*
* Derived from the read-mod example from relay-examples by Tom Zanussi.
*/
+
+#define pr_fmt(fmt) "mmiotrace: " fmt
+
#define DEBUG 1
#include <linux/module.h>
#include <linux/debugfs.h>
+#include <linux/slab.h>
#include <linux/uaccess.h>
-#include <asm/io.h>
+#include <linux/io.h>
#include <linux/version.h>
#include <linux/kallsyms.h>
#include <asm/pgtable.h>
#include <asm/e820.h> /* for ISA_START_ADDRESS */
#include <asm/atomic.h>
#include <linux/percpu.h>
+#include <linux/cpu.h>
#include "pf_in.h"
-#define NAME "mmiotrace: "
-
struct trap_reason {
unsigned long addr;
unsigned long ip;
struct remap_trace {
struct list_head list;
struct kmmio_probe probe;
- unsigned long phys;
+ resource_size_t phys;
unsigned long id;
};
static DEFINE_PER_CPU(struct trap_reason, pf_reason);
static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace);
-#if 0 /* XXX: no way gather this info anymore */
-/* Access to this is not per-cpu. */
-static DEFINE_PER_CPU(atomic_t, dropped);
-#endif
-
-static struct dentry *marker_file;
-
static DEFINE_MUTEX(mmiotrace_mutex);
static DEFINE_SPINLOCK(trace_lock);
static atomic_t mmiotrace_enabled;
* 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_record is allowed.
+ * - 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 int nommiotrace;
-static int ISA_trace;
static int trace_pc;
module_param(filter_offset, ulong, 0);
module_param(nommiotrace, bool, 0);
-module_param(ISA_trace, bool, 0);
module_param(trace_pc, bool, 0);
MODULE_PARM_DESC(filter_offset, "Start address of traced mappings.");
MODULE_PARM_DESC(nommiotrace, "Disable actual MMIO tracing.");
-MODULE_PARM_DESC(ISA_trace, "Do not exclude the low ISA range.");
MODULE_PARM_DESC(trace_pc, "Record address of faulting instructions.");
static bool is_enabled(void)
return atomic_read(&mmiotrace_enabled);
}
-#if 0 /* XXX: needs rewrite */
-/*
- * Write callback for the debugfs entry:
- * Read a marker and write it to the mmio trace log
- */
-static ssize_t write_marker(struct file *file, const char __user *buffer,
- size_t count, loff_t *ppos)
-{
- char *event = NULL;
- struct mm_io_header *headp;
- ssize_t len = (count > 65535) ? 65535 : count;
-
- event = kzalloc(sizeof(*headp) + len, GFP_KERNEL);
- if (!event)
- return -ENOMEM;
-
- headp = (struct mm_io_header *)event;
- headp->type = MMIO_MAGIC | (MMIO_MARKER << MMIO_OPCODE_SHIFT);
- headp->data_len = len;
-
- if (copy_from_user(event + sizeof(*headp), buffer, len)) {
- kfree(event);
- return -EFAULT;
- }
-
- spin_lock_irq(&trace_lock);
-#if 0 /* XXX: convert this to use tracing */
- if (is_enabled())
- relay_write(chan, event, sizeof(*headp) + len);
- else
-#endif
- len = -EINVAL;
- spin_unlock_irq(&trace_lock);
- kfree(event);
- return len;
-}
-#endif
-
static void print_pte(unsigned long address)
{
- int level;
+ unsigned int level;
pte_t *pte = lookup_address(address, &level);
if (!pte) {
- pr_err(NAME "Error in %s: no pte for page 0x%08lx\n",
- __func__, address);
+ pr_err("Error in %s: no pte for page 0x%08lx\n",
+ __func__, address);
return;
}
if (level == PG_LEVEL_2M) {
- pr_emerg(NAME "4MB pages are not currently supported: "
- "0x%08lx\n", address);
+ pr_emerg("4MB pages are not currently supported: 0x%08lx\n",
+ address);
BUG();
}
- pr_info(NAME "pte for 0x%lx: 0x%lx 0x%lx\n", address, pte_val(*pte),
- pte_val(*pte) & _PAGE_PRESENT);
+ pr_info("pte for 0x%lx: 0x%llx 0x%llx\n",
+ address,
+ (unsigned long long)pte_val(*pte),
