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From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org,
	Dan Williams <dan.j.williams@intel.com>,
	Bjorn Helgaas <helgaas@kernel.org>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Ben Widawsky <ben.widawsky@intel.com>,
	Chris Browy <cbrowy@avery-design.com>,
	linux-acpi@vger.kernel.org, alison.schofield@intel.com,
	vishal.l.verma@intel.com, ira.weiny@intel.com,
	linuxarm@huawei.com, Fangjian <f.fangjian@huawei.com>
Subject: Re: [RFC PATCH v2 3/4] cxl/mem: Add CDAT table reading from DOE
Date: Wed, 14 Apr 2021 14:14:34 -0400
Message-ID: <YHcxChBDpxoopJT8@dhcp-10-154-113-106.vpn.oracle.com> (raw)
In-Reply-To: <20210413160159.935663-4-Jonathan.Cameron@huawei.com>

> +static int cdat_to_buffer(struct pcie_doe *doe, u32 *buffer, size_t length)
> +{
> +	int entry_handle = 0;
> +	int rc;
> +
> +	do {
> +		u32 cdat_request_pl = CDAT_DOE_REQ(entry_handle);
> +		u32 cdat_response_pl[32];
> +		struct pcie_doe_exchange ex = {
> +			.vid = PCI_DVSEC_VENDOR_ID_CXL,
> +			.protocol = CXL_DOE_PROTOCOL_TABLE_ACCESS,
> +			.request_pl = &cdat_request_pl,
> +			.request_pl_sz = sizeof(cdat_request_pl),
> +			.response_pl = cdat_response_pl,
> +			.response_pl_sz = sizeof(cdat_response_pl),
> +		};
> +		size_t entry_dw;
> +		u32 *entry;
> +
> +		rc = pcie_doe_sync(doe, &ex);
> +		if (rc < 0)
> +			return rc;
> +
> +		entry = cdat_response_pl + 1;
> +		entry_dw = rc / sizeof(u32);

Could you >> 2?
> +		/* Skip Header */
> +		entry_dw -= 1;
> +		entry_dw = min(length / 4, entry_dw);

Ditto here on length?

Also should you double check that length is not greater than
sizeof(cdat_respone_pl)?

> +		memcpy(buffer, entry, entry_dw * sizeof(u32));
> +		length -= entry_dw * sizeof(u32);

Would it be just easier to convert length at the start to be >> 2
instead of this * and / ?


> +		buffer += entry_dw;
> +		entry_handle = FIELD_GET(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, cdat_response_pl[0]);
> +
> +	} while (entry_handle != 0xFFFF);
> +
> +	return 0;
> +}
> +

  reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-13 16:01 [RFC PATCH v2 0/4] PCI Data Object Exchange support + CXL CDAT Jonathan Cameron
2021-04-13 16:01 ` [RFC PATCH v2 1/4] PCI: Add vendor define ID for the PCI SIG Jonathan Cameron
2021-04-13 16:34   ` Bjorn Helgaas
2021-04-13 18:21     ` Jonathan Cameron
2021-04-13 18:38       ` Bjorn Helgaas
2021-04-13 16:01 ` [RFC PATCH v2 2/4] PCI/doe: Initial support PCI Data Object Exchange Jonathan Cameron
2021-04-13 19:49   ` Bjorn Helgaas
2021-04-13 16:01 ` [RFC PATCH v2 3/4] cxl/mem: Add CDAT table reading from DOE Jonathan Cameron
2021-04-14 18:14   ` Konrad Rzeszutek Wilk [this message]
2021-04-14 18:50     ` Ben Widawsky
2021-04-13 16:01 ` [RFC PATCH v2 4/4] cxl/mem: Add a debug parser for CDAT commands Jonathan Cameron

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