From 9e1bd3fc85b3be2576eb72529f33ccaab206c330 Mon Sep 17 00:00:00 2001 From: Linghui Wu Date: Tue, 30 Jun 2026 10:58:04 +0800 Subject: [PATCH] FROMLIST: wifi: ath10k: snoc: use memcpy_fromio() for MSA ramdump On WCN3990/SNOC the MSA region is mapped with devm_memremap(MEMREMAP_WT). On arm64 such a mapping is not Normal-cacheable, so unaligned accesses to it are not permitted. ath10k_msa_dump_memory() copies the region with a plain memcpy(), whose optimized __pi_memcpy_generic implementation issues wide/unaligned loads. This triggers an alignment fault (FSC=0x21) Oops in ath10k_snoc_fw_crashed_dump() while collecting the devcoredump: Unable to handle kernel paging request ... FSC=0x21: alignment fault pc : __pi_memcpy_generic lr : ath10k_snoc_fw_crashed_dump [ath10k_snoc] The Oops both leaves the firmware RAM dump buffer zeroed (no dump is captured) and crashes the kernel, which in turn breaks modem SSR recovery. Use memcpy_fromio(), which only performs accesses that are valid for such a device-memory mapping. The generic memcpy_fromio() implementation aligns the source before issuing word-sized reads and stores the destination with put_unaligned(), so it is also safe for the coherent DMA allocation used on the non-reserved-memory path. ath11k and ath12k use the same pattern when copying target memory into crash dumps, so call it unconditionally here too. The MEMREMAP_WT pointer is a plain void *, so an explicit __iomem cast is needed; use __force to keep sparse happy. Tested-on: WCN3990 hw1.0 SNOC WLAN.HL.3.3.7.c5-00107-QCAHLSWMTPL-1 Fixes: 3f14b73c3843 ("ath10k: Enable MSA region dump support for WCN3990") Signed-off-by: Linghui Wu Link: https://lore.kernel.org/all/20260727072629.2297208-1-linghui.wu@oss.qualcomm.com/ --- drivers/net/wireless/ath/ath10k/snoc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/snoc.c b/drivers/net/wireless/ath/ath10k/snoc.c index b3f6424c17d36..0785ea2b8270f 100644 --- a/drivers/net/wireless/ath/ath10k/snoc.c +++ b/drivers/net/wireless/ath/ath10k/snoc.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -1456,11 +1457,15 @@ static void ath10k_msa_dump_memory(struct ath10k *ar, hdr->length = cpu_to_le32(ar->msa.mem_size); if (current_region->len < ar->msa.mem_size) { - memcpy(buf, ar->msa.vaddr, current_region->len); + memcpy_fromio(buf, + (const void __iomem __force *)ar->msa.vaddr, + current_region->len); ath10k_warn(ar, "msa dump length is less than msa size %x, %x\n", current_region->len, ar->msa.mem_size); } else { - memcpy(buf, ar->msa.vaddr, ar->msa.mem_size); + memcpy_fromio(buf, + (const void __iomem __force *)ar->msa.vaddr, + ar->msa.mem_size); } }