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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wbflush.c (2093B)


      1/*
      2 * Setup the right wbflush routine for the different DECstations.
      3 *
      4 * Created with information from:
      5 *	DECstation 3100 Desktop Workstation Functional Specification
      6 *	DECstation 5000/200 KN02 System Module Functional Specification
      7 *	mipsel-linux-objdump --disassemble vmunix | grep "wbflush" :-)
      8 *
      9 * This file is subject to the terms and conditions of the GNU General Public
     10 * License.  See the file "COPYING" in the main directory of this archive
     11 * for more details.
     12 *
     13 * Copyright (C) 1998 Harald Koerfgen
     14 * Copyright (C) 2002 Maciej W. Rozycki
     15 */
     16
     17#include <linux/export.h>
     18#include <linux/init.h>
     19
     20#include <asm/bootinfo.h>
     21#include <asm/wbflush.h>
     22#include <asm/barrier.h>
     23
     24static void wbflush_kn01(void);
     25static void wbflush_kn210(void);
     26static void wbflush_mips(void);
     27
     28void (*__wbflush) (void);
     29
     30void __init wbflush_setup(void)
     31{
     32	switch (mips_machtype) {
     33	case MACH_DS23100:
     34	case MACH_DS5000_200:	/* DS5000 3max */
     35		__wbflush = wbflush_kn01;
     36		break;
     37	case MACH_DS5100:	/* DS5100 MIPSMATE */
     38		__wbflush = wbflush_kn210;
     39		break;
     40	case MACH_DS5000_1XX:	/* DS5000/100 3min */
     41	case MACH_DS5000_XX:	/* Personal DS5000/2x */
     42	case MACH_DS5000_2X0:	/* DS5000/240 3max+ */
     43	case MACH_DS5900:	/* DS5900 bigmax */
     44	default:
     45		__wbflush = wbflush_mips;
     46		break;
     47	}
     48}
     49
     50/*
     51 * For the DS3100 and DS5000/200 the R2020/R3220 writeback buffer functions
     52 * as part of Coprocessor 0.
     53 */
     54static void wbflush_kn01(void)
     55{
     56    asm(".set\tpush\n\t"
     57	".set\tnoreorder\n\t"
     58	"1:\tbc0f\t1b\n\t"
     59	"nop\n\t"
     60	".set\tpop");
     61}
     62
     63/*
     64 * For the DS5100 the writeback buffer seems to be a part of Coprocessor 3.
     65 * But CP3 has to enabled first.
     66 */
     67static void wbflush_kn210(void)
     68{
     69    asm(".set\tpush\n\t"
     70	".set\tnoreorder\n\t"
     71	"mfc0\t$2,$12\n\t"
     72	"lui\t$3,0x8000\n\t"
     73	"or\t$3,$2,$3\n\t"
     74	"mtc0\t$3,$12\n\t"
     75	"nop\n"
     76	"1:\tbc3f\t1b\n\t"
     77	"nop\n\t"
     78	"mtc0\t$2,$12\n\t"
     79	"nop\n\t"
     80	".set\tpop"
     81	: : : "$2", "$3");
     82}
     83
     84/*
     85 * I/O ASIC systems use a standard writeback buffer that gets flushed
     86 * upon an uncached read.
     87 */
     88static void wbflush_mips(void)
     89{
     90	__fast_iob();
     91}
     92EXPORT_SYMBOL(__wbflush);