[PATCH v12 12/12] crypto: qce - Communicate the base physical address to the dmaengine

Bartosz Golaszewski
2026-03-10T15:45:11Z

In order to communicate to the BAM DMA engine which address should be
used as a scratchpad for dummy writes related to BAM pipe locking,
fill out and attach the provided metadata struct to the descriptor as
well as mark the RX channel as such using the slave config struct.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
drivers/crypto/qce/dma.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/drivers/crypto/qce/dma.c b/drivers/crypto/qce/dma.c
index ba7a52fd4c6349d59c075c346f75741defeb6034..6ab352261223c3c4815a01e84238447e8e61e040 100644
--- a/drivers/crypto/qce/dma.c
+++ b/drivers/crypto/qce/dma.c
@@ -11,6 +11,7 @@

#include "core.h"
#include "dma.h"
+#include "regs-v5.h"

#define QCE_IGNORE_BUF_SZ (2 * QCE_BAM_BURST_SIZE)
#define QCE_BAM_CMD_SGL_SIZE 128
@@ -43,6 +44,7 @@ void qce_clear_bam_transaction(struct qce_device *qce)

int qce_submit_cmd_desc(struct qce_device *qce)
{
+ struct bam_desc_metadata meta = { .scratchpad_addr = qce->base_phys + REG_VERSION };
struct qce_desc_info *qce_desc = qce->dma.bam_txn->desc;
struct qce_bam_transaction *bam_txn = qce->dma.bam_txn;
struct dma_async_tx_descriptor *dma_desc;
@@ -64,6 +66,12 @@ int qce_submit_cmd_desc(struct qce_device *qce)
return -ENOMEM;
}

+ ret = dmaengine_desc_attach_metadata(dma_desc, &meta, 0);
+ if (ret) {
+ dma_unmap_sg(qce->dev, bam_txn->wr_sgl, bam_txn->wr_sgl_cnt, DMA_TO_DEVICE);
+ return ret;
+ }
+
qce_desc->dma_desc = dma_desc;
cookie = dmaengine_submit(qce_desc->dma_desc);

@@ -109,7 +117,9 @@ void qce_write_dma(struct qce_device *qce, unsigned int offset, u32 val)
int devm_qce_dma_request(struct qce_device *qce)
{
struct qce_dma_data *dma = &qce->dma;
+ struct dma_slave_config cfg = { };
struct device *dev = qce->dev;
+ int ret;

dma->txchan = devm_dma_request_chan(dev, "tx");
if (IS_ERR(dma->txchan))
@@ -121,6 +131,11 @@ int devm_qce_dma_request(struct qce_device *qce)
return dev_err_probe(dev, PTR_ERR(dma->rxchan),
"Failed to get RX DMA channel\n");

+ cfg.direction = DMA_MEM_TO_DEV;
+ ret = dmaengine_slave_config(dma->rxchan, &cfg);
+ if (ret)
+ return ret;
+
dma->result_buf = devm_kmalloc(dev, QCE_RESULT_BUF_SZ + QCE_IGNORE_BUF_SZ, GFP_KERNEL);
if (!dma->result_buf)
return -ENOMEM;

--
2.47.3