| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 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 */ |