arch/x86/xen/xen-head.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /* Xen-specific pieces of head.S, intended to be included in the right
   3         place in head.S */
   4
   5 #ifdef CONFIG_XEN
   6
   7 #include <linux/elfnote.h>
   8 #include <linux/init.h>
   9
  10 #include <asm/boot.h>
  11 #include <asm/asm.h>
  12 #include <asm/msr.h>
  13 #include <asm/page_types.h>
  14 #include <asm/percpu.h>
  15 #include <asm/unwind_hints.h>
  16
  17 #include <xen/interface/elfnote.h>
  18 #include <xen/interface/features.h>
  19 #include <xen/interface/xen.h>
  20 #include <xen/interface/xen-mca.h>
  21 #include <asm/xen/interface.h>
  22
  23 .pushsection .noinstr.text, "ax"
  24         .balign PAGE_SIZE
  25 SYM_CODE_START(hypercall_page)
  26         .rept (PAGE_SIZE / 32)
  27                 UNWIND_HINT_FUNC
  28                 ANNOTATE_NOENDBR
  29                 ANNOTATE_UNRET_SAFE
  30                 ret
  31                 /*
  32                  * Xen will write the hypercall page, and sort out ENDBR.
  33                  */
  34                 .skip 31, 0xcc
  35         .endr
  36
  37 #define HYPERCALL(n) \
  38         .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
  39         .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
  40 #include <asm/xen-hypercalls.h>
  41 #undef HYPERCALL
  42 SYM_CODE_END(hypercall_page)
  43 .popsection
  44
  45 #ifdef CONFIG_XEN_PV
  46         __INIT
  47 SYM_CODE_START(startup_xen)
  48         UNWIND_HINT_EMPTY
  49         ANNOTATE_NOENDBR
  50         cld
  51
  52         mov initial_stack(%rip), %rsp
  53
  54         /* Set up %gs.
  55          *
  56          * The base of %gs always points to fixed_percpu_data.  If the
  57          * stack protector canary is enabled, it is located at %gs:40.
  58          * Note that, on SMP, the boot cpu uses init data section until
  59          * the per cpu areas are set up.
  60          */
  61         movl    $MSR_GS_BASE,%ecx
  62         movq    $INIT_PER_CPU_VAR(fixed_percpu_data),%rax
  63         cdq
  64         wrmsr
  65
  66         mov     %rsi, %rdi
  67         call xen_start_kernel
  68 SYM_CODE_END(startup_xen)
  69         __FINIT
  70
  71 #ifdef CONFIG_XEN_PV_SMP
  72 .pushsection .text
  73 SYM_CODE_START(asm_cpu_bringup_and_idle)
  74         UNWIND_HINT_EMPTY
  75         ENDBR
  76
  77         call cpu_bringup_and_idle
  78 SYM_CODE_END(asm_cpu_bringup_and_idle)
  79 .popsection
  80 #endif
  81 #endif
  82
  83         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
  84         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
  85         ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
  86 #ifdef CONFIG_X86_32
  87         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
  88 #else
  89         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
  90         /* Map the p2m table to a 512GB-aligned user address. */
  91         ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))
  92 #endif
  93 #ifdef CONFIG_XEN_PV
  94         ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
  95 #endif
  96         ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
  97         ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,
  98                 .ascii "!writable_page_tables|pae_pgdir_above_4gb")
  99         ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
 100                 .long (1 << XENFEAT_writable_page_tables) |       \
 101                       (1 << XENFEAT_dom0) |                       \
 102                       (1 << XENFEAT_linux_rsdp_unrestricted))
 103         ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
 104         ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
 105         ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
 106                 .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
 107         ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
 108         ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
 109         ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
 110         ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
 111
 112 #endif /*CONFIG_XEN */