xref: /openbsd-src/sys/arch/amd64/include/cpu_full.h (revision d9ff679e897778e4bbfb04d7040d7d7d06b28db0)
1 /*	$OpenBSD: cpu_full.h,v 1.5 2019/05/17 19:07:47 guenther Exp $	*/
2 /*
3  * Copyright (c) 2018 Philip Guenther <guenther@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #ifndef _MACHINE_CPU_FULL_H_
19 #define _MACHINE_CPU_FULL_H_
20 
21 #include <sys/param.h>			/* offsetof, PAGE_SIZE */
22 #include <machine/segments.h>
23 #include <machine/tss.h>
24 
25 /*
26  * The layout of the full per-CPU information, including TSS, GDT,
27  * trampoline stacks, and cpu_info described in <machine/cpu.h>
28  */
29 struct cpu_info_full {
30 	/* page mapped kRO in u-k */
31 	union {
32 		struct {
33 			struct x86_64_tss	uu_tss;
34 			uint64_t		uu_gdt[GDT_SIZE / 8];
35 		} u_tssgdt;
36 		char			u_align[PAGE_SIZE];
37 	} cif_RO;
38 #define cif_tss	cif_RO.u_tssgdt.uu_tss
39 #define cif_gdt	cif_RO.u_tssgdt.uu_gdt
40 
41 	/* start of page mapped kRW in u-k */
42 	uint64_t cif_tramp_stack[(PAGE_SIZE / 4
43 		- offsetof(struct cpu_info, ci_PAGEALIGN)) / sizeof(uint64_t)];
44 	uint64_t cif_dblflt_stack[(PAGE_SIZE / 4) / sizeof(uint64_t)];
45 	uint64_t cif_nmi_stack[(2 * PAGE_SIZE / 4) / sizeof(uint64_t)];
46 
47 	/*
48 	 * Beginning of this hangs over into the kRW page; rest is
49 	 * unmapped in u-k
50 	 */
51 	struct cpu_info cif_cpu;
52 } __aligned(PAGE_SIZE);
53 
54 /* tss, align shim, and gdt must fit in a page */
55 CTASSERT(_ALIGN(sizeof(struct x86_64_tss)) +
56 	 sizeof(struct mem_segment_descriptor) * (NGDT_MEM + 2*NGDT_SYS)
57 	 < PAGE_SIZE);
58 
59 /* verify expected alignment */
60 CTASSERT(offsetof(struct cpu_info_full, cif_cpu.ci_PAGEALIGN) % PAGE_SIZE == 0);
61 
62 /* verify total size is multiple of page size */
63 CTASSERT(sizeof(struct cpu_info_full) % PAGE_SIZE == 0);
64 
65 extern struct cpu_info_full cpu_info_full_primary;
66 
67 /* Now make sure the cpu_info_primary macro is correct */
68 CTASSERT(&cpu_info_primary - &cpu_info_full_primary.cif_cpu == 0);
69 
70 #endif /* _MACHINE_CPU_FULL_H_ */
71