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-rw-r--r--arch/powerpc/oprofile/cell/spu_task_sync.c657
1 files changed, 657 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 000000000..489f99310
--- /dev/null
+++ b/arch/powerpc/oprofile/cell/spu_task_sync.c
@@ -0,0 +1,657 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Cell Broadband Engine OProfile Support
+ *
+ * (C) Copyright IBM Corporation 2006
+ *
+ * Author: Maynard Johnson <maynardj@us.ibm.com>
+ */
+
+/* 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/fs.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/numa.h>
+#include <linux/oprofile.h>
+#include <linux/slab.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;
+static int spu_prof_num_nodes;
+
+struct spu_buffer spu_buff[MAX_NUMNODES * SPUS_PER_NODE];
+struct delayed_work spu_work;
+static unsigned max_spu_buff;
+
+static void spu_buff_add(unsigned long int value, int spu)
+{
+ /* spu buff is a circular buffer. Add entries to the
+ * head. Head is the index to store the next value.
+ * The buffer is full when there is one available entry
+ * in the queue, i.e. head and tail can't be equal.
+ * That way we can tell the difference between the
+ * buffer being full versus empty.
+ *
+ * ASSUMPTION: the buffer_lock is held when this function
+ * is called to lock the buffer, head and tail.
+ */
+ int full = 1;
+
+ if (spu_buff[spu].head >= spu_buff[spu].tail) {
+ if ((spu_buff[spu].head - spu_buff[spu].tail)
+ < (max_spu_buff - 1))
+ full = 0;
+
+ } else if (spu_buff[spu].tail > spu_buff[spu].head) {
+ if ((spu_buff[spu].tail - spu_buff[spu].head)
+ > 1)
+ full = 0;
+ }
+
+ if (!full) {
+ spu_buff[spu].buff[spu_buff[spu].head] = value;
+ spu_buff[spu].head++;
+
+ if (spu_buff[spu].head >= max_spu_buff)
+ spu_buff[spu].head = 0;
+ } else {
+ /* From the user's perspective make the SPU buffer
+ * size management/overflow look like we are using
+ * per cpu buffers. The user uses the same
+ * per cpu parameter to adjust the SPU buffer size.
+ * Increment the sample_lost_overflow to inform
+ * the user the buffer size needs to be increased.
+ */
+ oprofile_cpu_buffer_inc_smpl_lost();
+ }
+}
+
+/* This function copies the per SPU buffers to the
+ * OProfile kernel buffer.
+ */
+static void sync_spu_buff(void)
+{
+ int spu;
+ unsigned long flags;
+ int curr_head;
+
+ for (spu = 0; spu < num_spu_nodes; spu++) {
+ /* In case there was an issue and the buffer didn't
+ * get created skip it.
+ */
+ if (spu_buff[spu].buff == NULL)
+ continue;
+
+ /* Hold the lock to make sure the head/tail
+ * doesn't change while spu_buff_add() is
+ * deciding if the buffer is full or not.
+ * Being a little paranoid.
+ */
+ spin_lock_irqsave(&buffer_lock, flags);
+ curr_head = spu_buff[spu].head;
+ spin_unlock_irqrestore(&buffer_lock, flags);
+
+ /* Transfer the current contents to the kernel buffer.
+ * data can still be added to the head of the buffer.
+ */
+ oprofile_put_buff(spu_buff[spu].buff,
+ spu_buff[spu].tail,
+ curr_head, max_spu_buff);
+
+ spin_lock_irqsave(&buffer_lock, flags);
+ spu_buff[spu].tail = curr_head;
+ spin_unlock_irqrestore(&buffer_lock, flags);
+ }
+
+}
+
+static void wq_sync_spu_buff(struct work_struct *work)
+{
+ /* move data from spu buffers to kernel buffer */
+ sync_spu_buff();
+
+ /* only reschedule if profiling is not done */
+ if (spu_prof_running)
+ schedule_delayed_work(&spu_work, DEFAULT_TIMER_EXPIRE);
+}
+
+/* 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",
+ __func__, __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(*info), GFP_KERNEL);
+ if (!info) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: create vma_map failed\n",
+ __func__, __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",
+ __func__, __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",
+ __func__, __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(const struct path *path)
+{
+ unsigned long cookie;
+
+ if (path->dentry->d_flags & DCACHE_COOKIE)
+ return (unsigned long)path->dentry;
+ get_dcookie(path, &cookie);
+ return cookie;
+}
+
+/* Look up the dcookie for the task's mm->exe_file,
+ * 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 vm_area_struct *vma;
+ struct file *exe_file;
+ struct mm_struct *mm = spu->mm;
+
+ if (!mm)
+ goto out;
+
+ exe_file = get_mm_exe_file(mm);
+ if (exe_file) {
+ app_cookie = fast_get_dcookie(&exe_file->f_path);
+ pr_debug("got dcookie for %pD\n", exe_file);
+ fput(exe_file);
+ }
+
+ mmap_read_lock(mm);
+ 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 %pD\n",
+ my_offset, spu_ref, vma->vm_file);
+ *offsetp = my_offset;
+ break;
+ }
+
+ *spu_bin_dcookie = fast_get_dcookie(&vma->vm_file->f_path);
+ pr_debug("got dcookie for %pD\n", vma->vm_file);
+
+ mmap_read_unlock(mm);
+
+out:
+ return app_cookie;
+
+fail_no_image_cookie:
+ mmap_read_unlock(mm);
+
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: Cannot find dcookie for SPU binary\n",
+ __func__, __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);
+ spu_buff_add(ESCAPE_CODE, spu->number);
+ spu_buff_add(SPU_CTX_SWITCH_CODE, spu->number);
+ spu_buff_add(spu->number, spu->number);
+ spu_buff_add(spu->pid, spu->number);
+ spu_buff_add(spu->tgid, spu->number);
+ spu_buff_add(app_dcookie, spu->number);
+ spu_buff_add(spu_cookie, spu->number);
+ spu_buff_add(offset, spu->number);
+
+ /* Set flag to indicate SPU PC data can now be written out. If
+ * the SPU program counter data is seen before an SPU context
+ * record is seen, the postprocessing will fail.
