cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fixmap.h (2543B)

      1/* SPDX-License-Identifier: GPL-2.0
      2 *
      3 * fixmap.h: compile-time virtual memory allocation
      4 *
      5 * Copyright (C) 1998 Ingo Molnar
      6 *
      7 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
      8 */
      9
     10#ifndef _ASM_FIXMAP_H
     11#define _ASM_FIXMAP_H
     12
     13#include <linux/kernel.h>
     14#include <linux/threads.h>
     15#include <asm/page.h>
     16
     17/*
     18 * Here we define all the compile-time 'special' virtual
     19 * addresses. The point is to have a constant address at
     20 * compile time, but to set the physical address only
     21 * in the boot process. We allocate these special  addresses
     22 * from the end of P3 backwards.
     23 * Also this lets us do fail-safe vmalloc(), we
     24 * can guarantee that these special addresses and
     25 * vmalloc()-ed addresses never overlap.
     26 *
     27 * these 'compile-time allocated' memory buffers are
     28 * fixed-size 4k pages. (or larger if used with an increment
     29 * highger than 1) use fixmap_set(idx,phys) to associate
     30 * physical memory with fixmap indices.
     31 *
     32 * TLB entries of such buffers will not be flushed across
     33 * task switches.
     34 */
     35
     36/*
     37 * on UP currently we will have no trace of the fixmap mechanizm,
     38 * no page table allocations, etc. This might change in the
     39 * future, say framebuffers for the console driver(s) could be
     40 * fix-mapped?
     41 */
     42enum fixed_addresses {
     43	/*
     44	 * The FIX_CMAP entries are used by kmap_coherent() to get virtual
     45	 * addresses which are of a known color, and so their values are
     46	 * important. __fix_to_virt(FIX_CMAP_END - n) must give an address
     47	 * which is the same color as a page (n<<PAGE_SHIFT).
     48	 */
     49#define FIX_N_COLOURS 8
     50	FIX_CMAP_BEGIN,
     51	FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS) - 1,
     52
     53#ifdef CONFIG_IOREMAP_FIXED
     54	/*
     55	 * FIX_IOREMAP entries are useful for mapping physical address
     56	 * space before ioremap() is useable, e.g. really early in boot
     57	 * before kmalloc() is working.
     58	 */
     59#define FIX_N_IOREMAPS	32
     60	FIX_IOREMAP_BEGIN,
     61	FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,
     62#endif
     63
     64	__end_of_fixed_addresses
     65};
     66
     67extern void __set_fixmap(enum fixed_addresses idx,
     68			 unsigned long phys, pgprot_t flags);
     69extern void __clear_fixmap(enum fixed_addresses idx, pgprot_t flags);
     70
     71/*
     72 * used by vmalloc.c.
     73 *
     74 * Leave one empty page between vmalloc'ed areas and
     75 * the start of the fixmap, and leave one page empty
     76 * at the top of mem..
     77 */
     78#define FIXADDR_TOP	(P4SEG - PAGE_SIZE)
     79#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
     80#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
     81
     82#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NOCACHE
     83
     84#include <asm-generic/fixmap.h>
     85
     86#endif