1/*
2 * fixmap.h: compile-time virtual memory allocation
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License.  See the file "COPYING" in the main directory of this archive
6 * for more details.
7 *
8 * Copyright (C) 1998 Ingo Molnar
9 *
10 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
11 * x86_32 and x86_64 integration by Gustavo F. Padovan, February 2009
12 */
13
14#ifndef _ASM_X86_FIXMAP_H
15#define _ASM_X86_FIXMAP_H
16
17#ifndef __ASSEMBLY__
18#include <linux/kernel.h>
19#include <asm/acpi.h>
20#include <asm/apicdef.h>
21#include <asm/page.h>
22#include <asm/pvclock.h>
23#ifdef CONFIG_X86_32
24#include <linux/threads.h>
25#include <asm/kmap_types.h>
26#else
27#include <uapi/asm/vsyscall.h>
28#endif
29
30/*
31 * We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
32 * uses fixmaps that relies on FIXADDR_TOP for proper address calculation.
33 * Because of this, FIXADDR_TOP x86 integration was left as later work.
34 */
35#ifdef CONFIG_X86_32
36/* used by vmalloc.c, vsyscall.lds.S.
37 *
38 * Leave one empty page between vmalloc'ed areas and
39 * the start of the fixmap.
40 */
41extern unsigned long __FIXADDR_TOP;
42#define FIXADDR_TOP	((unsigned long)__FIXADDR_TOP)
43#else
44#define FIXADDR_TOP	(round_up(VSYSCALL_ADDR + PAGE_SIZE, 1<<PMD_SHIFT) - \
45			 PAGE_SIZE)
46#endif
47
48
49/*
50 * Here we define all the compile-time 'special' virtual
51 * addresses. The point is to have a constant address at
52 * compile time, but to set the physical address only
53 * in the boot process.
54 * for x86_32: We allocate these special addresses
55 * from the end of virtual memory (0xfffff000) backwards.
56 * Also this lets us do fail-safe vmalloc(), we
57 * can guarantee that these special addresses and
58 * vmalloc()-ed addresses never overlap.
59 *
60 * These 'compile-time allocated' memory buffers are
61 * fixed-size 4k pages (or larger if used with an increment
62 * higher than 1). Use set_fixmap(idx,phys) to associate
63 * physical memory with fixmap indices.
64 *
65 * TLB entries of such buffers will not be flushed across
66 * task switches.
67 */
68enum fixed_addresses {
69#ifdef CONFIG_X86_32
70	FIX_HOLE,
71#else
72#ifdef CONFIG_X86_VSYSCALL_EMULATION
73	VSYSCALL_PAGE = (FIXADDR_TOP - VSYSCALL_ADDR) >> PAGE_SHIFT,
74#endif
75#ifdef CONFIG_PARAVIRT_CLOCK
76	PVCLOCK_FIXMAP_BEGIN,
77	PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1,
78#endif
79#endif
80	FIX_DBGP_BASE,
81	FIX_EARLYCON_MEM_BASE,
82#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
83	FIX_OHCI1394_BASE,
84#endif
85#ifdef CONFIG_X86_LOCAL_APIC
86	FIX_APIC_BASE,	/* local (CPU) APIC) -- required for SMP or not */
87#endif
88#ifdef CONFIG_X86_IO_APIC
89	FIX_IO_APIC_BASE_0,
90	FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
91#endif
92	FIX_RO_IDT,	/* Virtual mapping for read-only IDT */
93#ifdef CONFIG_X86_32
94	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
95	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
96#ifdef CONFIG_PCI_MMCONFIG
97	FIX_PCIE_MCFG,
98#endif
99#endif
100#ifdef CONFIG_PARAVIRT
101	FIX_PARAVIRT_BOOTMAP,
102#endif
103	FIX_TEXT_POKE1,	/* reserve 2 pages for text_poke() */
104	FIX_TEXT_POKE0, /* first page is last, because allocation is backward */
105#ifdef	CONFIG_X86_INTEL_MID
106	FIX_LNW_VRTC,
107#endif
108	__end_of_permanent_fixed_addresses,
109
110	/*
111	 * 512 temporary boot-time mappings, used by early_ioremap(),
112	 * before ioremap() is functional.
113	 *
114	 * If necessary we round it up to the next 512 pages boundary so
115	 * that we can have a single pgd entry and a single pte table:
116	 */
117#define NR_FIX_BTMAPS		64
118#define FIX_BTMAPS_SLOTS	8
119#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
120	FIX_BTMAP_END =
121	 (__end_of_permanent_fixed_addresses ^
122	  (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) &
123	 -PTRS_PER_PTE
124	 ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS -
125	   (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1))
126	 : __end_of_permanent_fixed_addresses,
127	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
128#ifdef CONFIG_X86_32
129	FIX_WP_TEST,
130#endif
131#ifdef CONFIG_INTEL_TXT
132	FIX_TBOOT_BASE,
133#endif
134	__end_of_fixed_addresses
135};
136
137
138extern void reserve_top_address(unsigned long reserve);
139
140#define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
141#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
142
143extern int fixmaps_set;
144
145extern pte_t *kmap_pte;
146extern pgprot_t kmap_prot;
147extern pte_t *pkmap_page_table;
148
149void __native_set_fixmap(enum fixed_addresses idx, pte_t pte);
150void native_set_fixmap(enum fixed_addresses idx,
151		       phys_addr_t phys, pgprot_t flags);
152
153#ifndef CONFIG_PARAVIRT
154static inline void __set_fixmap(enum fixed_addresses idx,
155				phys_addr_t phys, pgprot_t flags)
156{
157	native_set_fixmap(idx, phys, flags);
158}
159#endif
160
161#include <asm-generic/fixmap.h>
162
163#define __late_set_fixmap(idx, phys, flags) __set_fixmap(idx, phys, flags)
164#define __late_clear_fixmap(idx) __set_fixmap(idx, 0, __pgprot(0))
165
166void __early_set_fixmap(enum fixed_addresses idx,
167			phys_addr_t phys, pgprot_t flags);
168
169#endif /* !__ASSEMBLY__ */
170#endif /* _ASM_X86_FIXMAP_H */
171