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-rw-r--r--arch/s390/oprofile/hwsampler.c1246
1 files changed, 1246 insertions, 0 deletions
diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c
new file mode 100644
index 00000000000..9daee91e6c3
--- /dev/null
+++ b/arch/s390/oprofile/hwsampler.c
@@ -0,0 +1,1246 @@
+/**
+ * arch/s390/oprofile/hwsampler.c
+ *
+ * Copyright IBM Corp. 2010
+ * Author: Heinz Graalfs <graalfs@de.ibm.com>
+ */
+
+#include <linux/kernel_stat.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/workqueue.h>
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/semaphore.h>
+#include <linux/oom.h>
+#include <linux/oprofile.h>
+
+#include <asm/lowcore.h>
+#include <asm/irq.h>
+
+#include "hwsampler.h"
+#include "op_counter.h"
+
+#define MAX_NUM_SDB 511
+#define MIN_NUM_SDB 1
+
+#define ALERT_REQ_MASK 0x4000000000000000ul
+#define BUFFER_FULL_MASK 0x8000000000000000ul
+
+#define EI_IEA (1 << 31) /* invalid entry address */
+#define EI_ISE (1 << 30) /* incorrect SDBT entry */
+#define EI_PRA (1 << 29) /* program request alert */
+#define EI_SACA (1 << 23) /* sampler authorization change alert */
+#define EI_LSDA (1 << 22) /* loss of sample data alert */
+
+DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
+
+struct hws_execute_parms {
+ void *buffer;
+ signed int rc;
+};
+
+DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
+EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);
+
+static DEFINE_MUTEX(hws_sem);
+static DEFINE_MUTEX(hws_sem_oom);
+
+static unsigned char hws_flush_all;
+static unsigned int hws_oom;
+static struct workqueue_struct *hws_wq;
+
+static unsigned int hws_state;
+enum {
+ HWS_INIT = 1,
+ HWS_DEALLOCATED,
+ HWS_STOPPED,
+ HWS_STARTED,
+ HWS_STOPPING };
+
+/* set to 1 if called by kernel during memory allocation */
+static unsigned char oom_killer_was_active;
+/* size of SDBT and SDB as of allocate API */
+static unsigned long num_sdbt = 100;
+static unsigned long num_sdb = 511;
+/* sampling interval (machine cycles) */
+static unsigned long interval;
+
+static unsigned long min_sampler_rate;
+static unsigned long max_sampler_rate;
+
+static int ssctl(void *buffer)
+{
+ int cc;
+
+ /* set in order to detect a program check */
+ cc = 1;
+
+ asm volatile(
+ "0: .insn s,0xB2870000,0(%1)\n"
+ "1: ipm %0\n"
+ " srl %0,28\n"
+ "2:\n"
+ EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
+ : "+d" (cc), "+a" (buffer)
+ : "m" (*((struct hws_ssctl_request_block *)buffer))
+ : "cc", "memory");
+
+ return cc ? -EINVAL : 0 ;
+}
+
+static int qsi(void *buffer)
+{
+ int cc;
+ cc = 1;
+
+ asm volatile(
+ "0: .insn s,0xB2860000,0(%1)\n"
+ "1: lhi %0,0\n"
+ "2:\n"
+ EX_TABLE(0b, 2b) EX_TABLE(1b, 2b)
+ : "=d" (cc), "+a" (buffer)
+ : "m" (*((struct hws_qsi_info_block *)buffer))
+ : "cc", "memory");
+
+ return cc ? -EINVAL : 0;
+}
+
+static void execute_qsi(void *parms)
+{
+ struct hws_execute_parms *ep = parms;
+
+ ep->rc = qsi(ep->buffer);
+}
+
+static void execute_ssctl(void *parms)
+{
+ struct hws_execute_parms *ep = parms;
+
+ ep->rc = ssctl(ep->buffer);
+}
+
+static int smp_ctl_ssctl_stop(int cpu)
+{
+ int rc;
+ struct hws_execute_parms ep;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ cb->ssctl.es = 0;
+ cb->ssctl.cs = 0;
+
+ ep.buffer = &cb->ssctl;
+ smp_call_function_single(cpu, execute_ssctl, &ep, 1);
+ rc = ep.rc;
+ if (rc) {
