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wifi: ath10k: snoc: use memcpy_fromio() for MSA ramdump

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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: 3f14b73c38 ("ath10k: Enable MSA region dump support for WCN3990")
Signed-off-by: Linghui Wu <linghui.wu@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260727072629.2297208-1-linghui.wu@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
This commit is contained in:
Linghui Wu
2026-07-27 12:56:29 +05:30
committed by Jeff Johnson
parent 35a3da9fe1
commit 4f25071afe
1 changed files with 7 additions and 2 deletions
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9
drivers/net/wireless/ath/ath10k/snoc.c
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@@ -6,6 +6,7 @@
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -1475,11 +1476,15 @@ 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);
}
}