Commit 55e26869 authored by Yanfei Xu's avatar Yanfei Xu Committed by Dave Jiang
Browse files

cxl/pci: Fix to record only non-zero ranges



The function cxl_dvsec_rr_decode() retrieves and records DVSEC ranges
into info->dvsec_range[], regardless of whether it is non-zero range,
and the variable info->ranges indicates the number of non-zero ranges.
However, in cxl_hdm_decode_init(), the validation for
info->dvsec_range[] occurs in a for loop that iterates based on
info->ranges. It may result in zero range to be validated but non-zero
range not be validated, in turn, the number of allowed ranges is to be
0. Address it by only record non-zero ranges.

This fix is not urgent as it requires a configuration that zeroes out
the first dvsec range while populating the second. This has not been
observed, but it is theoretically possible. If this gets picked up for
-stable, no harm done, but there is no urgency to backport.

Fixes: 560f7855 ("cxl/pci: Retrieve CXL DVSEC memory info")
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarYanfei Xu <yanfei.xu@intel.com>
Reviewed-by: default avatarAlison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20240828084231.1378789-2-yanfei.xu@intel.com


Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
parent d75ccd4f
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+1 −7
Original line number Diff line number Diff line
@@ -390,10 +390,6 @@ int cxl_dvsec_rr_decode(struct device *dev, int d,

		size |= temp & CXL_DVSEC_MEM_SIZE_LOW_MASK;
		if (!size) {
			info->dvsec_range[i] = (struct range) {
				.start = 0,
				.end = CXL_RESOURCE_NONE,
			};
			continue;
		}

@@ -411,12 +407,10 @@ int cxl_dvsec_rr_decode(struct device *dev, int d,

		base |= temp & CXL_DVSEC_MEM_BASE_LOW_MASK;

		info->dvsec_range[i] = (struct range) {
		info->dvsec_range[ranges++] = (struct range) {
			.start = base,
			.end = base + size - 1
		};

		ranges++;
	}

	info->ranges = ranges;