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/******************************************************************************
* hypercall.S
*
* Xen hypercall wrappers
*
* Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/*
* The Xen hypercall calling convention is very similar to the procedure
* call standard for the ARM 64-bit architecture: the first parameter is
* passed in x0, the second in x1, the third in x2, the fourth in x3 and
* the fifth in x4.
*
* The hypercall number is passed in x16.
*
* The return value is in x0.
*
* The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
* hypercall tag.
*
* Parameter structs passed to hypercalls are laid out according to
* the ARM 64-bit EABI standard.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-uaccess.h>
#include <xen/interface/xen.h>
#define XEN_IMM 0xEA1
#define HYPERCALL_SIMPLE(hypercall) \
SYM_FUNC_START(HYPERVISOR_##hypercall) \
mov x16, #__HYPERVISOR_##hypercall; \
hvc XEN_IMM; \
ret; \
SYM_FUNC_END(HYPERVISOR_##hypercall)
#define HYPERCALL0 HYPERCALL_SIMPLE
#define HYPERCALL1 HYPERCALL_SIMPLE
#define HYPERCALL2 HYPERCALL_SIMPLE
#define HYPERCALL3 HYPERCALL_SIMPLE
#define HYPERCALL4 HYPERCALL_SIMPLE
#define HYPERCALL5 HYPERCALL_SIMPLE
.text
HYPERCALL2(xen_version);
HYPERCALL3(console_io);
HYPERCALL3(grant_table_op);
HYPERCALL2(sched_op);
HYPERCALL2(event_channel_op);
HYPERCALL2(hvm_op);
HYPERCALL2(memory_op);
HYPERCALL2(physdev_op);
HYPERCALL3(vcpu_op);
HYPERCALL1(tmem_op);
HYPERCALL1(platform_op_raw);
HYPERCALL2(multicall);
HYPERCALL2(vm_assist);
HYPERCALL3(dm_op);
SYM_FUNC_START(privcmd_call)
mov x16, x0
mov x0, x1
mov x1, x2
mov x2, x3
mov x3, x4
mov x4, x5
/*
* Privcmd calls are issued by the userspace. The kernel needs to
* enable access to TTBR0_EL1 as the hypervisor would issue stage 1
* translations to user memory via AT instructions. Since AT
* instructions are not affected by the PAN bit (ARMv8.1), we only
* need the explicit uaccess_enable/disable if the TTBR0 PAN emulation
* is enabled (it implies that hardware UAO and PAN disabled).
*/
uaccess_ttbr0_enable x6, x7, x8
hvc XEN_IMM
/*
* Disable userspace access from kernel once the hyp call completed.
*/
uaccess_ttbr0_disable x6, x7
ret
SYM_FUNC_END(privcmd_call);
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