From patchwork Tue Feb 15 16:28:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 543022 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9E27C433EF for ; Tue, 15 Feb 2022 16:28:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239940AbiBOQ26 (ORCPT ); Tue, 15 Feb 2022 11:28:58 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:41584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231887AbiBOQ26 (ORCPT ); Tue, 15 Feb 2022 11:28:58 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51F677090D; Tue, 15 Feb 2022 08:28:47 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EC3776181D; Tue, 15 Feb 2022 16:28:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B90BC340EB; Tue, 15 Feb 2022 16:28:45 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="Jbh1/sC3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1644942523; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=o3Ex2y2ELI7nEV0J59rjOlWmWPabW9O5Loaxgl/Yv3E=; b=Jbh1/sC3FCtx0yDMtWLi5jsXL/5ERvlGM1sDJ1QrgCv+1RqkqedRZ7ySMvfJZ8JbKS5xFk BUxirU90d/HSwivk+QPU2dcYF240boXb9SZwBzjGhid0uSRf0WeHcKvDY5qCGEQ4uIpL/X FpxxfEEnUaJvO2QcB1dsgvYPHjRK37M= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id fd01509d (TLSv1.3:AEAD-AES256-GCM-SHA384:256:NO); Tue, 15 Feb 2022 16:28:42 +0000 (UTC) From: "Jason A. Donenfeld" To: miaoqing@codeaurora.org, "Jason Cooper" , "Sepehrdad, Pouyan" , ath9k-devel , "linux-wireless@vger.kernel.org" , "Kalle Valo" , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Dominik Brodowski , Linux Crypto Mailing List , Herbert Xu , LKML , Netdev Cc: "Jason A. Donenfeld" Subject: [PATCH] ath9k: use hw_random API instead of directly dumping into random.c Date: Tue, 15 Feb 2022 17:28:12 +0100 Message-Id: <20220215162812.195716-1-Jason@zx2c4.com> In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hardware random number generators are supposed to use the hw_random framework. This commit turns ath9k's kthread-based design into a proper hw_random driver. This compiles, but I have no hardware or other ability to determine whether it works. I'll leave further development up to the ath9k and hw_random maintainers. Cc: Toke Høiland-Jørgensen Cc: Kalle Valo Cc: Dominik Brodowski Cc: Herbert Xu Signed-off-by: Jason A. Donenfeld --- drivers/net/wireless/ath/ath9k/ath9k.h | 2 +- drivers/net/wireless/ath/ath9k/rng.c | 62 +++++++++----------------- 2 files changed, 23 insertions(+), 41 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h index ef6f5ea06c1f..142f472903dc 100644 --- a/drivers/net/wireless/ath/ath9k/ath9k.h +++ b/drivers/net/wireless/ath/ath9k/ath9k.h @@ -1072,7 +1072,7 @@ struct ath_softc { #ifdef CONFIG_ATH9K_HWRNG u32 rng_last; - struct task_struct *rng_task; + struct hwrng rng_ops; #endif }; diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c index aae2bd3cac69..369b222908ba 100644 --- a/drivers/net/wireless/ath/ath9k/rng.c +++ b/drivers/net/wireless/ath/ath9k/rng.c @@ -22,9 +22,6 @@ #include "hw.h" #include "ar9003_phy.h" -#define ATH9K_RNG_BUF_SIZE 320 -#define ATH9K_RNG_ENTROPY(x) (((x) * 8 * 10) >> 5) /* quality: 10/32 */ - static DECLARE_WAIT_QUEUE_HEAD(rng_queue); static int ath9k_rng_data_read(struct ath_softc *sc, u32 *buf, u32 buf_size) @@ -72,61 +69,46 @@ static u32 ath9k_rng_delay_get(u32 fail_stats) return delay; } -static int ath9k_rng_kthread(void *data) +static int ath9k_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { + struct ath_softc *sc = container_of(rng, struct ath_softc, rng_ops); int bytes_read; - struct ath_softc *sc = data; - u32 *rng_buf; - u32 delay, fail_stats = 0; - - rng_buf = kmalloc_array(ATH9K_RNG_BUF_SIZE, sizeof(u32), GFP_KERNEL); - if (!rng_buf) - goto out; - - while (!kthread_should_stop()) { - bytes_read = ath9k_rng_data_read(sc, rng_buf, - ATH9K_RNG_BUF_SIZE); - if (unlikely(!bytes_read)) { - delay = ath9k_rng_delay_get(++fail_stats); - wait_event_interruptible_timeout(rng_queue, - kthread_should_stop(), - msecs_to_jiffies(delay)); - continue; - } - - fail_stats = 0; - - /* sleep until entropy bits under write_wakeup_threshold */ - add_hwgenerator_randomness((void *)rng_buf, bytes_read, - ATH9K_RNG_ENTROPY(bytes_read)); - } + u32 fail_stats = 0; - kfree(rng_buf); -out: - sc->rng_task = NULL; +retry: + bytes_read = ath9k_rng_data_read(sc, buf, max); + if (unlikely(!bytes_read) && wait) { + msleep(ath9k_rng_delay_get(++fail_stats)); + goto retry; + } - return 0; + return bytes_read; } void ath9k_rng_start(struct ath_softc *sc) { struct ath_hw *ah = sc->sc_ah; + int ret; - if (sc->rng_task) + if (sc->rng_ops.read) return; if (!AR_SREV_9300_20_OR_LATER(ah)) return; - sc->rng_task = kthread_run(ath9k_rng_kthread, sc, "ath9k-hwrng"); - if (IS_ERR(sc->rng_task)) - sc->rng_task = NULL; + sc->rng_ops.name = "ath9k"; + sc->rng_ops.read = ath9k_rng_read; + sc->rng_ops.quality = 320; + + ret = devm_hwrng_register(sc->dev, &sc->rng_ops); + if (ret) + sc->rng_ops.read = NULL; } void ath9k_rng_stop(struct ath_softc *sc) { - if (sc->rng_task) { - kthread_stop(sc->rng_task); - sc->rng_task = NULL; + if (sc->rng_ops.read) { + devm_hwrng_unregister(sc->dev, &sc->rng_ops); + sc->rng_ops.read = NULL; } }