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0f0023c649
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: Wojciech Drewek <wojciech.drewek@intel.com> Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
113 lines
3.0 KiB
C
113 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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// SPDX-FileCopyrightText: Copyright Red Hat
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#include <linux/bitfield.h>
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#include <linux/cleanup.h>
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#include <linux/mutex.h>
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#include <linux/pci.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/xarray.h>
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#include "ice_adapter.h"
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static DEFINE_XARRAY(ice_adapters);
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static DEFINE_MUTEX(ice_adapters_mutex);
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/* PCI bus number is 8 bits. Slot is 5 bits. Domain can have the rest. */
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#define INDEX_FIELD_DOMAIN GENMASK(BITS_PER_LONG - 1, 13)
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#define INDEX_FIELD_BUS GENMASK(12, 5)
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#define INDEX_FIELD_SLOT GENMASK(4, 0)
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static unsigned long ice_adapter_index(const struct pci_dev *pdev)
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{
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unsigned int domain = pci_domain_nr(pdev->bus);
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WARN_ON(domain > FIELD_MAX(INDEX_FIELD_DOMAIN));
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return FIELD_PREP(INDEX_FIELD_DOMAIN, domain) |
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FIELD_PREP(INDEX_FIELD_BUS, pdev->bus->number) |
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FIELD_PREP(INDEX_FIELD_SLOT, PCI_SLOT(pdev->devfn));
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}
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static struct ice_adapter *ice_adapter_new(void)
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{
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struct ice_adapter *adapter;
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adapter = kzalloc(sizeof(*adapter), GFP_KERNEL);
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if (!adapter)
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return NULL;
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spin_lock_init(&adapter->ptp_gltsyn_time_lock);
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refcount_set(&adapter->refcount, 1);
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return adapter;
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}
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static void ice_adapter_free(struct ice_adapter *adapter)
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{
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kfree(adapter);
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}
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/**
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* ice_adapter_get - Get a shared ice_adapter structure.
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* @pdev: Pointer to the pci_dev whose driver is getting the ice_adapter.
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*
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* Gets a pointer to a shared ice_adapter structure. Physical functions (PFs)
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* of the same multi-function PCI device share one ice_adapter structure.
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* The ice_adapter is reference-counted. The PF driver must use ice_adapter_put
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* to release its reference.
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*
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* Context: Process, may sleep.
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* Return: Pointer to ice_adapter on success.
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* ERR_PTR() on error. -ENOMEM is the only possible error.
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*/
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struct ice_adapter *ice_adapter_get(const struct pci_dev *pdev)
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{
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unsigned long index = ice_adapter_index(pdev);
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struct ice_adapter *adapter;
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int err;
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scoped_guard(mutex, &ice_adapters_mutex) {
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err = xa_insert(&ice_adapters, index, NULL, GFP_KERNEL);
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if (err == -EBUSY) {
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adapter = xa_load(&ice_adapters, index);
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refcount_inc(&adapter->refcount);
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return adapter;
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}
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if (err)
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return ERR_PTR(err);
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adapter = ice_adapter_new();
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if (!adapter)
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return ERR_PTR(-ENOMEM);
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xa_store(&ice_adapters, index, adapter, GFP_KERNEL);
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}
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return adapter;
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}
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/**
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* ice_adapter_put - Release a reference to the shared ice_adapter structure.
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* @pdev: Pointer to the pci_dev whose driver is releasing the ice_adapter.
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*
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* Releases the reference to ice_adapter previously obtained with
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* ice_adapter_get.
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*
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* Context: Process, may sleep.
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*/
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void ice_adapter_put(const struct pci_dev *pdev)
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{
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unsigned long index = ice_adapter_index(pdev);
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struct ice_adapter *adapter;
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scoped_guard(mutex, &ice_adapters_mutex) {
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adapter = xa_load(&ice_adapters, index);
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if (WARN_ON(!adapter))
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return;
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if (!refcount_dec_and_test(&adapter->refcount))
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return;
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WARN_ON(xa_erase(&ice_adapters, index) != adapter);
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}
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ice_adapter_free(adapter);
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}
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