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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /arch/xtensa/include/asm/fixmap.h | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/xtensa/include/asm/fixmap.h')
-rw-r--r-- | arch/xtensa/include/asm/fixmap.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/fixmap.h b/arch/xtensa/include/asm/fixmap.h new file mode 100644 index 000000000..a06ffb0c6 --- /dev/null +++ b/arch/xtensa/include/asm/fixmap.h @@ -0,0 +1,79 @@ +/* + * fixmap.h: compile-time virtual memory allocation + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +#ifdef CONFIG_HIGHMEM +#include <linux/threads.h> +#include <linux/pgtable.h> +#include <asm/kmap_types.h> +#endif + +/* + * Here we define all the compile-time 'special' virtual + * addresses. The point is to have a constant address at + * compile time, but to set the physical address only + * in the boot process. We allocate these special addresses + * from the start of the consistent memory region upwards. + * Also this lets us do fail-safe vmalloc(), we + * can guarantee that these special addresses and + * vmalloc()-ed addresses never overlap. + * + * these 'compile-time allocated' memory buffers are + * fixed-size 4k pages. (or larger if used with an increment + * higher than 1) use fixmap_set(idx,phys) to associate + * physical memory with fixmap indices. + */ +enum fixed_addresses { +#ifdef CONFIG_HIGHMEM + /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_BEGIN, + FIX_KMAP_END = FIX_KMAP_BEGIN + + (KM_TYPE_NR * NR_CPUS * DCACHE_N_COLORS) - 1, +#endif + __end_of_fixed_addresses +}; + +#define FIXADDR_TOP (XCHAL_KSEG_CACHED_VADDR - PAGE_SIZE) +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) + +#define __fix_to_virt(x) (FIXADDR_START + ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) (((x) - FIXADDR_START) >> PAGE_SHIFT) + +#ifndef __ASSEMBLY__ +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without translation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static __always_inline unsigned long fix_to_virt(const unsigned int idx) +{ + /* Check if this memory layout is broken because fixmap overlaps page + * table. + */ + BUILD_BUG_ON(FIXADDR_START < + TLBTEMP_BASE_1 + TLBTEMP_SIZE); + BUILD_BUG_ON(idx >= __end_of_fixed_addresses); + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#endif + +#endif |