/* * 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->trace_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(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->trace_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) 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 = (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; /* 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, .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 trace_event_call *call = &event_mmiotrace_rw; struct ring_buffer *buffer = tr->trace_buffer.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 (!call_filter_check_discard(call, entry, buffer, event)) trace_buffer_unlock_commit(tr, buffer, event, 0, pc); } void mmio_trace_rw(struct mmiotrace_rw *rw) { struct trace_array *tr = mmio_trace_array; struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.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 trace_event_call *call = &event_mmiotrace_map; struct ring_buffer *buffer = tr->trace_buffer.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 (!call_filter_check_discard(call, entry, buffer, event)) trace_buffer_unlock_commit(tr, 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 = per_cpu_ptr(tr->trace_buffer.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); }