From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout05.his.huawei.com (canpmsgout05.his.huawei.com [113.46.200.220]) (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 791163AA4F6; Wed, 1 Apr 2026 08:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.220 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775031425; cv=none; b=qEYKxrbjtTvSzDynQqWdn3olOMFjV5aTYlP5inX4boEWScChfADnciG2J3RytxFzt/7eoxsceBdC6tBtgrtaRpiUCkx4G5GB8QYPGt6W2nGCDKic3nw/BGSIG6Iygc1mNSTAHJizcB6cuH5HxK2OvyqgGikkGxjWeTm8o7c9bLA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775031425; c=relaxed/simple; bh=EKUkpbq7JSTnCQVDsQ7Bo7f2ZKWsZtAK12DNKf/nJlk=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CYpHRzXWOMVXI9pAjYHpZJU18u4gwvr2FmZ1EfO98vQUibGNMJ9Tm8MZEXvMjyh43tiVvBk5NiFIRgHMlvXQoifZj5uAMKRUiqD9KYSdrhMeb5dgVFttLIGiDFQqaBdgH5KLvLqwRSAtJMX/RAc/wZmnNUnRx7WJO1hvqXdlrYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=qLgUdTXy; arc=none smtp.client-ip=113.46.200.220 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="qLgUdTXy" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=hE9w7JoPF7q5rCf6KhhEJWJqCptovuDZd/Iy/+tLfKo=; b=qLgUdTXyB2huFMYWwsBs6yJ/F+9lt0zGJ2NBn+WC66I23Xw4lD/MYLZdp/AaESL9MDwbvh4PG 4g/cCYoR/67GmTbgs1X5afshxewzUwAWGLnOlgBOHKQjEtF2bK4P57/PDC46EmJDfRwKl3h1FiZ k+9EKAAKSPQbPzHjYnS4Cu4= Received: from mail.maildlp.com (unknown [172.19.163.0]) by canpmsgout05.his.huawei.com (SkyGuard) with ESMTPS id 4flyPP34Mzz12LG4; Wed, 1 Apr 2026 16:11:37 +0800 (CST) Received: from kwepemk500009.china.huawei.com (unknown [7.202.194.94]) by mail.maildlp.com (Postfix) with ESMTPS id B64C540537; Wed, 1 Apr 2026 16:17:00 +0800 (CST) Received: from localhost.localdomain (10.50.163.32) by kwepemk500009.china.huawei.com (7.202.194.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 1 Apr 2026 16:16:58 +0800 From: Chengwen Feng To: Bjorn Helgaas , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" CC: Jonathan Corbet , WANG Xuerui , Thomas Gleixner , Dave Hansen , "H . Peter Anvin" , Juergen Gross , Boris Ostrovsky , Len Brown , Sunil V L , Mark Rutland , Jonathan Cameron , Kees Cook , Yanteng Si , Sean Christopherson , Kai Huang , Tom Lendacky , Thomas Huth , Thorsten Blum , Kevin Loughlin , Zheyun Shen , Peter Zijlstra , Pawan Gupta , Xin Li , "Ahmed S . Darwish" , Sohil Mehta , Ilkka Koskinen , Robin Murphy , James Clark , Besar Wicaksono , Ma Ke , Wei Huang , Andy Gospodarek , Somnath Kotur , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RESEND v10 8/8] PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM Date: Wed, 1 Apr 2026 16:16:40 +0800 Message-ID: <20260401081640.26875-9-fengchengwen@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20260401081640.26875-1-fengchengwen@huawei.com> References: <20260401081640.26875-1-fengchengwen@huawei.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-ClientProxiedBy: kwepems200001.china.huawei.com (7.221.188.67) To kwepemk500009.china.huawei.com (7.202.194.94) pcie_tph_get_cpu_st() uses the Query Cache Locality Features _DSM [1] to retrieve the TPH Steering Tag for memory associated with the CPU identified by its "cpu_uid" parameter, a Linux logical CPU ID. The _DSM requires an ACPI Processor UID, which pcie_tph_get_cpu_st() previously assumed was the same as the Linux logical CPU ID. This is true on x86 but not on arm64, so pcie_tph_get_cpu_st() returned the wrong Steering Tag, resulting in incorrect TPH functionality on arm64. Convert the Linux logical CPU ID to the ACPI Processor UID with acpi_get_cpu_uid() before passing it to the _DSM. Additionally, rename the pcie_tph_get_cpu_st() parameter from "cpu_uid" to "cpu" to reflect that it represents a logical CPU ID (not an ACPI Processor UID). [1] According to ECN_TPH-ST_Revision_20200924 (https://members.pcisig.com/wg/PCI-SIG/document/15470), the