit(EFI_64BIT, &efi.flags);
135}