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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promlib.c (1614B)

      1/*
      2 * This file is subject to the terms and conditions of the GNU General Public
      3 * License.  See the file "COPYING" in the main directory of this archive
      4 * for more details.
      5 *
      6 * Copyright (C) 1996 David S. Miller (dm@sgi.com)
      7 * Compatibility with board caches, Ulf Carlsson
      8 */
      9#include <linux/kernel.h>
     10#include <asm/sgialib.h>
     11#include <asm/bcache.h>
     12#include <asm/setup.h>
     13
     14#if defined(CONFIG_64BIT) && defined(CONFIG_FW_ARC32)
     15/*
     16 * For 64bit kernels working with a 32bit ARC PROM pointer arguments
     17 * for ARC calls need to reside in CKEG0/1. But as soon as the kernel
     18 * switches to it's first kernel thread stack is set to an address in
     19 * XKPHYS, so anything on stack can't be used anymore. This is solved
     20 * by using a * static declartion variables are put into BSS, which is
     21 * linked to a CKSEG0 address. Since this is only used on UP platforms
     22 * there is not spinlock needed
     23 */
     24#define O32_STATIC	static
     25#else
     26#define O32_STATIC
     27#endif
     28
     29/*
     30 * IP22 boardcache is not compatible with board caches.	 Thus we disable it
     31 * during romvec action.  Since r4xx0.c is always compiled and linked with your
     32 * kernel, this shouldn't cause any harm regardless what MIPS processor you
     33 * have.
     34 *
     35 * The ARC write and read functions seem to interfere with the serial lines
     36 * in some way. You should be careful with them.
     37 */
     38
     39void prom_putchar(char c)
     40{
     41	O32_STATIC ULONG cnt;
     42	O32_STATIC CHAR it;
     43
     44	it = c;
     45
     46	bc_disable();
     47	ArcWrite(1, &it, 1, &cnt);
     48	bc_enable();
     49}
     50
     51char prom_getchar(void)
     52{
     53	O32_STATIC ULONG cnt;
     54	O32_STATIC CHAR c;
     55
     56	bc_disable();
     57	ArcRead(0, &c, 1, &cnt);
     58	bc_enable();
     59
     60	return c;
     61}