[PATCH v4 07/25] dmaengine: sdxi: Allocate context control DMA pool

[Nathan Lynch via B4 Relay <devnull+nathan.lynch.amd.com@kernel.org>]

From: Nathan Lynch <nathan.lynch@amd.com>

Each SDXI context has a control block (CXT_CTL) that identifies its
descriptor ring, context status block, and write index.

Define the CXT_CTL layout and create a DMA pool for them during
function initialization.

Co-developed-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Signed-off-by: Nathan Lynch <nathan.lynch@amd.com>
---
 drivers/dma/sdxi/device.c | 21 ++++++++++++++++++++-
 drivers/dma/sdxi/hw.h     | 11 +++++++++++
 drivers/dma/sdxi/sdxi.h   |  2 ++
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sdxi/device.c b/drivers/dma/sdxi/device.c
index baf55f6b6826..acc955b088ba 100644
--- a/drivers/dma/sdxi/device.c
+++ b/drivers/dma/sdxi/device.c
@@ -9,6 +9,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
 #include <linux/export.h>
 #include <linux/iopoll.h>
 #include <linux/jiffies.h>
@@ -351,6 +352,24 @@ static int sdxi_fn_activate(struct sdxi_dev *sdxi)
 	return 0;
 }
 
+static int sdxi_device_init(struct sdxi_dev *sdxi)
+{
+	struct device *dev = sdxi->dev;
+	size_t size, align;
+	int err;
+
+	size = align = sizeof(struct sdxi_cxt_ctl);
+	sdxi->cxt_ctl_pool = dmam_pool_create("CXT_CTL", dev, size, align, 0);
+	if (!sdxi->cxt_ctl_pool)
+		return -ENOMEM;
+
+	err = sdxi_fn_activate(sdxi);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 int sdxi_register(struct device *dev, const struct sdxi_bus_ops *ops)
 {
 	struct sdxi_dev *sdxi;
@@ -372,7 +391,7 @@ int sdxi_register(struct device *dev, const struct sdxi_bus_ops *ops)
 	if (err)
 		return err;
 
-	return sdxi_fn_activate(sdxi);
+	return sdxi_device_init(sdxi);
 }
 EXPORT_SYMBOL_NS_GPL(sdxi_register, "SDXI");
 
diff --git a/drivers/dma/sdxi/hw.h b/drivers/dma/sdxi/hw.h
index 0551c2b52980..82c6b4a20cde 100644
--- a/drivers/dma/sdxi/hw.h
+++ b/drivers/dma/sdxi/hw.h
@@ -47,4 +47,15 @@ struct sdxi_cxt_L1_table {
 };
 static_assert(sizeof(struct sdxi_cxt_L1_table) == 4096);
 
+/* SDXI 1.0 Table 3-4: Context Control (CXT_CTL) */
+struct sdxi_cxt_ctl {
+	__le64 ds_ring_ptr;
+	__le32 ds_ring_sz;
+	__u8 rsvd_0[4];
+	__le64 cxt_sts_ptr;
+	__le64 write_index_ptr;
+	__u8 rsvd_1[32];
+} __packed __aligned(64);
+static_assert(sizeof(struct sdxi_cxt_ctl) == 64);
+
 #endif /* DMA_SDXI_HW_H */
diff --git a/drivers/dma/sdxi/sdxi.h b/drivers/dma/sdxi/sdxi.h
index 856a3838eec3..356a47ed39da 100644
--- a/drivers/dma/sdxi/sdxi.h
+++ b/drivers/dma/sdxi/sdxi.h
@@ -49,6 +49,8 @@ struct sdxi_dev {
 	struct sdxi_cxt_L1_table *L1_table;
 	dma_addr_t L1_dma;
 
+	struct dma_pool *cxt_ctl_pool;
+
 	bool has_mailbox;
 
 	const struct sdxi_bus_ops *bus_ops;

-- 
2.56.0