Merge tag 'for-linus-4.16-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git...
[muen/linux.git] / 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 #ifdef CONFIG_XEN_PV
24         __INIT
25 ENTRY(startup_xen)
26         UNWIND_HINT_EMPTY
27         cld
28
29         /* Clear .bss */
30         xor %eax,%eax
31         mov $__bss_start, %_ASM_DI
32         mov $__bss_stop, %_ASM_CX
33         sub %_ASM_DI, %_ASM_CX
34         shr $__ASM_SEL(2, 3), %_ASM_CX
35         rep __ASM_SIZE(stos)
36
37         mov %_ASM_SI, xen_start_info
38         mov $init_thread_union+THREAD_SIZE, %_ASM_SP
39
40 #ifdef CONFIG_X86_64
41         /* Set up %gs.
42          *
43          * The base of %gs always points to the bottom of the irqstack
44          * union.  If the stack protector canary is enabled, it is
45          * located at %gs:40.  Note that, on SMP, the boot cpu uses
46          * init data section till per cpu areas are set up.
47          */
48         movl    $MSR_GS_BASE,%ecx
49         movq    $INIT_PER_CPU_VAR(irq_stack_union),%rax
50         cdq
51         wrmsr
52 #endif
53
54         jmp xen_start_kernel
55 END(startup_xen)
56         __FINIT
57 #endif
58
59 .pushsection .text
60         .balign PAGE_SIZE
61 ENTRY(hypercall_page)
62         .rept (PAGE_SIZE / 32)
63                 UNWIND_HINT_EMPTY
64                 .skip 32
65         .endr
66
67 #define HYPERCALL(n) \
68         .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
69         .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
70 #include <asm/xen-hypercalls.h>
71 #undef HYPERCALL
72 END(hypercall_page)
73 .popsection
74
75         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
76         ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
77         ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
78 #ifdef CONFIG_X86_32
79         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
80 #else
81         ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
82         /* Map the p2m table to a 512GB-aligned user address. */
83         ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))
84 #endif
85 #ifdef CONFIG_XEN_PV
86         ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
87 #endif
88         ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
89         ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,
90                 .ascii "!writable_page_tables|pae_pgdir_above_4gb")
91         ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
92                 .long (1 << XENFEAT_writable_page_tables) | (1 << XENFEAT_dom0))
93         ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
94         ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
95         ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
96                 .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
97         ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
98         ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
99         ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
100         ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
101
102 #endif /*CONFIG_XEN */