ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/arm/kvm/hyp/hyp-entry.S b/marvell/linux/arch/arm/kvm/hyp/hyp-entry.S
new file mode 100644
index 0000000..fe3d781
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+++ b/marvell/linux/arch/arm/kvm/hyp/hyp-entry.S
@@ -0,0 +1,295 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/linkage.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+
+ .arch_extension virt
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+.macro load_vcpu reg
+ mrc p15, 4, \reg, c13, c0, 2 @ HTPIDR
+.endm
+
+/********************************************************************
+ * Hypervisor exception vector and handlers
+ *
+ *
+ * The KVM/ARM Hypervisor ABI is defined as follows:
+ *
+ * Entry to Hyp mode from the host kernel will happen _only_ when an HVC
+ * instruction is issued since all traps are disabled when running the host
+ * kernel as per the Hyp-mode initialization at boot time.
+ *
+ * HVC instructions cause a trap to the vector page + offset 0x14 (see hyp_hvc
+ * below) when the HVC instruction is called from SVC mode (i.e. a guest or the
+ * host kernel) and they cause a trap to the vector page + offset 0x8 when HVC
+ * instructions are called from within Hyp-mode.
+ *
+ * Hyp-ABI: Calling HYP-mode functions from host (in SVC mode):
+ * Switching to Hyp mode is done through a simple HVC #0 instruction. The
+ * exception vector code will check that the HVC comes from VMID==0.
+ * - r0 contains a pointer to a HYP function
+ * - r1, r2, and r3 contain arguments to the above function.
+ * - The HYP function will be called with its arguments in r0, r1 and r2.
+ * On HYP function return, we return directly to SVC.
+ *
+ * Note that the above is used to execute code in Hyp-mode from a host-kernel
+ * point of view, and is a different concept from performing a world-switch and
+ * executing guest code SVC mode (with a VMID != 0).
+ */
+
+ .align 5
+__kvm_hyp_vector:
+ .global __kvm_hyp_vector
+
+ @ Hyp-mode exception vector
+ W(b) hyp_reset
+ W(b) hyp_undef
+ W(b) hyp_svc
+ W(b) hyp_pabt
+ W(b) hyp_dabt
+ W(b) hyp_hvc
+ W(b) hyp_irq
+ W(b) hyp_fiq
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ .align 5
+__kvm_hyp_vector_ic_inv:
+ .global __kvm_hyp_vector_ic_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 0 /* ICIALLU */
+ isb
+
+ b decode_vectors
+
+ .align 5
+__kvm_hyp_vector_bp_inv:
+ .global __kvm_hyp_vector_bp_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
+ isb
+
+decode_vectors:
+
+#ifdef CONFIG_THUMB2_KERNEL
+ /*
+ * Yet another silly hack: Use VPIDR as a temp register.
+ * Thumb2 is really a pain, as SP cannot be used with most
+ * of the bitwise instructions. The vect_br macro ensures
+ * things gets cleaned-up.
+ */
+ mcr p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mov r0, sp
+ and r0, r0, #7
+ sub sp, sp, r0
+ push {r1, r2}
+ mov r1, r0
+ mrc p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mrc p15, 0, r2, c0, c0, 0 /* MIDR */
+ mcr p15, 4, r2, c0, c0, 0 /* VPIDR */
+#endif
+
+.macro vect_br val, targ
+ARM( eor sp, sp, #\val )
+ARM( tst sp, #7 )
+ARM( eorne sp, sp, #\val )
+
+THUMB( cmp r1, #\val )
+THUMB( popeq {r1, r2} )
+
+ beq \targ
+.endm
+
+ vect_br 0, hyp_fiq
+ vect_br 1, hyp_irq
+ vect_br 2, hyp_hvc
+ vect_br 3, hyp_dabt
+ vect_br 4, hyp_pabt
+ vect_br 5, hyp_svc
+ vect_br 6, hyp_undef
+ vect_br 7, hyp_reset
+#endif
+
+.macro invalid_vector label, cause
+ .align
+\label: mov r0, #\cause
+ b __hyp_panic
+.endm
+
+ invalid_vector hyp_reset ARM_EXCEPTION_RESET
+ invalid_vector hyp_undef ARM_EXCEPTION_UNDEFINED
+ invalid_vector hyp_svc ARM_EXCEPTION_SOFTWARE
+ invalid_vector hyp_pabt ARM_EXCEPTION_PREF_ABORT
+ invalid_vector hyp_fiq ARM_EXCEPTION_FIQ
+
+ENTRY(__hyp_do_panic)
+ mrs lr, cpsr
+ bic lr, lr, #MODE_MASK
+ orr lr, lr, #SVC_MODE
+THUMB( orr lr, lr, #PSR_T_BIT )
+ msr spsr_cxsf, lr
+ ldr lr, =panic
+ msr ELR_hyp, lr
+ ldr lr, =__kvm_call_hyp
+ clrex
+ eret
+ENDPROC(__hyp_do_panic)
+
+hyp_hvc:
+ /*
+ * Getting here is either because of a trap from a guest,
+ * or from executing HVC from the host kernel, which means
+ * "do something in Hyp mode".
