kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-13 07:31:07 +00:00
Code Issues Releases Packages Activity

wifi: ath12k: align QMI target memory to 64 KB

Browse source 
ath12k_qmi_alloc_chunk() allocates the target memory chunks the firmware
requests via dma_alloc_coherent() and hands the resulting physical
addresses to the firmware. The firmware does not require every chunk to
be aligned, but each unaligned chunk consumes extra TLB entries when the
firmware maps it, and too many unaligned chunks exhaust the TLB and make
the firmware crash. The firmware team recommends aligning the chunks to
64 KB so that the TLB stays within budget. dma_alloc_coherent() only
guarantees page alignment, so a chunk can end up unaligned.

Align the physical address handed to the firmware to 64 KB. A natural
allocation is often already 64 KB aligned, so try the exact size first
and keep it when it happens to be aligned; only when it is not, free it
and over-allocate by SZ_64K - PAGE_SIZE and round the base up. Since the
DMA allocator already guarantees page alignment, that padding is enough
to reach the next 64 KB boundary. Record the raw allocation in
paddr_unaligned/vaddr_unaligned/total_size so the chunk can still be
freed correctly.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3
Tested-on: QCC2072 hw1.0 PCI WLAN.COL.1.0.c2-00074-QCACOLSWPL_V1_TO_SILICONZ-1

Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260730-ath12k-align-qmi-memory-v1-3-0fef98dda614@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
This commit is contained in:
Baochen Qiang 2026-07-30 14:17:42 +08:00 • committed by Jeff Johnson
commit f7f05c4433
2 changed files with 65 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files