aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/oprofile/cell/spu_task_sync.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/oprofile/cell/spu_task_sync.c')
-rw-r--r--arch/powerpc/oprofile/cell/spu_task_sync.c484
1 files changed, 484 insertions, 0 deletions
diff --git a/arch/powerpc/oprofile/cell/spu_task_sync.c b/arch/powerpc/oprofile/cell/spu_task_sync.c
new file mode 100644
index 00000000000..133665754a7
--- /dev/null
+++ b/arch/powerpc/oprofile/cell/spu_task_sync.c
@@ -0,0 +1,484 @@
+/*
+ * Cell Broadband Engine OProfile Support
+ *
+ * (C) Copyright IBM Corporation 2006
+ *
+ * Author: Maynard Johnson <maynardj@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+/* The purpose of this file is to handle SPU event task switching
+ * and to record SPU context information into the OProfile
+ * event buffer.
+ *
+ * Additionally, the spu_sync_buffer function is provided as a helper
+ * for recoding actual SPU program counter samples to the event buffer.
+ */
+#include <linux/dcookies.h>
+#include <linux/kref.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/numa.h>
+#include <linux/oprofile.h>
+#include <linux/spinlock.h>
+#include "pr_util.h"
+
+#define RELEASE_ALL 9999
+
+static DEFINE_SPINLOCK(buffer_lock);
+static DEFINE_SPINLOCK(cache_lock);
+static int num_spu_nodes;
+int spu_prof_num_nodes;
+int last_guard_val[MAX_NUMNODES * 8];
+
+/* Container for caching information about an active SPU task. */
+struct cached_info {
+ struct vma_to_fileoffset_map *map;
+ struct spu *the_spu; /* needed to access pointer to local_store */
+ struct kref cache_ref;
+};
+
+static struct cached_info *spu_info[MAX_NUMNODES * 8];
+
+static void destroy_cached_info(struct kref *kref)
+{
+ struct cached_info *info;
+
+ info = container_of(kref, struct cached_info, cache_ref);
+ vma_map_free(info->map);
+ kfree(info);
+ module_put(THIS_MODULE);
+}
+
+/* Return the cached_info for the passed SPU number.
+ * ATTENTION: Callers are responsible for obtaining the
+ * cache_lock if needed prior to invoking this function.
+ */
+static struct cached_info *get_cached_info(struct spu *the_spu, int spu_num)
+{
+ struct kref *ref;
+ struct cached_info *ret_info;
+
+ if (spu_num >= num_spu_nodes) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: Invalid index %d into spu info cache\n",
+ __FUNCTION__, __LINE__, spu_num);
+ ret_info = NULL;
+ goto out;
+ }
+ if (!spu_info[spu_num] && the_spu) {
+ ref = spu_get_profile_private_kref(the_spu->ctx);
+ if (ref) {
+ spu_info[spu_num] = container_of(ref, struct cached_info, cache_ref);
+ kref_get(&spu_info[spu_num]->cache_ref);
+ }
+ }
+
+ ret_info = spu_info[spu_num];
+ out:
+ return ret_info;
+}
+
+
+/* Looks for cached info for the passed spu. If not found, the
+ * cached info is created for the passed spu.
+ * Returns 0 for success; otherwise, -1 for error.
+ */
+static int
+prepare_cached_spu_info(struct spu *spu, unsigned long objectId)
+{
+ unsigned long flags;
+ struct vma_to_fileoffset_map *new_map;
+ int retval = 0;
+ struct cached_info *info;
+
+ /* We won't bother getting cache_lock here since
+ * don't do anything with the cached_info that's returned.
+ */
+ info = get_cached_info(spu, spu->number);
+
+ if (info) {
+ pr_debug("Found cached SPU info.\n");
+ goto out;
+ }
+
+ /* Create cached_info and set spu_info[spu->number] to point to it.
+ * spu->number is a system-wide value, not a per-node value.
