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Date: Tue, 9 Apr 2024 09:33:53 -0500
From: Bjorn Helgaas <helgaas@kernel.org>
To: Alexey Kardashevskiy <aik@amd.com>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Bjorn Helgaas <bhelgaas@google.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Lukas Wunner <lukas@wunner.de>
Subject: Re: [PATCH kernel v3] PCI/DOE: Support discovery version 2
Message-ID: <20240409143353.GA2073836@bhelgaas>
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In-Reply-To: <20240307022006.3657433-1-aik@amd.com>

On Thu, Mar 07, 2024 at 01:20:06PM +1100, Alexey Kardashevskiy wrote:
> PCIe r6.1, sec 6.30.1.1 defines a "DOE Discovery Version" field in
> the DOE Discovery Request Data Object Contents (3rd DW) as:
> 
> 15:8 DOE Discovery Version – must be 02h if the Capability Version in
> the Data Object Exchange Extended Capability is 02h or greater.
> 
> Add support for the version on devices with the DOE v2 capability.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@amd.com>

Applied with Sathy's reviewed-by to pci/doe for v6.10, thanks!

> ---
> Changes:
> v3:
> * updated subject line
> * dropped "DISCOVER_" from the new field macro
> 
> v2:
> * added the section number to the commit log
> ---
>  include/uapi/linux/pci_regs.h |  1 +
>  drivers/pci/doe.c             | 11 ++++++++---
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index a39193213ff2..fbca743b2b86 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -1144,6 +1144,7 @@
>  #define PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH		0x0003ffff
>  
>  #define PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX		0x000000ff
> +#define PCI_DOE_DATA_OBJECT_DISC_REQ_3_VER		0x0000ff00
>  #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID		0x0000ffff
>  #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL		0x00ff0000
>  #define PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX	0xff000000
> diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
> index 61f0531d2b1d..c94c2b0767f3 100644
> --- a/drivers/pci/doe.c
> +++ b/drivers/pci/doe.c
> @@ -381,11 +381,13 @@ static void pci_doe_task_complete(struct pci_doe_task *task)
>  	complete(task->private);
>  }
>  
> -static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid,
> +static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 capver, u8 *index, u16 *vid,
>  			     u8 *protocol)
>  {
>  	u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX,
> -				    *index);
> +				    *index) |
> +			 FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_VER,
> +				    (capver >= 2) ? 2 : 0);
>  	__le32 request_pl_le = cpu_to_le32(request_pl);
>  	__le32 response_pl_le;
>  	u32 response_pl;
> @@ -419,13 +421,16 @@ static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
>  {
>  	u8 index = 0;
>  	u8 xa_idx = 0;
> +	u32 hdr = 0;
> +
> +	pci_read_config_dword(doe_mb->pdev, doe_mb->cap_offset, &hdr);
>  
>  	do {
>  		int rc;
>  		u16 vid;
>  		u8 prot;
>  
> -		rc = pci_doe_discovery(doe_mb, &index, &vid, &prot);
> +		rc = pci_doe_discovery(doe_mb, PCI_EXT_CAP_VER(hdr), &index, &vid, &prot);
>  		if (rc)
>  			return rc;
>  
> -- 
> 2.41.0
>