[PATCH 6.6 013/160] wifi: ath11k: Use dma_alloc_noncoherent for rx_tid buffer allocation

Greg Kroah-Hartman
2026-04-08T18:20:52Z

From: P Praneesh <quic_ppranees@quicinc.com>

[ Upstream commit eeadc6baf8b3dcd32787cc84f0473dc2a2850370 ]

Currently, the driver allocates cacheable DMA buffers for the rx_tid
structure using kzalloc() and dma_map_single(). These buffers are
long-lived and can persist for the lifetime of the peer, which is not
advisable. Instead of using kzalloc() and dma_map_single() for allocating
cacheable DMA buffers, utilize the dma_alloc_noncoherent() helper for the
allocation of long-lived cacheable DMA buffers, such as the peer's rx_tid.
Since dma_alloc_noncoherent() returns unaligned physical and virtual
addresses, align them internally before use within the driver. This
ensures proper allocation of non-coherent memory through the kernel
helper.

Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Signed-off-by: P Praneesh <quic_ppranees@quicinc.com>
Tested-by: Tim Harvey <tharvey@gateworks.com>
Link: https://patch.msgid.link/20250119164219.647059-3-quic_ppranees@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
Stable-dep-of: e225b36f83d7 ("wifi: ath11k: Pass the correct value of each TID during a stop AMPDU session")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/ath11k/dp.h | 6 +-
drivers/net/wireless/ath/ath11k/dp_rx.c | 117 +++++++++++-------------
2 files changed, 58 insertions(+), 65 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp.h b/drivers/net/wireless/ath/ath11k/dp.h
index 2f6dd69d3be27..0ce26f76bb815 100644
--- a/drivers/net/wireless/ath/ath11k/dp.h
+++ b/drivers/net/wireless/ath/ath11k/dp.h
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: BSD-3-Clause-Clear */
/*
* Copyright (c) 2018-2019 The Linux Foundation. All rights reserved.
- * Copyright (c) 2021-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021-2023, 2025 Qualcomm Innovation Center, Inc. All rights reserved.
*/

#ifndef ATH11K_DP_H
@@ -20,7 +20,6 @@ struct ath11k_ext_irq_grp;

struct dp_rx_tid {
u8 tid;
- u32 *vaddr;
dma_addr_t paddr;
u32 size;
u32 ba_win_sz;
@@ -37,6 +36,9 @@ struct dp_rx_tid {
/* Timer info related to fragments */
struct timer_list frag_timer;
struct ath11k_base *ab;
+ u32 *vaddr_unaligned;
+ dma_addr_t paddr_unaligned;
+ u32 unaligned_size;
};

#define DP_REO_DESC_FREE_THRESHOLD 64
diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index c37722a727309..411749e8e209e 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: BSD-3-Clause-Clear
/*
* Copyright (c) 2018-2019 The Linux Foundation. All rights reserved.
- * Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021-2025 Qualcomm Innovation Center, Inc. All rights reserved.
*/

#include <linux/ieee80211.h>
@@ -675,11 +675,11 @@ void ath11k_dp_reo_cmd_list_cleanup(struct ath11k_base *ab)
list_for_each_entry_safe(cmd, tmp, &dp->reo_cmd_list, list) {
list_del(&cmd->list);
rx_tid = &cmd->data;
- if (rx_tid->vaddr) {
- dma_unmap_single(ab->dev, rx_tid->paddr,
- rx_tid->size, DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ if (rx_tid->vaddr_unaligned) {
+ dma_free_noncoherent(ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}
kfree(cmd);
}
@@ -689,11 +689,11 @@ void ath11k_dp_reo_cmd_list_cleanup(struct ath11k_base *ab)
list_del(&cmd_cache->list);
dp->reo_cmd_cache_flush_count--;
rx_tid = &cmd_cache->data;
- if (rx_tid->vaddr) {
- dma_unmap_single(ab->dev, rx_tid->paddr,
- rx_tid->size, DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ if (rx_tid->vaddr_unaligned) {
+ dma_free_noncoherent(ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}
kfree(cmd_cache);
}
@@ -708,11 +708,11 @@ static void ath11k_dp_reo_cmd_free(struct ath11k_dp *dp, void *ctx,
if (status != HAL_REO_CMD_SUCCESS)
ath11k_warn(dp->ab, "failed to flush rx tid hw desc, tid %d status %d\n",
rx_tid->tid, status);
- if (rx_tid->vaddr) {
- dma_unmap_single(dp->ab->dev, rx_tid->paddr, rx_tid->size,
- DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ if (rx_tid->vaddr_unaligned) {
+ dma_free_noncoherent(dp->ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}
}

@@ -749,10 +749,10 @@ static void ath11k_dp_reo_cache_flush(struct ath11k_base *ab,
if (ret) {
ath11k_err(ab, "failed to send HAL_REO_CMD_FLUSH_CACHE cmd, tid %d (%d)\n",
rx_tid->tid, ret);
- dma_unmap_single(ab->dev, rx_tid->paddr, rx_tid->size,
- DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ dma_free_noncoherent(ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}
}

