From: Frank.Li@oss.nxp.com
To: Jon Mason <jdmason@kudzu.us>, Dave Jiang <dave.jiang@intel.com>,
Allen Hubbe <allenbh@gmail.com>, Frank Li <Frank.Li@nxp.com>,
ntb@lists.linux.dev (open list:NTB DRIVER CORE),
linux-kernel@vger.kernel.org (open list)
Cc: imx@lists.linux.dev, vkoul@kernel.org
Subject: [PATCH 1/1] ntb: use dmaengine_get_dma_device() instead of chan->device->dev
Date: Fri, 18 Sep 2026 16:41:48 -0400 [thread overview]
Message-ID: <20260918204152.2364336-1-Frank.Li@oss.nxp.com> (raw)
From: Frank Li <Frank.Li@nxp.com>
Replace direct dma_chan::device::dev access with the proper
dmaengine_get_dma_device() accessor in IIO DMA consumers.
chan->device->dev is not always the device used for DMA mapping.
Some DMA engines support per-channel IOMMU mappings, so different
channels may use different DMA devices. dmaengine_get_dma_device()
returns the correct device for each channel.
This also prepares for making the DMA engine provider data structures
private. DMA consumers should not access DMA engine internals directly.
Assisted-by: LLM
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
drivers/ntb/ntb_transport.c | 29 +++++++++++++++++------------
drivers/ntb/test/ntb_perf.c | 14 ++++++++------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 45144abfb7aad..895418c243642 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -1519,6 +1519,7 @@ static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
struct ntb_transport_qp *qp = entry->qp;
struct dma_chan *chan = qp->rx_dma_chan;
struct dma_device *device;
+ struct device *dma_dev;
size_t pay_off, buff_off, len;
struct dmaengine_unmap_data *unmap;
dma_cookie_t cookie;
@@ -1526,27 +1527,28 @@ static int ntb_async_rx_submit(struct ntb_queue_entry *entry, void *offset)
len = entry->len;
device = chan->device;
+ dma_dev = dmaengine_get_dma_device(chan);
pay_off = (size_t)offset & ~PAGE_MASK;
buff_off = (size_t)buf & ~PAGE_MASK;
if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
goto err;
- unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOWAIT);
+ unmap = dmaengine_get_unmap_data(dma_dev, 2, GFP_NOWAIT);
if (!unmap)
goto err;
unmap->len = len;
- unmap->addr[0] = dma_map_phys(device->dev, virt_to_phys(offset),
+ unmap->addr[0] = dma_map_phys(dma_dev, virt_to_phys(offset),
len, DMA_TO_DEVICE, 0);
- if (dma_mapping_error(device->dev, unmap->addr[0]))
+ if (dma_mapping_error(dma_dev, unmap->addr[0]))
goto err_get_unmap;
unmap->to_cnt = 1;
- unmap->addr[1] = dma_map_phys(device->dev, virt_to_phys(buf),
+ unmap->addr[1] = dma_map_phys(dma_dev, virt_to_phys(buf),
len, DMA_FROM_DEVICE, 0);
- if (dma_mapping_error(device->dev, unmap->addr[1]))
+ if (dma_mapping_error(dma_dev, unmap->addr[1]))
goto err_get_unmap;
unmap->from_cnt = 1;
@@ -1856,6 +1858,7 @@ static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
{
struct dma_async_tx_descriptor *txd;
struct dma_chan *chan = qp->tx_dma_chan;
+ struct device *dma_dev = dmaengine_get_dma_device(chan);
struct dma_device *device;
size_t len = entry->len;
void *buf = entry->buf;
@@ -1872,14 +1875,14 @@ static int ntb_async_tx_submit(struct ntb_transport_qp *qp,
if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
goto err;
- unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOWAIT);
+ unmap = dmaengine_get_unmap_data(dma_dev, 1, GFP_NOWAIT);
if (!unmap)
goto err;
unmap->len = len;
- unmap->addr[0] = dma_map_phys(device->dev, virt_to_phys(buf),
+ unmap->addr[0] = dma_map_phys(dma_dev, virt_to_phys(buf),
len, DMA_TO_DEVICE, 0);
- if (dma_mapping_error(device->dev, unmap->addr[0]))
+ if (dma_mapping_error(dma_dev, unmap->addr[0]))
