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