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From: Bjorn Helgaas <helgaas@kernel.org>
To: Terry Bowman <terry.bowman@amd.com>
Cc: dave@stgolabs.net, jonathan.cameron@huawei.com,
	dave.jiang@intel.com, alison.schofield@intel.com,
	dan.j.williams@intel.com, bhelgaas@google.com,
	shiju.jose@huawei.com, ming.li@zohomail.com,
	Smita.KoralahalliChannabasappa@amd.com, rrichter@amd.com,
	dan.carpenter@linaro.org, PradeepVineshReddy.Kodamati@amd.com,
	lukas@wunner.de, Benjamin.Cheatham@amd.com,
	sathyanarayanan.kuppuswamy@linux.intel.com,
	linux-cxl@vger.kernel.org, alucerop@amd.com, ira.weiny@intel.com,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [PATCH v13 20/25] CXL/PCI: Introduce CXL Port protocol error handlers
Date: Mon, 8 Dec 2025 12:37:49 -0600	[thread overview]
Message-ID: <20251208183749.GA3302551@bhelgaas> (raw)
In-Reply-To: <20251104001001.3833651-21-terry.bowman@amd.com>

On Mon, Nov 03, 2025 at 06:09:56PM -0600, Terry Bowman wrote:
> Add CXL protocol error handlers for CXL Port devices (Root Ports,
> Downstream Ports, and Upstream Ports). Implement cxl_port_cor_error_detected()
> and cxl_port_error_detected() to handle correctable and uncorrectable errors
> respectively.
> 
> Introduce cxl_get_ras_base() to retrieve the cached RAS register base
> address for a given CXL port. This function supports CXL Root Ports,
> Downstream Ports, and Upstream Ports by returning their previously mapped
> RAS register addresses.
> 
> Add device lock assertions to protect against concurrent device or RAS
> register removal during error handling. The port error handlers require
> two device locks:
> 
> 1. The port's CXL parent device - RAS registers are mapped using devm_*
>    functions with the parent port as the host. Locking the parent prevents
>    the RAS registers from being unmapped during error handling.
> 
> 2. The PCI device (pdev->dev) - Locking prevents concurrent modifications
>    to the PCI device structure during error handling.
> 
> The lock assertions added here will be satisfied by device locks introduced
> in a subsequent patch.

Weird.  Can't you add the lock assertions at the same time you add the
locks?

> Introduce get_pci_cxl_host_dev() to return the device responsible for
> managing the RAS register mapping. This function increments the reference
> count on the host device to prevent premature resource release during error
> handling. The caller is responsible for decrementing the reference count.
> For CXL endpoints, which manage resources without a separate host device,
> this function returns NULL.
> 
> Update the AER driver's is_cxl_error() to recognize CXL Port devices in
> addition to CXL Endpoints, as both now have CXL-specific error handlers.
> 
> Signed-off-by: Terry Bowman <terry.bowman@amd.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> @@ -1573,6 +1573,7 @@ static struct cxl_port *find_cxl_port_by_uport(struct device *uport_dev)
>  		return to_cxl_port(dev);
>  	return NULL;
>  }
> +EXPORT_SYMBOL_NS_GPL(find_cxl_port_by_uport, "CXL");

The usual export question: is there a modular caller()?

> +	dev_warn_once(dev, "Error: Unsupported device type (%X)", pci_pcie_type(pdev));

Maybe "%#x" (add 0x prefix and use lower-case hex, unless there's a
different CXL convention)?