+ */
+ info = kzalloc(sizeof(struct cached_info), GFP_KERNEL);
+ if (!info) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: create vma_map failed\n",
+ __FUNCTION__, __LINE__);
+ retval = -ENOMEM;
+ goto err_alloc;
+ }
+ new_map = create_vma_map(spu, objectId);
+ if (!new_map) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: create vma_map failed\n",
+ __FUNCTION__, __LINE__);
+ retval = -ENOMEM;
+ goto err_alloc;
+ }
+
+ pr_debug("Created vma_map\n");
+ info->map = new_map;
+ info->the_spu = spu;
+ kref_init(&info->cache_ref);
+ spin_lock_irqsave(&cache_lock, flags);
+ spu_info[spu->number] = info;
+ /* Increment count before passing off ref to SPUFS. */
+ kref_get(&info->cache_ref);
+
+ /* We increment the module refcount here since SPUFS is
+ * responsible for the final destruction of the cached_info,
+ * and it must be able to access the destroy_cached_info()
+ * function defined in the OProfile module. We decrement
+ * the module refcount in destroy_cached_info.
+ */
+ try_module_get(THIS_MODULE);
+ spu_set_profile_private_kref(spu->ctx, &info->cache_ref,
+ destroy_cached_info);
+ spin_unlock_irqrestore(&cache_lock, flags);
+ goto out;
+
+err_alloc:
+ kfree(info);
+out:
+ return retval;
+}
+
+/*
+ * NOTE: The caller is responsible for locking the
+ * cache_lock prior to calling this function.
+ */
+static int release_cached_info(int spu_index)
+{
+ int index, end;
+
+ if (spu_index == RELEASE_ALL) {
+ end = num_spu_nodes;
+ index = 0;
+ } else {
+ if (spu_index >= num_spu_nodes) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: "
+ "Invalid index %d into spu info cache\n",
+ __FUNCTION__, __LINE__, spu_index);
+ goto out;
+ }
+ end = spu_index + 1;
+ index = spu_index;
+ }
+ for (; index < end; index++) {
+ if (spu_info[index]) {
+ kref_put(&spu_info[index]->cache_ref,
+ destroy_cached_info);
+ spu_info[index] = NULL;
+ }
+ }
+
+out:
+ return 0;
+}
+
+/* The source code for fast_get_dcookie was "borrowed"
+ * from drivers/oprofile/buffer_sync.c.
+ */
+
+/* Optimisation. We can manage without taking the dcookie sem
+ * because we cannot reach this code without at least one
+ * dcookie user still being registered (namely, the reader
+ * of the event buffer).
+ */
+static inline unsigned long fast_get_dcookie(struct dentry *dentry,
+ struct vfsmount *vfsmnt)
+{
+ unsigned long cookie;
+
+ if (dentry->d_cookie)
+ return (unsigned long)dentry;
+ get_dcookie(dentry, vfsmnt, &cookie);
+ return cookie;
+}
+
+/* Look up the dcookie for the task's first VM_EXECUTABLE mapping,
+ * which corresponds loosely to "application name". Also, determine
+ * the offset for the SPU ELF object. If computed offset is
+ * non-zero, it implies an embedded SPU object; otherwise, it's a
+ * separate SPU binary, in which case we retrieve it's dcookie.
+ * For the embedded case, we must determine if SPU ELF is embedded
+ * in the executable application or another file (i.e., shared lib).
+ * If embedded in a shared lib, we must get the dcookie and return
+ * that to the caller.
