From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9765264A76; Tue, 8 Apr 2025 11:19:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744111194; cv=none; b=uJ0MgC2r2tbimw4H+ykFwOgxanR4uy8HdlSQID+0He5M05zfVv3JTsKGTMAjpLo20tcd1h/DoQhqvFlAhEFplpUpb6iZS8tPmb4UWD9JYxO3/9FXkrtCqWnBRv5EXwpjxcGdrKkLbrmyEcSIwTiVTrhmnsZbpoiJ3HC5l+XVRks= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744111194; c=relaxed/simple; bh=Soj7Qa9lXMK+VHnb185ZIbupMDhUOMSjD1uY37sNRhI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RdXT/s6MuzCgiPQaSOw3T8fxOUUq7/O8TwRHCEA1dvWbCxzL1Ws62RpeJoDU3kVNLnDoCSvV+TGMVvB7CdWYCIVK+7TplzycFz66QlzKQVcxgGLzqnjwJMVcJBUDA73QWGVtvLYv7eat3MXXFI0v+Lfx+tIbc8ijOd389ktyZVQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hUQuZcWg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hUQuZcWg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FCC6C4CEE7; Tue, 8 Apr 2025 11:19:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744111194; bh=Soj7Qa9lXMK+VHnb185ZIbupMDhUOMSjD1uY37sNRhI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hUQuZcWgCGIrkNlmJS1woLLlyoHsciWotnUyDK4//+mm3XdUBFhe+lYLU/6EPKg9D uDl2P8OudYOqBRn9xw93Bl5uRkWkwqemzpbLW8/FN4m/0OuWZbEpDGSvPQivwWAd/x QC6WhnXWdZvGOE46XFi5stwZH29SA39z+3Z6of6A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tushar Dave , Bjorn Helgaas , Jason Gunthorpe , Kuppuswamy Sathyanarayanan , Sasha Levin Subject: [PATCH 6.14 294/731] PCI/ACS: Fix pci=config_acs= parameter Date: Tue, 8 Apr 2025 12:43:11 +0200 Message-ID: <20250408104921.117129999@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104914.247897328@linuxfoundation.org> References: <20250408104914.247897328@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tushar Dave [ Upstream commit 9cf8a952d57b422d3ff8a9a0163f8adf694f4b2b ] Commit 47c8846a49ba ("PCI: Extend ACS configurability") introduced bugs that fail to configure ACS ctrl to the value specified by the kernel parameter. Essentially there are two bugs: 1) When ACS is configured for multiple PCI devices using 'config_acs' kernel parameter, it results into error "PCI: Can't parse ACS command line parameter". This is due to a bug that doesn't preserve the ACS mask, but instead overwrites the mask with value 0. For example, using 'config_acs' to configure ACS ctrl for multiple BDFs fails: Kernel command line: pci=config_acs=1111011@0020:02:00.0;101xxxx@0039:00:00.0 "dyndbg=file drivers/pci/pci.c +p" PCI: Can't parse ACS command line parameter pci 0020:02:00.0: ACS mask = 0x007f pci 0020:02:00.0: ACS flags = 0x007b pci 0020:02:00.0: Configured ACS to 0x007b After this fix: Kernel command line: pci=config_acs=1111011@0020:02:00.0;101xxxx@0039:00:00.0 "dyndbg=file drivers/pci/pci.c +p" pci 0020:02:00.0: ACS mask = 0x007f pci 0020:02:00.0: ACS flags = 0x007b pci 0020:02:00.0: ACS control = 0x005f pci 0020:02:00.0: ACS fw_ctrl = 0x0053 pci 0020:02:00.0: Configured ACS to 0x007b pci 0039:00:00.0: ACS mask = 0x0070 pci 0039:00:00.0: ACS flags = 0x0050 pci 0039:00:00.0: ACS control = 0x001d pci 0039:00:00.0: ACS fw_ctrl = 0x0000 pci 0039:00:00.0: Configured ACS to 0x0050 2) In the bit manipulation logic, we copy the bit from the