cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

rtlx-mt.c (3231B)

      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) 2005 MIPS Technologies, Inc.  All rights reserved.
      7 * Copyright (C) 2013 Imagination Technologies Ltd.
      8 */
      9#include <linux/device.h>
     10#include <linux/fs.h>
     11#include <linux/err.h>
     12#include <linux/wait.h>
     13#include <linux/sched.h>
     14#include <linux/interrupt.h>
     15#include <linux/irq.h>
     16
     17#include <asm/mips_mt.h>
     18#include <asm/vpe.h>
     19#include <asm/rtlx.h>
     20
     21static int major;
     22
     23static void rtlx_dispatch(void)
     24{
     25	if (read_c0_cause() & read_c0_status() & C_SW0)
     26		do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ);
     27}
     28
     29/*
     30 * Interrupt handler may be called before rtlx_init has otherwise had
     31 * a chance to run.
     32 */
     33static irqreturn_t rtlx_interrupt(int irq, void *dev_id)
     34{
     35	unsigned int vpeflags;
     36	unsigned long flags;
     37	int i;
     38
     39	local_irq_save(flags);
     40	vpeflags = dvpe();
     41	set_c0_status(0x100 << MIPS_CPU_RTLX_IRQ);
     42	irq_enable_hazard();
     43	evpe(vpeflags);
     44	local_irq_restore(flags);
     45
     46	for (i = 0; i < RTLX_CHANNELS; i++) {
     47		wake_up(&channel_wqs[i].lx_queue);
     48		wake_up(&channel_wqs[i].rt_queue);
     49	}
     50
     51	return IRQ_HANDLED;
     52}
     53
     54static int rtlx_irq_num = MIPS_CPU_IRQ_BASE + MIPS_CPU_RTLX_IRQ;
     55
     56void _interrupt_sp(void)
     57{
     58	unsigned long flags;
     59
     60	local_irq_save(flags);
     61	dvpe();
     62	settc(1);
     63	write_vpe_c0_cause(read_vpe_c0_cause() | C_SW0);
     64	evpe(EVPE_ENABLE);
     65	local_irq_restore(flags);
     66}
     67
     68int __init rtlx_module_init(void)
     69{
     70	struct device *dev;
     71	int i, err;
     72
     73	if (!cpu_has_mipsmt) {
     74		pr_warn("VPE loader: not a MIPS MT capable processor\n");
     75		return -ENODEV;
     76	}
     77
     78	if (aprp_cpu_index() == 0) {
     79		pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
     80			"Pass maxtcs=<n> argument as kernel argument\n");
     81
     82		return -ENODEV;
     83	}
     84
     85	major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
     86	if (major < 0) {
     87		pr_err("rtlx_module_init: unable to register device\n");
     88		return major;
     89	}
     90
     91	/* initialise the wait queues */
     92	for (i = 0; i < RTLX_CHANNELS; i++) {
     93		init_waitqueue_head(&channel_wqs[i].rt_queue);
     94		init_waitqueue_head(&channel_wqs[i].lx_queue);
     95		atomic_set(&channel_wqs[i].in_open, 0);
     96		mutex_init(&channel_wqs[i].mutex);
     97
     98		dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
     99				    "%s%d", RTLX_MODULE_NAME, i);
    100		if (IS_ERR(dev)) {
    101			while (i--)
    102				device_destroy(mt_class, MKDEV(major, i));
    103
    104			err = PTR_ERR(dev);
    105			goto out_chrdev;
    106		}
    107	}
    108
    109	/* set up notifiers */
    110	rtlx_notify.start = rtlx_starting;
    111	rtlx_notify.stop = rtlx_stopping;
    112	vpe_notify(aprp_cpu_index(), &rtlx_notify);
    113
    114	if (cpu_has_vint) {
    115		aprp_hook = rtlx_dispatch;
    116	} else {
    117		pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
    118		err = -ENODEV;
    119		goto out_class;
    120	}
    121
    122	err = request_irq(rtlx_irq_num, rtlx_interrupt, 0, "RTLX", rtlx);
    123	if (err)
    124		goto out_class;
    125
    126	return 0;
    127
    128out_class:
    129	for (i = 0; i < RTLX_CHANNELS; i++)
    130		device_destroy(mt_class, MKDEV(major, i));
    131out_chrdev:
    132	unregister_chrdev(major, RTLX_MODULE_NAME);
    133
    134	return err;
    135}
    136
    137void __exit rtlx_module_exit(void)
    138{
    139	int i;
    140
    141	for (i = 0; i < RTLX_CHANNELS; i++)
    142		device_destroy(mt_class, MKDEV(major, i));
    143
    144	unregister_chrdev(major, RTLX_MODULE_NAME);
    145
    146	aprp_hook = NULL;
    147}