1/****************************************************************************** 2 * hypercall.S 3 * 4 * Xen hypercall wrappers 5 * 6 * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2012 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License version 2 10 * as published by the Free Software Foundation; or, when distributed 11 * separately from the Linux kernel or incorporated into other 12 * software packages, subject to the following license: 13 * 14 * Permission is hereby granted, free of charge, to any person obtaining a copy 15 * of this source file (the "Software"), to deal in the Software without 16 * restriction, including without limitation the rights to use, copy, modify, 17 * merge, publish, distribute, sublicense, and/or sell copies of the Software, 18 * and to permit persons to whom the Software is furnished to do so, subject to 19 * the following conditions: 20 * 21 * The above copyright notice and this permission notice shall be included in 22 * all copies or substantial portions of the Software. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 27 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 28 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 29 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 30 * IN THE SOFTWARE. 31 */ 32 33/* 34 * The Xen hypercall calling convention is very similar to the ARM 35 * procedure calling convention: the first paramter is passed in r0, the 36 * second in r1, the third in r2 and the fourth in r3. Considering that 37 * Xen hypercalls have 5 arguments at most, the fifth paramter is passed 38 * in r4, differently from the procedure calling convention of using the 39 * stack for that case. 40 * 41 * The hypercall number is passed in r12. 42 * 43 * The return value is in r0. 44 * 45 * The hvc ISS is required to be 0xEA1, that is the Xen specific ARM 46 * hypercall tag. 47 */ 48 49#include <linux/linkage.h> 50#include <asm/assembler.h> 51#include <xen/interface/xen.h> 52 53 54/* HVC 0xEA1 */ 55#ifdef CONFIG_THUMB2_KERNEL 56#define xen_hvc .word 0xf7e08ea1 57#else 58#define xen_hvc .word 0xe140ea71 59#endif 60 61#define HYPERCALL_SIMPLE(hypercall) \ 62ENTRY(HYPERVISOR_##hypercall) \ 63 mov r12, #__HYPERVISOR_##hypercall; \ 64 xen_hvc; \ 65 mov pc, lr; \ 66ENDPROC(HYPERVISOR_##hypercall) 67 68#define HYPERCALL0 HYPERCALL_SIMPLE 69#define HYPERCALL1 HYPERCALL_SIMPLE 70#define HYPERCALL2 HYPERCALL_SIMPLE 71#define HYPERCALL3 HYPERCALL_SIMPLE 72#define HYPERCALL4 HYPERCALL_SIMPLE 73 74#define HYPERCALL5(hypercall) \ 75ENTRY(HYPERVISOR_##hypercall) \ 76 stmdb sp!, {r4} \ 77 ldr r4, [sp, #4] \ 78 mov r12, #__HYPERVISOR_##hypercall; \ 79 xen_hvc \ 80 ldm sp!, {r4} \ 81 mov pc, lr \ 82ENDPROC(HYPERVISOR_##hypercall) 83 84 .text 85 86HYPERCALL2(xen_version); 87HYPERCALL3(console_io); 88HYPERCALL3(grant_table_op); 89HYPERCALL2(sched_op); 90HYPERCALL2(event_channel_op); 91HYPERCALL2(hvm_op); 92HYPERCALL2(memory_op); 93HYPERCALL2(physdev_op); 94 95ENTRY(privcmd_call) 96 stmdb sp!, {r4} 97 mov r12, r0 98 mov r0, r1 99 mov r1, r2 100 mov r2, r3 101 ldr r3, [sp, #8] 102 ldr r4, [sp, #4] 103 xen_hvc 104 ldm sp!, {r4} 105 mov pc, lr 106ENDPROC(privcmd_call); 107