@@ -802,10 +802,10 @@ static void ath11k_dp_rx_tid_del_func(struct ath11k_dp *dp, void *ctx,

return;
free_desc:
- dma_unmap_single(ab->dev, rx_tid->paddr, rx_tid->size,
- DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ dma_free_noncoherent(ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}

void ath11k_peer_rx_tid_delete(struct ath11k *ar,
@@ -831,14 +831,16 @@ void ath11k_peer_rx_tid_delete(struct ath11k *ar,
if (ret != -ESHUTDOWN)
ath11k_err(ar->ab, "failed to send HAL_REO_CMD_UPDATE_RX_QUEUE cmd, tid %d (%d)\n",
tid, ret);
- dma_unmap_single(ar->ab->dev, rx_tid->paddr, rx_tid->size,
- DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ dma_free_noncoherent(ar->ab->dev, rx_tid->unaligned_size,
+ rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;
}

rx_tid->paddr = 0;
+ rx_tid->paddr_unaligned = 0;
rx_tid->size = 0;
+ rx_tid->unaligned_size = 0;
}

static int ath11k_dp_rx_link_desc_return(struct ath11k_base *ab,
@@ -982,10 +984,9 @@ static void ath11k_dp_rx_tid_mem_free(struct ath11k_base *ab,
if (!rx_tid->active)
goto unlock_exit;

- dma_unmap_single(ab->dev, rx_tid->paddr, rx_tid->size,
- DMA_BIDIRECTIONAL);
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
+ dma_free_noncoherent(ab->dev, rx_tid->unaligned_size, rx_tid->vaddr_unaligned,
+ rx_tid->paddr_unaligned, DMA_BIDIRECTIONAL);
+ rx_tid->vaddr_unaligned = NULL;

rx_tid->active = false;

@@ -1000,9 +1001,8 @@ int ath11k_peer_rx_tid_setup(struct ath11k *ar, const u8 *peer_mac, int vdev_id,
struct ath11k_base *ab = ar->ab;
struct ath11k_peer *peer;
struct dp_rx_tid *rx_tid;
- u32 hw_desc_sz;
- u32 *addr_aligned;
- void *vaddr;
+ u32 hw_desc_sz, *vaddr;
+ void *vaddr_unaligned;
dma_addr_t paddr;
int ret;

@@ -1050,49 +1050,40 @@ int ath11k_peer_rx_tid_setup(struct ath11k *ar, const u8 *peer_mac, int vdev_id,
else
hw_desc_sz = ath11k_hal_reo_qdesc_size(DP_BA_WIN_SZ_MAX, tid);

- vaddr = kzalloc(hw_desc_sz + HAL_LINK_DESC_ALIGN - 1, GFP_ATOMIC);
- if (!vaddr) {
+ rx_tid->unaligned_size = hw_desc_sz + HAL_LINK_DESC_ALIGN - 1;
+ vaddr_unaligned = dma_alloc_noncoherent(ab->dev, rx_tid->unaligned_size, &paddr,
+ DMA_BIDIRECTIONAL, GFP_ATOMIC);
+ if (!vaddr_unaligned) {
spin_unlock_bh(&ab->base_lock);
return -ENOMEM;
}

- addr_aligned = PTR_ALIGN(vaddr, HAL_LINK_DESC_ALIGN);
-
- ath11k_hal_reo_qdesc_setup(addr_aligned, tid, ba_win_sz,
- ssn, pn_type);
-
- paddr = dma_map_single(ab->dev, addr_aligned, hw_desc_sz,
- DMA_BIDIRECTIONAL);
-
- ret = dma_mapping_error(ab->dev, paddr);
- if (ret) {
- spin_unlock_bh(&ab->base_lock);
- ath11k_warn(ab, "failed to setup dma map for peer %pM rx tid %d: %d\n",
- peer_mac, tid, ret);
- goto err_mem_free;
- }
-
- rx_tid->vaddr = vaddr;
- rx_tid->paddr = paddr;
+ rx_tid->vaddr_unaligned = vaddr_unaligned;
+ vaddr = PTR_ALIGN(vaddr_unaligned, HAL_LINK_DESC_ALIGN);
+ rx_tid->paddr_unaligned = paddr;
+ rx_tid->paddr = rx_tid->paddr_unaligned + ((unsigned long)vaddr -
+ (unsigned long)rx_tid->vaddr_unaligned);
+ ath11k_hal_reo_qdesc_setup(vaddr, tid, ba_win_sz, ssn, pn_type);
rx_tid->size = hw_desc_sz;
rx_tid->active = true;

+ /* After dma_alloc_noncoherent, vaddr is being modified for reo qdesc setup.
+ * Since these changes are not reflected in the device, driver now needs to
+ * explicitly call dma_sync_single_for_device.
+ */
+ dma_sync_single_for_device(ab->dev, rx_tid->paddr,
+ rx_tid->size,
+ DMA_TO_DEVICE);
spin_unlock_bh(&ab->base_lock);

- ret = ath11k_wmi_peer_rx_reorder_queue_setup(ar, vdev_id, peer_mac,
- paddr, tid, 1, ba_win_sz);
+ ret = ath11k_wmi_peer_rx_reorder_queue_setup(ar, vdev_id, peer_mac, rx_tid->paddr,
+ tid, 1, ba_win_sz);
if (ret) {
ath11k_warn(ar->ab, "failed to setup rx reorder queue for peer %pM tid %d: %d\n",
peer_mac, tid, ret);
ath11k_dp_rx_tid_mem_free(ab, peer_mac, vdev_id, tid);
}

- return ret;
-
-err_mem_free:
- kfree(rx_tid->vaddr);
- rx_tid->vaddr = NULL;
-
return ret;
}

--
2.53.0