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 0000000..1336657
--- /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;
+}
+
+