cxl/acpi: Restore HBIW check before dereferencing platform_data

Commit 4fe516d2ad1a ("cxl/acpi: Make the XOR calculations available
for testing") split xormap handling code to create a reusable helper
function but inadvertently dropped the check of HBIW values before
dereferencing cxlrd->platform_data. When HBIW is 1 or 3, no xormaps
are needed and platform_data may be NULL, leading to a potential NULL
pointer dereference.

Affects platform configs using XOR Arithmetic with HBIWs of 1 or 3,
when performing DPA->HPA address translation for CXL events. Those
events would be any of poison ops, general media, or dram.

Restore the early return check for HBIW values of 1 and 3 before
dereferencing platform_data.

Fixes: 4fe516d2ad1a ("cxl/acpi: Make the XOR calculations available for testing")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260109194946.431083-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

0 files changed, 0 insertions, 0 deletions