| /****************************************************************************** |
| * 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 <linux/uaccess.h> |
| #include <xen/interface/xen.h> |
| |
| |
| #define XEN_IMM 0xEA1 |
| |
| #define HYPERCALL_SIMPLE(hypercall) \ |
| ENTRY(HYPERVISOR_##hypercall) \ |
| mov x16, #__HYPERVISOR_##hypercall; \ |
| hvc XEN_IMM; \ |
| ret; \ |
| 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_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); |
| |
| ENTRY(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 |
| hvc XEN_IMM |
| |
| /* |
| * Disable userspace access from kernel once the hyp call completed. |
| */ |
| uaccess_ttbr0_disable x6 |
| ret |
| ENDPROC(privcmd_call); |