From patchwork Mon Nov 23 17:59:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jani Nikula X-Patchwork-Id: 11925907 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F3FAC63777 for ; Mon, 23 Nov 2020 18:01:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3529220781 for ; Mon, 23 Nov 2020 18:01:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390630AbgKWSAH (ORCPT ); Mon, 23 Nov 2020 13:00:07 -0500 Received: from mga18.intel.com ([134.134.136.126]:9945 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390610AbgKWSAH (ORCPT ); Mon, 23 Nov 2020 13:00:07 -0500 IronPort-SDR: pBNKLOF1sk6eefNQ+eje0MH4tymOhndepAsnWV7Xbd9VqzZ1QxhPJSzLE2GgNKyR5j7hsYDh5v wmGJPJdqek4w== X-IronPort-AV: E=McAfee;i="6000,8403,9814"; a="159581607" X-IronPort-AV: E=Sophos;i="5.78,364,1599548400"; d="scan'208";a="159581607" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2020 10:00:05 -0800 IronPort-SDR: uwGS3K3pbOs/n8e3wfn9KSb+BAlxZAUWi5s9FXtFaA2IazgHHzCxCxY6XTxNpdDDAwGpPReZG2 LHtz1I4W769g== X-IronPort-AV: E=Sophos;i="5.78,364,1599548400"; d="scan'208";a="536180669" Received: from suygunge-mobl.ger.corp.intel.com (HELO localhost) ([10.249.40.108]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2020 10:00:01 -0800 From: Jani Nikula To: linux-kernel@vger.kernel.org Cc: Christoph Hellwig , Andrew Morton , intel-gfx@lists.freedesktop.org, jani.nikula@intel.com, linux-block@vger.kernel.org, Jens Axboe , ath11k@lists.infradead.org, ath10k@lists.infradead.org, Kalle Valo , linux-wireless@vger.kernel.org, QCA ath9k Development Subject: [PATCH 4/9] relay: allow the use of const callback structs Date: Mon, 23 Nov 2020 19:59:24 +0200 Message-Id: X-Mailer: git-send-email 2.20.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org None of the relay users require the use of mutable structs for callbacks, however the relay code does. Instead of assigning the default callback for subbuf_start, add a wrapper to conditionally call the client callback if available, and fall back to default behaviour otherwise. This lets all relay users make their struct rchan_callbacks const data. Cc: linux-block@vger.kernel.org Cc: Jens Axboe Cc: ath11k@lists.infradead.org Cc: ath10k@lists.infradead.org Cc: Kalle Valo Cc: linux-wireless@vger.kernel.org Cc: QCA ath9k Development Cc: intel-gfx@lists.freedesktop.org Cc: Christoph Hellwig Signed-off-by: Jani Nikula Reviewed-by: Christoph Hellwig --- v2: Simplify after nuking some callbacks and making some others mandatory in previous patches, as per Christoph's review comments. I thought about adding wrappers for the now-mandatory create_buf_file and remove_buf_file as well, for consistency, but ended up leaving them out. --- include/linux/relay.h | 4 ++-- kernel/relay.c | 35 +++++++++++------------------------ 2 files changed, 13 insertions(+), 26 deletions(-) diff --git a/include/linux/relay.h b/include/linux/relay.h index 99d024475ba5..72b876dd5cb8 100644 --- a/include/linux/relay.h +++ b/include/linux/relay.h @@ -62,7 +62,7 @@ struct rchan size_t subbuf_size; /* sub-buffer size */ size_t n_subbufs; /* number of sub-buffers per buffer */ size_t alloc_size; /* total buffer size allocated */ - struct rchan_callbacks *cb; /* client callbacks */ + const struct rchan_callbacks *cb; /* client callbacks */ struct kref kref; /* channel refcount */ void *private_data; /* for user-defined data */ size_t last_toobig; /* tried to log event > subbuf size */ @@ -157,7 +157,7 @@ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, - struct rchan_callbacks *cb, + const struct rchan_callbacks *cb, void *private_data); extern int relay_late_setup_files(struct rchan *chan, const char *base_filename, diff --git a/kernel/relay.c b/kernel/relay.c index dd4ec4ec07f3..02bdba5372cb 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -252,19 +252,14 @@ EXPORT_SYMBOL_GPL(relay_buf_full); * High-level relay kernel API and associated functions. */ -/* - * rchan_callback implementations defining default channel behavior. Used - * in place of corresponding NULL values in client callback struct. - */ - -/* - * subbuf_start() default callback. Does nothing. - */ -static int subbuf_start_default_callback (struct rchan_buf *buf, - void *subbuf, - void *prev_subbuf, - size_t prev_padding) +/* subbuf_start callback wrapper */ +static int cb_subbuf_start(struct rchan_buf *buf, void *subbuf, + void *prev_subbuf, size_t prev_padding) { + if (buf->chan->cb->subbuf_start) + return buf->chan->cb->subbuf_start(buf, subbuf, + prev_subbuf, prev_padding); + if (relay_buf_full(buf)) return 0; @@ -314,7 +309,7 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init) for (i = 0; i < buf->chan->n_subbufs; i++) buf->padding[i] = 0; - buf->chan->cb->subbuf_start(buf, buf->data, NULL, 0); + cb_subbuf_start(buf, buf->data, NULL, 0); } /** @@ -442,14 +437,6 @@ static void relay_close_buf(struct rchan_buf *buf) kref_put(&buf->kref, relay_remove_buf); } -static void setup_callbacks(struct rchan *chan, - struct rchan_callbacks *cb) -{ - if (!cb->subbuf_start) - cb->subbuf_start = subbuf_start_default_callback; - chan->cb = cb; -} - int relay_prepare_cpu(unsigned int cpu) { struct rchan *chan; @@ -495,7 +482,7 @@ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, - struct rchan_callbacks *cb, + const struct rchan_callbacks *cb, void *private_data) { unsigned int i; @@ -529,7 +516,7 @@ struct rchan *relay_open(const char *base_filename, chan->has_base_filename = 1; strlcpy(chan->base_filename, base_filename, NAME_MAX); } - setup_callbacks(chan, cb); + chan->cb = cb; kref_init(&chan->kref); mutex_lock(&relay_channels_mutex); @@ -712,7 +699,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; new = buf->start + new_subbuf * buf->chan->subbuf_size; buf->offset = 0; - if (!buf->chan->cb->subbuf_start(buf, new, old, buf->prev_padding)) { + if (!cb_subbuf_start(buf, new, old, buf->prev_padding)) { buf->offset = buf->chan->subbuf_size + 1; return 0; }