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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malta-amon.c (1997B)

      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) 2007 MIPS Technologies, Inc.  All rights reserved.
      7 * Copyright (C) 2013 Imagination Technologies Ltd.
      8 *
      9 * Arbitrary Monitor Interface
     10 */
     11#include <linux/kernel.h>
     12#include <linux/smp.h>
     13
     14#include <asm/addrspace.h>
     15#include <asm/mipsmtregs.h>
     16#include <asm/mips-boards/launch.h>
     17#include <asm/vpe.h>
     18
     19int amon_cpu_avail(int cpu)
     20{
     21	struct cpulaunch *launch = (struct cpulaunch *)CKSEG0ADDR(CPULAUNCH);
     22
     23	if (cpu < 0 || cpu >= NCPULAUNCH) {
     24		pr_debug("avail: cpu%d is out of range\n", cpu);
     25		return 0;
     26	}
     27
     28	launch += cpu;
     29	if (!(launch->flags & LAUNCH_FREADY)) {
     30		pr_debug("avail: cpu%d is not ready\n", cpu);
     31		return 0;
     32	}
     33	if (launch->flags & (LAUNCH_FGO|LAUNCH_FGONE)) {
     34		pr_debug("avail: too late.. cpu%d is already gone\n", cpu);
     35		return 0;
     36	}
     37
     38	return 1;
     39}
     40
     41int amon_cpu_start(int cpu,
     42		    unsigned long pc, unsigned long sp,
     43		    unsigned long gp, unsigned long a0)
     44{
     45	volatile struct cpulaunch *launch =
     46		(struct cpulaunch  *)CKSEG0ADDR(CPULAUNCH);
     47
     48	if (!amon_cpu_avail(cpu))
     49		return -1;
     50	if (cpu == smp_processor_id()) {
     51		pr_debug("launch: I am cpu%d!\n", cpu);
     52		return -1;
     53	}
     54	launch += cpu;
     55
     56	pr_debug("launch: starting cpu%d\n", cpu);
     57
     58	launch->pc = pc;
     59	launch->gp = gp;
     60	launch->sp = sp;
     61	launch->a0 = a0;
     62
     63	smp_wmb();		/* Target must see parameters before go */
     64	launch->flags |= LAUNCH_FGO;
     65	smp_wmb();		/* Target must see go before we poll  */
     66
     67	while ((launch->flags & LAUNCH_FGONE) == 0)
     68		;
     69	smp_rmb();	/* Target will be updating flags soon */
     70	pr_debug("launch: cpu%d gone!\n", cpu);
     71
     72	return 0;
     73}
     74
     75#ifdef CONFIG_MIPS_VPE_LOADER_CMP
     76int vpe_run(struct vpe *v)
     77{
     78	struct vpe_notifications *n;
     79
     80	if (amon_cpu_start(aprp_cpu_index(), v->__start, 0, 0, 0) < 0)
     81		return -1;
     82
     83	list_for_each_entry(n, &v->notify, list)
     84		n->start(VPE_MODULE_MINOR);
     85
     86	return 0;
     87}
     88#endif