cxl/region: Use do_div() for 64-bit modulo operation

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div64_u64_rem() was the wrong choice for doing a modulo operation
and it was used incorrectly, causing a kernel oops by passing NULL
as the remainder parameter. Replace it with the do_div() helper
that does the intended math (gran_offset = offset % gran) and is
architecture safe.

This bug appeared during testing of unaligned address translations.
The visibility to userspace would be limited to folks doing poison
injection or clear by HPA on unaligned regions.

Fixes: 78b50b598462 ("cxl/region: Translate HPA to DPA and memdev in unaligned regions")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260117044732.567831-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

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Alison Schofield 2026-01-16 20:47:30 -08:00 • committed by Dave Jiang

parent b51792fd91

commit 064c098790

1 changed files with 2 additions and 1 deletions

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drivers/cxl/core/region.c

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