Re: [PATCH V2 2/9] PCI: Extend Root Port Driver to support RCEC

From: "Kuppuswamy, Sathyanarayanan"  <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Sean V Kelley <sean.v.kelley@intel.com>,
	bhelgaas@google.com, Jonathan.Cameron@huawei.com,
	rjw@rjwysocki.net, ashok.raj@intel.com, tony.luck@intel.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Subject: Re: [PATCH V2 2/9] PCI: Extend Root Port Driver to support RCEC
Date: Wed, 26 Aug 2020 09:16:13 -0700	[thread overview]
Message-ID: <fe1e4832-a634-66d8-96dc-4ad980dabd1a@linux.intel.com> (raw)
In-Reply-To: <20200804194052.193272-3-sean.v.kelley@intel.com>


On 8/4/20 12:40 PM, Sean V Kelley wrote:
> From: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
> 
> If a Root Complex Integrated Endpoint (RCiEP) is implemented, errors may
> optionally be sent to a corresponding Root Complex Event Collector (RCEC).
> Each RCiEP must be associated with no more than one RCEC. Interface errors
> are reported to the OS by RCECs.
> 
> For an RCEC (technically not a Bridge), error messages "received" from
> associated RCiEPs must be enabled for "transmission" in order to cause a
> System Error via the Root Control register or (when the Advanced Error
> Reporting Capability is present) reporting via the Root Error Command
> register and logging in the Root Error Status register and Error Source
> Identification register.
> 
> Given the commonality with Root Ports and the need to also support AER
> and PME services for RCECs, extend the Root Port driver to support RCEC
> devices through the addition of the RCEC Class ID to the driver
> structure.
> 
> Co-developed-by: Sean V Kelley <sean.v.kelley@intel.com>
> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
> Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
> ---
>   drivers/pci/pcie/portdrv_core.c | 8 ++++----
>   drivers/pci/pcie/portdrv_pci.c  | 5 ++++-
>   2 files changed, 8 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index 50a9522ab07d..5d4a400094fc 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -234,11 +234,11 @@ static int get_port_device_capability(struct pci_dev *dev)
>   #endif
>   
>   	/*
> -	 * Root ports are capable of generating PME too.  Root Complex
> -	 * Event Collectors can also generate PMEs, but we don't handle
> -	 * those yet.
> +	 * Root ports and Root Complex Event Collectors are capable
> +	 * of generating PME too.
>   	 */
> -	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
> +	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
> +	     pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) &&
>   	    (pcie_ports_native || host->native_pme)) {
>   		services |= PCIE_PORT_SERVICE_PME;
What about AER service? Don't you need to enable it for RCEC?
>   
> diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
> index 3a3ce40ae1ab..4d880679b9b1 100644
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -106,7 +106,8 @@ static int pcie_portdrv_probe(struct pci_dev *dev,
>   	if (!pci_is_pcie(dev) ||
>   	    ((pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) &&
>   	     (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM) &&
> -	     (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)))
> +	     (pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM) &&
> +	     (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)))
>   		return -ENODEV;
>   
>   	status = pcie_port_device_register(dev);
> @@ -195,6 +196,8 @@ static const struct pci_device_id port_pci_ids[] = {
>   	{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x00), ~0) },
>   	/* subtractive decode PCI-to-PCI bridge, class type is 060401h */
>   	{ PCI_DEVICE_CLASS(((PCI_CLASS_BRIDGE_PCI << 8) | 0x01), ~0) },
> +	/* handle any Root Complex Event Collector */
> +	{ PCI_DEVICE_CLASS(((PCI_CLASS_SYSTEM_RCEC << 8) | 0x00), ~0) },
>   	{ },
>   };
>   
> 

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer