1 files changed, 475 insertions, 0 deletions
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_counter.c b/drivers/net/ethernet/marvell/prestera/prestera_counter.c
new file mode 100644
index 000000000000..4cd53a2dae46
--- /dev/null
+++ b/drivers/net/ethernet/marvell/prestera/prestera_counter.c
@@ -0,0 +1,475 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2021 Marvell International Ltd. All rights reserved */
+
+#include "prestera.h"
+#include "prestera_hw.h"
+#include "prestera_acl.h"
+#include "prestera_counter.h"
+
+#define COUNTER_POLL_TIME	(msecs_to_jiffies(1000))
+#define COUNTER_RESCHED_TIME	(msecs_to_jiffies(50))
+#define COUNTER_BULK_SIZE	(256)
+
+struct prestera_counter {
+	struct prestera_switch *sw;
+	struct delayed_work stats_dw;
+	struct mutex mtx;  /* protect block_list */
+	struct prestera_counter_block **block_list;
+	u32 total_read;
+	u32 block_list_len;
+	u32 curr_idx;
+	bool is_fetching;
+};
+
+struct prestera_counter_block {
+	struct list_head list;
+	u32 id;
+	u32 offset;
+	u32 num_counters;
+	u32 client;
+	struct idr counter_idr;
+	refcount_t refcnt;
+	struct mutex mtx;  /* protect stats and counter_idr */
+	struct prestera_counter_stats *stats;
+	u8 *counter_flag;
+	bool is_updating;
+	bool full;
+};
+
+enum {
+	COUNTER_FLAG_READY = 0,
+	COUNTER_FLAG_INVALID = 1
+};
+
+static bool
+prestera_counter_is_ready(struct prestera_counter_block *block, u32 id)
+{
+	return block->counter_flag[id - block->offset] == COUNTER_FLAG_READY;
+}
+
+static void prestera_counter_lock(struct prestera_counter *counter)
+{
+	mutex_lock(&counter->mtx);
+}
+
+static void prestera_counter_unlock(struct prestera_counter *counter)
+{
+	mutex_unlock(&counter->mtx);
+}
+
+static void prestera_counter_block_lock(struct prestera_counter_block *block)
+{
+	mutex_lock(&block->mtx);
+}
+
+static void prestera_counter_block_unlock(struct prestera_counter_block *block)
+{
+	mutex_unlock(&block->mtx);
+}
+
+static bool prestera_counter_block_incref(struct prestera_counter_block *block)
+{
+	return refcount_inc_not_zero(&block->refcnt);
+}
+
+static bool prestera_counter_block_decref(struct prestera_counter_block *block)
+{
+	return refcount_dec_and_test(&block->refcnt);
+}
+
+/* must be called with prestera_counter_block_lock() */
+static void prestera_counter_stats_clear(struct prestera_counter_block *block,
+					 u32 counter_id)
+{
+	memset(&block->stats[counter_id - block->offset], 0,
+	       sizeof(*block->stats));
+}
+
+static struct prestera_counter_block *
+prestera_counter_block_lookup_not_full(struct prestera_counter *counter,
+				       u32 client)
+{
+	u32 i;
+
+	prestera_counter_lock(counter);
+	for (i = 0; i < counter->block_list_len; i++) {
+		if (counter->block_list[i] &&
+		    counter->block_list[i]->client == client &&
+		    !counter->block_list[i]->full &&
+		    prestera_counter_block_incref(counter->block_list[i])) {
+			prestera_counter_unlock(counter);
+			return counter->block_list[i];
+		}
+	}
+	prestera_counter_unlock(counter);
+
+	return NULL;
+}
+
+static int prestera_counter_block_list_add(struct prestera_counter *counter,
+					   struct prestera_counter_block *block)
+{
+	struct prestera_counter_block **arr;
+	u32 i;
+
+	prestera_counter_lock(counter);
+
+	for (i = 0; i < counter->block_list_len; i++) {
+		if (counter->block_list[i])
+			continue;
+
+		counter->block_list[i] = block;
+		prestera_counter_unlock(counter);
+		return 0;
+	}
+
+	arr = krealloc(counter->block_list, (counter->block_list_len + 1) *
+		       sizeof(*counter->block_list), GFP_KERNEL);
+	if (!arr) {
+		prestera_counter_unlock(counter);
+		return -ENOMEM;
+	}
+
+	counter->block_list = arr;
+	counter->block_list[counter->block_list_len] = block;
+	counter->block_list_len++;
+	prestera_counter_unlock(counter);
+	return 0;
+}
+
+static struct prestera_counter_block *
+prestera_counter_block_get(struct prestera_counter *counter, u32 client)
+{
+	struct prestera_counter_block *block;
+	int err;
+
+	block = prestera_counter_block_lookup_not_full(counter, client);
+	if (block)
