From patchwork Thu Oct 31 13:42:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takashi Iwai X-Patchwork-Id: 13857924 X-Patchwork-Delegate: bhelgaas@google.com Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E6E619D89D; Thu, 31 Oct 2024 13:41:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730382121; cv=none; b=IXCPil5o91TSiWHd1ik22c1aCMbuvK3emkwJsU+830Sj3yzoNZYfq17dPbhyiXxf1tBKxWfCo7O1mrL/KO/LV07VFlpYxM3sLvGCH3cwwKG6dJgvih2GzUcuZX1DczV2nWsl1dMd2L/2FnwXp6tx0qD6CfRI1e8vJNRo0SPdpLo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730382121; c=relaxed/simple; bh=dX+Q+XTiQ/fBA2vx3HZFedzv4T+DlVnkntUE8vdFJI0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kdW7fpwcKDSzdXo1MUJDUYWkJUd7gmidkVV7r2pN6SHIVA6lzBaxrsf80BRwkZmZWCyrVdgDrAIYXmItmtURUir7xbS51fDPzOvJBUScYSOt+c7/yvdWKcm15J3WZUfEw1gW7UklAMM8wTM186jOlZcC2ZvX3krbn39VhTaakCI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=qHIsKmBk; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=NA4uWHNo; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=qHIsKmBk; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=NA4uWHNo; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="qHIsKmBk"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="NA4uWHNo"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="qHIsKmBk"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="NA4uWHNo" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BB36021D29; Thu, 31 Oct 2024 13:41:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1730382117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=P4rYzf0RxbUG+jDjrbpen3xgKQiObxthKPJBOOFcRx0=; b=qHIsKmBkENyfPE5A/DNju/MtMLTEB9uPhbaP5RHYODo8O2LxoupKVsRW10LFW92iDbqzBo 1vtd2yAOTVsqcvS+yZ8hTFU0pHOWiFkZFL1OyaATcBkWZAk8SLcrmMxw5VVsZvTVr5mt4c kIxd8XfUgJUNDjW+9AW0UMSHX3vJaEE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1730382117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=P4rYzf0RxbUG+jDjrbpen3xgKQiObxthKPJBOOFcRx0=; b=NA4uWHNokwHSqCs1m38pO6DynSSiX5mL48DaoMPaEy0j5VS80oEtRYjj6ggiHRDLskfpRg 7G+vQLBPQ6yTKADw== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1730382117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=P4rYzf0RxbUG+jDjrbpen3xgKQiObxthKPJBOOFcRx0=; b=qHIsKmBkENyfPE5A/DNju/MtMLTEB9uPhbaP5RHYODo8O2LxoupKVsRW10LFW92iDbqzBo 1vtd2yAOTVsqcvS+yZ8hTFU0pHOWiFkZFL1OyaATcBkWZAk8SLcrmMxw5VVsZvTVr5mt4c kIxd8XfUgJUNDjW+9AW0UMSHX3vJaEE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1730382117; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=P4rYzf0RxbUG+jDjrbpen3xgKQiObxthKPJBOOFcRx0=; b=NA4uWHNokwHSqCs1m38pO6DynSSiX5mL48DaoMPaEy0j5VS80oEtRYjj6ggiHRDLskfpRg 7G+vQLBPQ6yTKADw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 8F8AB13A53; Thu, 31 Oct 2024 13:41:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id jHitISWJI2dFfAAAD6G6ig (envelope-from ); Thu, 31 Oct 2024 13:41:57 +0000 From: Takashi Iwai To: Bjorn Helgaas Cc: Philipp Stanner , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] PCI: Restore the original INTX_DISABLE bit by pcim_intx() Date: Thu, 31 Oct 2024 14:42:56 +0100 Message-ID: <20241031134300.10296-1-tiwai@suse.de> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Score: -2.80 X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:mid,suse.de:email]; RCVD_TLS_ALL(0.00)[] X-Spam-Flag: NO X-Spam-Level: pcim_intx() tries to restore the INTx bit at removal via devres, but there is a chance that it restores a wrong value. Because the value to be restored is blindly assumed to be the negative of the enable argument, when a driver calls pcim_intx() unnecessarily for the already enabled state, it'll restore to the disabled state in turn. That is, the function assumes the case like: // INTx == 1 pcim_intx(pdev, 0); // old INTx value assumed to be 1 -> correct but it might be like the following, too: // INTx == 0 pcim_intx(pdev, 0); // old INTx value assumed to be 1 -> wrong Also, when a driver calls pcim_intx() multiple times with different enable argument values, the last one will win no matter what value it is. This can lead to inconsistency, e.g. // INTx == 1 pcim_intx(pdev, 0); // OK ... pcim_intx(pdev, 1); // now old INTx wrongly assumed to be 0 This patch addresses those inconsistencies by saving the original INTx state at the first pcim_intx() call. For that, get_or_create_intx_devres() is folded into pcim_intx() caller side; it allows us to simply check the already allocated devres and record the original INTx along with the devres_alloc() call. Fixes: 25216afc9db5 ("PCI: Add managed pcim_intx()") Cc: stable@vger.kernel.org # 6.11+ Link: https://lore.kernel.org/87v7xk2ps5.wl-tiwai@suse.de Signed-off-by: Takashi Iwai --- v1->v2: refactoring, fold get_or_create_intx_devres() into the caller instead of retrieving the original INTx there. Also add comments and improve the patch description. drivers/pci/devres.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c index b133967faef8..c93d4d4499a0 100644 --- a/drivers/pci/devres.c +++ b/drivers/pci/devres.c @@ -438,19 +438,12 @@ static void pcim_intx_restore(struct device *dev, void *data) __pcim_intx(pdev, res->orig_intx); } -static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) +static void save_orig_intx(struct pci_dev *pdev, struct pcim_intx_devres *res) { - struct pcim_intx_devres *res; + u16 pci_command; - res = devres_find(dev, pcim_intx_restore, NULL, NULL); - if (res) - return res; - - res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL); - if (res) - devres_add(dev, res); - - return res; + pci_read_config_word(pdev, PCI_COMMAND, &pci_command); + res->orig_intx = !(pci_command & PCI_COMMAND_INTX_DISABLE); } /** @@ -466,12 +459,23 @@ static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) int pcim_intx(struct pci_dev *pdev, int enable) { struct pcim_intx_devres *res; + struct device *dev = &pdev->dev; - res = get_or_create_intx_devres(&pdev->dev); - if (!res) - return -ENOMEM; + /* + * pcim_intx() must only restore the INTx value that existed before the + * driver was loaded, i.e., before it called pcim_intx() for the + * first time. + */ + res = devres_find(dev, pcim_intx_restore, NULL, NULL); + if (!res) { + res = devres_alloc(pcim_intx_restore, sizeof(*res), GFP_KERNEL); + if (!res) + return -ENOMEM; + + save_orig_intx(pdev, res); + devres_add(dev, res); + } - res->orig_intx = !enable; __pcim_intx(pdev, enable); return 0;