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
+ dump_stack();
+ }
+
+ ep.buffer = &cb->qsi;
+ smp_call_function_single(cpu, execute_qsi, &ep, 1);
+
+ if (cb->qsi.es || cb->qsi.cs) {
+ printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
+ dump_stack();
+ }
+
+ return rc;
+}
+
+static int smp_ctl_ssctl_deactivate(int cpu)
+{
+ int rc;
+ struct hws_execute_parms ep;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ cb->ssctl.es = 1;
+ cb->ssctl.cs = 0;
+
+ ep.buffer = &cb->ssctl;
+ smp_call_function_single(cpu, execute_ssctl, &ep, 1);
+ rc = ep.rc;
+ if (rc)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
+
+ ep.buffer = &cb->qsi;
+ smp_call_function_single(cpu, execute_qsi, &ep, 1);
+
+ if (cb->qsi.cs)
+ printk(KERN_EMERG "CPUMF sampling was not set inactive.\n");
+
+ return rc;
+}
+
+static int smp_ctl_ssctl_enable_activate(int cpu, unsigned long interval)
+{
+ int rc;
+ struct hws_execute_parms ep;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ cb->ssctl.h = 1;
+ cb->ssctl.tear = cb->first_sdbt;
+ cb->ssctl.dear = *(unsigned long *) cb->first_sdbt;
+ cb->ssctl.interval = interval;
+ cb->ssctl.es = 1;
+ cb->ssctl.cs = 1;
+
+ ep.buffer = &cb->ssctl;
+ smp_call_function_single(cpu, execute_ssctl, &ep, 1);
+ rc = ep.rc;
+ if (rc)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
+
+ ep.buffer = &cb->qsi;
+ smp_call_function_single(cpu, execute_qsi, &ep, 1);
+ if (ep.rc)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF QSI failed.\n", cpu);
+
+ return rc;
+}
+
+static int smp_ctl_qsi(int cpu)
+{
+ struct hws_execute_parms ep;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ ep.buffer = &cb->qsi;
+ smp_call_function_single(cpu, execute_qsi, &ep, 1);
+
+ return ep.rc;
+}
+
+static inline unsigned long *trailer_entry_ptr(unsigned long v)
+{
+ void *ret;
+
+ ret = (void *)v;
+ ret += PAGE_SIZE;
+ ret -= sizeof(struct hws_trailer_entry);
+
+ return (unsigned long *) ret;
+}
+
+/* prototypes for external interrupt handler and worker */
+static void hws_ext_handler(unsigned int ext_int_code,
+ unsigned int param32, unsigned long param64);
+
+static void worker(struct work_struct *work);
+
+static void add_samples_to_oprofile(unsigned cpu, unsigned long *,
+ unsigned long *dear);
+
+static void init_all_cpu_buffers(void)
+{
+ int cpu;
+ struct hws_cpu_buffer *cb;
+
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ memset(cb, 0, sizeof(struct hws_cpu_buffer));
+ }
+}
+
+static int is_link_entry(unsigned long *s)
+{
+ return *s & 0x1ul ? 1 : 0;
+}
+
+static unsigned long *get_next_sdbt(unsigned long *s)
+{
+ return (unsigned long *) (*s & ~0x1ul);
+}
+
+static int prepare_cpu_buffers(void)
+{
+ int cpu;
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ rc = 0;
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ atomic_set(&cb->ext_params, 0);
+ cb->worker_entry = 0;
+ cb->sample_overflow = 0;
+ cb->req_alert = 0;
+ cb->incorrect_sdbt_entry = 0;
+ cb->invalid_entry_address = 0;
+ cb->loss_of_sample_data = 0;
+ cb->sample_auth_change_alert = 0;
+ cb->finish = 0;
+ cb->oom = 0;
+ cb->stop_mode = 0;
+ }
+
+ return rc;
+}
+
+/*
+ * allocate_sdbt() - allocate sampler memory
+ * @cpu: the cpu for which sampler memory is allocated
+ *
+ * A 4K page is allocated for each requested SDBT.
+ * A maximum of 511 4K pages are allocated for the SDBs in each of the SDBTs.
+ * Set ALERT_REQ mask in each SDBs trailer.
