| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 - ARM Ltd |
| 3 | * Author: Marc Zyngier <marc.zyngier@arm.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | */ |
| 17 | |
| 18 | #include <linux/linkage.h> |
| 19 | #include <asm/asm-offsets.h> |
| 20 | #include <asm/kvm_arm.h> |
| 21 | #include <asm/kvm_asm.h> |
| 22 | |
| 23 | .arch_extension virt |
| 24 | |
| 25 | .text |
| 26 | .pushsection .hyp.text, "ax" |
| 27 | |
| 28 | #define USR_REGS_OFFSET (CPU_CTXT_GP_REGS + GP_REGS_USR) |
| 29 | |
| 30 | /* int __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host) */ |
| 31 | ENTRY(__guest_enter) |
| 32 | @ Save host registers |
| 33 | add r1, r1, #(USR_REGS_OFFSET + S_R4) |
| 34 | stm r1!, {r4-r12} |
| 35 | str lr, [r1, #4] @ Skip SP_usr (already saved) |
| 36 | |
| 37 | @ Restore guest registers |
| 38 | add r0, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R0) |
| 39 | ldr lr, [r0, #S_LR] |
| 40 | ldm r0, {r0-r12} |
| 41 | |
| 42 | clrex |
| 43 | eret |
| 44 | ENDPROC(__guest_enter) |
| 45 | |
| 46 | ENTRY(__guest_exit) |
| 47 | /* |
| 48 | * return convention: |
| 49 | * guest r0, r1, r2 saved on the stack |
| 50 | * r0: vcpu pointer |
| 51 | * r1: exception code |
| 52 | */ |
| 53 | |
| 54 | add r2, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R3) |
| 55 | stm r2!, {r3-r12} |
| 56 | str lr, [r2, #4] |
| 57 | add r2, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R0) |
| 58 | pop {r3, r4, r5} @ r0, r1, r2 |
| 59 | stm r2, {r3-r5} |
| 60 | |
| 61 | ldr r0, [r0, #VCPU_HOST_CTXT] |
| 62 | add r0, r0, #(USR_REGS_OFFSET + S_R4) |
| 63 | ldm r0!, {r4-r12} |
| 64 | ldr lr, [r0, #4] |
| 65 | |
| 66 | mov r0, r1 |
| 67 | mrs r1, SPSR |
| 68 | mrs r2, ELR_hyp |
| 69 | mrc p15, 4, r3, c5, c2, 0 @ HSR |
| 70 | |
| 71 | /* |
| 72 | * Force loads and stores to complete before unmasking aborts |
| 73 | * and forcing the delivery of the exception. This gives us a |
| 74 | * single instruction window, which the handler will try to |
| 75 | * match. |
| 76 | */ |
| 77 | dsb sy |
| 78 | cpsie a |
| 79 | |
| 80 | .global abort_guest_exit_start |
| 81 | abort_guest_exit_start: |
| 82 | |
| 83 | isb |
| 84 | |
| 85 | .global abort_guest_exit_end |
| 86 | abort_guest_exit_end: |
| 87 | |
| 88 | /* |
| 89 | * If we took an abort, r0[31] will be set, and cmp will set |
| 90 | * the N bit in PSTATE. |
| 91 | */ |
| 92 | cmp r0, #0 |
| 93 | msrmi SPSR_cxsf, r1 |
| 94 | msrmi ELR_hyp, r2 |
| 95 | mcrmi p15, 4, r3, c5, c2, 0 @ HSR |
| 96 | |
| 97 | bx lr |
| 98 | ENDPROC(__guest_exit) |
| 99 | |
| 100 | /* |
| 101 | * If VFPv3 support is not available, then we will not switch the VFP |
| 102 | * registers; however cp10 and cp11 accesses will still trap and fallback |
| 103 | * to the regular coprocessor emulation code, which currently will |
| 104 | * inject an undefined exception to the guest. |
| 105 | */ |
| 106 | #ifdef CONFIG_VFPv3 |
| 107 | ENTRY(__vfp_guest_restore) |
| 108 | push {r3, r4, lr} |
| 109 | |
| 110 | @ NEON/VFP used. Turn on VFP access. |
| 111 | mrc p15, 4, r1, c1, c1, 2 @ HCPTR |
| 112 | bic r1, r1, #(HCPTR_TCP(10) | HCPTR_TCP(11)) |
| 113 | mcr p15, 4, r1, c1, c1, 2 @ HCPTR |
| 114 | isb |
| 115 | |
| 116 | @ Switch VFP/NEON hardware state to the guest's |
| 117 | mov r4, r0 |
| 118 | ldr r0, [r0, #VCPU_HOST_CTXT] |
| 119 | add r0, r0, #CPU_CTXT_VFP |
| 120 | bl __vfp_save_state |
| 121 | add r0, r4, #(VCPU_GUEST_CTXT + CPU_CTXT_VFP) |
| 122 | bl __vfp_restore_state |
| 123 | |
| 124 | pop {r3, r4, lr} |
| 125 | pop {r0, r1, r2} |
| 126 | clrex |
| 127 | eret |
| 128 | ENDPROC(__vfp_guest_restore) |
| 129 | #endif |
| 130 | |
| 131 | .popsection |
| 132 | |