+ */
+ spu_buff[spu->number].ctx_sw_seen = 1;
+
+ 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;
+}
+
+static int oprofile_spu_buff_create(void)
+{
+ int spu;
+
+ max_spu_buff = oprofile_get_cpu_buffer_size();
+
+ for (spu = 0; spu < num_spu_nodes; spu++) {
+ /* create circular buffers to store the data in.
+ * use locks to manage accessing the buffers
+ */
+ spu_buff[spu].head = 0;
+ spu_buff[spu].tail = 0;
+
+ /*
+ * Create a buffer for each SPU. Can't reliably
+ * create a single buffer for all spus due to not
+ * enough contiguous kernel memory.
+ */
+
+ spu_buff[spu].buff = kzalloc((max_spu_buff
+ * sizeof(unsigned long)),
+ GFP_KERNEL);
+
+ if (!spu_buff[spu].buff) {
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: oprofile_spu_buff_create "
+ "failed to allocate spu buffer %d.\n",
+ __func__, __LINE__, spu);
+
+ /* release the spu buffers that have been allocated */
+ while (spu >= 0) {
+ kfree(spu_buff[spu].buff);
+ spu_buff[spu].buff = 0;
+ spu--;
+ }
+ return -ENOMEM;
+ }
+ }
+ return 0;
+}
+
+/* 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 spu;
+ 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;
+ INIT_DELAYED_WORK(&spu_work, wq_sync_spu_buff);
+
+ /* create buffer for storing the SPU data to put in
+ * the kernel buffer.
+ */
+ ret = oprofile_spu_buff_create();
+ if (ret)
+ goto out;
+
+ spin_lock_irqsave(&buffer_lock, flags);
+ for (spu = 0; spu < num_spu_nodes; spu++) {
+ spu_buff_add(ESCAPE_CODE, spu);
+ spu_buff_add(SPU_PROFILING_CODE, spu);
+ spu_buff_add(num_spu_nodes, spu);
+ }
+ spin_unlock_irqrestore(&buffer_lock, flags);
+
+ for (spu = 0; spu < num_spu_nodes; spu++) {
+ spu_buff[spu].ctx_sw_seen = 0;
+ spu_buff[spu].last_guard_val = 0;
+ }
+
+ /* Register for SPU events */
+ register_ret = spu_switch_event_register(&spu_active);
+ if (register_ret) {
+ ret = SYNC_START_ERROR;
+ goto out;
+ }
+
+ 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 context "
+ "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 != spu_buff[spu_num].last_guard_val) {
+ spu_buff[spu_num].last_guard_val = grd_val;
+ /* Drop the rest of the samples. */
+ break;
+ }
+
+ /* We must ensure that the SPU context switch has been written
+ * out before samples for the SPU. Otherwise, the SPU context
+ * information is not available and the postprocessing of the
+ * SPU PC will fail with no available anonymous map information.
+ */
+ if (spu_buff[spu_num].ctx_sw_seen)
+ spu_buff_add((file_offset | spu_num_shifted),
+ spu_num);
+ }
+ spin_unlock(&buffer_lock);
+out:
+ spin_unlock_irqrestore(&cache_lock, flags);
+}
+
+
+int spu_sync_stop(void)
+{
+ unsigned long flags = 0;
+ int ret;
+ int k;
+
+ ret = spu_switch_event_unregister(&spu_active);
+
+ if (ret)
+ printk(KERN_ERR "SPU_PROF: "
+ "%s, line %d: spu_switch_event_unregister " \
+ "returned %d\n",
+ __func__, __LINE__, ret);
+
+ /* flush any remaining data in the per SPU buffers */
+ sync_spu_buff();
+
+ spin_lock_irqsave(&cache_lock, flags);
+ ret = release_cached_info(RELEASE_ALL);
+ spin_unlock_irqrestore(&cache_lock, flags);
+
+ /* remove scheduled work queue item rather then waiting
+ * for every queued entry to execute. Then flush pending
+ * system wide buffer to event buffer.
+ */
+ cancel_delayed_work(&spu_work);
+
+ for (k = 0; k < num_spu_nodes; k++) {
+ spu_buff[k].ctx_sw_seen = 0;
+
+ /*
+ * spu_sys_buff will be null if there was a problem
+ * allocating the buffer. Only delete if it exists.
+ */
+ kfree(spu_buff[k].buff);
+ spu_buff[k].buff = 0;
+ }
+ pr_debug("spu_sync_stop -- done.\n");
+ return ret;
+}
+
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