2 * fixmap.h: compile-time virtual memory allocation
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
8 * Copyright (C) 1998 Ingo Molnar
10 * Copyright 2008 Freescale Semiconductor Inc.
11 * Port to powerpc added by Kumar Gala
18 #include <linux/sizes.h>
19 #include <linux/pgtable.h>
22 #include <linux/threads.h>
23 #include <asm/kmap_size.h>
27 #define FIXADDR_TOP (IOREMAP_END + FIXADDR_SIZE)
29 #define FIXADDR_SIZE 0
31 #include <asm/kasan.h>
32 #define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE)
34 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
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.
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.
53 * TLB entries of such buffers will not be flushed across
56 enum fixed_addresses {
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,
63 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
64 FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
67 /* For IMMR we need an aligned 512K area */
68 #define FIX_IMMR_SIZE (512 * 1024 / PAGE_SIZE)
70 FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
73 #ifdef CONFIG_PPC_83xx
74 /* For IMMR we need an aligned 2M area */
75 #define FIX_IMMR_SIZE (SZ_2M / PAGE_SIZE)
77 FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
81 #endif /* CONFIG_PPC32 */
82 __end_of_permanent_fixed_addresses,
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)
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
93 #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
94 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
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)
100 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
101 #define FIXMAP_PAGE_IO PAGE_KERNEL_NCG
103 #include <asm-generic/fixmap.h>
105 static inline void __set_fixmap(enum fixed_addresses idx,
106 phys_addr_t phys, pgprot_t flags)
108 BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC64) && __FIXADDR_SIZE > FIXADDR_SIZE);
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))
115 map_kernel_page(__fix_to_virt(idx), phys, flags);
118 #define __early_set_fixmap __set_fixmap
120 #endif /* !__ASSEMBLY__ */