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94 lines
2.6 KiB
C
94 lines
2.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* zfcp device driver
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*
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* Functions to handle diagnostics.
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*
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* Copyright IBM Corp. 2018
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*/
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#include <linux/spinlock.h>
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#include <linux/jiffies.h>
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#include <linux/string.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include "zfcp_diag.h"
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#include "zfcp_ext.h"
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#include "zfcp_def.h"
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/* Max age of data in a diagnostics buffer before it needs a refresh (in ms). */
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#define ZFCP_DIAG_MAX_AGE (5 * 1000)
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/**
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* zfcp_diag_adapter_setup() - Setup storage for adapter diagnostics.
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* @adapter: the adapter to setup diagnostics for.
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*
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* Creates the data-structures to store the diagnostics for an adapter. This
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* overwrites whatever was stored before at &zfcp_adapter->diagnostics!
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*
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* Return:
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* * 0 - Everyting is OK
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* * -ENOMEM - Could not allocate all/parts of the data-structures;
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* &zfcp_adapter->diagnostics remains unchanged
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*/
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int zfcp_diag_adapter_setup(struct zfcp_adapter *const adapter)
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{
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struct zfcp_diag_adapter *diag;
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struct zfcp_diag_header *hdr;
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diag = kzalloc(sizeof(*diag), GFP_KERNEL);
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if (diag == NULL)
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return -ENOMEM;
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/* setup header for port_data */
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hdr = &diag->port_data.header;
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spin_lock_init(&hdr->access_lock);
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hdr->buffer = &diag->port_data.data;
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hdr->buffer_size = sizeof(diag->port_data.data);
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/* set the timestamp so that the first test on age will always fail */
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hdr->timestamp = jiffies - msecs_to_jiffies(ZFCP_DIAG_MAX_AGE);
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adapter->diagnostics = diag;
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return 0;
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}
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/**
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* zfcp_diag_adapter_free() - Frees all adapter diagnostics allocations.
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* @adapter: the adapter whose diagnostic structures should be freed.
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*
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* Frees all data-structures in the given adapter that store diagnostics
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* information. Can savely be called with partially setup diagnostics.
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*/
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void zfcp_diag_adapter_free(struct zfcp_adapter *const adapter)
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{
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kfree(adapter->diagnostics);
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adapter->diagnostics = NULL;
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}
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/**
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* zfcp_diag_update_xdata() - Update a diagnostics buffer.
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* @hdr: the meta data to update.
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* @data: data to use for the update.
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* @incomplete: flag stating whether the data in @data is incomplete.
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*/
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void zfcp_diag_update_xdata(struct zfcp_diag_header *const hdr,
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const void *const data, const bool incomplete)
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{
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const unsigned long capture_timestamp = jiffies;
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unsigned long flags;
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spin_lock_irqsave(&hdr->access_lock, flags);
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/* make sure we never go into the past with an update */
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if (!time_after_eq(capture_timestamp, hdr->timestamp))
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goto out;
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hdr->timestamp = capture_timestamp;
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hdr->incomplete = incomplete;
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memcpy(hdr->buffer, data, hdr->buffer_size);
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out:
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spin_unlock_irqrestore(&hdr->access_lock, flags);
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}
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