/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 */

#ifndef __ARM_KVM_ASM_H__
#define __ARM_KVM_ASM_H__

#include <asm/hyp_image.h>
#include <asm/insn.h>
#include <asm/virt.h>
#include <asm/sysreg.h>

#define ARM_EXIT_WITH_SERROR_BIT  31
#define ARM_EXCEPTION_CODE(x)   ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
#define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
#define ARM_SERROR_PENDING(x)   !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))

#define ARM_EXCEPTION_IRQ   0
#define ARM_EXCEPTION_EL1_SERROR  1
#define ARM_EXCEPTION_TRAP   2
#define ARM_EXCEPTION_IL   3
/* The hyp-stub will return this for any kvm_call_hyp() call */
#define ARM_EXCEPTION_HYP_GONE   HVC_STUB_ERR

#define kvm_arm_exception_type     \
 {ARM_EXCEPTION_IRQ,  "IRQ"  }, \
 {ARM_EXCEPTION_EL1_SERROR,  "SERROR" }, \
 {ARM_EXCEPTION_TRAP,   "TRAP"  }, \
 {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }

/*
 * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
 * that jumps over this.
 */
#define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE)

#define KVM_HOST_SMCCC_ID(id)      \
 ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,    \
      ARM_SMCCC_SMC_64,    \
      ARM_SMCCC_OWNER_VENDOR_HYP,   \
      (id))

#define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)

#define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init   0

#ifndef __ASSEMBLY__

#include <linux/mm.h>

enum __kvm_host_smccc_func {
 /* Hypercalls available only prior to pKVM finalisation */
 /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
 __KVM_HOST_SMCCC_FUNC___pkvm_init = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
 __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
 __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector,
 __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
 __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
 __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
 __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,

 /* Hypercalls available after pKVM finalisation */
 __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
 __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
 __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
 __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
 __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
 __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
 __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
 __KVM_HOST_SMCCC_FUNC___vgic_v3_save_vmcr_aprs,
 __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
 __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
 __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
 __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
 __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
 __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
 __KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
};

#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
#define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[]

/*
 * Define a pair of symbols sharing the same name but one defined in
 * VHE and the other in nVHE hyp implementations.
 */
#define DECLARE_KVM_HYP_SYM(sym)  \
 DECLARE_KVM_VHE_SYM(sym);  \
 DECLARE_KVM_NVHE_SYM(sym)

#define DECLARE_KVM_VHE_PER_CPU(type, sym) \
 DECLARE_PER_CPU(type, sym)
#define DECLARE_KVM_NVHE_PER_CPU(type, sym) \
 DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))

#define DECLARE_KVM_HYP_PER_CPU(type, sym) \
 DECLARE_KVM_VHE_PER_CPU(type, sym); \
 DECLARE_KVM_NVHE_PER_CPU(type, sym)

/*
 * Compute pointer to a symbol defined in nVHE percpu region.
 * Returns NULL if percpu memory has not been allocated yet.
 */
#define this_cpu_ptr_nvhe_sym(sym) per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
#define per_cpu_ptr_nvhe_sym(sym, cpu)      \
 ({         \
  unsigned long base, off;     \
  base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];  \
  off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -   \
        (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);  \
  base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \
 })

#if defined(__KVM_NVHE_HYPERVISOR__)

#define CHOOSE_NVHE_SYM(sym) sym
#define CHOOSE_HYP_SYM(sym) CHOOSE_NVHE_SYM(sym)

/* The nVHE hypervisor shouldn't even try to access VHE symbols */
extern void *__nvhe_undefined_symbol;
#define CHOOSE_VHE_SYM(sym)  __nvhe_undefined_symbol
#define this_cpu_ptr_hyp_sym(sym) (&__nvhe_undefined_symbol)
#define per_cpu_ptr_hyp_sym(sym, cpu) (&__nvhe_undefined_symbol)

#elif defined(__KVM_VHE_HYPERVISOR__)

#define CHOOSE_VHE_SYM(sym) sym
#define CHOOSE_HYP_SYM(sym) CHOOSE_VHE_SYM(sym)

/* The VHE hypervisor shouldn't even try to access nVHE symbols */
extern void *__vhe_undefined_symbol;
#define CHOOSE_NVHE_SYM(sym)  __vhe_undefined_symbol
#define this_cpu_ptr_hyp_sym(sym) (&__vhe_undefined_symbol)
#define per_cpu_ptr_hyp_sym(sym, cpu) (&__vhe_undefined_symbol)

#else

/*
 * BIG FAT WARNINGS:
 *
 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
 *   to has_vhe(). has_vhe() is implemented as a *final* capability,
 *   while this is used early at boot time, when the capabilities are
 *   not final yet....
 *
 * - Don't let the nVHE hypervisor have access to this, as it will
 *   pick the *wrong* symbol (yes, it runs at EL2...).
 */
#define CHOOSE_HYP_SYM(sym)  (is_kernel_in_hyp_mode() \
        ? CHOOSE_VHE_SYM(sym) \
        : CHOOSE_NVHE_SYM(sym))

#define this_cpu_ptr_hyp_sym(sym) (is_kernel_in_hyp_mode() \
        ? this_cpu_ptr(&sym)  \
        : this_cpu_ptr_nvhe_sym(sym))

#define per_cpu_ptr_hyp_sym(sym, cpu) (is_kernel_in_hyp_mode() \
        ? per_cpu_ptr(&sym, cpu) \
        : per_cpu_ptr_nvhe_sym(sym, cpu))

