include/asm/fixmap.h

0001 /*
0002  * fixmap.h: compile-time virtual memory allocation
0003  *
0004  * This file is subject to the terms and conditions of the GNU General Public
0005  * License.  See the file "COPYING" in the main directory of this archive
0006  * for more details.
0007  *
0008  * Copyright (C) 1998 Ingo Molnar
0009  *
0010  * Copyright 2008 Freescale Semiconductor Inc.
0011  *   Port to powerpc added by Kumar Gala
0012  */
0013
0014 #ifndef _ASM_FIXMAP_H
0015 #define _ASM_FIXMAP_H
0016
0017 #ifndef __ASSEMBLY__
0018 #include <linux/sizes.h>
0019 #include <linux/pgtable.h>
0020 #include <asm/page.h>
0021 #ifdef CONFIG_HIGHMEM
0022 #include <linux/threads.h>
0023 #include <asm/kmap_size.h>
0024 #endif
0025
0026 #ifdef CONFIG_PPC64
0027 #define FIXADDR_TOP (IOREMAP_END + FIXADDR_SIZE)
0028 #else
0029 #define FIXADDR_SIZE    0
0030 #ifdef CONFIG_KASAN
0031 #include <asm/kasan.h>
0032 #define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE)
0033 #else
0034 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE))
0035 #endif
0036 #endif
0037
0038 /*
0039  * Here we define all the compile-time 'special' virtual
0040  * addresses. The point is to have a constant address at
0041  * compile time, but to set the physical address only
0042  * in the boot process. We allocate these special addresses
0043  * from the end of virtual memory (0xfffff000) backwards.
0044  * Also this lets us do fail-safe vmalloc(), we
0045  * can guarantee that these special addresses and
0046  * vmalloc()-ed addresses never overlap.
0047  *
0048  * these 'compile-time allocated' memory buffers are
0049  * fixed-size 4k pages. (or larger if used with an increment
0050  * highger than 1) use fixmap_set(idx,phys) to associate
0051  * physical memory with fixmap indices.
0052  *
0053  * TLB entries of such buffers will not be flushed across
0054  * task switches.
0055  */
0056 enum fixed_addresses {
0057     FIX_HOLE,
0058 #ifdef CONFIG_PPC32
0059     /* reserve the top 128K for early debugging purposes */
0060     FIX_EARLY_DEBUG_TOP = FIX_HOLE,
0061     FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K, PAGE_SIZE)/PAGE_SIZE)-1,
0062 #ifdef CONFIG_HIGHMEM
0063     FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
0064     FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
0065 #endif
0066 #ifdef CONFIG_PPC_8xx
0067     /* For IMMR we need an aligned 512K area */
0068 #define FIX_IMMR_SIZE   (512 * 1024 / PAGE_SIZE)
0069     FIX_IMMR_START,
0070     FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
0071                FIX_IMMR_SIZE,
0072 #endif
0073 #ifdef CONFIG_PPC_83xx
0074     /* For IMMR we need an aligned 2M area */
0075 #define FIX_IMMR_SIZE   (SZ_2M / PAGE_SIZE)
0076     FIX_IMMR_START,
0077     FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
0078                FIX_IMMR_SIZE,
0079 #endif
0080     /* FIX_PCIE_MCFG, */
0081 #endif /* CONFIG_PPC32 */
0082     __end_of_permanent_fixed_addresses,
0083
0084 #define NR_FIX_BTMAPS       (SZ_256K / PAGE_SIZE)
0085 #define FIX_BTMAPS_SLOTS    16
0086 #define TOTAL_FIX_BTMAPS    (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
0087
0088     FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
0089     FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
0090     __end_of_fixed_addresses
0091 };
0092
0093 #define __FIXADDR_SIZE  (__end_of_fixed_addresses << PAGE_SHIFT)
0094 #define FIXADDR_START       (FIXADDR_TOP - __FIXADDR_SIZE)
0095
0096 #define FIXMAP_ALIGNED_SIZE (ALIGN(FIXADDR_TOP, PGDIR_SIZE) - \
0097                  ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE))
0098 #define FIXMAP_PTE_SIZE (FIXMAP_ALIGNED_SIZE / PGDIR_SIZE * PTE_TABLE_SIZE)
0099
0100 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
0101 #define FIXMAP_PAGE_IO  PAGE_KERNEL_NCG
0102
0103 #include <asm-generic/fixmap.h>
0104
0105 static inline void __set_fixmap(enum fixed_addresses idx,
0106                 phys_addr_t phys, pgprot_t flags)
0107 {
0108     BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC64) && __FIXADDR_SIZE > FIXADDR_SIZE);
0109
0110     if (__builtin_constant_p(idx))
0111         BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
0112     else if (WARN_ON(idx >= __end_of_fixed_addresses))
0113         return;
0114     if (pgprot_val(flags))
0115         map_kernel_page(__fix_to_virt(idx), phys, flags);
0116     else
0117         unmap_kernel_page(__fix_to_virt(idx));
0118 }
0119
0120 #define __early_set_fixmap  __set_fixmap
0121
0122 #endif /* !__ASSEMBLY__ */
0123 #endif