+ * Returns zero if successful, <0 otherwise.
+ */
+static int allocate_sdbt(int cpu)
+{
+ int j, k, rc;
+ unsigned long *sdbt;
+ unsigned long sdb;
+ unsigned long *tail;
+ unsigned long *trailer;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ if (cb->first_sdbt)
+ return -EINVAL;
+
+ sdbt = NULL;
+ tail = sdbt;
+
+ for (j = 0; j < num_sdbt; j++) {
+ sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL);
+
+ mutex_lock(&hws_sem_oom);
+ /* OOM killer might have been activated */
+ barrier();
+ if (oom_killer_was_active || !sdbt) {
+ if (sdbt)
+ free_page((unsigned long)sdbt);
+
+ goto allocate_sdbt_error;
+ }
+ if (cb->first_sdbt == 0)
+ cb->first_sdbt = (unsigned long)sdbt;
+
+ /* link current page to tail of chain */
+ if (tail)
+ *tail = (unsigned long)(void *)sdbt + 1;
+
+ mutex_unlock(&hws_sem_oom);
+
+ for (k = 0; k < num_sdb; k++) {
+ /* get and set SDB page */
+ sdb = get_zeroed_page(GFP_KERNEL);
+
+ mutex_lock(&hws_sem_oom);
+ /* OOM killer might have been activated */
+ barrier();
+ if (oom_killer_was_active || !sdb) {
+ if (sdb)
+ free_page(sdb);
+
+ goto allocate_sdbt_error;
+ }
+ *sdbt = sdb;
+ trailer = trailer_entry_ptr(*sdbt);
+ *trailer = ALERT_REQ_MASK;
+ sdbt++;
+ mutex_unlock(&hws_sem_oom);
+ }
+ tail = sdbt;
+ }
+ mutex_lock(&hws_sem_oom);
+ if (oom_killer_was_active)
+ goto allocate_sdbt_error;
+
+ rc = 0;
+ if (tail)
+ *tail = (unsigned long)
+ ((void *)cb->first_sdbt) + 1;
+
+allocate_sdbt_exit:
+ mutex_unlock(&hws_sem_oom);
+ return rc;
+
+allocate_sdbt_error:
+ rc = -ENOMEM;
+ goto allocate_sdbt_exit;
+}
+
+/*
+ * deallocate_sdbt() - deallocate all sampler memory
+ *
+ * For each online CPU all SDBT trees are deallocated.
+ * Returns the number of freed pages.
+ */
+static int deallocate_sdbt(void)
+{
+ int cpu;
+ int counter;
+
+ counter = 0;
+
+ for_each_online_cpu(cpu) {
+ unsigned long start;
+ unsigned long sdbt;
+ unsigned long *curr;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ if (!cb->first_sdbt)
+ continue;
+
+ sdbt = cb->first_sdbt;
+ curr = (unsigned long *) sdbt;
+ start = sdbt;
+
+ /* we'll free the SDBT after all SDBs are processed... */
+ while (1) {
+ if (!*curr || !sdbt)
+ break;
+
+ /* watch for link entry reset if found */
+ if (is_link_entry(curr)) {
+ curr = get_next_sdbt(curr);
+ if (sdbt)
+ free_page(sdbt);
+
+ /* we are done if we reach the start */
+ if ((unsigned long) curr == start)
+ break;
+ else
+ sdbt = (unsigned long) curr;
+ } else {
+ /* process SDB pointer */
+ if (*curr) {
+ free_page(*curr);
+ curr++;
+ }
+ }
+ counter++;
+ }
+ cb->first_sdbt = 0;
+ }
+ return counter;
+}
+
+static int start_sampling(int cpu)
+{
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ rc = smp_ctl_ssctl_enable_activate(cpu, interval);
+ if (rc) {
+ printk(KERN_INFO "hwsampler: CPU %d ssctl failed.\n", cpu);
+ goto start_exit;
+ }
+
+ rc = -EINVAL;
+ if (!cb->qsi.es) {
+ printk(KERN_INFO "hwsampler: CPU %d ssctl not enabled.\n", cpu);
+ goto start_exit;
+ }
+
+ if (!cb->qsi.cs) {
+ printk(KERN_INFO "hwsampler: CPU %d ssctl not active.\n", cpu);
+ goto start_exit;
+ }
+
+ printk(KERN_INFO
+ "hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
+ cpu, interval);
+
+ rc = 0;
+
+start_exit:
+ return rc;
+}
+
+static int stop_sampling(int cpu)
