xref: /openbmc/linux/arch/x86/xen/xen-head.S (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
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
14#include <xen/interface/elfnote.h>
15#include <xen/interface/features.h>
16#include <xen/interface/xen.h>
17#include <xen/interface/xen-mca.h>
18#include <asm/xen/interface.h>
19
20#ifdef CONFIG_XEN_PV
21	__INIT
22ENTRY(startup_xen)
23	cld
24
25	/* Clear .bss */
26	xor %eax,%eax
27	mov $__bss_start, %_ASM_DI
28	mov $__bss_stop, %_ASM_CX
29	sub %_ASM_DI, %_ASM_CX
30	shr $__ASM_SEL(2, 3), %_ASM_CX
31	rep __ASM_SIZE(stos)
32
33	mov %_ASM_SI, xen_start_info
34	mov $init_thread_union+THREAD_SIZE, %_ASM_SP
35
36	jmp xen_start_kernel
37
38	__FINIT
39#endif
40
41.pushsection .text
42	.balign PAGE_SIZE
43ENTRY(hypercall_page)
44	.skip PAGE_SIZE
45
46#define HYPERCALL(n) \
47	.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
48	.type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
49#include <asm/xen-hypercalls.h>
50#undef HYPERCALL
51
52.popsection
53
54	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
55	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
56	ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")
57#ifdef CONFIG_X86_32
58	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __PAGE_OFFSET)
59#else
60	ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE,      _ASM_PTR __START_KERNEL_map)
61	/* Map the p2m table to a 512GB-aligned user address. */
62	ELFNOTE(Xen, XEN_ELFNOTE_INIT_P2M,       .quad (PUD_SIZE * PTRS_PER_PUD))
63#endif
64#ifdef CONFIG_XEN_PV
65	ELFNOTE(Xen, XEN_ELFNOTE_ENTRY,          _ASM_PTR startup_xen)
66#endif
67	ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
68	ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,
69		.ascii "!writable_page_tables|pae_pgdir_above_4gb")
70	ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
71		.long (1 << XENFEAT_writable_page_tables) | (1 << XENFEAT_dom0))
72	ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE,       .asciz "yes")
73	ELFNOTE(Xen, XEN_ELFNOTE_LOADER,         .asciz "generic")
74	ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
75		.quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
76	ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
77	ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN,  .long 1)
78	ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW,   _ASM_PTR __HYPERVISOR_VIRT_START)
79	ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET,   _ASM_PTR 0)
80
81#endif /*CONFIG_XEN */
82