mailbox: zynqmp: Enable Bufferless IPI usage on Versal-based SOC's

On Xilinx-AMD Versal and Versal-NET, there exist both
inter-processor-interrupts with corresponding message buffers and without
such buffers.

Add a routine that, if the corresponding DT compatible
string "xlnx,versal-ipi-mailbox" is used then a Versal-based SOC
can use a mailbox Device Tree entry where both host and remote
can use either of the buffered or bufferless interrupts.

Signed-off-by: Ben Levinsky <ben.levinsky@amd.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index 56ba7135db545c62a9190e7beecc262a237f9e28..1cb553cced903af5ef61222f9eb38e4ae91bd46a 100644 (file)
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -52,6 +52,13 @@
 #define IPI_MB_CHNL_TX 0 /* IPI mailbox TX channel */
 #define IPI_MB_CHNL_RX 1 /* IPI mailbox RX channel */
 
+/* IPI Message Buffer Information */
+#define RESP_OFFSET    0x20U
+#define DEST_OFFSET    0x40U
+#define IPI_BUF_SIZE   0x20U
+#define DST_BIT_POS    9U
+#define SRC_BITMASK    GENMASK(11, 8)
+
 /**
  * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
  * @is_opened: indicate if the IPI channel is opened
@@ -169,9 +176,11 @@ static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
                if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
                        if (mchan->is_opened) {
                                msg = mchan->rx_buf;
-                               msg->len = mchan->req_buf_size;
-                               memcpy_fromio(msg->data, mchan->req_buf,
-                                             msg->len);
+                               if (msg) {
+                                       msg->len = mchan->req_buf_size;
+                                       memcpy_fromio(msg->data, mchan->req_buf,
+                                                     msg->len);
+                               }
                                mbox_chan_received_data(chan, (void *)msg);
                                status = IRQ_HANDLED;
                        }
@@ -281,26 +290,26 @@ static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
 
        if (mchan->chan_type == IPI_MB_CHNL_TX) {
                /* Send request message */
-               if (msg && msg->len > mchan->req_buf_size) {
+               if (msg && msg->len > mchan->req_buf_size && mchan->req_buf) {
                        dev_err(dev, "channel %d message length %u > max %lu\n",
                                mchan->chan_type, (unsigned int)msg->len,
                                mchan->req_buf_size);
                        return -EINVAL;
                }
-               if (msg && msg->len)
+               if (msg && msg->len && mchan->req_buf)
                        memcpy_toio(mchan->req_buf, msg->data, msg->len);
                /* Kick IPI mailbox to send message */
                arg0 = SMC_IPI_MAILBOX_NOTIFY;
                zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
        } else {
                /* Send response message */
-               if (msg && msg->len > mchan->resp_buf_size) {
+               if (msg && msg->len > mchan->resp_buf_size && mchan->resp_buf) {
                        dev_err(dev, "channel %d message length %u > max %lu\n",
                                mchan->chan_type, (unsigned int)msg->len,
                                mchan->resp_buf_size);
                        return -EINVAL;
                }
-               if (msg && msg->len)
+               if (msg && msg->len && mchan->resp_buf)
                        memcpy_toio(mchan->resp_buf, msg->data, msg->len);
                arg0 = SMC_IPI_MAILBOX_ACK;
                zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
@@ -636,6 +645,109 @@ static int zynqmp_ipi_setup(struct zynqmp_ipi_mbox *ipi_mbox,
        return 0;
 }
 
