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 F028126B0A9; Tue, 8 Apr 2025 12:12:52 +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=1744114373; cv=none; b=gBjqzkM0WNopRLZN0ib+O6ndTELy6Es3iktmRMKBFocBT70grtkhS/7bCXWPOvpZqOsYq8DMJiF87n3SGA9eN8ZAr21Afwq2FC7Len+mvmkeGMUBU2fg3C0FCT1hKtI+eILYGozOFj3S5uKiqorFzEONru8KaJqkiO3eEh1QyTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744114373; c=relaxed/simple; bh=A7D3IXYFJf0zhs7gjQSCtYK5dIuREplWtY7BTGljpAQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VRfwhy6+dyIleyxfaiMXufkdqAhmxHXwNLIKeDwNlQKRtiyH70YItoD22gaOuDL/wvx1S2M9WKzsSvyh/v8LsXfXblXB4yLA4TKTIo8nEXFHWwxsq3EuYfEtO5qhQPQ78WbsmXUPU2TAmvFNLTvvqLXdExEbm13ipU8OsWSvQ2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NZ3hKc+a; 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="NZ3hKc+a" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 815F4C4CEE5; Tue, 8 Apr 2025 12:12:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744114372; bh=A7D3IXYFJf0zhs7gjQSCtYK5dIuREplWtY7BTGljpAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NZ3hKc+a5yyIYkYMqqHn3704Zlg/X3W3AvOxRx5Mmud9Iose1gb8TojpIehTvdmvb 1XcXPRCsxxf0dXHYCSYh3mISMI14oc+x7U07hZN35VvPHn/zQC42a/SP3Ij2NrhXoU HurIF897XINFW9d+ugaCQuqV2v/3YCosFFvGdWnw= 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 6.13 080/499] PCI/ACS: Fix pci=config_acs= parameter Date: Tue, 8 Apr 2025 12:44:52 +0200 Message-ID: <20250408104853.221082028@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104851.256868745@linuxfoundation.org> References: <20250408104851.256868745@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-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 b0ae4bc1a1bee..db437572be472 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -955,8 +955,10 @@ 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; @@ -964,7 +966,7 @@ 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) { @@ -972,6 +974,8 @@ 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') { @@ -1028,10 +1032,14 @@ 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