|  | /* | 
|  | * Memory mapped I/O tracing | 
|  | * | 
|  | * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi> | 
|  | */ | 
|  |  | 
|  | #define DEBUG 1 | 
|  |  | 
|  | #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; | 
|  |  | 
|  | tracing_reset_online_cpus(tr); | 
|  | } | 
|  |  | 
|  | 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 int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) | 
|  | { | 
|  | int ret = 0; | 
|  | int i; | 
|  | resource_size_t start, end; | 
|  | const struct pci_driver *drv = pci_dev_driver(dev); | 
|  |  | 
|  | /* XXX: incomplete checks for trace_seq_printf() return value */ | 
|  | ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", | 
|  | dev->bus->number, dev->devfn, | 
|  | dev->vendor, dev->device, dev->irq); | 
|  | /* | 
|  | * XXX: is pci_resource_to_user() appropriate, since we are | 
|  | * supposed to interpret the __ioremap() phys_addr argument based on | 
|  | * these printed values? | 
|  | */ | 
|  | for (i = 0; i < 7; i++) { | 
|  | pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); | 
|  | ret += trace_seq_printf(s, " %llx", | 
|  | (unsigned long long)(start | | 
|  | (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); | 
|  | } | 
|  | for (i = 0; i < 7; i++) { | 
|  | pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); | 
|  | ret += trace_seq_printf(s, " %llx", | 
|  | dev->resource[i].start < dev->resource[i].end ? | 
|  | (unsigned long long)(end - start) + 1 : 0); | 
|  | } | 
|  | if (drv) | 
|  | ret += trace_seq_printf(s, " %s\n", drv->name); | 
|  | else | 
|  | ret += trace_seq_printf(s, " \n"); | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | 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_printf(s, "VERSION 20070824\n"); | 
|  |  | 
|  | hiter = kzalloc(sizeof(*hiter), GFP_KERNEL); | 
|  | if (!hiter) | 
|  | return; | 
|  |  | 
|  | hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); | 
|  | iter->private = hiter; | 
|  | } | 
|  |  | 
|  | /* XXX: This is not called when the pipe is closed! */ | 
|  | 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->tr->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_warning("mmiotrace has lost events.\n"); | 
|  | overrun_detected = true; | 
|  | goto print_out; | 
|  | } | 
|  |  | 
|  | if (!hiter) | 
|  | 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; | 
|  | int ret = 1; | 
|  |  | 
|  | trace_assign_type(field, entry); | 
|  | rw = &field->rw; | 
|  |  | 
|  | switch (rw->opcode) { | 
|  | case MMIO_READ: | 
|  | ret = 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: | 
|  | ret = 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: | 
|  | ret = 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: | 
|  | ret = trace_seq_printf(s, "rw what?\n"); | 
|  | break; | 
|  | } | 
|  | if (ret) | 
|  | return TRACE_TYPE_HANDLED; | 
|  | return TRACE_TYPE_PARTIAL_LINE; | 
|  | } | 
|  |  | 
|  | 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; | 
|  | int ret; | 
|  |  | 
|  | trace_assign_type(field, entry); | 
|  | m = &field->map; | 
|  |  | 
|  | switch (m->opcode) { | 
|  | case MMIO_PROBE: | 
|  | ret = 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: | 
|  | ret = trace_seq_printf(s, | 
|  | "UNMAP %u.%06lu %d 0x%lx %d\n", | 
|  | secs, usec_rem, m->map_id, 0UL, 0); | 
|  | break; | 
|  | default: | 
|  | ret = trace_seq_printf(s, "map what?\n"); | 
|  | break; | 
|  | } | 
|  | if (ret) | 
|  | return TRACE_TYPE_HANDLED; | 
|  | return TRACE_TYPE_PARTIAL_LINE; | 
|  | } | 
|  |  | 
|  | static enum print_line_t mmio_print_mark(struct trace_iterator *iter) | 
|  | { | 
|  | struct trace_entry *entry = iter->ent; | 
|  | struct print_entry *print = (struct print_entry *)entry; | 
|  | const char *msg		= print->buf; | 
|  | 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; | 
|  | int ret; | 
|  |  | 
|  | /* The trailing newline must be in the message. */ | 
|  | ret = trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg); | 
|  | if (!ret) | 
|  | return TRACE_TYPE_PARTIAL_LINE; | 
|  |  | 
|  | return TRACE_TYPE_HANDLED; | 
|  | } | 
|  |  | 
|  | 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, | 
|  | .read		= mmio_read, | 
|  | .print_line	= mmio_print_line, | 
|  | }; | 
|  |  | 
|  | __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 trace_array_cpu *data, | 
|  | struct mmiotrace_rw *rw) | 
|  | { | 
|  | struct ftrace_event_call *call = &event_mmiotrace_rw; | 
|  | struct ring_buffer *buffer = tr->buffer; | 
|  | struct ring_buffer_event *event; | 
|  | struct trace_mmiotrace_rw *entry; | 
|  | int pc = preempt_count(); | 
|  |  | 
|  | event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW, | 
|  | sizeof(*entry), 0, pc); | 
|  | if (!event) { | 
|  | atomic_inc(&dropped_count); | 
|  | return; | 
|  | } | 
|  | entry	= ring_buffer_event_data(event); | 
|  | entry->rw			= *rw; | 
|  |  | 
|  | if (!filter_check_discard(call, entry, buffer, event)) | 
|  | trace_buffer_unlock_commit(buffer, event, 0, pc); | 
|  | } | 
|  |  | 
|  | void mmio_trace_rw(struct mmiotrace_rw *rw) | 
|  | { | 
|  | struct trace_array *tr = mmio_trace_array; | 
|  | struct trace_array_cpu *data = tr->data[smp_processor_id()]; | 
|  | __trace_mmiotrace_rw(tr, data, rw); | 
|  | } | 
|  |  | 
|  | static void __trace_mmiotrace_map(struct trace_array *tr, | 
|  | struct trace_array_cpu *data, | 
|  | struct mmiotrace_map *map) | 
|  | { | 
|  | struct ftrace_event_call *call = &event_mmiotrace_map; | 
|  | struct ring_buffer *buffer = tr->buffer; | 
|  | struct ring_buffer_event *event; | 
|  | struct trace_mmiotrace_map *entry; | 
|  | int pc = preempt_count(); | 
|  |  | 
|  | event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP, | 
|  | sizeof(*entry), 0, pc); | 
|  | if (!event) { | 
|  | atomic_inc(&dropped_count); | 
|  | return; | 
|  | } | 
|  | entry	= ring_buffer_event_data(event); | 
|  | entry->map			= *map; | 
|  |  | 
|  | if (!filter_check_discard(call, entry, buffer, event)) | 
|  | trace_buffer_unlock_commit(buffer, event, 0, pc); | 
|  | } | 
|  |  | 
|  | void mmio_trace_mapping(struct mmiotrace_map *map) | 
|  | { | 
|  | struct trace_array *tr = mmio_trace_array; | 
|  | struct trace_array_cpu *data; | 
|  |  | 
|  | preempt_disable(); | 
|  | data = tr->data[smp_processor_id()]; | 
|  | __trace_mmiotrace_map(tr, data, map); | 
|  | preempt_enable(); | 
|  | } | 
|  |  | 
|  | int mmio_trace_printk(const char *fmt, va_list args) | 
|  | { | 
|  | return trace_vprintk(0, fmt, args); | 
|  | } |