| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 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 <asm/opcodes-virt.h> |
| 52 | #include <xen/interface/xen.h> |
| 53 | |
| 54 | |
| 55 | #define XEN_IMM 0xEA1 |
| 56 | |
| 57 | #define HYPERCALL_SIMPLE(hypercall) \ |
| 58 | ENTRY(HYPERVISOR_##hypercall) \ |
| 59 | mov r12, #__HYPERVISOR_##hypercall; \ |
| 60 | __HVC(XEN_IMM); \ |
| 61 | ret lr; \ |
| 62 | ENDPROC(HYPERVISOR_##hypercall) |
| 63 | |
| 64 | #define HYPERCALL0 HYPERCALL_SIMPLE |
| 65 | #define HYPERCALL1 HYPERCALL_SIMPLE |
| 66 | #define HYPERCALL2 HYPERCALL_SIMPLE |
| 67 | #define HYPERCALL3 HYPERCALL_SIMPLE |
| 68 | #define HYPERCALL4 HYPERCALL_SIMPLE |
| 69 | |
| 70 | #define HYPERCALL5(hypercall) \ |
| 71 | ENTRY(HYPERVISOR_##hypercall) \ |
| 72 | stmdb sp!, {r4} \ |
| 73 | ldr r4, [sp, #4] \ |
| 74 | mov r12, #__HYPERVISOR_##hypercall; \ |
| 75 | __HVC(XEN_IMM); \ |
| 76 | ldm sp!, {r4} \ |
| 77 | ret lr \ |
| 78 | ENDPROC(HYPERVISOR_##hypercall) |
| 79 | |
| 80 | .text |
| 81 | |
| 82 | HYPERCALL2(xen_version); |
| 83 | HYPERCALL3(console_io); |
| 84 | HYPERCALL3(grant_table_op); |
| 85 | HYPERCALL2(sched_op); |
| 86 | HYPERCALL2(event_channel_op); |
| 87 | HYPERCALL2(hvm_op); |
| 88 | HYPERCALL2(memory_op); |
| 89 | HYPERCALL2(physdev_op); |
| 90 | HYPERCALL3(vcpu_op); |
| 91 | HYPERCALL1(tmem_op); |
| 92 | HYPERCALL1(platform_op_raw); |
| 93 | HYPERCALL2(multicall); |
| 94 | HYPERCALL2(vm_assist); |
| 95 | HYPERCALL3(dm_op); |
| 96 | |
| 97 | ENTRY(privcmd_call) |
| 98 | stmdb sp!, {r4} |
| 99 | mov r12, r0 |
| 100 | mov r0, r1 |
| 101 | mov r1, r2 |
| 102 | mov r2, r3 |
| 103 | ldr r3, [sp, #8] |
| 104 | /* |
| 105 | * Privcmd calls are issued by the userspace. We need to allow the |
| 106 | * kernel to access the userspace memory before issuing the hypercall. |
| 107 | */ |
| 108 | uaccess_enable r4 |
| 109 | |
| 110 | /* r4 is loaded now as we use it as scratch register before */ |
| 111 | ldr r4, [sp, #4] |
| 112 | __HVC(XEN_IMM) |
| 113 | |
| 114 | /* |
| 115 | * Disable userspace access from kernel. This is fine to do it |
| 116 | * unconditionally as no set_fs(KERNEL_DS)/set_fs(get_ds()) is |
| 117 | * called before. |
| 118 | */ |
| 119 | uaccess_disable r4 |
| 120 | |
| 121 | ldm sp!, {r4} |
| 122 | ret lr |
| 123 | ENDPROC(privcmd_call); |