// SPDX-License-Identifier: GPL-2.0/* * Memory mapped I/O tracing * * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi> */ #include <linux/kernel.h>#include <linux/mmiotrace.h>#include <linux/pci.h>#include <linux/slab.h>#include <linux/time.h> #include <linux/atomic.h> #include "trace.h"#include "trace_output.h" struct header_iter {	struct pci_dev *dev;}; static struct trace_array *mmio_trace_array;static bool overrun_detected;static unsigned long prev_overruns;static atomic_t dropped_count; static void mmio_reset_data(struct trace_array *tr){	overrun_detected = false;	prev_overruns = 0;	atomic_set(&dropped_count, 0); 	tracing_reset_online_cpus(&tr->array_buffer);} static int mmio_trace_init(struct trace_array *tr){	pr_debug("in %s\n", __func__);	mmio_trace_array = tr; 	mmio_reset_data(tr);	enable_mmiotrace();	return 0;} static void mmio_trace_reset(struct trace_array *tr){	pr_debug("in %s\n", __func__); 	disable_mmiotrace();	mmio_reset_data(tr);	mmio_trace_array = NULL;} static void mmio_trace_start(struct trace_array *tr){	pr_debug("in %s\n", __func__);	mmio_reset_data(tr);} static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev){	int i;	resource_size_t start, end;	const struct pci_driver *drv = pci_dev_driver(dev); 	trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",			 dev->bus->number, dev->devfn,			 dev->vendor, dev->device, dev->irq);	for (i = 0; i < 7; i++) {		start = dev->resource[i].start;		trace_seq_printf(s, " %llx",			(unsigned long long)(start |			(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));	}	for (i = 0; i < 7; i++) {		start = dev->resource[i].start;		end = dev->resource[i].end;		trace_seq_printf(s, " %llx",			dev->resource[i].start < dev->resource[i].end ?			(unsigned long long)(end - start) + 1 : 0);	}	if (drv)		trace_seq_printf(s, " %s\n", drv->name);	else		trace_seq_puts(s, " \n");} static void destroy_header_iter(struct header_iter *hiter){	if (!hiter)		return;	pci_dev_put(hiter->dev);	kfree(hiter);} static void mmio_pipe_open(struct trace_iterator *iter){	struct header_iter *hiter;	struct trace_seq *s = &iter->seq; 	trace_seq_puts(s, "VERSION 20070824\n"); 	hiter = kzalloc_obj(*hiter);	if (!hiter)		return; 	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);	iter->private = hiter;} static void mmio_close(struct trace_iterator *iter){	struct header_iter *hiter = iter->private;	destroy_header_iter(hiter);	iter->private = NULL;} static unsigned long count_overruns(struct trace_iterator *iter){	unsigned long cnt = atomic_xchg(&dropped_count, 0);	unsigned long over = ring_buffer_overruns(iter->array_buffer->buffer); 	if (over > prev_overruns)		cnt += over - prev_overruns;	prev_overruns = over;	return cnt;} static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,				char __user *ubuf, size_t cnt, loff_t *ppos){	ssize_t ret;	struct header_iter *hiter = iter->private;	struct trace_seq *s = &iter->seq;	unsigned long n; 	n = count_overruns(iter);	if (n) {		/* XXX: This is later than where events were lost. */		trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);		if (!overrun_detected)			pr_warn("mmiotrace has lost events\n");		overrun_detected = true;		goto print_out;	} 	if (!hiter || !hiter->dev)		return 0; 	mmio_print_pcidev(s, hiter->dev);	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev); 	if (!hiter->dev) {		destroy_header_iter(hiter);		iter->private = NULL;	} print_out:	ret = trace_seq_to_user(s, ubuf, cnt);	return (ret == -EBUSY) ? 0 : ret;} static enum print_line_t mmio_print_rw(struct trace_iterator *iter){	struct trace_entry *entry = iter->ent;	struct trace_mmiotrace_rw *field;	struct mmiotrace_rw *rw;	struct trace_seq *s	= &iter->seq;	unsigned long long t	= ns2usecs(iter->ts);	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);	unsigned secs		= (unsigned long)t; 	trace_assign_type(field, entry);	rw = &field->rw; 	switch (rw->opcode) {	case MMIO_READ:		trace_seq_printf(s,			"R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",			rw->width, secs, usec_rem, rw->map_id,			(unsigned long long)rw->phys,			rw->value, rw->pc, 0);		break;	case MMIO_WRITE:		trace_seq_printf(s,			"W %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",			rw->width, secs, usec_rem, rw->map_id,			(unsigned long long)rw->phys,			rw->value, rw->pc, 0);		break;	case MMIO_UNKNOWN_OP:		trace_seq_printf(s,			"UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx,"			"%02lx 0x%lx %d\n",			secs, usec_rem, rw->map_id,			(unsigned long long)rw->phys,			(rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,			(rw->value >> 0) & 0xff, rw->pc, 0);		break;	default:		trace_seq_puts(s, "rw what?