+{
+ unsigned long v;
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ if (!rc && !cb->qsi.es)
+ printk(KERN_INFO "hwsampler: CPU %d, already stopped.\n", cpu);
+
+ rc = smp_ctl_ssctl_stop(cpu);
+ if (rc) {
+ printk(KERN_INFO "hwsampler: CPU %d, ssctl stop error %d.\n",
+ cpu, rc);
+ goto stop_exit;
+ }
+
+ printk(KERN_INFO "hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu);
+
+stop_exit:
+ v = cb->req_alert;
+ if (v)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF Request alert,"
+ " count=%lu.\n", cpu, v);
+
+ v = cb->loss_of_sample_data;
+ if (v)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF Loss of sample data,"
+ " count=%lu.\n", cpu, v);
+
+ v = cb->invalid_entry_address;
+ if (v)
+ printk(KERN_ERR "hwsampler: CPU %d CPUMF Invalid entry address,"
+ " count=%lu.\n", cpu, v);
+
+ v = cb->incorrect_sdbt_entry;
+ if (v)
+ printk(KERN_ERR
+ "hwsampler: CPU %d CPUMF Incorrect SDBT address,"
+ " count=%lu.\n", cpu, v);
+
+ v = cb->sample_auth_change_alert;
+ if (v)
+ printk(KERN_ERR
+ "hwsampler: CPU %d CPUMF Sample authorization change,"
+ " count=%lu.\n", cpu, v);
+
+ return rc;
+}
+
+static int check_hardware_prerequisites(void)
+{
+ if (!test_facility(68))
+ return -EOPNOTSUPP;
+ return 0;
+}
+/*
+ * hws_oom_callback() - the OOM callback function
+ *
+ * In case the callback is invoked during memory allocation for the
+ * hw sampler, all obtained memory is deallocated and a flag is set
+ * so main sampler memory allocation can exit with a failure code.
+ * In case the callback is invoked during sampling the hw sampler
+ * is deactivated for all CPUs.
+ */
+static int hws_oom_callback(struct notifier_block *nfb,
+ unsigned long dummy, void *parm)
+{
+ unsigned long *freed;
+ int cpu;
+ struct hws_cpu_buffer *cb;
+
+ freed = parm;
+
+ mutex_lock(&hws_sem_oom);
+
+ if (hws_state == HWS_DEALLOCATED) {
+ /* during memory allocation */
+ if (oom_killer_was_active == 0) {
+ oom_killer_was_active = 1;
+ *freed += deallocate_sdbt();
+ }
+ } else {
+ int i;
+ cpu = get_cpu();
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ if (!cb->oom) {
+ for_each_online_cpu(i) {
+ smp_ctl_ssctl_deactivate(i);
+ cb->oom = 1;
+ }
+ cb->finish = 1;
+
+ printk(KERN_INFO
+ "hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
+ cpu);
+ }
+ }
+
+ mutex_unlock(&hws_sem_oom);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block hws_oom_notifier = {
+ .notifier_call = hws_oom_callback
+};
+
+static int hws_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ /* We do not have sampler space available for all possible CPUs.
+ All CPUs should be online when hw sampling is activated. */
+ return (hws_state <= HWS_DEALLOCATED) ? NOTIFY_OK : NOTIFY_BAD;
+}
+
+static struct notifier_block hws_cpu_notifier = {
+ .notifier_call = hws_cpu_callback
+};
+
+/**
+ * hwsampler_deactivate() - set hardware sampling temporarily inactive
+ * @cpu: specifies the CPU to be set inactive.
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_deactivate(unsigned int cpu)
+{
+ /*
+ * Deactivate hw sampling temporarily and flush the buffer
+ * by pushing all the pending samples to oprofile buffer.
+ *
+ * This function can be called under one of the following conditions:
+ * Memory unmap, task is exiting.
