1*4882a593Smuzhiyun/****************************************************************************** 2*4882a593Smuzhiyun * hypercall.S 3*4882a593Smuzhiyun * 4*4882a593Smuzhiyun * Xen hypercall wrappers 5*4882a593Smuzhiyun * 6*4882a593Smuzhiyun * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * This program is free software; you can redistribute it and/or 9*4882a593Smuzhiyun * modify it under the terms of the GNU General Public License version 2 10*4882a593Smuzhiyun * as published by the Free Software Foundation; or, when distributed 11*4882a593Smuzhiyun * separately from the Linux kernel or incorporated into other 12*4882a593Smuzhiyun * software packages, subject to the following license: 13*4882a593Smuzhiyun * 14*4882a593Smuzhiyun * Permission is hereby granted, free of charge, to any person obtaining a copy 15*4882a593Smuzhiyun * of this source file (the "Software"), to deal in the Software without 16*4882a593Smuzhiyun * restriction, including without limitation the rights to use, copy, modify, 17*4882a593Smuzhiyun * merge, publish, distribute, sublicense, and/or sell copies of the Software, 18*4882a593Smuzhiyun * and to permit persons to whom the Software is furnished to do so, subject to 19*4882a593Smuzhiyun * the following conditions: 20*4882a593Smuzhiyun * 21*4882a593Smuzhiyun * The above copyright notice and this permission notice shall be included in 22*4882a593Smuzhiyun * all copies or substantial portions of the Software. 23*4882a593Smuzhiyun * 24*4882a593Smuzhiyun * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25*4882a593Smuzhiyun * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26*4882a593Smuzhiyun * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 27*4882a593Smuzhiyun * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 28*4882a593Smuzhiyun * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 29*4882a593Smuzhiyun * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 30*4882a593Smuzhiyun * IN THE SOFTWARE. 31*4882a593Smuzhiyun */ 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun/* 34*4882a593Smuzhiyun * The Xen hypercall calling convention is very similar to the procedure 35*4882a593Smuzhiyun * call standard for the ARM 64-bit architecture: the first parameter is 36*4882a593Smuzhiyun * passed in x0, the second in x1, the third in x2, the fourth in x3 and 37*4882a593Smuzhiyun * the fifth in x4. 38*4882a593Smuzhiyun * 39*4882a593Smuzhiyun * The hypercall number is passed in x16. 40*4882a593Smuzhiyun * 41*4882a593Smuzhiyun * The return value is in x0. 42*4882a593Smuzhiyun * 43*4882a593Smuzhiyun * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM 44*4882a593Smuzhiyun * hypercall tag. 45*4882a593Smuzhiyun * 46*4882a593Smuzhiyun * Parameter structs passed to hypercalls are laid out according to 47*4882a593Smuzhiyun * the ARM 64-bit EABI standard. 48*4882a593Smuzhiyun */ 49*4882a593Smuzhiyun 50*4882a593Smuzhiyun#include <linux/linkage.h> 51*4882a593Smuzhiyun#include <asm/assembler.h> 52*4882a593Smuzhiyun#include <asm/asm-uaccess.h> 53*4882a593Smuzhiyun#include <xen/interface/xen.h> 54*4882a593Smuzhiyun 55*4882a593Smuzhiyun 56*4882a593Smuzhiyun#define XEN_IMM 0xEA1 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun#define HYPERCALL_SIMPLE(hypercall) \ 59*4882a593SmuzhiyunSYM_FUNC_START(HYPERVISOR_##hypercall) \ 60*4882a593Smuzhiyun mov x16, #__HYPERVISOR_##hypercall; \ 61*4882a593Smuzhiyun hvc XEN_IMM; \ 62*4882a593Smuzhiyun ret; \ 63*4882a593SmuzhiyunSYM_FUNC_END(HYPERVISOR_##hypercall) 64*4882a593Smuzhiyun 65*4882a593Smuzhiyun#define HYPERCALL0 HYPERCALL_SIMPLE 66*4882a593Smuzhiyun#define HYPERCALL1 HYPERCALL_SIMPLE 67*4882a593Smuzhiyun#define HYPERCALL2 HYPERCALL_SIMPLE 68*4882a593Smuzhiyun#define HYPERCALL3 HYPERCALL_SIMPLE 69*4882a593Smuzhiyun#define HYPERCALL4 HYPERCALL_SIMPLE 70*4882a593Smuzhiyun#define HYPERCALL5 HYPERCALL_SIMPLE 71*4882a593Smuzhiyun 72*4882a593Smuzhiyun .text 73*4882a593Smuzhiyun 74*4882a593SmuzhiyunHYPERCALL2(xen_version); 75*4882a593SmuzhiyunHYPERCALL3(console_io); 76*4882a593SmuzhiyunHYPERCALL3(grant_table_op); 77*4882a593SmuzhiyunHYPERCALL2(sched_op); 78*4882a593SmuzhiyunHYPERCALL2(event_channel_op); 79*4882a593SmuzhiyunHYPERCALL2(hvm_op); 80*4882a593SmuzhiyunHYPERCALL2(memory_op); 81*4882a593SmuzhiyunHYPERCALL2(physdev_op); 82*4882a593SmuzhiyunHYPERCALL3(vcpu_op); 83*4882a593SmuzhiyunHYPERCALL1(tmem_op); 84*4882a593SmuzhiyunHYPERCALL1(platform_op_raw); 85*4882a593SmuzhiyunHYPERCALL2(multicall); 86*4882a593SmuzhiyunHYPERCALL2(vm_assist); 87*4882a593SmuzhiyunHYPERCALL3(dm_op); 88*4882a593Smuzhiyun 89*4882a593SmuzhiyunSYM_FUNC_START(privcmd_call) 90*4882a593Smuzhiyun mov x16, x0 91*4882a593Smuzhiyun mov x0, x1 92*4882a593Smuzhiyun mov x1, x2 93*4882a593Smuzhiyun mov x2, x3 94*4882a593Smuzhiyun mov x3, x4 95*4882a593Smuzhiyun mov x4, x5 96*4882a593Smuzhiyun /* 97*4882a593Smuzhiyun * Privcmd calls are issued by the userspace. The kernel needs to 98*4882a593Smuzhiyun * enable access to TTBR0_EL1 as the hypervisor would issue stage 1 99*4882a593Smuzhiyun * translations to user memory via AT instructions. Since AT 100*4882a593Smuzhiyun * instructions are not affected by the PAN bit (ARMv8.1), we only 101*4882a593Smuzhiyun * need the explicit uaccess_enable/disable if the TTBR0 PAN emulation 102*4882a593Smuzhiyun * is enabled (it implies that hardware UAO and PAN disabled). 103*4882a593Smuzhiyun */ 104*4882a593Smuzhiyun uaccess_ttbr0_enable x6, x7, x8 105*4882a593Smuzhiyun hvc XEN_IMM 106*4882a593Smuzhiyun 107*4882a593Smuzhiyun /* 108*4882a593Smuzhiyun * Disable userspace access from kernel once the hyp call completed. 109*4882a593Smuzhiyun */ 110*4882a593Smuzhiyun uaccess_ttbr0_disable x6, x7 111*4882a593Smuzhiyun ret 112*4882a593SmuzhiyunSYM_FUNC_END(privcmd_call); 113