firmware settings when mask bit 0. For example, 'disable_acs_redir' fails to clear all three ACS P2P redir bits due to the wrong bit fiddling: Kernel command line: pci=disable_acs_redir=0020:02:00.0;0030:02:00.0;0039:00:00.0 "dyndbg=file drivers/pci/pci.c +p" pci 0020:02:00.0: ACS mask = 0x002c pci 0020:02:00.0: ACS flags = 0xffd3 pci 0020:02:00.0: Configured ACS to 0xfffb pci 0030:02:00.0: ACS mask = 0x002c pci 0030:02:00.0: ACS flags = 0xffd3 pci 0030:02:00.0: Configured ACS to 0xffdf pci 0039:00:00.0: ACS mask = 0x002c pci 0039:00:00.0: ACS flags = 0xffd3 pci 0039:00:00.0: Configured ACS to 0xffd3 After this fix: Kernel command line: pci=disable_acs_redir=0020:02:00.0;0030:02:00.0;0039:00:00.0 "dyndbg=file drivers/pci/pci.c +p" pci 0020:02:00.0: ACS mask = 0x002c pci 0020:02:00.0: ACS flags = 0xffd3 pci 0020:02:00.0: ACS control = 0x007f pci 0020:02:00.0: ACS fw_ctrl = 0x007b pci 0020:02:00.0: Configured ACS to 0x0053 pci 0030:02:00.0: ACS mask = 0x002c pci 0030:02:00.0: ACS flags = 0xffd3 pci 0030:02:00.0: ACS control = 0x005f pci 0030:02:00.0: ACS fw_ctrl = 0x005f pci 0030:02:00.0: Configured ACS to 0x0053 pci 0039:00:00.0: ACS mask = 0x002c pci 0039:00:00.0: ACS flags = 0xffd3 pci 0039:00:00.0: ACS control = 0x001d pci 0039:00:00.0: ACS fw_ctrl = 0x0000 pci 0039:00:00.0: Configured ACS to 0x0000 Link: https://lore.kernel.org/r/20250207030338.456887-1-tdave@nvidia.com Fixes: 47c8846a49ba ("PCI: Extend ACS configurability") Signed-off-by: Tushar Dave Signed-off-by: Bjorn Helgaas Reviewed-by: Jason Gunthorpe Reviewed-by: Kuppuswamy Sathyanarayanan Signed-off-by: Sasha Levin --- drivers/pci/pci.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 869d204a70a37..23609dd123f95 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -954,8 +954,10 @@ struct pci_acs { }; static void __pci_config_acs(struct pci_dev *dev, struct pci_acs *caps, - const char *p, u16 mask, u16 flags) + const char *p, const u16 acs_mask, const u16 acs_flags) { + u16 flags = acs_flags; + u16 mask = acs_mask; char *delimit; int ret = 0; @@ -963,7 +965,7 @@ static void __pci_config_acs(struct pci_dev *dev, struct pci_acs *caps, return; while (*p) { - if (!mask) { + if (!acs_mask) { /* Check for ACS flags */ delimit = strstr(p, "@"); if (delimit) { @@ -971,6 +973,8 @@ static void __pci_config_acs(struct pci_dev *dev, struct pci_acs *caps, u32 shift = 0; end = delimit - p - 1; + mask = 0; + flags = 0; while (end > -1) { if (*(p + end) == '0') { @@ -1027,10 +1031,14 @@ static void __pci_config_acs(struct pci_dev *dev, struct pci_acs *caps, pci_dbg(dev, "ACS mask = %#06x\n", mask); pci_dbg(dev, "ACS flags = %#06x\n", flags); + pci_dbg(dev, "ACS control = %#06x\n", caps->ctrl); + pci_dbg(dev, "ACS fw_ctrl = %#06x\n", caps->fw_ctrl); - /* If mask is 0 then we copy the bit from the firmware setting. */ - caps->ctrl = (caps->ctrl & ~mask) | (caps->fw_ctrl & mask); - caps->ctrl |= flags; + /* + * For mask bits that are 0, copy them from the firmware setting + * and apply flags for all the mask bits that are 1. + */ + caps->ctrl = (caps->fw_ctrl & ~mask) | (flags & mask); pci_info(dev, "Configured ACS to %#06x\n", caps->ctrl); } -- 2.39.5