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 C7304189BB0; Sun, 7 Sep 2025 20:24:55 +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=1757276695; cv=none; b=Y5l0ql058TnTrfQFg1TaMUK5VoGaYoJBke+i7OmpxxfKqkduXBgGkB9jLZEDX2J4WVc/xFNB+iGuamPYmapWrWcpLsHsw+IfTKRD0etPJS5WHg2ZcN2oR4r6QBgcVoV9TfDXJpUaYiB09KFOEezMLgUisSxuC34ntGOuE81/3gY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757276695; c=relaxed/simple; bh=2WyPavsNqRawZXGBt5jB4f3QBMs5cPHIxOkROJ/IyrA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mS/j+OCjwyvQC9U6tsk3fRXEvNpY1ticdaVNdDqhLtl6tJM3g1VQMne7l44+5FHnlBYZ74CNzI01S7zncEvlaYcBQqF+EQq/Z4UytamiEt5cEa0mJCLjkVMjaniBpQ7nN41u3BROqMJwxINR39J/yQdhAYb2uLzqJU9l0yClY2w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SdvYqF2J; 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="SdvYqF2J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21B9CC4CEF0; Sun, 7 Sep 2025 20:24:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757276695; bh=2WyPavsNqRawZXGBt5jB4f3QBMs5cPHIxOkROJ/IyrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SdvYqF2JvTDaPK8qQLtfXvpDANfjxoQ6T3QQ9JRsGJB/Hy9uLhQNmeD0i9AbCyR/x fLP/jxz4s3e9rnt2czp3PDhzDF/FuzS9XdlSTUCfP6A0shDCrVm2185AlHVd1HdnRu FSDX1CEF9viqHdytB8/7FL2K+DD3r8ZKUwgqoMv4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jonathan Currier , Thomas Gleixner , Sasha Levin Subject: [PATCH 6.6 080/121] PCI/MSI: Add an option to write MSIX ENTRY_DATA before any reads Date: Sun, 7 Sep 2025 21:58:36 +0200 Message-ID: <20250907195611.890788497@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195609.817339617@linuxfoundation.org> References: <20250907195609.817339617@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jonathan Currier [ Upstream commit cf761e3dacc6ad5f65a4886d00da1f9681e6805a ] Commit 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries") introduced a readl() from ENTRY_VECTOR_CTRL before the writel() to ENTRY_DATA. This is correct, however some hardware, like the Sun Neptune chips, the NIU module, will cause an error and/or fatal trap if any MSIX table entry is read before the corresponding ENTRY_DATA field is written to. Add an optional early writel() in msix_prepare_msi_desc(). Fixes: 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries") Signed-off-by: Jonathan Currier Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20241117234843.19236-2-dullfire@yahoo.com [ Adjust context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi/msi.c | 3 +++ include/linux/pci.h | 2 ++ 2 files changed, 5 insertions(+) --- a/drivers/pci/msi/msi.c +++ b/drivers/pci/msi/msi.c @@ -610,6 +610,9 @@ void msix_prepare_msi_desc(struct pci_de if (desc->pci.msi_attrib.can_mask) { void __iomem *addr = pci_msix_desc_addr(desc); + /* Workaround for SUN NIU insanity, which requires write before read */ + if (dev->dev_flags & PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST) + writel(0, addr + PCI_MSIX_ENTRY_DATA); desc->pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); } } --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -245,6 +245,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11), /* Device does honor MSI masking despite saying otherwise */ PCI_DEV_FLAGS_HAS_MSI_MASKING = (__force pci_dev_flags_t) (1 << 12), + /* Device requires write to PCI_MSIX_ENTRY_DATA before any MSIX reads */ + PCI_DEV_FLAGS_MSIX_TOUCH_ENTRY_DATA_FIRST = (__force pci_dev_flags_t) (1 << 13), }; enum pci_irq_reroute_variant {