[PATCH net-next 03/15] netdevsim: Add devlink-trap policer support

[Ido Schimmel <idosch@idosch.org>]

From: Ido Schimmel <idosch@mellanox.com>

Register three dummy packet trap policers with devlink and implement
callbacks to change their parameters and read their counters.

This will be used later on in the series to test the devlink-trap
policer infrastructure.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
---
 drivers/net/netdevsim/dev.c       | 96 ++++++++++++++++++++++++++++++-
 drivers/net/netdevsim/netdevsim.h |  1 +
 2 files changed, 96 insertions(+), 1 deletion(-)

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 7bfd0622cef1..ce74adbf0e8b 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -192,6 +192,9 @@ static int nsim_dev_debugfs_init(struct nsim_dev *nsim_dev)
 			    &nsim_dev->fail_reload);
 	debugfs_create_file("trap_flow_action_cookie", 0600, nsim_dev->ddir,
 			    nsim_dev, &nsim_dev_trap_fa_cookie_fops);
+	debugfs_create_bool("fail_trap_policer_counter_get", 0600,
+			    nsim_dev->ddir,
+			    &nsim_dev->fail_trap_policer_counter_get);
 	return 0;
 }
 
@@ -363,6 +366,7 @@ struct nsim_trap_item {
 struct nsim_trap_data {
 	struct delayed_work trap_report_dw;
 	struct nsim_trap_item *trap_items_arr;
+	u64 *trap_policers_cnt_arr;
 	struct nsim_dev *nsim_dev;
 	spinlock_t trap_lock;	/* Protects trap_items_arr */
 };
@@ -397,6 +401,12 @@ enum {
 			    DEVLINK_TRAP_GROUP_GENERIC_ID_##_group_id,	      \
 			    NSIM_TRAP_METADATA)
 
+static const struct devlink_trap_policer nsim_trap_policers_arr[] = {
+	DEVLINK_TRAP_POLICER(1, 1000, 128),
+	DEVLINK_TRAP_POLICER(2, 2000, 256),
+	DEVLINK_TRAP_POLICER(3, 3000, 512),
+};
+
 static const struct devlink_trap_group nsim_trap_groups_arr[] = {
 	DEVLINK_TRAP_GROUP_GENERIC(L2_DROPS),
 	DEVLINK_TRAP_GROUP_GENERIC(L3_DROPS),
@@ -539,6 +549,7 @@ static void nsim_dev_trap_report_work(struct work_struct *work)
 
 static int nsim_dev_traps_init(struct devlink *devlink)
 {
+	size_t policers_count = ARRAY_SIZE(nsim_trap_policers_arr);
 	struct nsim_dev *nsim_dev = devlink_priv(devlink);
 	struct nsim_trap_data *nsim_trap_data;
 	int err;
@@ -555,6 +566,14 @@ static int nsim_dev_traps_init(struct devlink *devlink)
 		goto err_trap_data_free;
 	}
 
+	nsim_trap_data->trap_policers_cnt_arr = kcalloc(policers_count,
+							sizeof(u64),
+							GFP_KERNEL);
+	if (!nsim_trap_data->trap_policers_cnt_arr) {
+		err = -ENOMEM;
+		goto err_trap_items_free;
+	}
+
 	/* The lock is used to protect the action state of the registered
 	 * traps. The value is written by user and read in delayed work when
 	 * iterating over all the traps.
@@ -563,10 +582,15 @@ static int nsim_dev_traps_init(struct devlink *devlink)
 	nsim_trap_data->nsim_dev = nsim_dev;
 	nsim_dev->trap_data = nsim_trap_data;
 
+	err = devlink_trap_policers_register(devlink, nsim_trap_policers_arr,
+					     policers_count);
+	if (err)
+		goto err_trap_policers_cnt_free;
+
 	err = devlink_trap_groups_register(devlink, nsim_trap_groups_arr,
 					   ARRAY_SIZE(nsim_trap_groups_arr));
 	if (err)
-		goto err_trap_items_free;
+		goto err_trap_policers_unregister;
 