goto err_get_unmap;
unmap->to_cnt = 1;
@@ -2026,6 +2029,7 @@ ntb_transport_create_queue(void *data, struct device *client_dev,
struct ntb_transport_qp *qp;
u64 qp_bit;
unsigned int free_queue;
+ struct device *tx_dev;
dma_cap_mask_t dma_mask;
int node;
int i;
@@ -2089,11 +2093,12 @@ ntb_transport_create_queue(void *data, struct device *client_dev,
qp->tx_mw_dma_addr = 0;
if (qp->tx_dma_chan) {
+ tx_dev = dmaengine_get_dma_device(qp->tx_dma_chan);
qp->tx_mw_dma_addr =
- dma_map_resource(qp->tx_dma_chan->device->dev,
+ dma_map_resource(tx_dev,
qp->tx_mw_phys, qp->tx_mw_size,
DMA_FROM_DEVICE, 0);
- if (dma_mapping_error(qp->tx_dma_chan->device->dev,
+ if (dma_mapping_error(tx_dev,
qp->tx_mw_dma_addr)) {
qp->tx_mw_dma_addr = 0;
goto err1;
@@ -2142,7 +2147,7 @@ ntb_transport_create_queue(void *data, struct device *client_dev,
while ((entry = ntb_list_rm(&qp->ntb_rx_q_lock, &qp->rx_free_q)))
kfree(entry);
if (qp->tx_mw_dma_addr)
- dma_unmap_resource(qp->tx_dma_chan->device->dev,
+ dma_unmap_resource(tx_dev,
qp->tx_mw_dma_addr, qp->tx_mw_size,
DMA_FROM_DEVICE, 0);
if (qp->tx_dma_chan)
@@ -2192,7 +2197,7 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp)
dma_sync_wait(chan, qp->last_cookie);
dmaengine_terminate_all(chan);
- dma_unmap_resource(chan->device->dev,
+ dma_unmap_resource(dmaengine_get_dma_device(chan),
qp->tx_mw_dma_addr, qp->tx_mw_size,
DMA_FROM_DEVICE, 0);
diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index dfd175f79e8f0..b936f15079df2 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -799,7 +799,7 @@ static int perf_copy_chunk(struct perf_thread *pthr,
goto ret_check_tsync;
}
- dma_dev = pthr->dma_chan->device->dev;
+ dma_dev = dmaengine_get_dma_device(pthr->dma_chan);
if (!is_dma_copy_aligned(pthr->dma_chan->device, offset_in_page(src),
offset_in_page(dst), len))
@@ -869,6 +869,7 @@ static bool perf_dma_filter(struct dma_chan *chan, void *data)
static int perf_init_test(struct perf_thread *pthr)
{
struct perf_ctx *perf = pthr->perf;
+ struct device *dma_dev;
dma_cap_mask_t dma_mask;
struct perf_peer *peer = pthr->perf->test_peer;
@@ -890,19 +891,20 @@ static int perf_init_test(struct perf_thread *pthr)
pthr->tidx);
goto err_free;
}
+ dma_dev = dmaengine_get_dma_device(pthr->dma_chan);
peer->dma_dst_addr =
- dma_map_resource(pthr->dma_chan->device->dev,
+ dma_map_resource(dma_dev,
peer->out_phys_addr, peer->outbuf_size,
DMA_FROM_DEVICE, 0);
- if (dma_mapping_error(pthr->dma_chan->device->dev,
+ if (dma_mapping_error(dma_dev,
peer->dma_dst_addr)) {
- dev_err(pthr->dma_chan->device->dev, "%d: Failed to map DMA addr\n",
+ dev_err(dma_dev, "%d: Failed to map DMA addr\n",
pthr->tidx);
peer->dma_dst_addr = 0;
dma_release_channel(pthr->dma_chan);
goto err_free;
}
- dev_dbg(pthr->dma_chan->device->dev, "%d: Map MMIO %pa to DMA addr %pad\n",
+ dev_dbg(dma_dev, "%d: Map MMIO %pa to DMA addr %pad\n",
pthr->tidx,
&peer->out_phys_addr,
&peer->dma_dst_addr);
@@ -1003,7 +1005,7 @@ static void perf_clear_test(struct perf_thread *pthr)
*/
(void)dmaengine_terminate_sync(pthr->dma_chan);
if (pthr->perf->test_peer->dma_dst_addr)
- dma_unmap_resource(pthr->dma_chan->device->dev,
+ dma_unmap_resource(dmaengine_get_dma_device(pthr->dma_chan),
pthr->perf->test_peer->dma_dst_addr,
pthr->perf->test_peer->outbuf_size,
DMA_FROM_DEVICE, 0);
--
2.43.0
next reply other threads:[~2026-09-18 20:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-18 20:41 Frank.Li [this message]
2026-09-18 20:53 ` [PATCH 1/1] ntb: use dmaengine_get_dma_device() instead of chan->device->dev sashiko-bot
2026-09-18 21:06 ` Frank Li
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