+		return block;
+
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (!block)
+		return ERR_PTR(-ENOMEM);
+
+	err = prestera_hw_counter_block_get(counter->sw, client,
+					    &block->id, &block->offset,
+					    &block->num_counters);
+	if (err)
+		goto err_block;
+
+	block->stats = kcalloc(block->num_counters,
+			       sizeof(*block->stats), GFP_KERNEL);
+	if (!block->stats) {
+		err = -ENOMEM;
+		goto err_stats;
+	}
+
+	block->counter_flag = kcalloc(block->num_counters,
+				      sizeof(*block->counter_flag),
+				      GFP_KERNEL);
+	if (!block->counter_flag) {
+		err = -ENOMEM;
+		goto err_flag;
+	}
+
+	block->client = client;
+	mutex_init(&block->mtx);
+	refcount_set(&block->refcnt, 1);
+	idr_init_base(&block->counter_idr, block->offset);
+
+	err = prestera_counter_block_list_add(counter, block);
+	if (err)
+		goto err_list_add;
+
+	return block;
+
+err_list_add:
+	idr_destroy(&block->counter_idr);
+	mutex_destroy(&block->mtx);
+	kfree(block->counter_flag);
+err_flag:
+	kfree(block->stats);
+err_stats:
+	prestera_hw_counter_block_release(counter->sw, block->id);
+err_block:
+	kfree(block);
+	return ERR_PTR(err);
+}
+
+static void prestera_counter_block_put(struct prestera_counter *counter,
+				       struct prestera_counter_block *block)
+{
+	u32 i;
+
+	if (!prestera_counter_block_decref(block))
+		return;
+
+	prestera_counter_lock(counter);
+	for (i = 0; i < counter->block_list_len; i++) {
+		if (counter->block_list[i] &&
+		    counter->block_list[i]->id == block->id) {
+			counter->block_list[i] = NULL;
+			break;
+		}
+	}
+	prestera_counter_unlock(counter);
+
+	WARN_ON(!idr_is_empty(&block->counter_idr));
+
+	prestera_hw_counter_block_release(counter->sw, block->id);
+	idr_destroy(&block->counter_idr);
+	mutex_destroy(&block->mtx);
+	kfree(block->stats);
+	kfree(block);
+}
+
+static int prestera_counter_get_vacant(struct prestera_counter_block *block,
+				       u32 *id)
+{
+	int free_id;
+
+	if (block->full)
+		return -ENOSPC;
+
+	prestera_counter_block_lock(block);
+	free_id = idr_alloc_cyclic(&block->counter_idr, NULL, block->offset,
+				   block->offset + block->num_counters,
+				   GFP_KERNEL);
+	if (free_id < 0) {
+		if (free_id == -ENOSPC)
+			block->full = true;
+
+		prestera_counter_block_unlock(block);
+		return free_id;
+	}
+	*id = free_id;
+	prestera_counter_block_unlock(block);
+
+	return 0;
+}
+
+int prestera_counter_get(struct prestera_counter *counter, u32 client,
+			 struct prestera_counter_block **bl, u32 *counter_id)
+{
+	struct prestera_counter_block *block;
+	int err;
+	u32 id;
+
+get_next_block:
+	block = prestera_counter_block_get(counter, client);
+	if (IS_ERR(block))
+		return PTR_ERR(block);
+
+	err = prestera_counter_get_vacant(block, &id);
+	if (err) {
+		prestera_counter_block_put(counter, block);
+
+		if (err == -ENOSPC)
+			goto get_next_block;
+
+		return err;
+	}
+
+	prestera_counter_block_lock(block);
+	if (block->is_updating)
+		block->counter_flag[id - block->offset] = COUNTER_FLAG_INVALID;
+	prestera_counter_block_unlock(block);
+
+	*counter_id = id;
+	*bl = block;
+
+	return 0;
+}
+
+void prestera_counter_put(struct prestera_counter *counter,
+			  struct prestera_counter_block *block, u32 counter_id)
+{
+	if (!block)
+		return;
+
+	prestera_counter_block_lock(block);
+	idr_remove(&block->counter_idr, counter_id);
+	block->full = false;
+	prestera_counter_stats_clear(block, counter_id);
+	prestera_counter_block_unlock(block);
+
+	prestera_hw_counter_clear(counter->sw, block->id, counter_id);
+	prestera_counter_block_put(counter, block);
+}
+
+static u32 prestera_counter_block_idx_next(struct prestera_counter *counter,
+					   u32 curr_idx)
+{
+	u32 idx, i, start = curr_idx + 1;
+
+	prestera_counter_lock(counter);
+	for (i = 0; i < counter->block_list_len; i++) {
+		idx = (start + i) % counter->block_list_len;
+		if (!counter->block_list[idx])
+			continue;
+
+		prestera_counter_unlock(counter);
+		return idx;
+	}
+	prestera_counter_unlock(counter);
+
+	return 0;
+}
+
+static struct prestera_counter_block *
