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/page_types.h>
  13 #include <asm/unwind_hints.h>
  14
  15 #include <xen/interface/elfnote.h>
  16 #include <xen/interface/features.h>
  17 #include <xen/interface/xen.h>
  18 #include <xen/interface/xen-mca.h>
  19 #include <asm/xen/interface.h>
  20
  21 #ifdef CONFIG_XEN_PV
  22         __INIT
  23 ENTRY(startup_xen)
  24         UNWIND_HINT_EMPTY
  25         cld
  26
  27         /* Clear .bss */
  28         xor %eax,%eax
  29         mov $__bss_start, %_ASM_DI
  30         mov $__bss_stop, %_ASM_CX
  31         sub %_ASM_DI, %_ASM_CX
  32         shr $__ASM_SEL(2, 3), %_ASM_CX
  33         rep __ASM_SIZE(stos)
  34
  35         mov %_ASM_SI, xen_start_info
  36         mov $init_thread_union+THREAD_SIZE, %_ASM_SP
  37
  38         jmp xen_start_kernel
  39 END(startup_xen)
  40         __FINIT
  41 #endif
  42
  43 .pushsection .text
  44         .balign PAGE_SIZE
  45 ENTRY(hypercall_page)
  46         .rept (PAGE_SIZE / 32)
  47                 UNWIND_HINT_EMPTY
  48                 .skip 32
  49         .endr
  50
  51 #define HYPERCALL(n) \
  52         .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
  53         .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
  54 #include <asm/xen-hypercalls.h>
  55 #undef HYPERCALL
  56 END(hypercall_page)
  57 .popsection
  58
  59         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
  60         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
  61         ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
  62 #ifdef CONFIG_X86_32
  63         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
  64 #else
  65         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
  66         /* Map the p2m table to a 512GB-aligned user address. */
  67         ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))
  68 #endif
  69 #ifdef CONFIG_XEN_PV
  70         ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
  71 #endif
  72         ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
  73         ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,
  74                 .ascii "!writable_page_tables|pae_pgdir_above_4gb")
  75         ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
  76                 .long (1 << XENFEAT_writable_page_tables) | (1 << XENFEAT_dom0))
  77         ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
  78         ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
  79         ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
  80                 .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
  81         ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
  82         ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
  83         ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
  84         ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
  85
  86 #endif /*CONFIG_XEN */