+/**
+ * versal_ipi_setup - Set up IPIs to support mixed usage of
+ *                              Buffered and Bufferless IPIs.
+ *
+ * @ipi_mbox: pointer to IPI mailbox private data structure
+ * @node: IPI mailbox device node
+ *
+ * Return: 0 for success, negative value for failure
+ */
+static int versal_ipi_setup(struct zynqmp_ipi_mbox *ipi_mbox,
+                           struct device_node *node)
+{
+       struct zynqmp_ipi_mchan *tx_mchan, *rx_mchan;
+       struct resource host_res, remote_res;
+       struct device_node *parent_node;
+       int host_idx, remote_idx;
+       struct device *mdev;
+
+       tx_mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
+       rx_mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
+       parent_node = of_get_parent(node);
+       mdev = &ipi_mbox->dev;
+
+       host_idx = zynqmp_ipi_mbox_get_buf_res(parent_node, "msg", &host_res);
+       remote_idx = zynqmp_ipi_mbox_get_buf_res(node, "msg", &remote_res);
+
+       /*
+        * Only set up buffers if both sides claim to have msg buffers.
+        * This is because each buffered IPI's corresponding msg buffers
+        * are reserved for use by other buffered IPI's.
+        */
+       if (!host_idx && !remote_idx) {
+               u32 host_src, host_dst, remote_src, remote_dst;
+               u32 buff_sz;
+
+               buff_sz = resource_size(&host_res);
+
+               host_src = host_res.start & SRC_BITMASK;
+               remote_src = remote_res.start & SRC_BITMASK;
+
+               host_dst = (host_src >> DST_BIT_POS) * DEST_OFFSET;
+               remote_dst = (remote_src >> DST_BIT_POS) * DEST_OFFSET;
+
+               /* Validate that IPI IDs is within IPI Message buffer space. */
+               if (host_dst >= buff_sz || remote_dst >= buff_sz) {
+                       dev_err(mdev,
+                               "Invalid IPI Message buffer values: %x %x\n",
+                               host_dst, remote_dst);
+                       return -EINVAL;
+               }
+
+               tx_mchan->req_buf = devm_ioremap(mdev,
+                                                host_res.start | remote_dst,
+                                                IPI_BUF_SIZE);
+               if (!tx_mchan->req_buf) {
+                       dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+                       return -ENOMEM;
+               }
+
+               tx_mchan->resp_buf = devm_ioremap(mdev,
+                                                 (remote_res.start | host_dst) +
+                                                 RESP_OFFSET, IPI_BUF_SIZE);
+               if (!tx_mchan->resp_buf) {
+                       dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+                       return -ENOMEM;
+               }
+
+               rx_mchan->req_buf = devm_ioremap(mdev,
+                                                remote_res.start | host_dst,
+                                                IPI_BUF_SIZE);
+               if (!rx_mchan->req_buf) {
+                       dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+                       return -ENOMEM;
+               }
+
+               rx_mchan->resp_buf = devm_ioremap(mdev,
+                                                 (host_res.start | remote_dst) +
+                                                 RESP_OFFSET, IPI_BUF_SIZE);
+               if (!rx_mchan->resp_buf) {
+                       dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+                       return -ENOMEM;
+               }
+
+               tx_mchan->resp_buf_size = IPI_BUF_SIZE;
+               tx_mchan->req_buf_size = IPI_BUF_SIZE;
+               tx_mchan->rx_buf = devm_kzalloc(mdev, IPI_BUF_SIZE +
+                                               sizeof(struct zynqmp_ipi_message),
+                                               GFP_KERNEL);
+               if (!tx_mchan->rx_buf)
+                       return -ENOMEM;
+
+               rx_mchan->resp_buf_size = IPI_BUF_SIZE;
+               rx_mchan->req_buf_size = IPI_BUF_SIZE;
+               rx_mchan->rx_buf = devm_kzalloc(mdev, IPI_BUF_SIZE +
+                                               sizeof(struct zynqmp_ipi_message),
+                                               GFP_KERNEL);
+               if (!rx_mchan->rx_buf)
+                       return -ENOMEM;
+       }
+
+       return 0;
+}
+
 /**
  * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
  *
@@ -743,6 +855,9 @@ static const struct of_device_id zynqmp_ipi_of_match[] = {
        { .compatible = "xlnx,zynqmp-ipi-mailbox",
          .data = &zynqmp_ipi_setup,
        },
+       { .compatible = "xlnx,versal-ipi-mailbox",
+         .data = &versal_ipi_setup,
+       },
        {},
 };
 MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);