diff options
Diffstat (limited to 'drivers/net/ethernet/intel/ice/ice_adapter.c')
-rw-r--r-- | drivers/net/ethernet/intel/ice/ice_adapter.c | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/ice/ice_adapter.c b/drivers/net/ethernet/intel/ice/ice_adapter.c new file mode 100644 index 0000000000..52d15ef7f4 --- /dev/null +++ b/drivers/net/ethernet/intel/ice/ice_adapter.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0-only +// SPDX-FileCopyrightText: Copyright Red Hat + +#include <linux/bitfield.h> +#include <linux/cleanup.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/xarray.h> +#include "ice_adapter.h" + +static DEFINE_XARRAY(ice_adapters); + +/* 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) +#define INDEX_FIELD_BUS GENMASK(12, 5) +#define INDEX_FIELD_SLOT GENMASK(4, 0) + +static unsigned long ice_adapter_index(const struct pci_dev *pdev) +{ + unsigned int domain = pci_domain_nr(pdev->bus); + + WARN_ON(domain > FIELD_MAX(INDEX_FIELD_DOMAIN)); + + return FIELD_PREP(INDEX_FIELD_DOMAIN, domain) | + FIELD_PREP(INDEX_FIELD_BUS, pdev->bus->number) | + FIELD_PREP(INDEX_FIELD_SLOT, PCI_SLOT(pdev->devfn)); +} + +static struct ice_adapter *ice_adapter_new(void) +{ + struct ice_adapter *adapter; + + adapter = kzalloc(sizeof(*adapter), GFP_KERNEL); + if (!adapter) + return NULL; + + spin_lock_init(&adapter->ptp_gltsyn_time_lock); + refcount_set(&adapter->refcount, 1); + + return adapter; +} + +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. + * + * Gets a pointer to a shared ice_adapter structure. Physical functions (PFs) + * of the same multi-function PCI device share one ice_adapter structure. + * The ice_adapter is reference-counted. The PF driver must use ice_adapter_put + * to release its reference. + * + * Context: Process, may sleep. + * Return: Pointer to ice_adapter on success. + * ERR_PTR() on error. -ENOMEM is the only possible error. + */ +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); + + 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; + } + ret = no_free_ptr(adapter); +unlock: + xa_unlock(&ice_adapters); + return ret; +} + +/** + * ice_adapter_put - Release a reference to the shared ice_adapter structure. + * @pdev: Pointer to the pci_dev whose driver is releasing the ice_adapter. + * + * Releases the reference to ice_adapter previously obtained with + * ice_adapter_get. + * + * Context: Any. + */ +void ice_adapter_put(const struct pci_dev *pdev) +{ + unsigned long index = ice_adapter_index(pdev); + struct ice_adapter *adapter; + + xa_lock(&ice_adapters); + adapter = xa_load(&ice_adapters, index); + if (WARN_ON(!adapter)) + goto unlock; + + if (!refcount_dec_and_test(&adapter->refcount)) + goto unlock; + + WARN_ON(__xa_erase(&ice_adapters, index) != adapter); + ice_adapter_free(adapter); +unlock: + xa_unlock(&ice_adapters); +} |