From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: From: Jani Nikula Subject: [PATCH 4/9] relay: allow the use of const callback structs Date: Mon, 23 Nov 2020 19:59:24 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: linux-kernel@vger.kernel.org Cc: Jens Axboe , linux-block@vger.kernel.org, jani.nikula@intel.com, intel-gfx@lists.freedesktop.org, linux-wireless@vger.kernel.org, QCA ath9k Development , ath10k@lists.infradead.org, Christoph Hellwig , Andrew Morton , ath11k@lists.infradead.org, Kalle Valo 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 --- 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; } -- 2.20.1 _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k