+ */
+static unsigned long
+get_exec_dcookie_and_offset(struct spu *spu, unsigned int *offsetp,
+ unsigned long *spu_bin_dcookie,
+ unsigned long spu_ref)
+{
+ unsigned long app_cookie = 0;
+ unsigned int my_offset = 0;
+ struct file *app = NULL;
+ struct vm_area_struct *vma;
+ struct mm_struct *mm = spu->mm;
+
+ if (!mm)
+ goto out;
+
+ down_read(&mm->mmap_sem);
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (!vma->vm_file)
+ continue;
+ if (!(vma->vm_flags & VM_EXECUTABLE))
+ continue;
+ app_cookie = fast_get_dcookie(vma->vm_file->f_dentry,
+ vma->vm_file->f_vfsmnt);
+ pr_debug("got dcookie for %s\n",
+ vma->vm_file->f_dentry->d_name.name);
+ app = vma->vm_file;
+ break;
+ }
+
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->vm_start > spu_ref || vma->vm_end <= spu_ref)
+ continue;
+ my_offset = spu_ref - vma->vm_start;
+ if (!vma->vm_file)
+ goto fail_no_image_cookie;
+
+ pr_debug("Found spu ELF at %X(object-id:%lx) for file %s\n",
+ my_offset, spu_ref,
+ vma->vm_file->f_dentry->d_name.name);
+ *offsetp = my_offset;
+ break;
+ }
+
+ *spu_bin_dcookie = fast_get_dcookie(vma->vm_file->f_dentry,
+ vma->vm_file->f_vfsmnt);
+ pr_debug("got dcookie for %s\n", vma->vm_file->f_dentry->d_name.name);
+
+ up_read(&mm->mmap_sem);
+
+out:
+ return app_cookie;
+
+fail_no_image_cookie:
+ up_read(&mm->mmap_sem);
+
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: Cannot find dcookie for SPU binary\n",
+ __FUNCTION__, __LINE__);
+ goto out;
+}
+
+
+
+/* This function finds or creates cached context information for the
+ * passed SPU and records SPU context information into the OProfile
+ * event buffer.
+ */
+static int process_context_switch(struct spu *spu, unsigned long objectId)
+{
+ unsigned long flags;
+ int retval;
+ unsigned int offset = 0;
+ unsigned long spu_cookie = 0, app_dcookie;
+
+ retval = prepare_cached_spu_info(spu, objectId);
+ if (retval)
+ goto out;
+
+ /* Get dcookie first because a mutex_lock is taken in that
+ * code path, so interrupts must not be disabled.
+ */
+ app_dcookie = get_exec_dcookie_and_offset(spu, &offset, &spu_cookie, objectId);
+ if (!app_dcookie || !spu_cookie) {
+ retval = -ENOENT;
+ goto out;
+ }
+
+ /* Record context info in event buffer */
+ spin_lock_irqsave(&buffer_lock, flags);
+ add_event_entry(ESCAPE_CODE);
+ add_event_entry(SPU_CTX_SWITCH_CODE);
+ add_event_entry(spu->number);
+ add_event_entry(spu->pid);
+ add_event_entry(spu->tgid);
+ add_event_entry(app_dcookie);
+ add_event_entry(spu_cookie);
+ add_event_entry(offset);
+ spin_unlock_irqrestore(&buffer_lock, flags);
+ smp_wmb(); /* insure spu event buffer updates are written */
+ /* don't want entries intermingled... */
+out:
+ return retval;
+}
+
+/*
+ * This function is invoked on either a bind_context or unbind_context.
+ * If called for an unbind_context, the val arg is 0; otherwise,
+ * it is the object-id value for the spu context.
+ * The data arg is of type 'struct spu *'.
+ */
+static int spu_active_notify(struct notifier_block *self, unsigned long val,
+ void *data)
+{
+ int retval;
+ unsigned long flags;
+ struct spu *the_spu = data;
+
+ pr_debug("SPU event notification arrived\n");
+ if (!val) {
+ spin_lock_irqsave(&cache_lock, flags);
+ retval = release_cached_info(the_spu->number);
+ spin_unlock_irqrestore(&cache_lock, flags);
+ } else {
+ retval = process_context_switch(the_spu, val);
+ }
+ return retval;
+}
+
+static struct notifier_block spu_active = {
+ .notifier_call = spu_active_notify,
+};
+
+static int number_of_online_nodes(void)
+{
+ u32 cpu; u32 tmp;
+ int nodes = 0;
+ for_each_online_cpu(cpu) {
+ tmp = cbe_cpu_to_node(cpu) + 1;
+ if (tmp > nodes)
+ nodes++;
+ }
+ return nodes;
+}
+
+/* The main purpose of this function is to synchronize
+ * OProfile with SPUFS by registering to be notified of
+ * SPU task switches.
