Commit 0f0023c6 authored by Przemek Kitszel's avatar Przemek Kitszel Committed by Tony Nguyen
Browse files

ice: do not init struct ice_adapter more times than needed 



Allocate and initialize struct ice_adapter object only once per physical
card instead of once per port. This is not a big deal by now, but we want
to extend this struct more and more in the near future. Our plans include
PTP stuff and a devlink instance representing whole-device/physical card.

Transactions requiring to be sleep-able (like those doing user (here ice)
memory allocation) must be performed with an additional (on top of xarray)
mutex. Adding it here removes need to xa_lock() manually.

Since this commit is a reimplementation of ice_adapter_get(), a rather new
scoped_guard() wrapper for locking is used to simplify the logic.

It's worth to mention that xa_insert() use gives us both slot reservation
and checks if it is already filled, what simplifies code a tiny bit.

Reviewed-by: default avatarWojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: default avatarPrzemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarMichal Schmidt <mschmidt@redhat.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent fdd288e9

drivers/net/ethernet/intel/ice/ice_adapter.c

+28 −32
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "ice_adapter.h"



static DEFINE_XARRAY(ice_adapters);

static DEFINE_MUTEX(ice_adapters_mutex);



/* PCI bus number is 8 bits. Slot is 5 bits. Domain can have the rest. */

#define INDEX_FIELD_DOMAIN GENMASK(BITS_PER_LONG - 1, 13)
@@ -47,8 +48,6 @@ static void ice_adapter_free(struct ice_adapter *adapter) 
	kfree(adapter);

}



DEFINE_FREE(ice_adapter_free, struct ice_adapter*, if (_T) ice_adapter_free(_T))



/**

 * ice_adapter_get - Get a shared ice_adapter structure.

 * @pdev: Pointer to the pci_dev whose driver is getting the ice_adapter.
@@ -64,27 +63,26 @@ DEFINE_FREE(ice_adapter_free, struct ice_adapter*, if (_T) ice_adapter_free(_T)) 
 */

struct ice_adapter *ice_adapter_get(const struct pci_dev *pdev)

{

	struct ice_adapter *ret, __free(ice_adapter_free) *adapter = NULL;

	unsigned long index = ice_adapter_index(pdev);

	struct ice_adapter *adapter;

	int err;



	scoped_guard(mutex, &ice_adapters_mutex) {

		err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL);

		if (err == -EBUSY) {

			adapter = xa_load(&ice_adapters, index);

			refcount_inc(&adapter->refcount);

			return adapter;

		}

		if (err)

			return ERR_PTR(err);



		adapter = ice_adapter_new();

		if (!adapter)

			return ERR_PTR(-ENOMEM);



	xa_lock(&ice_adapters);

	ret = __xa_cmpxchg(&ice_adapters, index, NULL, adapter, GFP_KERNEL);

	if (xa_is_err(ret)) {

		ret = ERR_PTR(xa_err(ret));

		goto unlock;

	}

	if (ret) {

		refcount_inc(&ret->refcount);

		goto unlock;

		xa_store(&ice_adapters, index, adapter, GFP_KERNEL);

	}

	ret = no_free_ptr(adapter);

unlock:

	xa_unlock(&ice_adapters);

	return ret;

	return adapter;

}



/**
@@ -94,23 +92,21 @@ struct ice_adapter *ice_adapter_get(const struct pci_dev *pdev) 
 * Releases the reference to ice_adapter previously obtained with

 * ice_adapter_get.

 *

 * Context: Any.

 * Context: Process, may sleep.

 */

void ice_adapter_put(const struct pci_dev *pdev)

{

	unsigned long index = ice_adapter_index(pdev);

	struct ice_adapter *adapter;



	xa_lock(&ice_adapters);

	scoped_guard(mutex, &ice_adapters_mutex) {

		adapter = xa_load(&ice_adapters, index);

		if (WARN_ON(!adapter))

		goto unlock;



			return;

		if (!refcount_dec_and_test(&adapter->refcount))

		goto unlock;

			return;



	WARN_ON(__xa_erase(&ice_adapters, index) != adapter);

		WARN_ON(xa_erase(&ice_adapters, index) != adapter);

	}

	ice_adapter_free(adapter);

unlock:

	xa_unlock(&ice_adapters);

}