+ */
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ rc = 0;
+ mutex_lock(&hws_sem);
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ if (hws_state == HWS_STARTED) {
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+ if (cb->qsi.cs) {
+ rc = smp_ctl_ssctl_deactivate(cpu);
+ if (rc) {
+ printk(KERN_INFO
+ "hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu);
+ cb->finish = 1;
+ hws_state = HWS_STOPPING;
+ } else {
+ hws_flush_all = 1;
+ /* Add work to queue to read pending samples.*/
+ queue_work_on(cpu, hws_wq, &cb->worker);
+ }
+ }
+ }
+ mutex_unlock(&hws_sem);
+
+ if (hws_wq)
+ flush_workqueue(hws_wq);
+
+ return rc;
+}
+
+/**
+ * hwsampler_activate() - activate/resume hardware sampling which was deactivated
+ * @cpu: specifies the CPU to be set active.
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_activate(unsigned int cpu)
+{
+ /*
+ * Re-activate hw sampling. This should be called in pair with
+ * hwsampler_deactivate().
+ */
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ rc = 0;
+ mutex_lock(&hws_sem);
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ if (hws_state == HWS_STARTED) {
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+ if (!cb->qsi.cs) {
+ hws_flush_all = 0;
+ rc = smp_ctl_ssctl_enable_activate(cpu, interval);
+ if (rc) {
+ printk(KERN_ERR
+ "CPU %d, CPUMF activate sampling failed.\n",
+ cpu);
+ }
+ }
+ }
+
+ mutex_unlock(&hws_sem);
+
+ return rc;
+}
+
+static void hws_ext_handler(unsigned int ext_int_code,
+ unsigned int param32, unsigned long param64)
+{
+ struct hws_cpu_buffer *cb;
+
+ kstat_cpu(smp_processor_id()).irqs[EXTINT_CPM]++;
+ cb = &__get_cpu_var(sampler_cpu_buffer);
+ atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32);
+ if (hws_wq)
+ queue_work(hws_wq, &cb->worker);
+}
+
+static int check_qsi_on_setup(void)
+{
+ int rc;
+ unsigned int cpu;
+ struct hws_cpu_buffer *cb;
+
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+ if (rc)
+ return -EOPNOTSUPP;
+
+ if (!cb->qsi.as) {
+ printk(KERN_INFO "hwsampler: CPUMF sampling is not authorized.\n");
+ return -EINVAL;
+ }
+
+ if (cb->qsi.es) {
+ printk(KERN_WARNING "hwsampler: CPUMF is still enabled.\n");
+ rc = smp_ctl_ssctl_stop(cpu);
+ if (rc)
+ return -EINVAL;
+
+ printk(KERN_INFO
+ "CPU %d, CPUMF Sampling stopped now.\n", cpu);
+ }
+ }
+ return 0;
+}
+
+static int check_qsi_on_start(void)
+{
+ unsigned int cpu;
+ int rc;
+ struct hws_cpu_buffer *cb;
+
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+
+ if (!cb->qsi.as)
+ return -EINVAL;
+
+ if (cb->qsi.es)
+ return -EINVAL;
+
+ if (cb->qsi.cs)
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static void worker_on_start(unsigned int cpu)
+{
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ cb->worker_entry = cb->first_sdbt;
+}
+
+static int worker_check_error(unsigned int cpu, int ext_params)
+{
+ int rc;
+ unsigned long *sdbt;
+ struct hws_cpu_buffer *cb;
+
+ rc = 0;
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ sdbt = (unsigned long *) cb->worker_entry;
+
+ if (!sdbt || !*sdbt)
+ return -EINVAL;
+
+ if (ext_params & EI_PRA)
+ cb->req_alert++;
+
+ if (ext_params & EI_LSDA)