+ (unsigned long long)pte_val(*pte) & _PAGE_PRESENT);
}
/*
static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr)
{
const struct trap_reason *my_reason = &get_cpu_var(pf_reason);
- pr_emerg(NAME "unexpected fault for address: 0x%08lx, "
- "last fault for address: 0x%08lx\n",
- addr, my_reason->addr);
+ pr_emerg("unexpected fault for address: 0x%08lx, last fault for address: 0x%08lx\n",
+ addr, my_reason->addr);
print_pte(addr);
print_symbol(KERN_EMERG "faulting IP is at %s\n", regs->ip);
print_symbol(KERN_EMERG "last faulting IP was at %s\n", my_reason->ip);
#ifdef __i386__
pr_emerg("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
- regs->ax, regs->bx, regs->cx, regs->dx);
+ regs->ax, regs->bx, regs->cx, regs->dx);
pr_emerg("esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
- regs->si, regs->di, regs->bp, regs->sp);
+ regs->si, regs->di, regs->bp, regs->sp);
#else
pr_emerg("rax: %016lx rcx: %016lx rdx: %016lx\n",
- regs->ax, regs->cx, regs->dx);
+ regs->ax, regs->cx, regs->dx);
pr_emerg("rsi: %016lx rdi: %016lx rbp: %016lx rsp: %016lx\n",
- regs->si, regs->di, regs->bp, regs->sp);
+ regs->si, regs->di, regs->bp, regs->sp);
#endif
put_cpu_var(pf_reason);
BUG();
struct mmiotrace_rw *my_trace = &get_cpu_var(cpu_trace);
const unsigned long instptr = instruction_pointer(regs);
const enum reason_type type = get_ins_type(instptr);
- struct remap_trace *trace = p->user_data;
+ struct remap_trace *trace = p->private;
/* it doesn't make sense to have more than one active trace per cpu */
if (my_reason->active_traces)
/* this should always return the active_trace count to 0 */
my_reason->active_traces--;
if (my_reason->active_traces) {
- pr_emerg(NAME "unexpected post handler");
+ pr_emerg("unexpected post handler");
BUG();
}
put_cpu_var(pf_reason);
}
-static void ioremap_trace_core(unsigned long offset, unsigned long size,
+static void ioremap_trace_core(resource_size_t offset, unsigned long size,
void __iomem *addr)
{
static atomic_t next_id;
struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL);
+ /* These are page-unaligned. */
struct mmiotrace_map map = {
.phys = offset,
.virt = (unsigned long)addr,
};
if (!trace) {
- pr_err(NAME "kmalloc failed in ioremap\n");
+ pr_err("kmalloc failed in ioremap\n");
return;
}
.len = size,
.pre_handler = pre,
.post_handler = post,
- .user_data = trace
+ .private = trace
},
.phys = offset,
.id = atomic_inc_return(&next_id)
map.map_id = trace->id;
spin_lock_irq(&trace_lock);
- if (!is_enabled())
+ if (!is_enabled()) {
+ kfree(trace);
goto not_enabled;
+ }
mmio_trace_mapping(&map);
list_add_tail(&trace->list, &trace_list);
spin_unlock_irq(&trace_lock);
}
-void
-mmiotrace_ioremap(unsigned long offset, unsigned long size, void __iomem *addr)
+void mmiotrace_ioremap(resource_size_t offset, unsigned long size,
+ void __iomem *addr)
{
if (!is_enabled()) /* recheck and proper locking in *_core() */
return;
- pr_debug(NAME "ioremap_*(0x%lx, 0x%lx) = %p\n", offset, size, addr);
+ pr_debug("ioremap_*(0x%llx, 0x%lx) = %p\n",
+ (unsigned long long)offset, size, addr);
if ((filter_offset) && (offset != filter_offset))
return;
ioremap_trace_core(offset, size, addr);
struct remap_trace *tmp;
struct remap_trace *found_trace = NULL;
- pr_debug(NAME "Unmapping %p.\n", addr);
+ pr_debug("Unmapping %p.\n", addr);
spin_lock_irq(&trace_lock);
if (!is_enabled())
iounmap_trace_core(addr);
}
+int mmiotrace_printk(const char *fmt, ...)