+ *
+ * NOTE: When profiling SPUs, we must ensure that only
+ * spu_sync_start is invoked and not the generic sync_start
+ * in drivers/oprofile/oprof.c. A return value of
+ * SKIP_GENERIC_SYNC or SYNC_START_ERROR will
+ * accomplish this.
+ */
+int spu_sync_start(void)
+{
+ int k;
+ int ret = SKIP_GENERIC_SYNC;
+ int register_ret;
+ unsigned long flags = 0;
+
+ spu_prof_num_nodes = number_of_online_nodes();
+ num_spu_nodes = spu_prof_num_nodes * 8;
+
+ spin_lock_irqsave(&buffer_lock, flags);
+ add_event_entry(ESCAPE_CODE);
+ add_event_entry(SPU_PROFILING_CODE);
+ add_event_entry(num_spu_nodes);
+ spin_unlock_irqrestore(&buffer_lock, flags);
+
+ /* Register for SPU events */
+ register_ret = spu_switch_event_register(&spu_active);
+ if (register_ret) {
+ ret = SYNC_START_ERROR;
+ goto out;
+ }
+
+ for (k = 0; k < (MAX_NUMNODES * 8); k++)
+ last_guard_val[k] = 0;
+ pr_debug("spu_sync_start -- running.\n");
+out:
+ return ret;
+}
+
+/* Record SPU program counter samples to the oprofile event buffer. */
+void spu_sync_buffer(int spu_num, unsigned int *samples,
+ int num_samples)
+{
+ unsigned long long file_offset;
+ unsigned long flags;
+ int i;
+ struct vma_to_fileoffset_map *map;
+ struct spu *the_spu;
+ unsigned long long spu_num_ll = spu_num;
+ unsigned long long spu_num_shifted = spu_num_ll << 32;
+ struct cached_info *c_info;
+
+ /* We need to obtain the cache_lock here because it's
+ * possible that after getting the cached_info, the SPU job
+ * corresponding to this cached_info may end, thus resulting
+ * in the destruction of the cached_info.
+ */
+ spin_lock_irqsave(&cache_lock, flags);
+ c_info = get_cached_info(NULL, spu_num);
+ if (!c_info) {
+ /* This legitimately happens when the SPU task ends before all
+ * samples are recorded.
+ * No big deal -- so we just drop a few samples.
+ */
+ pr_debug("SPU_PROF: No cached SPU contex "
+ "for SPU #%d. Dropping samples.\n", spu_num);
+ goto out;
+ }
+
+ map = c_info->map;
+ the_spu = c_info->the_spu;
+ spin_lock(&buffer_lock);
+ for (i = 0; i < num_samples; i++) {
+ unsigned int sample = *(samples+i);
+ int grd_val = 0;
+ file_offset = 0;
+ if (sample == 0)
+ continue;
+ file_offset = vma_map_lookup( map, sample, the_spu, &grd_val);
+
+ /* If overlays are used by this SPU application, the guard
+ * value is non-zero, indicating which overlay section is in
+ * use. We need to discard samples taken during the time
+ * period which an overlay occurs (i.e., guard value changes).
+ */
+ if (grd_val && grd_val != last_guard_val[spu_num]) {
+ last_guard_val[spu_num] = grd_val;
+ /* Drop the rest of the samples. */
+ break;
+ }
+
+ add_event_entry(file_offset | spu_num_shifted);
+ }
+ spin_unlock(&buffer_lock);
+out:
+ spin_unlock_irqrestore(&cache_lock, flags);
+}
+
+
+int spu_sync_stop(void)
+{
+ unsigned long flags = 0;
+ int ret = spu_switch_event_unregister(&spu_active);
+ if (ret) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: spu_switch_event_unregister returned %d\n",
+ __FUNCTION__, __LINE__, ret);
+ goto out;
+ }
+
+ spin_lock_irqsave(&cache_lock, flags);
+ ret = release_cached_info(RELEASE_ALL);
+ spin_unlock_irqrestore(&cache_lock, flags);
+out:
+ pr_debug("spu_sync_stop -- done.\n");
+ return ret;
+}
+
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-01 09:03:58 +0000