\n");		break;	} 	return trace_handle_return(s);} static enum print_line_t mmio_print_map(struct trace_iterator *iter){	struct trace_entry *entry = iter->ent;	struct trace_mmiotrace_map *field;	struct mmiotrace_map *m;	struct trace_seq *s	= &iter->seq;	unsigned long long t	= ns2usecs(iter->ts);	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);	unsigned secs		= (unsigned long)t; 	trace_assign_type(field, entry);	m = &field->map; 	switch (m->opcode) {	case MMIO_PROBE:		trace_seq_printf(s,			"MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",			secs, usec_rem, m->map_id,			(unsigned long long)m->phys, m->virt, m->len,			0UL, 0);		break;	case MMIO_UNPROBE:		trace_seq_printf(s,			"UNMAP %u.%06lu %d 0x%lx %d\n",			secs, usec_rem, m->map_id, 0UL, 0);		break;	default:		trace_seq_puts(s, "map what?\n");		break;	} 	return trace_handle_return(s);} static enum print_line_t mmio_print_mark(struct trace_iterator *iter){	struct trace_entry *entry = iter->ent;	struct print_entry *print;	const char *msg;	struct trace_seq *s	= &iter->seq;	unsigned long long t	= ns2usecs(iter->ts);	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);	unsigned secs		= (unsigned long)t; 	trace_assign_type(print, entry);	msg = print->buf; 	/* The trailing newline must be in the message. */	trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg); 	return trace_handle_return(s);} static enum print_line_t mmio_print_line(struct trace_iterator *iter){	switch (iter->ent->type) {	case TRACE_MMIO_RW:		return mmio_print_rw(iter);	case TRACE_MMIO_MAP:		return mmio_print_map(iter);	case TRACE_PRINT:		return mmio_print_mark(iter);	default:		return TRACE_TYPE_HANDLED; /* ignore unknown entries */	}} static struct tracer mmio_tracer __read_mostly ={	.name		= "mmiotrace",	.init		= mmio_trace_init,	.reset		= mmio_trace_reset,	.start		= mmio_trace_start,	.pipe_open	= mmio_pipe_open,	.close		= mmio_close,	.pipe_close	= mmio_close,	.read		= mmio_read,	.print_line	= mmio_print_line,	.noboot		= true,}; __init static int init_mmio_trace(void){	return register_tracer(&mmio_tracer);}device_initcall(init_mmio_trace); static void __trace_mmiotrace_rw(struct trace_array *tr,				struct mmiotrace_rw *rw){	struct trace_buffer *buffer;	struct ring_buffer_event *event;	struct trace_mmiotrace_rw *entry;	unsigned int trace_ctx; 	if (!tr)		return; 	buffer = tr->array_buffer.buffer;	trace_ctx = tracing_gen_ctx_flags(0);	event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW,					  sizeof(*entry), trace_ctx);	if (!event) {		atomic_inc(&dropped_count);		return;	}	entry	= ring_buffer_event_data(event);	entry->rw			= *rw; 	trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);} void mmio_trace_rw(struct mmiotrace_rw *rw){	struct trace_array *tr = mmio_trace_array;	__trace_mmiotrace_rw(tr, rw);} static void __trace_mmiotrace_map(struct trace_array *tr,				struct mmiotrace_map *map){	struct trace_buffer *buffer;	struct ring_buffer_event *event;	struct trace_mmiotrace_map *entry;	unsigned int trace_ctx; 	if (!tr)		return; 	buffer = tr->array_buffer.buffer;	trace_ctx = tracing_gen_ctx_flags(0);	event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP,					  sizeof(*entry), trace_ctx);	if (!event) {		atomic_inc(&dropped_count);		return;	}	entry	= ring_buffer_event_data(event);	entry->map			= *map; 	trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);} void mmio_trace_mapping(struct mmiotrace_map *map){	struct trace_array *tr = mmio_trace_array;	__trace_mmiotrace_map(tr, map);} int mmio_trace_printk(const char *fmt, va_list args){	return trace_vprintk(0, fmt, args);}