+prestera_counter_block_get_by_idx(struct prestera_counter *counter, u32 idx)
+{
+	if (idx >= counter->block_list_len)
+		return NULL;
+
+	prestera_counter_lock(counter);
+
+	if (!counter->block_list[idx] ||
+	    !prestera_counter_block_incref(counter->block_list[idx])) {
+		prestera_counter_unlock(counter);
+		return NULL;
+	}
+
+	prestera_counter_unlock(counter);
+	return counter->block_list[idx];
+}
+
+static void prestera_counter_stats_work(struct work_struct *work)
+{
+	struct delayed_work *dl_work =
+		container_of(work, struct delayed_work, work);
+	struct prestera_counter *counter =
+		container_of(dl_work, struct prestera_counter, stats_dw);
+	struct prestera_counter_block *block;
+	u32 resched_time = COUNTER_POLL_TIME;
+	u32 count = COUNTER_BULK_SIZE;
+	bool done = false;
+	int err;
+	u32 i;
+
+	block = prestera_counter_block_get_by_idx(counter, counter->curr_idx);
+	if (!block) {
+		if (counter->is_fetching)
+			goto abort;
+
+		goto next;
+	}
+
+	if (!counter->is_fetching) {
+		err = prestera_hw_counter_trigger(counter->sw, block->id);
+		if (err)
+			goto abort;
+
+		prestera_counter_block_lock(block);
+		block->is_updating = true;
+		prestera_counter_block_unlock(block);
+
+		counter->is_fetching = true;
+		counter->total_read = 0;
+		resched_time = COUNTER_RESCHED_TIME;
+		goto resched;
+	}
+
+	prestera_counter_block_lock(block);
+	err = prestera_hw_counters_get(counter->sw, counter->total_read,
+				       &count, &done,
+				       &block->stats[counter->total_read]);
+	prestera_counter_block_unlock(block);
+	if (err)
+		goto abort;
+
+	counter->total_read += count;
+	if (!done || counter->total_read < block->num_counters) {
+		resched_time = COUNTER_RESCHED_TIME;
+		goto resched;
+	}
+
+	for (i = 0; i < block->num_counters; i++) {
+		if (block->counter_flag[i] == COUNTER_FLAG_INVALID) {
+			prestera_counter_block_lock(block);
+			block->counter_flag[i] = COUNTER_FLAG_READY;
+			memset(&block->stats[i], 0, sizeof(*block->stats));
+			prestera_counter_block_unlock(block);
+		}
+	}
+
+	prestera_counter_block_lock(block);
+	block->is_updating = false;
+	prestera_counter_block_unlock(block);
+
+	goto next;
+abort:
+	prestera_hw_counter_abort(counter->sw);
+next:
+	counter->is_fetching = false;
+	counter->curr_idx =
+		prestera_counter_block_idx_next(counter, counter->curr_idx);
+resched:
+	if (block)
+		prestera_counter_block_put(counter, block);
+
+	schedule_delayed_work(&counter->stats_dw, resched_time);
+}
+
+/* Can be executed without rtnl_lock().
+ * So pay attention when something changing.
+ */
+int prestera_counter_stats_get(struct prestera_counter *counter,
+			       struct prestera_counter_block *block,
+			       u32 counter_id, u64 *packets, u64 *bytes)
+{
+	if (!block || !prestera_counter_is_ready(block, counter_id)) {
+		*packets = 0;
+		*bytes = 0;
+		return 0;
+	}
+
+	prestera_counter_block_lock(block);
+	*packets = block->stats[counter_id - block->offset].packets;
+	*bytes = block->stats[counter_id - block->offset].bytes;
+
+	prestera_counter_stats_clear(block, counter_id);
+	prestera_counter_block_unlock(block);
+
+	return 0;
+}
+
+int prestera_counter_init(struct prestera_switch *sw)
+{
+	struct prestera_counter *counter;
+
+	counter = kzalloc(sizeof(*counter), GFP_KERNEL);
+	if (!counter)
+		return -ENOMEM;
+
+	counter->block_list = kzalloc(sizeof(*counter->block_list), GFP_KERNEL);
+	if (!counter->block_list) {
+		kfree(counter);
+		return -ENOMEM;
+	}
+
+	mutex_init(&counter->mtx);
+	counter->block_list_len = 1;
+	counter->sw = sw;
+	sw->counter = counter;
+
+	INIT_DELAYED_WORK(&counter->stats_dw, prestera_counter_stats_work);
+	schedule_delayed_work(&counter->stats_dw, COUNTER_POLL_TIME);
+
+	return 0;
+}
+
+void prestera_counter_fini(struct prestera_switch *sw)
+{
+	struct prestera_counter *counter = sw->counter;
+	u32 i;
+
+	cancel_delayed_work_sync(&counter->stats_dw);
+
+	for (i = 0; i < counter->block_list_len; i++)
+		WARN_ON(counter->block_list[i]);
+
+	mutex_destroy(&counter->mtx);
+	kfree(counter->block_list);
+	kfree(counter);
+}