+ cb->loss_of_sample_data++;
+
+ if (ext_params & EI_IEA) {
+ cb->invalid_entry_address++;
+ rc = -EINVAL;
+ }
+
+ if (ext_params & EI_ISE) {
+ cb->incorrect_sdbt_entry++;
+ rc = -EINVAL;
+ }
+
+ if (ext_params & EI_SACA) {
+ cb->sample_auth_change_alert++;
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+static void worker_on_finish(unsigned int cpu)
+{
+ int rc, i;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ if (cb->finish) {
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+ if (cb->qsi.es) {
+ printk(KERN_INFO
+ "hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
+ cpu);
+ rc = smp_ctl_ssctl_stop(cpu);
+ if (rc)
+ printk(KERN_INFO
+ "hwsampler: CPU %d, CPUMF Deactivation failed.\n",
+ cpu);
+
+ for_each_online_cpu(i) {
+ if (i == cpu)
+ continue;
+ if (!cb->finish) {
+ cb->finish = 1;
+ queue_work_on(i, hws_wq,
+ &cb->worker);
+ }
+ }
+ }
+ }
+}
+
+static void worker_on_interrupt(unsigned int cpu)
+{
+ unsigned long *sdbt;
+ unsigned char done;
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ sdbt = (unsigned long *) cb->worker_entry;
+
+ done = 0;
+ /* do not proceed if stop was entered,
+ * forget the buffers not yet processed */
+ while (!done && !cb->stop_mode) {
+ unsigned long *trailer;
+ struct hws_trailer_entry *te;
+ unsigned long *dear = 0;
+
+ trailer = trailer_entry_ptr(*sdbt);
+ /* leave loop if no more work to do */
+ if (!(*trailer & BUFFER_FULL_MASK)) {
+ done = 1;
+ if (!hws_flush_all)
+ continue;
+ }
+
+ te = (struct hws_trailer_entry *)trailer;
+ cb->sample_overflow += te->overflow;
+
+ add_samples_to_oprofile(cpu, sdbt, dear);
+
+ /* reset trailer */
+ xchg((unsigned char *) te, 0x40);
+
+ /* advance to next sdb slot in current sdbt */
+ sdbt++;
+ /* in case link bit is set use address w/o link bit */
+ if (is_link_entry(sdbt))
+ sdbt = get_next_sdbt(sdbt);
+
+ cb->worker_entry = (unsigned long)sdbt;
+ }
+}
+
+static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
+ unsigned long *dear)
+{
+ struct hws_data_entry *sample_data_ptr;
+ unsigned long *trailer;
+
+ trailer = trailer_entry_ptr(*sdbt);
+ if (dear) {
+ if (dear > trailer)
+ return;
+ trailer = dear;
+ }
+
+ sample_data_ptr = (struct hws_data_entry *)(*sdbt);
+
+ while ((unsigned long *)sample_data_ptr < trailer) {
+ struct pt_regs *regs = NULL;
+ struct task_struct *tsk = NULL;
+
+ /*
+ * Check sampling mode, 1 indicates basic (=customer) sampling
+ * mode.
+ */
+ if (sample_data_ptr->def != 1) {
+ /* sample slot is not yet written */
+ break;
+ } else {
+ /* make sure we don't use it twice,
+ * the next time the sampler will set it again */
+ sample_data_ptr->def = 0;
+ }
+
+ /* Get pt_regs. */
+ if (sample_data_ptr->P == 1) {
+ /* userspace sample */
+ unsigned int pid = sample_data_ptr->prim_asn;
+ if (!counter_config.user)
+ goto skip_sample;
+ rcu_read_lock();
+ tsk = pid_task(find_vpid(pid), PIDTYPE_PID);
+ if (tsk)
+ regs = task_pt_regs(tsk);
+ rcu_read_unlock();
+ } else {
+ /* kernelspace sample */
+ if (!counter_config.kernel)
+ goto skip_sample;
+ regs = task_pt_regs(current);
+ }
+
+ mutex_lock(&hws_sem);
+ oprofile_add_ext_hw_sample(sample_data_ptr->ia, regs, 0,
