i3c: mipi-i3c-hci: Consolidate spinlocks

commit fa12bb903bc3ed1826e355d267fe134bde95e23c upstream.

The MIPI I3C HCI driver currently uses separate spinlocks for different
contexts (PIO vs. DMA rings).  This split is unnecessary and complicates
upcoming fixes.  The driver does not support concurrent PIO and DMA
operation, and it only supports a single DMA ring, so a single lock is
sufficient for all paths.

Introduce a unified spinlock in struct i3c_hci, switch both PIO and DMA
code to use it, and remove the per-context locks.

No functional change is intended in this patch.

Fixes: 9ad9a52cce282 ("i3c/master: introduce the mipi-i3c-hci driver")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260306072451.11131-5-adrian.hunter@intel.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 9 deletions

diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c
index 710faa46a00f..67dc34163d51 100644
--- a/drivers/i3c/master/mipi-i3c-hci/pio.c
+++ b/drivers/i3c/master/mipi-i3c-hci/pio.c
@@ -124,7 +124,6 @@ struct hci_pio_ibi_data {
 };
 
 struct hci_pio_data {
-	spinlock_t lock;
 	struct hci_xfer *curr_xfer, *xfer_queue;
 	struct hci_xfer *curr_rx, *rx_queue;
 	struct hci_xfer *curr_tx, *tx_queue;
@@ -146,7 +145,6 @@ static int hci_pio_init(struct i3c_hci *hci)
 		return -ENOMEM;
 
 	hci->io_data = pio;
-	spin_lock_init(&pio->lock);
 
 	size_val = pio_reg_read(QUEUE_SIZE);
 	dev_info(&hci->master.dev, "CMD/RESP FIFO = %ld entries\n",
@@ -609,7 +607,7 @@ static int hci_pio_queue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n)
 		xfer[i].data_left = xfer[i].data_len;
 	}
 
-	spin_lock_irq(&pio->lock);
+	spin_lock_irq(&hci->lock);
 	prev_queue_tail = pio->xfer_queue;
 	pio->xfer_queue = &xfer[n - 1];
 	if (pio->curr_xfer) {
@@ -623,7 +621,7 @@ static int hci_pio_queue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n)
 			pio_reg_read(INTR_STATUS),
 			pio_reg_read(INTR_SIGNAL_ENABLE));
 	}
-	spin_unlock_irq(&pio->lock);
+	spin_unlock_irq(&hci->lock);
 	return 0;
 }
 
@@ -694,14 +692,14 @@ static bool hci_pio_dequeue_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int
 	struct hci_pio_data *pio = hci->io_data;
 	int ret;
 
-	spin_lock_irq(&pio->lock);
+	spin_lock_irq(&hci->lock);
 	dev_dbg(&hci->master.dev, "n=%d status=%#x/%#x", n,
 		pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
 	dev_dbg(&hci->master.dev, "main_status = %#x/%#x",
 		readl(hci->base_regs + 0x20), readl(hci->base_regs + 0x28));
 
 	ret = hci_pio_dequeue_xfer_common(hci, pio, xfer, n);
-	spin_unlock_irq(&pio->lock);
+	spin_unlock_irq(&hci->lock);
 	return ret;
 }
 
@@ -994,13 +992,13 @@ static bool hci_pio_irq_handler(struct i3c_hci *hci)
 	struct hci_pio_data *pio = hci->io_data;
 	u32 status;
 
-	spin_lock(&pio->lock);
+	spin_lock(&hci->lock);
 	status = pio_reg_read(INTR_STATUS);
 	dev_dbg(&hci->master.dev, "PIO_INTR_STATUS %#x/%#x",
 		status, pio->enabled_irqs);
 	status &= pio->enabled_irqs | STAT_LATENCY_WARNINGS;
 	if (!status) {
-		spin_unlock(&pio->lock);
+		spin_unlock(&hci->lock);
 		return false;
 	}
 
@@ -1036,7 +1034,7 @@ static bool hci_pio_irq_handler(struct i3c_hci *hci)
 	pio_reg_write(INTR_SIGNAL_ENABLE, pio->enabled_irqs);
 	dev_dbg(&hci->master.dev, "PIO_INTR_STATUS %#x/%#x",
 		pio_reg_read(INTR_STATUS), pio_reg_read(INTR_SIGNAL_ENABLE));
-	spin_unlock(&pio->lock);
+	spin_unlock(&hci->lock);
 	return true;
 }