#define CHOOSE_VHE_SYM(sym) sym
#define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym)

#endif

struct kvm_nvhe_init_params {
 unsigned long mair_el2;
 unsigned long tcr_el2;
 unsigned long tpidr_el2;
 unsigned long stack_hyp_va;
 unsigned long stack_pa;
 phys_addr_t pgd_pa;
 unsigned long hcr_el2;
 unsigned long vttbr;
 unsigned long vtcr;
 unsigned long tmp;
};

/*
 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
 * hyp_panic() in non-protected mode.
 *
 * @stack_base:                 hyp VA of the hyp_stack base.
 * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
 * @fp:                         hyp FP where the backtrace begins.
 * @pc:                         hyp PC where the backtrace begins.
 */
struct kvm_nvhe_stacktrace_info {
 unsigned long stack_base;
 unsigned long overflow_stack_base;
 unsigned long fp;
 unsigned long pc;
};

/* Translate a kernel address @ptr into its equivalent linear mapping */
#define kvm_ksym_ref(ptr)      \
 ({        \
  void *val = (ptr);     \
  if (!is_kernel_in_hyp_mode())    \
   val = lm_alias((ptr));    \
  val;       \
  })
#define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))

struct kvm;
struct kvm_vcpu;
struct kvm_s2_mmu;

DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
#define __kvm_hyp_init  CHOOSE_NVHE_SYM(__kvm_hyp_init)
#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector)

extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
DECLARE_KVM_NVHE_SYM(__per_cpu_start);
DECLARE_KVM_NVHE_SYM(__per_cpu_end);

DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)

extern void __kvm_flush_vm_context(void);
extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
         int level);
extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
      phys_addr_t ipa,
      int level);
extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
     phys_addr_t start, unsigned long pages);
extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);

extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);

extern void __kvm_timer_set_cntvoff(u64 cntvoff);
extern void __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
extern void __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
extern void __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);

extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);

extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);

extern u64 __vgic_v3_get_gic_config(void);
extern void __vgic_v3_init_lrs(void);

#define __KVM_EXTABLE(from, to)      \
 " .pushsection __kvm_ex_table, \"a\"\n"  \
 " .align  3\n"     \
 " .long  (" #from " - .), (" #to " - .)\n" \
 " .popsection\n"


#define __kvm_at(at_op, addr)      \
( {          \
 int __kvm_at_err = 0;      \
 u64 spsr, elr;       \
 asm volatile(       \
 " mrs %1, spsr_el2\n"     \
 " mrs %2, elr_el2\n"     \
 "1: " __msr_s(at_op, "%3") "\n"    \
 " isb\n"       \
 " b 9f\n"      \
 "2: msr spsr_el2, %1\n"     \
 " msr elr_el2, %2\n"     \
 " mov %w0, %4\n"     \
 "9:\n"        \
 __KVM_EXTABLE(1b, 2b)      \
 : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)  \
 : "r" (addr), "i" (-EFAULT));     \
 __kvm_at_err;       \
} )

void __noreturn hyp_panic(void);
asmlinkage void kvm_unexpected_el2_exception(void);
asmlinkage void __noreturn hyp_panic(void);
asmlinkage void __noreturn hyp_panic_bad_stack(void);
asmlinkage void kvm_unexpected_el2_exception(void);
struct kvm_cpu_context;
void handle_trap(struct kvm_cpu_context *host_ctxt);
asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
void __noreturn __pkvm_init_finalise(void);
void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
void kvm_patch_vector_branch(struct alt_instr *alt,
 __le32 *origptr, __le32 *updptr, int nr_inst);
void kvm_get_kimage_voffset(struct alt_instr *alt,
 __le32 *origptr, __le32 *updptr, int nr_inst);
void kvm_compute_final_ctr_el0(struct alt_instr *alt,
 __le32 *origptr, __le32 *updptr, int nr_inst);
void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
 u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);

#else /* __ASSEMBLY__ */

.macro get_host_ctxt reg, tmp
 adr_this_cpu \reg, kvm_host_data, \tmp
 add \reg, \reg, #HOST_DATA_CONTEXT
.endm

.macro get_vcpu_ptr vcpu, ctxt
 get_host_ctxt \ctxt, \vcpu
 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm

.macro get_loaded_vcpu vcpu, ctxt
 adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm

.macro set_loaded_vcpu vcpu, ctxt, tmp
 adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
 str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm

/*
 * KVM extable for unexpected exceptions.
 * Create a struct kvm_exception_table_entry output to a section that can be
 * mapped by EL2. The table is not sorted.
 *
 * The caller must ensure:
 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
 */
.macro _kvm_extable, from, to
 .pushsection __kvm_ex_table, "a"
 .align  3
 .long  (\from - .), (\to - .)
 .popsection
.endm

#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
#define CPU_LR_OFFSET  CPU_XREG_OFFSET(30)
#define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8)

/*
 * We treat x18 as callee-saved as the host may use it as a platform
 * register (e.g. for shadow call stack).
 */
.macro save_callee_saved_regs ctxt
 str x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 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
 // We require \ctxt is not x18-x28
 ldr x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
 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

.macro save_sp_el0 ctxt, tmp
 mrs \tmp, sp_el0
 str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
.endm

.macro restore_sp_el0 ctxt, tmp
 ldr \tmp,   [\ctxt, #CPU_SP_EL0_OFFSET]
 msr sp_el0, \tmp
.endm

#endif

#endif /* __ARM_KVM_ASM_H__ */