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-rw-r--r--arch/x86/xen/xen-head.S104
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
new file mode 100644
index 000000000..5077ead5e
--- /dev/null
+++ b/arch/x86/xen/xen-head.S
@@ -0,0 +1,104 @@
+/* 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 <asm/boot.h>
+#include <asm/asm.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
+ENTRY(startup_xen)
+ UNWIND_HINT_EMPTY
+ cld
+
+ /* Clear .bss */
+ xor %eax,%eax
+ mov $__bss_start, %_ASM_DI
+ mov $__bss_stop, %_ASM_CX
+ sub %_ASM_DI, %_ASM_CX
+ shr $__ASM_SEL(2, 3), %_ASM_CX
+ rep __ASM_SIZE(stos)
+
+ mov %_ASM_SI, xen_start_info
+ mov $init_thread_union+THREAD_SIZE, %_ASM_SP
+
+#ifdef CONFIG_X86_64
+ /* Set up %gs.
+ *
+ * The base of %gs always points to the bottom of the irqstack
+ * union. If the stack protector canary is enabled, it is
+ * located at %gs:40. Note that, on SMP, the boot cpu uses
+ * init data section till per cpu areas are set up.
+ */
+ movl $MSR_GS_BASE,%ecx
+ movq $INIT_PER_CPU_VAR(irq_stack_union),%rax
+ cdq
+ wrmsr
+#endif
+
+ jmp xen_start_kernel
+END(startup_xen)
+ __FINIT
+#endif
+
+.pushsection .text
+ .balign PAGE_SIZE
+ENTRY(hypercall_page)
+ .rept (PAGE_SIZE / 32)
+ UNWIND_HINT_EMPTY
+ .skip 32
+ .endr
+
+#define HYPERCALL(n) \
+ .equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
+ .type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
+#include <asm/xen-hypercalls.h>
+#undef HYPERCALL
+END(hypercall_page)
+.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_X86_32
+ ELFNOTE(Xen, XEN_ELFNOTE_VIRT_BASE, _ASM_PTR __PAGE_OFFSET)
+#else
+ 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))
+#endif
+#ifdef CONFIG_XEN_PV
+ ELFNOTE(Xen, XEN_ELFNOTE_ENTRY, _ASM_PTR startup_xen)
+#endif
+ ELFNOTE(Xen, XEN_ELFNOTE_HYPERCALL_PAGE, _ASM_PTR hypercall_page)
+ ELFNOTE(Xen, XEN_ELFNOTE_FEATURES,
+ .ascii "!writable_page_tables|pae_pgdir_above_4gb")
+ ELFNOTE(Xen, XEN_ELFNOTE_SUPPORTED_FEATURES,
+ .long (1 << XENFEAT_writable_page_tables) | \
+ (1 << XENFEAT_dom0) | \
+ (1 << XENFEAT_linux_rsdp_unrestricted))
+ ELFNOTE(Xen, XEN_ELFNOTE_PAE_MODE, .asciz "yes")
+ ELFNOTE(Xen, XEN_ELFNOTE_LOADER, .asciz "generic")
+ ELFNOTE(Xen, XEN_ELFNOTE_L1_MFN_VALID,
+ .quad _PAGE_PRESENT; .quad _PAGE_PRESENT)
+ ELFNOTE(Xen, XEN_ELFNOTE_SUSPEND_CANCEL, .long 1)
+ ELFNOTE(Xen, XEN_ELFNOTE_MOD_START_PFN, .long 1)
+ ELFNOTE(Xen, XEN_ELFNOTE_HV_START_LOW, _ASM_PTR __HYPERVISOR_VIRT_START)
+ ELFNOTE(Xen, XEN_ELFNOTE_PADDR_OFFSET, _ASM_PTR 0)
+
+#endif /*CONFIG_XEN */