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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hvCall_inst.c (3297B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (C) 2006 Mike Kravetz IBM Corporation
      4 *
      5 * Hypervisor Call Instrumentation
      6 */
      7
      8#include <linux/kernel.h>
      9#include <linux/percpu.h>
     10#include <linux/debugfs.h>
     11#include <linux/seq_file.h>
     12#include <linux/cpumask.h>
     13#include <asm/hvcall.h>
     14#include <asm/firmware.h>
     15#include <asm/cputable.h>
     16#include <asm/trace.h>
     17#include <asm/machdep.h>
     18
     19/* For hcall instrumentation. One structure per-hcall, per-CPU */
     20struct hcall_stats {
     21	unsigned long	num_calls;	/* number of calls (on this CPU) */
     22	unsigned long	tb_total;	/* total wall time (mftb) of calls. */
     23	unsigned long	purr_total;	/* total cpu time (PURR) of calls. */
     24	unsigned long	tb_start;
     25	unsigned long	purr_start;
     26};
     27#define HCALL_STAT_ARRAY_SIZE	((MAX_HCALL_OPCODE >> 2) + 1)
     28
     29static DEFINE_PER_CPU(struct hcall_stats[HCALL_STAT_ARRAY_SIZE], hcall_stats);
     30
     31/*
     32 * Routines for displaying the statistics in debugfs
     33 */
     34static void *hc_start(struct seq_file *m, loff_t *pos)
     35{
     36	if ((int)*pos < (HCALL_STAT_ARRAY_SIZE-1))
     37		return (void *)(unsigned long)(*pos + 1);
     38
     39	return NULL;
     40}
     41
     42static void *hc_next(struct seq_file *m, void *p, loff_t * pos)
     43{
     44	++*pos;
     45
     46	return hc_start(m, pos);
     47}
     48
     49static void hc_stop(struct seq_file *m, void *p)
     50{
     51}
     52
     53static int hc_show(struct seq_file *m, void *p)
     54{
     55	unsigned long h_num = (unsigned long)p;
     56	struct hcall_stats *hs = m->private;
     57
     58	if (hs[h_num].num_calls) {
     59		if (cpu_has_feature(CPU_FTR_PURR))
     60			seq_printf(m, "%lu %lu %lu %lu\n", h_num<<2,
     61				   hs[h_num].num_calls,
     62				   hs[h_num].tb_total,
     63				   hs[h_num].purr_total);
     64		else
     65			seq_printf(m, "%lu %lu %lu\n", h_num<<2,
     66				   hs[h_num].num_calls,
     67				   hs[h_num].tb_total);
     68	}
     69
     70	return 0;
     71}
     72
     73static const struct seq_operations hcall_inst_sops = {
     74        .start = hc_start,
     75        .next  = hc_next,
     76        .stop  = hc_stop,
     77        .show  = hc_show
     78};
     79
     80DEFINE_SEQ_ATTRIBUTE(hcall_inst);
     81
     82#define	HCALL_ROOT_DIR		"hcall_inst"
     83#define CPU_NAME_BUF_SIZE	32
     84
     85
     86static void probe_hcall_entry(void *ignored, unsigned long opcode, unsigned long *args)
     87{
     88	struct hcall_stats *h;
     89
     90	if (opcode > MAX_HCALL_OPCODE)
     91		return;
     92
     93	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
     94	h->tb_start = mftb();
     95	h->purr_start = mfspr(SPRN_PURR);
     96}
     97
     98static void probe_hcall_exit(void *ignored, unsigned long opcode, long retval,
     99			     unsigned long *retbuf)
    100{
    101	struct hcall_stats *h;
    102
    103	if (opcode > MAX_HCALL_OPCODE)
    104		return;
    105
    106	h = this_cpu_ptr(&hcall_stats[opcode / 4]);
    107	h->num_calls++;
    108	h->tb_total += mftb() - h->tb_start;
    109	h->purr_total += mfspr(SPRN_PURR) - h->purr_start;
    110}
    111
    112static int __init hcall_inst_init(void)
    113{
    114	struct dentry *hcall_root;
    115	char cpu_name_buf[CPU_NAME_BUF_SIZE];
    116	int cpu;
    117
    118	if (!firmware_has_feature(FW_FEATURE_LPAR))
    119		return 0;
    120
    121	if (register_trace_hcall_entry(probe_hcall_entry, NULL))
    122		return -EINVAL;
    123
    124	if (register_trace_hcall_exit(probe_hcall_exit, NULL)) {
    125		unregister_trace_hcall_entry(probe_hcall_entry, NULL);
    126		return -EINVAL;
    127	}
    128
    129	hcall_root = debugfs_create_dir(HCALL_ROOT_DIR, NULL);
    130
    131	for_each_possible_cpu(cpu) {
    132		snprintf(cpu_name_buf, CPU_NAME_BUF_SIZE, "cpu%d", cpu);
    133		debugfs_create_file(cpu_name_buf, 0444, hcall_root,
    134				    per_cpu(hcall_stats, cpu),
    135				    &hcall_inst_fops);
    136	}
    137
    138	return 0;
    139}
    140machine_device_initcall(pseries, hcall_inst_init);