  reply	other threads:[~2025-12-08 18:37 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-04  0:09 [PATCH v13 00/25] Enable CXL PCIe Port Protocol Error handling and logging Terry Bowman
2025-11-04  0:09 ` [PATCH v13 01/25] CXL/PCI: Move CXL DVSEC definitions into uapi/linux/pci_regs.h Terry Bowman
2025-12-06  0:31   ` Bjorn Helgaas
2025-12-06  0:41     ` dan.j.williams
2025-12-06  1:56       ` Bjorn Helgaas
2025-12-06  4:56         ` dan.j.williams
2025-11-04  0:09 ` [PATCH v13 02/25] PCI/CXL: Introduce pcie_is_cxl() Terry Bowman
2025-12-06  0:45   ` Bjorn Helgaas
2025-12-08 15:26     ` Bowman, Terry
2025-12-08 18:33       ` Bjorn Helgaas
2025-11-04  0:09 ` [PATCH v13 03/25] cxl/pci: Remove unnecessary CXL Endpoint handling helper functions Terry Bowman
2025-11-04  0:09 ` [PATCH v13 04/25] cxl/pci: Remove unnecessary CXL RCH " Terry Bowman
2025-11-04  0:09 ` [PATCH v13 05/25] cxl: Remove CXL VH handling in CONFIG_PCIEAER_CXL conditional blocks from core/pci.c Terry Bowman
2025-11-04  0:09 ` [PATCH v13 06/25] cxl: Move CXL driver's RCH error handling into core/ras_rch.c Terry Bowman
2025-11-04  0:09 ` [PATCH v13 07/25] CXL/AER: Replace device_lock() in cxl_rch_handle_error_iter() with guard() lock Terry Bowman
2025-12-08 18:05   ` Bjorn Helgaas
2025-11-04  0:09 ` [PATCH v13 08/25] CXL/AER: Move AER drivers RCH error handling into pcie/aer_cxl_rch.c Terry Bowman
2025-12-08 18:06   ` Bjorn Helgaas
2025-12-08 21:28     ` Bowman, Terry
2025-12-10 21:57       ` Bowman, Terry
2025-12-10 23:12         ` Bjorn Helgaas
2025-11-04  0:09 ` [PATCH v13 09/25] PCI/AER: Report CXL or PCIe bus error type in trace logging Terry Bowman
2025-11-04  0:09 ` [PATCH v13 10/25] cxl/pci: Update RAS handler interfaces to also support CXL Ports Terry Bowman
2025-11-04  0:09 ` [PATCH v13 11/25] cxl/pci: Log message if RAS registers are unmapped Terry Bowman
2025-11-04  0:09 ` [PATCH v13 12/25] cxl/pci: Unify CXL trace logging for CXL Endpoints and CXL Ports Terry Bowman
2025-11-04  0:09 ` [PATCH v13 13/25] cxl/pci: Update cxl_handle_cor_ras() to return early if no RAS errors Terry Bowman
2025-11-04  0:09 ` [PATCH v13 14/25] cxl/pci: Map CXL Endpoint Port and CXL Switch Port RAS registers Terry Bowman
2025-11-04  0:09 ` [PATCH v13 15/25] CXL/PCI: Introduce PCI_ERS_RESULT_PANIC Terry Bowman
2025-11-04  0:09 ` [PATCH v13 16/25] CXL/AER: Introduce pcie/aer_cxl_vh.c in AER driver for forwarding CXL errors Terry Bowman
2025-12-08 18:36   ` Bjorn Helgaas
2025-11-04  0:09 ` [PATCH v13 17/25] cxl: Introduce cxl_pci_drv_bound() to check for bound driver Terry Bowman
2025-11-04  0:09 ` [PATCH v13 18/25] cxl: Change CXL handlers to use guard() instead of scoped_guard() Terry Bowman
2025-11-04  0:09 ` [PATCH v13 19/25] cxl/pci: Introduce CXL protocol error handlers for Endpoints Terry Bowman
2025-11-04  0:09 ` [PATCH v13 20/25] CXL/PCI: Introduce CXL Port protocol error handlers Terry Bowman
2025-12-08 18:37   ` Bjorn Helgaas [this message]
2025-12-09 15:17     ` Bowman, Terry
2025-11-04  0:09 ` [PATCH v13 21/25] PCI/AER: Dequeue forwarded CXL error Terry Bowman
2025-11-04  0:09 ` [PATCH v13 22/25] CXL/PCI: Export and rename merge_result() to pci_ers_merge_result() Terry Bowman
2025-12-08 18:38   ` Bjorn Helgaas

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