/******************************************************************************
* hypercall.S
*
* Xen hypercall wrappers
*
* Stefano Stabellini <[email protected]>, 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 ARM
* procedure calling convention: the first paramter is passed in r0, the
* second in r1, the third in r2 and the fourth in r3. Considering that
* Xen hypercalls have 5 arguments at most, the fifth paramter is passed
* in r4, differently from the procedure calling convention of using the
* stack for that case.
*
* The hypercall number is passed in r12.
*
* The return value is in r0.
*
* The hvc ISS is required to be 0xEA1, that is the Xen specific ARM
* hypercall tag.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/opcodes-virt.h>
#include <xen/interface/xen.h>
#define XEN_IMM 0xEA1
#define HYPERCALL_SIMPLE(hypercall) \
ENTRY(HYPERVISOR_##hypercall) \
mov r12, #__HYPERVISOR_##hypercall; \
__HVC(XEN_IMM); \
ret lr; \
ENDPROC(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) \
ENTRY(HYPERVISOR_##hypercall) \
stmdb sp!, {r4} \
ldr r4, [sp, #4] \
mov r12, #__HYPERVISOR_##hypercall; \
__HVC(XEN_IMM); \
ldm sp!, {r4} \
ret lr \
ENDPROC(HYPERVISOR_##hypercall)
.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(platform_op_raw);
HYPERCALL2(multicall);
HYPERCALL2(vm_assist);
HYPERCALL3(dm_op);
ENTRY(privcmd_call)
stmdb sp!, {r4}
mov r12, r0
mov r0, r1
mov r1, r2
mov r2, r3
ldr r3, [sp, #8]
/*
* Privcmd calls are issued by the userspace. We need to allow the
* kernel to access the userspace memory before issuing the hypercall.
*/
uaccess_enable r4
/* r4 is loaded now as we use it as scratch register before */
ldr r4, [sp, #4]
__HVC(XEN_IMM)
/*
* Disable userspace access from kernel. This is fine to do it
* unconditionally as no set_fs(KERNEL_DS) is called before.
*/
uaccess_disable r4
ldm sp!, {r4}
ret lr
ENDPROC(privcmd_call);
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