/* SPDX-License-Identifier: GPL-2.0 */
/* Xen-specific pieces of head.S, intended to be included in the right
        place in head.S */

#ifdef CONFIG_XEN

#include <linux/elfnote.h>
#include <linux/init.h>
#include <linux/instrumentation.h>

#include <asm/boot.h>
#include <asm/asm.h>
#include <asm/frame.h>
#include <asm/msr.h>
#include <asm/page_types.h>
#include <asm/percpu.h>
#include <asm/unwind_hints.h>

#include <xen/interface/elfnote.h>
#include <xen/interface/features.h>
#include <xen/interface/xen.h>
#include <xen/interface/xen-mca.h>
#include <asm/xen/interface.h>

#ifdef CONFIG_XEN_PV
        __INIT
SYM_CODE_START(startup_xen)
        UNWIND_HINT_END_OF_STACK
        ANNOTATE_NOENDBR
        cld

        leaq    __top_init_kernel_stack(%rip), %rsp

        /*
         * Set up GSBASE.
         * Note that, on SMP, the boot cpu uses init data section until
         * the per cpu areas are set up.
         */
        movl    $MSR_GS_BASE,%ecx
        xorl    %eax, %eax
        xorl    %edx, %edx
        wrmsr

        mov     %rsi, %rdi
        call xen_start_kernel
SYM_CODE_END(startup_xen)
        __FINIT

#ifdef CONFIG_XEN_PV_SMP
.pushsection .text
SYM_CODE_START(asm_cpu_bringup_and_idle)
        UNWIND_HINT_END_OF_STACK
        ENDBR

        call cpu_bringup_and_idle
SYM_CODE_END(asm_cpu_bringup_and_idle)

SYM_CODE_START(xen_cpu_bringup_again)
        UNWIND_HINT_FUNC
        mov     %rdi, %rsp
        UNWIND_HINT_REGS
        call    cpu_bringup_and_idle
SYM_CODE_END(xen_cpu_bringup_again)
.popsection
#endif
#endif

        .pushsection .noinstr.text, "ax"
/*
 * Xen hypercall interface to the hypervisor.
 *
 * Input:
 *     %eax: hypercall number
 *   32-bit:
 *     %ebx, %ecx, %edx, %esi, %edi: args 1..5 for the hypercall
 *   64-bit:
 *     %rdi, %rsi, %rdx, %r10, %r8: args 1..5 for the hypercall
 * Output: %[er]ax
 */
SYM_FUNC_START(xen_hypercall_hvm)
        ENDBR
        FRAME_BEGIN
        /* Save all relevant registers (caller save and arguments). */
#ifdef CONFIG_X86_32
        push %eax
        push %ebx
        push %ecx
        push %edx
        push %esi
        push %edi
#else
        push %rax
        push %rcx
        push %rdx
        push %rdi
        push %rsi
        push %r11
        push %r10
        push %r9
        push %r8
#endif
        /* Set the vendor specific function. */
        call __xen_hypercall_setfunc
        /* Set ZF = 1 if AMD, Restore saved registers. */
#ifdef CONFIG_X86_32
        lea xen_hypercall_amd, %ebx
        cmp %eax, %ebx
        pop %edi
        pop %esi
        pop %edx
        pop %ecx
        pop %ebx
        pop %eax
#else
        lea xen_hypercall_amd(%rip), %rcx
        cmp %rax, %rcx
        pop %r8
        pop %r9
        pop %r10
        pop %r11
        pop %rsi
        pop %rdi
        pop %rdx
        pop %rcx
        pop %rax
#endif
        FRAME_END
        /* Use correct hypercall function. */
        jz xen_hypercall_amd
        jmp xen_hypercall_intel
SYM_FUNC_END(xen_hypercall_hvm)

SYM_FUNC_START(xen_hypercall_amd)
        ANNOTATE_NOENDBR
        vmmcall
        RET
SYM_FUNC_END(xen_hypercall_amd)

SYM_FUNC_START(xen_hypercall_intel)
        ANNOTATE_NOENDBR
        vmcall
        RET
SYM_FUNC_END(xen_hypercall_intel)
        .popsection

        ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
        ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
        ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
#ifdef CONFIG_XEN_PV
        ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
        /* Map the p2m table to a 512GB-aligned user address. */
        ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))
        ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          .globl xen_elfnote_entry;
                xen_elfnote_entry: _ASM_PTR xen_elfnote_entry_value - .)
        ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,       .ascii "!writable_page_tables")
        ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
        ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
                .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
        ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
        ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
# define FEATURES_PV (1 << XENFEAT_writable_page_tables)
#else
# define FEATURES_PV 0
#endif
#ifdef CONFIG_XEN_PVH
# define FEATURES_PVH (1 << XENFEAT_linux_rsdp_unrestricted)
#else
# define FEATURES_PVH 0
#endif
#ifdef CONFIG_XEN_DOM0
# define FEATURES_DOM0 (1 << XENFEAT_dom0)
#else
# define FEATURES_DOM0 0
#endif
        ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
                .long FEATURES_PV | FEATURES_PVH | FEATURES_DOM0)
        ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
        ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)

#endif /*CONFIG_XEN */