Re: [PATCH v2 04/10] cxl/pci: Use synchronous API for DOE

From: Ira Weiny <ira.weiny@intel.com>
To: Lukas Wunner <lukas@wunner.de>,
	Bjorn Helgaas <helgaas@kernel.org>, <linux-pci@vger.kernel.org>
Cc: Gregory Price <gregory.price@memverge.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	"Dan Williams" <dan.j.williams@intel.com>,
	Alison Schofield <alison.schofield@intel.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	"Dave Jiang" <dave.jiang@intel.com>,
	"Li, Ming" <ming4.li@intel.com>, Hillf Danton <hdanton@sina.com>,
	Ben Widawsky <bwidawsk@kernel.org>, <linuxarm@huawei.com>,
	<linux-cxl@vger.kernel.org>
Subject: Re: [PATCH v2 04/10] cxl/pci: Use synchronous API for DOE
Date: Mon, 23 Jan 2023 16:52:19 -0800	[thread overview]
Message-ID: <63cf2bc3cf76_521a294a1@iweiny-mobl.notmuch> (raw)
In-Reply-To: <b5469cbb8a3e138a1c709ed3eaab02d7ca8e84b2.1674468099.git.lukas@wunner.de>

Lukas Wunner wrote:
> A synchronous API for DOE has just been introduced.  Convert CXL CDAT
> retrieval over to it.
> 
> Tested-by: Ira Weiny <ira.weiny@intel.com>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
> ---
>  drivers/cxl/core/pci.c | 62 ++++++++++++++----------------------------
>  1 file changed, 20 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index 57764e9cd19d..a02a2b005e6a 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -487,51 +487,26 @@ static struct pci_doe_mb *find_cdat_doe(struct device *uport)
>  		    CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) |		\
>  	 FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle)))
>  
> -static void cxl_doe_task_complete(struct pci_doe_task *task)
> -{
> -	complete(task->private);
> -}
> -
> -struct cdat_doe_task {
> -	u32 request_pl;
> -	u32 response_pl[32];
> -	struct completion c;
> -	struct pci_doe_task task;
> -};
> -
> -#define DECLARE_CDAT_DOE_TASK(req, cdt)                       \
> -struct cdat_doe_task cdt = {                                  \
> -	.c = COMPLETION_INITIALIZER_ONSTACK(cdt.c),           \
> -	.request_pl = req,				      \
> -	.task = {                                             \
> -		.prot.vid = PCI_DVSEC_VENDOR_ID_CXL,        \
> -		.prot.type = CXL_DOE_PROTOCOL_TABLE_ACCESS, \
> -		.request_pl = &cdt.request_pl,                \
> -		.request_pl_sz = sizeof(cdt.request_pl),      \
> -		.response_pl = cdt.response_pl,               \
> -		.response_pl_sz = sizeof(cdt.response_pl),    \
> -		.complete = cxl_doe_task_complete,            \
> -		.private = &cdt.c,                            \
> -	}                                                     \
> -}
> -
>  static int cxl_cdat_get_length(struct device *dev,
>  			       struct pci_doe_mb *cdat_doe,
>  			       size_t *length)
>  {
> -	DECLARE_CDAT_DOE_TASK(CDAT_DOE_REQ(0), t);
> +	u32 request = CDAT_DOE_REQ(0);
> +	u32 response[32];
>  	int rc;
>  
> -	rc = pci_doe_submit_task(cdat_doe, &t.task);
> +	rc = pci_doe(cdat_doe, PCI_DVSEC_VENDOR_ID_CXL,
> +		     CXL_DOE_PROTOCOL_TABLE_ACCESS,
> +		     &request, sizeof(request),
> +		     &response, sizeof(response));
>  	if (rc < 0) {
> -		dev_err(dev, "DOE submit failed: %d", rc);
> +		dev_err(dev, "DOE failed: %d", rc);
>  		return rc;
>  	}
> -	wait_for_completion(&t.c);
> -	if (t.task.rv < sizeof(u32))
> +	if (rc < sizeof(u32))
>  		return -EIO;
>  
> -	*length = t.response_pl[1];
> +	*length = response[1];
>  	dev_dbg(dev, "CDAT length %zu\n", *length);
>  
>  	return 0;
> @@ -546,26 +521,29 @@ static int cxl_cdat_read_table(struct device *dev,
>  	int entry_handle = 0;
>  
>  	do {
> -		DECLARE_CDAT_DOE_TASK(CDAT_DOE_REQ(entry_handle), t);
> +		u32 request = CDAT_DOE_REQ(entry_handle);
> +		u32 response[32];
>  		size_t entry_dw;
>  		u32 *entry;
>  		int rc;
>  
> -		rc = pci_doe_submit_task(cdat_doe, &t.task);
> +		rc = pci_doe(cdat_doe, PCI_DVSEC_VENDOR_ID_CXL,
> +			     CXL_DOE_PROTOCOL_TABLE_ACCESS,
> +			     &request, sizeof(request),
> +			     &response, sizeof(response));
>  		if (rc < 0) {
> -			dev_err(dev, "DOE submit failed: %d", rc);
> +			dev_err(dev, "DOE failed: %d", rc);
>  			return rc;
>  		}
> -		wait_for_completion(&t.c);
>  		/* 1 DW header + 1 DW data min */
> -		if (t.task.rv < (2 * sizeof(u32)))
> +		if (rc < (2 * sizeof(u32)))
>  			return -EIO;
>  
>  		/* Get the CXL table access header entry handle */
>  		entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE,
> -					 t.response_pl[0]);
> -		entry = t.response_pl + 1;
> -		entry_dw = t.task.rv / sizeof(u32);
> +					 response[0]);
> +		entry = response + 1;
> +		entry_dw = rc / sizeof(u32);
>  		/* Skip Header */
>  		entry_dw -= 1;
>  		entry_dw = min(length / sizeof(u32), entry_dw);
> -- 
> 2.39.1
>