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