[PATCH for-next v2 1/2] RDMA/erdma: Introduce dma pool for hardware responses of CMDQ requests

[Cheng Xu <chengyou@xxxxxxxxxxxxxxxxx>]

Hardware response, such as the result of query statistics, may be too
long to be directly accommodated within the CQE structure. To address
this, we introduce a DMA pool to hold the hardware's responses of CMDQ
requests.

Signed-off-by: Cheng Xu <chengyou@xxxxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/erdma/erdma.h      |  2 ++
 drivers/infiniband/hw/erdma/erdma_hw.h   |  2 ++
 drivers/infiniband/hw/erdma/erdma_main.c | 24 ++++++++++++++++++++++--
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/hw/erdma/erdma.h b/drivers/infiniband/hw/erdma/erdma.h
index f190111840e9..5df401a30cb9 100644
--- a/drivers/infiniband/hw/erdma/erdma.h
+++ b/drivers/infiniband/hw/erdma/erdma.h
@@ -212,6 +212,8 @@ struct erdma_dev {
 
 	atomic_t num_ctx;
 	struct list_head cep_list;
+
+	struct dma_pool *resp_pool;
 };
 
 static inline void *get_queue_entry(void *qbuf, u32 idx, u32 depth, u32 shift)
diff --git a/drivers/infiniband/hw/erdma/erdma_hw.h b/drivers/infiniband/hw/erdma/erdma_hw.h
index 9d316fdc6f9a..4baabf1f2b08 100644
--- a/drivers/infiniband/hw/erdma/erdma_hw.h
+++ b/drivers/infiniband/hw/erdma/erdma_hw.h
@@ -357,6 +357,8 @@ struct erdma_cmdq_reflush_req {
 	u32 rq_pi;
 };
 
+#define ERDMA_HW_RESP_SIZE 256
+
 /* cap qword 0 definition */
 #define ERDMA_CMD_DEV_CAP_MAX_CQE_MASK GENMASK_ULL(47, 40)
 #define ERDMA_CMD_DEV_CAP_FLAGS_MASK GENMASK_ULL(31, 24)
diff --git a/drivers/infiniband/hw/erdma/erdma_main.c b/drivers/infiniband/hw/erdma/erdma_main.c
index 0880c79a978c..e4df5bf89cd0 100644
--- a/drivers/infiniband/hw/erdma/erdma_main.c
+++ b/drivers/infiniband/hw/erdma/erdma_main.c
@@ -172,14 +172,30 @@ static int erdma_device_init(struct erdma_dev *dev, struct pci_dev *pdev)
 {
 	int ret;
 
+	dev->resp_pool = dma_pool_create("erdma_resp_pool", &pdev->dev,
+					 ERDMA_HW_RESP_SIZE, ERDMA_HW_RESP_SIZE,
+					 0);
+	if (!dev->resp_pool)
+		return -ENOMEM;
+
 	ret = dma_set_mask_and_coherent(&pdev->dev,
 					DMA_BIT_MASK(ERDMA_PCI_WIDTH));
 	if (ret)
-		return ret;
+		goto destroy_pool;
 
 	dma_set_max_seg_size(&pdev->dev, UINT_MAX);
 
 	return 0;
+
+destroy_pool:
+	dma_pool_destroy(dev->resp_pool);
+
+	return ret;
+}
+
+static void erdma_device_uninit(struct erdma_dev *dev)
+{
+	dma_pool_destroy(dev->resp_pool);
 }
 
 static void erdma_hw_reset(struct erdma_dev *dev)
@@ -273,7 +289,7 @@ static int erdma_probe_dev(struct pci_dev *pdev)
 
 	err = erdma_request_vectors(dev);
 	if (err)
-		goto err_iounmap_func_bar;
+		goto err_uninit_device;
 
 	err = erdma_comm_irq_init(dev);
 	if (err)
@@ -314,6 +330,9 @@ static int erdma_probe_dev(struct pci_dev *pdev)
 err_free_vectors:
 	pci_free_irq_vectors(dev->pdev);
 
+err_uninit_device:
+	erdma_device_uninit(dev);
+
 err_iounmap_func_bar:
 	devm_iounmap(&pdev->dev, dev->func_bar);
 
@@ -339,6 +358,7 @@ static void erdma_remove_dev(struct pci_dev *pdev)
 	erdma_aeq_destroy(dev);
 	erdma_comm_irq_uninit(dev);
 	pci_free_irq_vectors(dev->pdev);
+	erdma_device_uninit(dev);
 
 	devm_iounmap(&pdev->dev, dev->func_bar);
 	pci_release_selected_regions(pdev, ERDMA_BAR_MASK);
-- 
2.31.1