+{
+ int ret = 0;
+ va_list args;
+ unsigned long flags;
+ va_start(args, fmt);
+
+ spin_lock_irqsave(&trace_lock, flags);
+ if (is_enabled())
+ ret = mmio_trace_printk(fmt, args);
+ spin_unlock_irqrestore(&trace_lock, flags);
+
+ va_end(args);
+ return ret;
+}
+EXPORT_SYMBOL(mmiotrace_printk);
+
static void clear_trace_list(void)
{
struct remap_trace *trace;
* Caller also ensures is_enabled() cannot change.
*/
list_for_each_entry(trace, &trace_list, list) {
- pr_notice(NAME "purging non-iounmapped "
- "trace @0x%08lx, size 0x%lx.\n",
- trace->probe.addr, trace->probe.len);
+ pr_notice("purging non-iounmapped trace @0x%08lx, size 0x%lx.\n",
+ trace->probe.addr, trace->probe.len);
if (!nommiotrace)
unregister_kmmio_probe(&trace->probe);
}
}
}
-#if 0 /* XXX: out of order */
-static struct file_operations fops_marker = {
- .owner = THIS_MODULE,
- .write = write_marker
-};
+#ifdef CONFIG_HOTPLUG_CPU
+static cpumask_var_t downed_cpus;
+
+static void enter_uniprocessor(void)
+{
+ int cpu;
+ int err;
+
+ if (downed_cpus == NULL &&
+ !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
+ pr_notice("Failed to allocate mask\n");
+ goto out;
+ }
+
+ get_online_cpus();
+ cpumask_copy(downed_cpus, cpu_online_mask);
+ cpumask_clear_cpu(cpumask_first(cpu_online_mask), downed_cpus);
+ if (num_online_cpus() > 1)
+ pr_notice("Disabling non-boot CPUs...\n");
+ put_online_cpus();
+
+ for_each_cpu(cpu, downed_cpus) {
+ err = cpu_down(cpu);
+ if (!err)
+ pr_info("CPU%d is down.\n", cpu);
+ else
+ pr_err("Error taking CPU%d down: %d\n", cpu, err);
+ }
+out:
+ if (num_online_cpus() > 1)
+ pr_warning("multiple CPUs still online, may miss events.\n");
+}
+
+/* __ref because leave_uniprocessor calls cpu_up which is __cpuinit,
+ but this whole function is ifdefed CONFIG_HOTPLUG_CPU */
+static void __ref leave_uniprocessor(void)
+{
+ int cpu;
+ int err;
+
+ if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
+ return;
+ pr_notice("Re-enabling CPUs...\n");
+ for_each_cpu(cpu, downed_cpus) {
+ err = cpu_up(cpu);
+ if (!err)
+ pr_info("enabled CPU%d.\n", cpu);
+ else
+ pr_err("cannot re-enable CPU%d: %d\n", cpu, err);
+ }
+}
+
+#else /* !CONFIG_HOTPLUG_CPU */
+static void enter_uniprocessor(void)
+{
+ if (num_online_cpus() > 1)
+ pr_warning("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)
if (is_enabled())
goto out;
-#if 0 /* XXX: tracing does not support text entries */
- marker_file = debugfs_create_file("marker", 0660, dir, NULL,
- &fops_marker);
- if (!marker_file)
- pr_err(NAME "marker file creation failed.\n");
-#endif
-
if (nommiotrace)
- pr_info(NAME "MMIO tracing disabled.\n");
- if (ISA_trace)
- pr_warning(NAME "Warning! low ISA range will be traced.\n");
+ pr_info("MMIO tracing disabled.\n");
+ kmmio_init();
+ enter_uniprocessor();
spin_lock_irq(&trace_lock);
atomic_inc(&mmiotrace_enabled);
spin_unlock_irq(&trace_lock);
- pr_info(NAME "enabled.\n");
+ pr_info("enabled.\n");
out:
mutex_unlock(&mmiotrace_mutex);
}
spin_unlock_irq(&trace_lock);
clear_trace_list(); /* guarantees: no more kmmio callbacks */
- if (marker_file) {
- debugfs_remove(marker_file);
- marker_file = NULL;
- }
-
- pr_info(NAME "disabled.\n");
+ leave_uniprocessor();
+ kmmio_cleanup();
+ pr_info("disabled.\n");
out:
mutex_unlock(&mmiotrace_mutex);
}