input is defined as: "If the target is a processor, then this field represents the ACPI Processor UID of the processor as specified in the MADT. If the target is a processor container, then this field represents the ACPI Processor UID of the processor container as specified in the PPTT." Fixes: d2e8a34876ce ("PCI/TPH: Add Steering Tag support") Cc: stable@vger.kernel.org Signed-off-by: Chengwen Feng Reviewed-by: Jonathan Cameron Reviewed-by: Bjorn Helgaas --- Documentation/PCI/tph.rst | 4 ++-- drivers/pci/tph.c | 16 +++++++++++----- include/linux/pci-tph.h | 4 ++-- 3 files changed, 15 insertions(+), 9 deletions(-) diff --git a/Documentation/PCI/tph.rst b/Documentation/PCI/tph.rst index e8993be64fd6..b6cf22b9bd90 100644 --- a/Documentation/PCI/tph.rst +++ b/Documentation/PCI/tph.rst @@ -79,10 +79,10 @@ To retrieve a Steering Tag for a target memory associated with a specific CPU, use the following function:: int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type type, - unsigned int cpu_uid, u16 *tag); + unsigned int cpu, u16 *tag); The `type` argument is used to specify the memory type, either volatile -or persistent, of the target memory. The `cpu_uid` argument specifies the +or persistent, of the target memory. The `cpu` argument specifies the CPU where the memory is associated to. After the ST value is retrieved, the device driver can use the following diff --git a/drivers/pci/tph.c b/drivers/pci/tph.c index ca4f97be7538..b67c9ad14bda 100644 --- a/drivers/pci/tph.c +++ b/drivers/pci/tph.c @@ -236,21 +236,27 @@ static int write_tag_to_st_table(struct pci_dev *pdev, int index, u16 tag) * with a specific CPU * @pdev: PCI device * @mem_type: target memory type (volatile or persistent RAM) - * @cpu_uid: associated CPU id + * @cpu: associated CPU id * @tag: Steering Tag to be returned * * Return the Steering Tag for a target memory that is associated with a - * specific CPU as indicated by cpu_uid. + * specific CPU as indicated by cpu. * * Return: 0 if success, otherwise negative value (-errno) */ int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type mem_type, - unsigned int cpu_uid, u16 *tag) + unsigned int cpu, u16 *tag) { #ifdef CONFIG_ACPI struct pci_dev *rp; acpi_handle rp_acpi_handle; union st_info info; + u32 cpu_uid; + int ret; + + ret = acpi_get_cpu_uid(cpu, &cpu_uid); + if (ret != 0) + return ret; rp = pcie_find_root_port(pdev); if (!rp || !rp->bus || !rp->bus->bridge) @@ -265,9 +271,9 @@ int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type mem_type, *tag = tph_extract_tag(mem_type, pdev->tph_req_type, &info); - pci_dbg(pdev, "get steering tag: mem_type=%s, cpu_uid=%d, tag=%#04x\n", + pci_dbg(pdev, "get steering tag: mem_type=%s, cpu=%d, tag=%#04x\n", (mem_type == TPH_MEM_TYPE_VM) ? "volatile" : "persistent", - cpu_uid, *tag); + cpu, *tag); return 0; #else diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h index ba28140ce670..be68cd17f2f8 100644 --- a/include/linux/pci-tph.h +++ b/include/linux/pci-tph.h @@ -25,7 +25,7 @@ int pcie_tph_set_st_entry(struct pci_dev *pdev, unsigned int index, u16 tag); int pcie_tph_get_cpu_st(struct pci_dev *dev, enum tph_mem_type mem_type, - unsigned int cpu_uid, u16 *tag); + unsigned int cpu, u16 *tag); void pcie_disable_tph(struct pci_dev *pdev); int pcie_enable_tph(struct pci_dev *pdev, int mode); u16 pcie_tph_get_st_table_size(struct pci_dev *pdev); @@ -36,7 +36,7 @@ static inline int pcie_tph_set_st_entry(struct pci_dev *pdev, { return -EINVAL; } static inline int pcie_tph_get_cpu_st(struct pci_dev *dev, enum tph_mem_type mem_type, - unsigned int cpu_uid, u16 *tag) + unsigned int cpu, u16 *tag) { return -EINVAL; } static inline void pcie_disable_tph(struct pci_dev *pdev) { } static inline int pcie_enable_tph(struct pci_dev *pdev, int mode) -- 2.17.1