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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/sh/include/asm/fixmap.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sh/include/asm/fixmap.h')
-rw-r--r-- | arch/sh/include/asm/fixmap.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/sh/include/asm/fixmap.h b/arch/sh/include/asm/fixmap.h new file mode 100644 index 000000000..b07fbc7f7 --- /dev/null +++ b/arch/sh/include/asm/fixmap.h @@ -0,0 +1,86 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * fixmap.h: compile-time virtual memory allocation + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +#include <linux/kernel.h> +#include <linux/threads.h> +#include <asm/page.h> + +/* + * 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 end of P3 backwards. + * 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 + * highger than 1) use fixmap_set(idx,phys) to associate + * physical memory with fixmap indices. + * + * TLB entries of such buffers will not be flushed across + * task switches. + */ + +/* + * on UP currently we will have no trace of the fixmap mechanizm, + * no page table allocations, etc. This might change in the + * future, say framebuffers for the console driver(s) could be + * fix-mapped? + */ +enum fixed_addresses { + /* + * The FIX_CMAP entries are used by kmap_coherent() to get virtual + * addresses which are of a known color, and so their values are + * important. __fix_to_virt(FIX_CMAP_END - n) must give an address + * which is the same color as a page (n<<PAGE_SHIFT). + */ +#define FIX_N_COLOURS 8 + FIX_CMAP_BEGIN, + FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1, + +#ifdef CONFIG_IOREMAP_FIXED + /* + * FIX_IOREMAP entries are useful for mapping physical address + * space before ioremap() is useable, e.g. really early in boot + * before kmalloc() is working. + */ +#define FIX_N_IOREMAPS 32 + FIX_IOREMAP_BEGIN, + FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1, +#endif + + __end_of_fixed_addresses +}; + +extern void __set_fixmap(enum fixed_addresses idx, + unsigned long phys, pgprot_t flags); +extern void __clear_fixmap(enum fixed_addresses idx, pgprot_t flags); + +/* + * used by vmalloc.c. + * + * Leave one empty page between vmalloc'ed areas and + * the start of the fixmap, and leave one page empty + * at the top of mem.. + */ +#define FIXADDR_TOP (P4SEG - PAGE_SIZE) +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE + +#include <asm-generic/fixmap.h> + +#endif |