+ */
+ push {r0, r1, r2}
+
+ @ Check syndrome register
+ mrc p15, 4, r1, c5, c2, 0 @ HSR
+ lsr r0, r1, #HSR_EC_SHIFT
+ cmp r0, #HSR_EC_HVC
+ bne guest_trap @ Not HVC instr.
+
+ /*
+ * Let's check if the HVC came from VMID 0 and allow simple
+ * switch to Hyp mode
+ */
+ mrrc p15, 6, r0, r2, c2
+ lsr r2, r2, #16
+ and r2, r2, #0xff
+ cmp r2, #0
+ bne guest_hvc_trap @ Guest called HVC
+
+ /*
+ * Getting here means host called HVC, we shift parameters and branch
+ * to Hyp function.
+ */
+ pop {r0, r1, r2}
+
+ /*
+ * Check if we have a kernel function, which is guaranteed to be
+ * bigger than the maximum hyp stub hypercall
+ */
+ cmp r0, #HVC_STUB_HCALL_NR
+ bhs 1f
+
+ /*
+ * Not a kernel function, treat it as a stub hypercall.
+ * Compute the physical address for __kvm_handle_stub_hvc
+ * (as the code lives in the idmaped page) and branch there.
+ * We hijack ip (r12) as a tmp register.
+ */
+ push {r1}
+ ldr r1, =kimage_voffset
+ ldr r1, [r1]
+ ldr ip, =__kvm_handle_stub_hvc
+ sub ip, ip, r1
+ pop {r1}
+
+ bx ip
+
+1:
+ /*
+ * Pushing r2 here is just a way of keeping the stack aligned to
+ * 8 bytes on any path that can trigger a HYP exception. Here,
+ * we may well be about to jump into the guest, and the guest
+ * exit would otherwise be badly decoded by our fancy
+ * "decode-exception-without-a-branch" code...
+ */
+ push {r2, lr}
+
+ mov lr, r0
+ mov r0, r1
+ mov r1, r2
+ mov r2, r3
+
+THUMB( orr lr, #1)
+ blx lr @ Call the HYP function
+
+ pop {r2, lr}
+ eret
+
+guest_hvc_trap:
+ movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ ldr r0, [sp] @ Guest's r0
+ teq r0, r2
+ bne guest_trap
+ add sp, sp, #12
+ @ Returns:
+ @ r0 = 0
+ @ r1 = HSR value (perfectly predictable)
+ @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+ mov r0, #0
+ eret
+
+guest_trap:
+ load_vcpu r0 @ Load VCPU pointer to r0
+
+#ifdef CONFIG_VFPv3
+ @ Check for a VFP access
+ lsr r1, r1, #HSR_EC_SHIFT
+ cmp r1, #HSR_EC_CP_0_13
+ beq __vfp_guest_restore
+#endif
+
+ mov r1, #ARM_EXCEPTION_HVC
+ b __guest_exit
+
+hyp_irq:
+ push {r0, r1, r2}
+ mov r1, #ARM_EXCEPTION_IRQ
+ load_vcpu r0 @ Load VCPU pointer to r0
+ b __guest_exit
+
+hyp_dabt:
+ push {r0, r1}
+ mrs r0, ELR_hyp
+ ldr r1, =abort_guest_exit_start
+THUMB( add r1, r1, #1)
+ cmp r0, r1
+ ldrne r1, =abort_guest_exit_end
+THUMB( addne r1, r1, #1)
+ cmpne r0, r1
+ pop {r0, r1}
+ bne __hyp_panic
+
+ orr r0, r0, #(1 << ARM_EXIT_WITH_ABORT_BIT)
+ eret
+
+ .ltorg
+
+ .popsection