+ !sample_data_ptr->P, tsk);
+ mutex_unlock(&hws_sem);
+ skip_sample:
+ sample_data_ptr++;
+ }
+}
+
+static void worker(struct work_struct *work)
+{
+ unsigned int cpu;
+ int ext_params;
+ struct hws_cpu_buffer *cb;
+
+ cb = container_of(work, struct hws_cpu_buffer, worker);
+ cpu = smp_processor_id();
+ ext_params = atomic_xchg(&cb->ext_params, 0);
+
+ if (!cb->worker_entry)
+ worker_on_start(cpu);
+
+ if (worker_check_error(cpu, ext_params))
+ return;
+
+ if (!cb->finish)
+ worker_on_interrupt(cpu);
+
+ if (cb->finish)
+ worker_on_finish(cpu);
+}
+
+/**
+ * hwsampler_allocate() - allocate memory for the hardware sampler
+ * @sdbt: number of SDBTs per online CPU (must be > 0)
+ * @sdb: number of SDBs per SDBT (minimum 1, maximum 511)
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_allocate(unsigned long sdbt, unsigned long sdb)
+{
+ int cpu, rc;
+ mutex_lock(&hws_sem);
+
+ rc = -EINVAL;
+ if (hws_state != HWS_DEALLOCATED)
+ goto allocate_exit;
+
+ if (sdbt < 1)
+ goto allocate_exit;
+
+ if (sdb > MAX_NUM_SDB || sdb < MIN_NUM_SDB)
+ goto allocate_exit;
+
+ num_sdbt = sdbt;
+ num_sdb = sdb;
+
+ oom_killer_was_active = 0;
+ register_oom_notifier(&hws_oom_notifier);
+
+ for_each_online_cpu(cpu) {
+ if (allocate_sdbt(cpu)) {
+ unregister_oom_notifier(&hws_oom_notifier);
+ goto allocate_error;
+ }
+ }
+ unregister_oom_notifier(&hws_oom_notifier);
+ if (oom_killer_was_active)
+ goto allocate_error;
+
+ hws_state = HWS_STOPPED;
+ rc = 0;
+
+allocate_exit:
+ mutex_unlock(&hws_sem);
+ return rc;
+
+allocate_error:
+ rc = -ENOMEM;
+ printk(KERN_ERR "hwsampler: CPUMF Memory allocation failed.\n");
+ goto allocate_exit;
+}
+
+/**
+ * hwsampler_deallocate() - deallocate hardware sampler memory
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_deallocate(void)
+{
+ int rc;
+
+ mutex_lock(&hws_sem);
+
+ rc = -EINVAL;
+ if (hws_state != HWS_STOPPED)
+ goto deallocate_exit;
+
+ ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
+ deallocate_sdbt();
+
+ hws_state = HWS_DEALLOCATED;
+ rc = 0;
+
+deallocate_exit:
+ mutex_unlock(&hws_sem);
+
+ return rc;
+}
+
+unsigned long hwsampler_query_min_interval(void)
+{
+ return min_sampler_rate;
+}
+
+unsigned long hwsampler_query_max_interval(void)
+{
+ return max_sampler_rate;
+}
+
+unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu)
+{
+ struct hws_cpu_buffer *cb;
+
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+
+ return cb->sample_overflow;
+}
+
+int hwsampler_setup(void)
+{
+ int rc;
+ int cpu;
+ struct hws_cpu_buffer *cb;
+
+ mutex_lock(&hws_sem);
+
+ rc = -EINVAL;
+ if (hws_state)
+ goto setup_exit;
+
+ hws_state = HWS_INIT;
+
+ init_all_cpu_buffers();
+
+ rc = check_hardware_prerequisites();
+ if (rc)
+ goto setup_exit;
+
+ rc = check_qsi_on_setup();
+ if (rc)
+ goto setup_exit;
+
+ rc = -EINVAL;
+ hws_wq = create_workqueue("hwsampler");
+ if (!hws_wq)
+ goto setup_exit;
+
+ register_cpu_notifier(&hws_cpu_notifier);
+
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ INIT_WORK(&cb->worker, worker);
+ rc = smp_ctl_qsi(cpu);
+ WARN_ON(rc);
+ if (min_sampler_rate != cb->qsi.min_sampl_rate) {
+ if (min_sampler_rate) {
+ printk(KERN_WARNING