 	err = devlink_traps_register(devlink, nsim_traps_arr,
 				     ARRAY_SIZE(nsim_traps_arr), NULL);
@@ -583,6 +607,11 @@ static int nsim_dev_traps_init(struct devlink *devlink)
 err_trap_groups_unregister:
 	devlink_trap_groups_unregister(devlink, nsim_trap_groups_arr,
 				       ARRAY_SIZE(nsim_trap_groups_arr));
+err_trap_policers_unregister:
+	devlink_trap_policers_unregister(devlink, nsim_trap_policers_arr,
+					 ARRAY_SIZE(nsim_trap_policers_arr));
+err_trap_policers_cnt_free:
+	kfree(nsim_trap_data->trap_policers_cnt_arr);
 err_trap_items_free:
 	kfree(nsim_trap_data->trap_items_arr);
 err_trap_data_free:
@@ -599,6 +628,9 @@ static void nsim_dev_traps_exit(struct devlink *devlink)
 				 ARRAY_SIZE(nsim_traps_arr));
 	devlink_trap_groups_unregister(devlink, nsim_trap_groups_arr,
 				       ARRAY_SIZE(nsim_trap_groups_arr));
+	devlink_trap_policers_unregister(devlink, nsim_trap_policers_arr,
+					 ARRAY_SIZE(nsim_trap_policers_arr));
+	kfree(nsim_dev->trap_data->trap_policers_cnt_arr);
 	kfree(nsim_dev->trap_data->trap_items_arr);
 	kfree(nsim_dev->trap_data);
 }
@@ -737,6 +769,66 @@ nsim_dev_devlink_trap_action_set(struct devlink *devlink,
 	return 0;
 }
 
+#define NSIM_DEV_TRAP_POLICER_MIN_RATE	1
+#define NSIM_DEV_TRAP_POLICER_MAX_RATE	8000
+#define NSIM_DEV_TRAP_POLICER_MIN_BURST	8
+#define NSIM_DEV_TRAP_POLICER_MAX_BURST	65536
+
+static int
+nsim_dev_devlink_trap_policer_set(struct devlink *devlink,
+				  const struct devlink_trap_policer *policer,
+				  u64 rate, u64 burst,
+				  struct netlink_ext_ack *extack)
+{
+	int bs = fls64(burst);
+
+	if (rate < NSIM_DEV_TRAP_POLICER_MIN_RATE) {
+		NL_SET_ERR_MSG_MOD(extack, "Policer rate lower than limit");
+		return -EINVAL;
+	}
+
+	if (rate > NSIM_DEV_TRAP_POLICER_MAX_RATE) {
+		NL_SET_ERR_MSG_MOD(extack, "Policer rate higher than limit");
+		return -EINVAL;
+	}
+
+	if (burst < NSIM_DEV_TRAP_POLICER_MIN_BURST) {
+		NL_SET_ERR_MSG_MOD(extack, "Policer burst size lower than limit");
+		return -EINVAL;
+	}
+
+	if (burst > NSIM_DEV_TRAP_POLICER_MAX_BURST) {
+		NL_SET_ERR_MSG_MOD(extack, "Policer burst size higher than limit");
+		return -EINVAL;
+	}
+
+	--bs;
+	if (burst != (1 << bs)) {
+		NL_SET_ERR_MSG_MOD(extack, "Policer burst size is not power of two");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+nsim_dev_devlink_trap_policer_counter_get(struct devlink *devlink,
+					  const struct devlink_trap_policer *policer,
+					  u64 *p_drops)
+{
+	struct nsim_dev *nsim_dev = devlink_priv(devlink);
+	u64 *cnt;
+
+	if (nsim_dev->fail_trap_policer_counter_get)
+		return -EINVAL;
+
+	cnt = &nsim_dev->trap_data->trap_policers_cnt_arr[policer->id - 1];
+	*p_drops = *cnt;
+	*cnt += jiffies % 64;
+
+	return 0;
+}
+
 static const struct devlink_ops nsim_dev_devlink_ops = {
 	.reload_down = nsim_dev_reload_down,
 	.reload_up = nsim_dev_reload_up,
@@ -744,6 +836,8 @@ static const struct devlink_ops nsim_dev_devlink_ops = {
 	.flash_update = nsim_dev_flash_update,
 	.trap_init = nsim_dev_devlink_trap_init,
 	.trap_action_set = nsim_dev_devlink_trap_action_set,
+	.trap_policer_set = nsim_dev_devlink_trap_policer_set,
+	.trap_policer_counter_get = nsim_dev_devlink_trap_policer_counter_get,
 };
 
 #define NSIM_DEV_MAX_MACS_DEFAULT 32
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index e46fc565b981..68788dae5625 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -180,6 +180,7 @@ struct nsim_dev {
 	struct nsim_dev_health health;
 	struct flow_action_cookie *fa_cookie;
 	spinlock_t fa_cookie_lock; /* protects fa_cookie */
+	bool fail_trap_policer_counter_get;
 };
 
 static inline struct net *nsim_dev_net(struct nsim_dev *nsim_dev)
-- 
2.24.1