diff options
Diffstat (limited to 'kernel/arch/s390/oprofile/hwsampler.c')
| -rw-r--r-- | kernel/arch/s390/oprofile/hwsampler.c | 1178 |
1 files changed, 1178 insertions, 0 deletions
diff --git a/kernel/arch/s390/oprofile/hwsampler.c b/kernel/arch/s390/oprofile/hwsampler.c new file mode 100644 index 000000000..ff9b4eb34 --- /dev/null +++ b/kernel/arch/s390/oprofile/hwsampler.c @@ -0,0 +1,1178 @@ +/* + * 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/facility.h> +#include <asm/cpu_mf.h> +#include <asm/irq.h> + +#include "hwsampler.h" +#include "op_counter.h" + +#define MAX_NUM_SDB 511 +#define MIN_NUM_SDB 1 + +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 unsigned int hws_alert; +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 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 = lsctl(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 void hws_ext_handler(struct ext_code ext_code, + unsigned int param32, unsigned long param64) +{ + struct hws_cpu_buffer *cb = this_cpu_ptr(&sampler_cpu_buffer); + + if (!(param32 & CPU_MF_INT_SF_MASK)) + return; + + if (!hws_alert) + return; + + inc_irq_stat(IRQEXT_CMS); + atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32); + + if (hws_wq) + queue_work(hws_wq, &cb->worker); +} + +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 void prepare_cpu_buffers(void) +{ + struct hws_cpu_buffer *cb; + int cpu; + + 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; + } +} + +/* + * 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 = SDB_TE_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 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 & CPU_MF_INT_SF_PRA) + cb->req_alert++; + + if (ext_params & CPU_MF_INT_SF_LSDA) + cb->loss_of_sample_data++; + + if (ext_params & CPU_MF_INT_SF_IAE) { + cb->invalid_entry_address++; + rc = -EINVAL; + } + + if (ext_params & CPU_MF_INT_SF_ISE) { + cb->incorrect_sdbt_entry++; + rc = -EINVAL; + } + + if (ext_params & CPU_MF_INT_SF_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 & SDB_TE_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_basic_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_basic_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; + + irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); + hws_alert = 0; + 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_irq(EXT_IRQ_MEASURE_ALERT, 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) { + irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT); + hws_alert = 0; + deallocate_sdbt(); + } + if (hws_wq) { + destroy_workqueue(hws_wq); + hws_wq = NULL; + } + + unregister_external_irq(EXT_IRQ_MEASURE_ALERT, 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; + + prepare_cpu_buffers(); + + 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 */ + hws_alert = 1; + irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT); + + 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 0; + } + 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; +} |