linux/arch/x86/mm/mmio-mod.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * Copyright (C) IBM Corporation, 2005
 *               Jeff Muizelaar, 2006, 2007
 *               Pekka Paalanen, 2008 <[email protected]>
 *
 * Derived from the read-mod example from relay-examples by Tom Zanussi.
 */

#define pr_fmt(fmt) …

#include <linux/moduleparam.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/mmiotrace.h>
#include <linux/pgtable.h>
#include <asm/e820/api.h> /* for ISA_START_ADDRESS */
#include <linux/atomic.h>
#include <linux/percpu.h>
#include <linux/cpu.h>

#include "pf_in.h"

struct trap_reason { … };

struct remap_trace { … };

/* Accessed per-cpu. */
static DEFINE_PER_CPU(struct trap_reason, pf_reason);
static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace);

static DEFINE_MUTEX(mmiotrace_mutex);
static DEFINE_SPINLOCK(trace_lock);
static atomic_t mmiotrace_enabled;
static LIST_HEAD(trace_list);		/* struct remap_trace */

/*
 * Locking in this file:
 * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections.
 * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex
 *   and trace_lock.
 * - Routines depending on is_enabled() must take trace_lock.
 * - trace_list users must hold trace_lock.
 * - is_enabled() guarantees that mmio_trace_{rw,mapping} are allowed.
 * - pre/post callbacks assume the effect of is_enabled() being true.
 */

/* module parameters */
static unsigned long	filter_offset;
static bool		nommiotrace;
static bool		trace_pc;

module_param(filter_offset, ulong, 0);
module_param(nommiotrace, bool, 0);
module_param(trace_pc, bool, 0);

MODULE_PARM_DESC(…) …;
MODULE_PARM_DESC(…) …;
MODULE_PARM_DESC(…) …;

static bool is_enabled(void)
{ … }

static void print_pte(unsigned long address)
{ … }

/*
 * For some reason the pre/post pairs have been called in an
 * unmatched order. Report and die.
 */
static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr)
{ … }

static void pre(struct kmmio_probe *p, struct pt_regs *regs,
						unsigned long addr)
{ … }

static void post(struct kmmio_probe *p, unsigned long condition,
							struct pt_regs *regs)
{ … }

static void ioremap_trace_core(resource_size_t offset, unsigned long size,
							void __iomem *addr)
{ … }

void mmiotrace_ioremap(resource_size_t offset, unsigned long size,
						void __iomem *addr)
{ … }

static void iounmap_trace_core(volatile void __iomem *addr)
{ … }

void mmiotrace_iounmap(volatile void __iomem *addr)
{ … }

int mmiotrace_printk(const char *fmt, ...)
{ … }
EXPORT_SYMBOL(…);

static void clear_trace_list(void)
{ … }

#ifdef CONFIG_HOTPLUG_CPU
static cpumask_var_t downed_cpus;

static void enter_uniprocessor(void)
{ … }

static void leave_uniprocessor(void)
{ … }

#else /* !CONFIG_HOTPLUG_CPU */
static void enter_uniprocessor(void)
{
	if (num_online_cpus() > 1)
		pr_warn("multiple CPUs are online, may miss events. "
			"Suggest booting with maxcpus=1 kernel argument.\n");
}

static void leave_uniprocessor(void)
{
}
#endif

void enable_mmiotrace(void)
{ … }

void disable_mmiotrace(void)
{ … }