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+/*
+ * Copyright (C) 2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+#include <asm/fpsimdmacros.h>
+#include <asm/kvm.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+#define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x)
+#define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x)
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+.macro save_callee_saved_regs ctxt
+ stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
+ stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
+ stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
+ stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
+ stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
+ stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
+.endm
+
+.macro restore_callee_saved_regs ctxt
+ ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
+ ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
+ ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
+ ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
+ ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
+ ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
+.endm
+
+/*
+ * u64 __guest_enter(struct kvm_vcpu *vcpu,
+ * struct kvm_cpu_context *host_ctxt);
+ */
+ENTRY(__guest_enter)
+ // x0: vcpu
+ // x1: host/guest context
+ // x2-x18: clobbered by macros
+
+ // Store the host regs
+ save_callee_saved_regs x1
+
+ // Preserve vcpu & host_ctxt for use at exit time
+ stp x0, x1, [sp, #-16]!
+
+ add x1, x0, #VCPU_CONTEXT
+
+ // Prepare x0-x1 for later restore by pushing them onto the stack
+ ldp x2, x3, [x1, #CPU_XREG_OFFSET(0)]
+ stp x2, x3, [sp, #-16]!
+
+ // x2-x18
+ ldp x2, x3, [x1, #CPU_XREG_OFFSET(2)]
+ ldp x4, x5, [x1, #CPU_XREG_OFFSET(4)]
+ ldp x6, x7, [x1, #CPU_XREG_OFFSET(6)]
+ ldp x8, x9, [x1, #CPU_XREG_OFFSET(8)]
+ ldp x10, x11, [x1, #CPU_XREG_OFFSET(10)]
+ ldp x12, x13, [x1, #CPU_XREG_OFFSET(12)]
+ ldp x14, x15, [x1, #CPU_XREG_OFFSET(14)]
+ ldp x16, x17, [x1, #CPU_XREG_OFFSET(16)]
+ ldr x18, [x1, #CPU_XREG_OFFSET(18)]
+
+ // x19-x29, lr
+ restore_callee_saved_regs x1
+
+ // Last bits of the 64bit state
+ ldp x0, x1, [sp], #16
+
+ // Do not touch any register after this!
+ eret
+ENDPROC(__guest_enter)
+
+ENTRY(__guest_exit)
+ // x0: vcpu
+ // x1: return code
+ // x2-x3: free
+ // x4-x29,lr: vcpu regs
+ // vcpu x0-x3 on the stack
+
+ add x2, x0, #VCPU_CONTEXT
+
+ stp x4, x5, [x2, #CPU_XREG_OFFSET(4)]
+ stp x6, x7, [x2, #CPU_XREG_OFFSET(6)]
+ stp x8, x9, [x2, #CPU_XREG_OFFSET(8)]
+ stp x10, x11, [x2, #CPU_XREG_OFFSET(10)]
+ stp x12, x13, [x2, #CPU_XREG_OFFSET(12)]
+ stp x14, x15, [x2, #CPU_XREG_OFFSET(14)]
+ stp x16, x17, [x2, #CPU_XREG_OFFSET(16)]
+ str x18, [x2, #CPU_XREG_OFFSET(18)]
+
+ ldp x6, x7, [sp], #16 // x2, x3
+ ldp x4, x5, [sp], #16 // x0, x1
+
+ stp x4, x5, [x2, #CPU_XREG_OFFSET(0)]
+ stp x6, x7, [x2, #CPU_XREG_OFFSET(2)]
+
+ save_callee_saved_regs x2
+
+ // Restore vcpu & host_ctxt from the stack
+ // (preserving return code in x1)
+ ldp x0, x2, [sp], #16
+ // Now restore the host regs
+ restore_callee_saved_regs x2
+
+ mov x0, x1
+ ret
+ENDPROC(__guest_exit)
+
+ENTRY(__fpsimd_guest_restore)
+ stp x4, lr, [sp, #-16]!
+
+ mrs x2, cptr_el2
+ bic x2, x2, #CPTR_EL2_TFP
+ msr cptr_el2, x2
+ isb
+
+ mrs x3, tpidr_el2
+
+ ldr x0, [x3, #VCPU_HOST_CONTEXT]
+ kern_hyp_va x0
+ add x0, x0, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
+ bl __fpsimd_save_state
+
+ add x2, x3, #VCPU_CONTEXT
+ add x0, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
+ bl __fpsimd_restore_state
+
+ // Skip restoring fpexc32 for AArch64 guests
+ mrs x1, hcr_el2
+ tbnz x1, #HCR_RW_SHIFT, 1f
+ ldr x4, [x3, #VCPU_FPEXC32_EL2]
+ msr fpexc32_el2, x4
+1:
+ ldp x4, lr, [sp], #16
+ ldp x2, x3, [sp], #16
+ ldp x0, x1, [sp], #16
+
+ eret
+ENDPROC(__fpsimd_guest_restore)