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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vpe-cmp.c (3721B)

      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) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
      7 * Copyright (C) 2013 Imagination Technologies Ltd.
      8 */
      9#include <linux/kernel.h>
     10#include <linux/device.h>
     11#include <linux/fs.h>
     12#include <linux/slab.h>
     13#include <linux/export.h>
     14
     15#include <asm/vpe.h>
     16
     17static int major;
     18
     19void cleanup_tc(struct tc *tc)
     20{
     21
     22}
     23
     24static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
     25			  const char *buf, size_t len)
     26{
     27	struct vpe *vpe = get_vpe(aprp_cpu_index());
     28	struct vpe_notifications *notifier;
     29
     30	list_for_each_entry(notifier, &vpe->notify, list)
     31		notifier->stop(aprp_cpu_index());
     32
     33	release_progmem(vpe->load_addr);
     34	vpe->state = VPE_STATE_UNUSED;
     35
     36	return len;
     37}
     38static DEVICE_ATTR(kill, S_IWUSR, NULL, store_kill);
     39
     40static ssize_t ntcs_show(struct device *cd, struct device_attribute *attr,
     41			 char *buf)
     42{
     43	struct vpe *vpe = get_vpe(aprp_cpu_index());
     44
     45	return sprintf(buf, "%d\n", vpe->ntcs);
     46}
     47
     48static ssize_t ntcs_store(struct device *dev, struct device_attribute *attr,
     49			  const char *buf, size_t len)
     50{
     51	struct vpe *vpe = get_vpe(aprp_cpu_index());
     52	unsigned long new;
     53	int ret;
     54
     55	ret = kstrtoul(buf, 0, &new);
     56	if (ret < 0)
     57		return ret;
     58
     59	/* APRP can only reserve one TC in a VPE and no more. */
     60	if (new != 1)
     61		return -EINVAL;
     62
     63	vpe->ntcs = new;
     64
     65	return len;
     66}
     67static DEVICE_ATTR_RW(ntcs);
     68
     69static struct attribute *vpe_attrs[] = {
     70	&dev_attr_kill.attr,
     71	&dev_attr_ntcs.attr,
     72	NULL,
     73};
     74ATTRIBUTE_GROUPS(vpe);
     75
     76static void vpe_device_release(struct device *cd)
     77{
     78	kfree(cd);
     79}
     80
     81static struct class vpe_class = {
     82	.name = "vpe",
     83	.owner = THIS_MODULE,
     84	.dev_release = vpe_device_release,
     85	.dev_groups = vpe_groups,
     86};
     87
     88static struct device vpe_device;
     89
     90int __init vpe_module_init(void)
     91{
     92	struct vpe *v = NULL;
     93	struct tc *t;
     94	int err;
     95
     96	if (!cpu_has_mipsmt) {
     97		pr_warn("VPE loader: not a MIPS MT capable processor\n");
     98		return -ENODEV;
     99	}
    100
    101	if (num_possible_cpus() - aprp_cpu_index() < 1) {
    102		pr_warn("No VPEs reserved for AP/SP, not initialize VPE loader\n"
    103			"Pass maxcpus=<n> argument as kernel argument\n");
    104		return -ENODEV;
    105	}
    106
    107	major = register_chrdev(0, VPE_MODULE_NAME, &vpe_fops);
    108	if (major < 0) {
    109		pr_warn("VPE loader: unable to register character device\n");
    110		return major;
    111	}
    112
    113	err = class_register(&vpe_class);
    114	if (err) {
    115		pr_err("vpe_class registration failed\n");
    116		goto out_chrdev;
    117	}
    118
    119	device_initialize(&vpe_device);
    120	vpe_device.class	= &vpe_class;
    121	vpe_device.parent	= NULL;
    122	dev_set_name(&vpe_device, "vpe_sp");
    123	vpe_device.devt = MKDEV(major, VPE_MODULE_MINOR);
    124	err = device_add(&vpe_device);
    125	if (err) {
    126		pr_err("Adding vpe_device failed\n");
    127		goto out_class;
    128	}
    129
    130	t = alloc_tc(aprp_cpu_index());
    131	if (!t) {
    132		pr_warn("VPE: unable to allocate TC\n");
    133		err = -ENOMEM;
    134		goto out_dev;
    135	}
    136
    137	/* VPE */
    138	v = alloc_vpe(aprp_cpu_index());
    139	if (v == NULL) {
    140		pr_warn("VPE: unable to allocate VPE\n");
    141		kfree(t);
    142		err = -ENOMEM;
    143		goto out_dev;
    144	}
    145
    146	v->ntcs = 1;
    147
    148	/* add the tc to the list of this vpe's tc's. */
    149	list_add(&t->tc, &v->tc);
    150
    151	/* TC */
    152	t->pvpe = v;	/* set the parent vpe */
    153
    154	return 0;
    155
    156out_dev:
    157	device_del(&vpe_device);
    158
    159out_class:
    160	class_unregister(&vpe_class);
    161
    162out_chrdev:
    163	unregister_chrdev(major, VPE_MODULE_NAME);
    164
    165	return err;
    166}
    167
    168void __exit vpe_module_exit(void)
    169{
    170	struct vpe *v, *n;
    171
    172	device_del(&vpe_device);
    173	class_unregister(&vpe_class);
    174	unregister_chrdev(major, VPE_MODULE_NAME);
    175
    176	/* No locking needed here */
    177	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list)
    178		if (v->state != VPE_STATE_UNUSED)
    179			release_vpe(v);
    180}