+ "hwsampler: different min sampler rate values.\n");
+ if (min_sampler_rate < cb->qsi.min_sampl_rate)
+ min_sampler_rate =
+ cb->qsi.min_sampl_rate;
+ } else
+ min_sampler_rate = cb->qsi.min_sampl_rate;
+ }
+ if (max_sampler_rate != cb->qsi.max_sampl_rate) {
+ if (max_sampler_rate) {
+ printk(KERN_WARNING
+ "hwsampler: different max sampler rate values.\n");
+ if (max_sampler_rate > cb->qsi.max_sampl_rate)
+ max_sampler_rate =
+ cb->qsi.max_sampl_rate;
+ } else
+ max_sampler_rate = cb->qsi.max_sampl_rate;
+ }
+ }
+ register_external_interrupt(0x1407, hws_ext_handler);
+
+ hws_state = HWS_DEALLOCATED;
+ rc = 0;
+
+setup_exit:
+ mutex_unlock(&hws_sem);
+ return rc;
+}
+
+int hwsampler_shutdown(void)
+{
+ int rc;
+
+ mutex_lock(&hws_sem);
+
+ rc = -EINVAL;
+ if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
+ mutex_unlock(&hws_sem);
+
+ if (hws_wq)
+ flush_workqueue(hws_wq);
+
+ mutex_lock(&hws_sem);
+
+ if (hws_state == HWS_STOPPED) {
+ ctl_clear_bit(0, 5); /* set bit 58 CR0 off */
+ deallocate_sdbt();
+ }
+ if (hws_wq) {
+ destroy_workqueue(hws_wq);
+ hws_wq = NULL;
+ }
+
+ unregister_external_interrupt(0x1407, hws_ext_handler);
+ hws_state = HWS_INIT;
+ rc = 0;
+ }
+ mutex_unlock(&hws_sem);
+
+ unregister_cpu_notifier(&hws_cpu_notifier);
+
+ return rc;
+}
+
+/**
+ * hwsampler_start_all() - start hardware sampling on all online CPUs
+ * @rate: specifies the used interval when samples are taken
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_start_all(unsigned long rate)
+{
+ int rc, cpu;
+
+ mutex_lock(&hws_sem);
+
+ hws_oom = 0;
+
+ rc = -EINVAL;
+ if (hws_state != HWS_STOPPED)
+ goto start_all_exit;
+
+ interval = rate;
+
+ /* fail if rate is not valid */
+ if (interval < min_sampler_rate || interval > max_sampler_rate)
+ goto start_all_exit;
+
+ rc = check_qsi_on_start();
+ if (rc)
+ goto start_all_exit;
+
+ rc = prepare_cpu_buffers();
+ if (rc)
+ goto start_all_exit;
+
+ for_each_online_cpu(cpu) {
+ rc = start_sampling(cpu);
+ if (rc)
+ break;
+ }
+ if (rc) {
+ for_each_online_cpu(cpu) {
+ stop_sampling(cpu);
+ }
+ goto start_all_exit;
+ }
+ hws_state = HWS_STARTED;
+ rc = 0;
+
+start_all_exit:
+ mutex_unlock(&hws_sem);
+
+ if (rc)
+ return rc;
+
+ register_oom_notifier(&hws_oom_notifier);
+ hws_oom = 1;
+ hws_flush_all = 0;
+ /* now let them in, 1407 CPUMF external interrupts */
+ ctl_set_bit(0, 5); /* set CR0 bit 58 */
+
+ return 0;
+}
+
+/**
+ * hwsampler_stop_all() - stop hardware sampling on all online CPUs
+ *
+ * Returns 0 on success, !0 on failure.
+ */
+int hwsampler_stop_all(void)
+{
+ int tmp_rc, rc, cpu;
+ struct hws_cpu_buffer *cb;
+
+ mutex_lock(&hws_sem);
+
+ rc = 0;
+ if (hws_state == HWS_INIT) {
+ mutex_unlock(&hws_sem);
+ return rc;
+ }
+ hws_state = HWS_STOPPING;
+ mutex_unlock(&hws_sem);
+
+ for_each_online_cpu(cpu) {
+ cb = &per_cpu(sampler_cpu_buffer, cpu);
+ cb->stop_mode = 1;
+ tmp_rc = stop_sampling(cpu);
+ if (tmp_rc)
+ rc = tmp_rc;
+ }
+
+ if (hws_wq)
+ flush_workqueue(hws_wq);
+
+ mutex_lock(&hws_sem);
+ if (hws_oom) {
+ unregister_oom_notifier(&hws_oom_notifier);
+ hws_oom = 0;
+ }
+ hws_state = HWS_STOPPED;
+ mutex_unlock(&hws_sem);
+
+ return rc;
+}