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 * Copyright 2008 Freescale Semiconductor Inc.
11 *   Port to powerpc added by Kumar Gala
12 */
13
14#ifndef _ASM_FIXMAP_H
15#define _ASM_FIXMAP_H
16
17#ifndef __ASSEMBLY__
18#include <linux/sizes.h>
19#include <linux/pgtable.h>
20#include <asm/page.h>
21#ifdef CONFIG_HIGHMEM
22#include <linux/threads.h>
23#include <asm/kmap_size.h>
24#endif
25
26#ifdef CONFIG_PPC64
27#define FIXADDR_TOP	(IOREMAP_END + FIXADDR_SIZE)
28#else
29#define FIXADDR_SIZE	0
30#ifdef CONFIG_KASAN
31#include <asm/kasan.h>
32#define FIXADDR_TOP	(KASAN_SHADOW_START - PAGE_SIZE)
33#else
34#define FIXADDR_TOP	((unsigned long)(-PAGE_SIZE))
35#endif
36#endif
37
38/*
39 * Here we define all the compile-time 'special' virtual
40 * addresses. The point is to have a constant address at
41 * compile time, but to set the physical address only
42 * in the boot process. We allocate these special addresses
43 * from the end of virtual memory (0xfffff000) backwards.
44 * Also this lets us do fail-safe vmalloc(), we
45 * can guarantee that these special addresses and
46 * vmalloc()-ed addresses never overlap.
47 *
48 * these 'compile-time allocated' memory buffers are
49 * fixed-size 4k pages. (or larger if used with an increment
50 * highger than 1) use fixmap_set(idx,phys) to associate
51 * physical memory with fixmap indices.
52 *
53 * TLB entries of such buffers will not be flushed across
54 * task switches.
55 */
56enum fixed_addresses {
57	FIX_HOLE,
58#ifdef CONFIG_PPC32
59	/* reserve the top 128K for early debugging purposes */
60	FIX_EARLY_DEBUG_TOP = FIX_HOLE,
61	FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K, PAGE_SIZE)/PAGE_SIZE)-1,
62#ifdef CONFIG_HIGHMEM
63	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */
64	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
65#endif
66#ifdef CONFIG_PPC_8xx
67	/* For IMMR we need an aligned 512K area */
68#define FIX_IMMR_SIZE	(512 * 1024 / PAGE_SIZE)
69	FIX_IMMR_START,
70	FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
71		       FIX_IMMR_SIZE,
72#endif
73#ifdef CONFIG_PPC_83xx
74	/* For IMMR we need an aligned 2M area */
75#define FIX_IMMR_SIZE	(SZ_2M / PAGE_SIZE)
76	FIX_IMMR_START,
77	FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
78		       FIX_IMMR_SIZE,
79#endif
80	/* FIX_PCIE_MCFG, */
81#endif /* CONFIG_PPC32 */
82	__end_of_permanent_fixed_addresses,
83
84#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
85#define FIX_BTMAPS_SLOTS	16
86#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
87
88	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
89	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
90	__end_of_fixed_addresses
91};
92
93#define __FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
94#define FIXADDR_START		(FIXADDR_TOP - __FIXADDR_SIZE)
95
96#define FIXMAP_ALIGNED_SIZE	(ALIGN(FIXADDR_TOP, PGDIR_SIZE) - \
97				 ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE))
98#define FIXMAP_PTE_SIZE	(FIXMAP_ALIGNED_SIZE / PGDIR_SIZE * PTE_TABLE_SIZE)
99
100#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
101#define FIXMAP_PAGE_IO	PAGE_KERNEL_NCG
102
103#include <asm-generic/fixmap.h>
104
105static inline void __set_fixmap(enum fixed_addresses idx,
106				phys_addr_t phys, pgprot_t flags)
107{
108	BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC64) && __FIXADDR_SIZE > FIXADDR_SIZE);
109
110	if (__builtin_constant_p(idx))
111		BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
112	else if (WARN_ON(idx >= __end_of_fixed_addresses))
113		return;
114	if (pgprot_val(flags))
115		map_kernel_page(__fix_to_virt(idx), phys, flags);
116	else
117		unmap_kernel_page(__fix_to_virt(idx));
118}
119
120#define __early_set_fixmap	__set_fixmap
121
122#endif /* !__ASSEMBLY__ */
123#endif
124