[PATCH 05/11] mailbox: bcm-pdc: streamline rx code
From: Rob Rice
Date: Mon Nov 14 2016 - 13:27:13 EST
Remove the unnecessary rmb() from the receive path.
If the rx ring has multiple messages ready, avoid reading
last_rx_curr multiple times from the register.
Signed-off-by: Rob Rice <rob.rice@xxxxxxxxxxxx>
Reviewed-by: Andy Gospodarek <gospo@xxxxxxxxxxxx>
---
drivers/mailbox/bcm-pdc-mailbox.c | 108 +++++++++++++++++---------------------
1 file changed, 48 insertions(+), 60 deletions(-)
diff --git a/drivers/mailbox/bcm-pdc-mailbox.c b/drivers/mailbox/bcm-pdc-mailbox.c
index fa3f484..2195760 100644
--- a/drivers/mailbox/bcm-pdc-mailbox.c
+++ b/drivers/mailbox/bcm-pdc-mailbox.c
@@ -570,27 +570,23 @@ pdc_build_txd(struct pdc_state *pdcs, dma_addr_t dma_addr, u32 buf_len,
}
/**
- * pdc_receive() - Receive a response message from a given SPU.
+ * pdc_receive_one() - Receive a response message from a given SPU.
* @pdcs: PDC state for the SPU to receive from
- * @mssg: mailbox message to be returned to client
*
* When the return code indicates success, the response message is available in
* the receive buffers provided prior to submission of the request.
*
- * Input:
- * pdcs - PDC state structure for the SPU to be polled
- * mssg - mailbox message to be returned to client. This function sets the
- * context pointer on the message to help the client associate the
- * response with a request.
- *
* Return: PDC_SUCCESS if one or more receive descriptors was processed
* -EAGAIN indicates that no response message is available
* -EIO an error occurred
*/
static int
-pdc_receive(struct pdc_state *pdcs, struct brcm_message *mssg)
+pdc_receive_one(struct pdc_state *pdcs)
{
struct device *dev = &pdcs->pdev->dev;
+ struct mbox_controller *mbc;
+ struct mbox_chan *chan;
+ struct brcm_message mssg;
u32 len, rx_status;
u32 num_frags;
int i;
@@ -599,29 +595,23 @@ pdc_receive(struct pdc_state *pdcs, struct brcm_message *mssg)
u32 rx_idx; /* ring index of start of receive frame */
dma_addr_t resp_hdr_daddr;
+ mbc = &pdcs->mbc;
+ chan = &mbc->chans[0];
+ mssg.type = BRCM_MESSAGE_SPU;
+
/*
* return if a complete response message is not yet ready.
* rxin_numd[rxin] is the number of fragments in the next msg
* to read.
*/
frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr, pdcs->nrxpost);
- if ((frags_rdy == 0) || (frags_rdy < pdcs->rxin_numd[pdcs->rxin])) {
- /* See if the hw has written more fragments than we know */
- pdcs->last_rx_curr =
- (ioread32((void *)&pdcs->rxregs_64->status0) &
- CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE;
- frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr,
- pdcs->nrxpost);
- if ((frags_rdy == 0) ||
- (frags_rdy < pdcs->rxin_numd[pdcs->rxin])) {
- /* No response ready */
- return -EAGAIN;
- }
- /* can't read descriptors/data until write index is read */
- rmb();
- }
+ if ((frags_rdy == 0) || (frags_rdy < pdcs->rxin_numd[pdcs->rxin]))
+ /* No response ready */
+ return -EAGAIN;
num_frags = pdcs->txin_numd[pdcs->txin];
+ WARN_ON(num_frags == 0);
+
dma_unmap_sg(dev, pdcs->src_sg[pdcs->txin],
sg_nents(pdcs->src_sg[pdcs->txin]), DMA_TO_DEVICE);
@@ -634,7 +624,7 @@ pdc_receive(struct pdc_state *pdcs, struct brcm_message *mssg)
rx_idx = pdcs->rxin;
num_frags = pdcs->rxin_numd[rx_idx];
/* Return opaque context with result */
- mssg->ctx = pdcs->rxp_ctx[rx_idx];
+ mssg.ctx = pdcs->rxp_ctx[rx_idx];
pdcs->rxp_ctx[rx_idx] = NULL;
resp_hdr = pdcs->resp_hdr[rx_idx];
resp_hdr_daddr = pdcs->resp_hdr_daddr[rx_idx];
@@ -674,12 +664,35 @@ pdc_receive(struct pdc_state *pdcs, struct brcm_message *mssg)
dma_pool_free(pdcs->rx_buf_pool, resp_hdr, resp_hdr_daddr);
+ mbox_chan_received_data(chan, &mssg);
+
pdcs->pdc_replies++;
- /* if we read one or more rx descriptors, claim success */
- if (num_frags > 0)
- return PDC_SUCCESS;
- else
- return -EIO;
+ return PDC_SUCCESS;
+}
+
+/**
+ * pdc_receive() - Process as many responses as are available in the rx ring.
+ * @pdcs: PDC state
+ *
+ * Called within the hard IRQ.
+ * Return:
+ */
+static int
+pdc_receive(struct pdc_state *pdcs)
+{
+ int rx_status;
+
+ /* read last_rx_curr from register once */
+ pdcs->last_rx_curr =
+ (ioread32((void *)&pdcs->rxregs_64->status0) &
+ CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE;
+
+ do {
+ /* Could be many frames ready */
+ rx_status = pdc_receive_one(pdcs);
+ } while (rx_status == PDC_SUCCESS);
+
+ return 0;
}
/**
@@ -946,14 +959,13 @@ static irqreturn_t pdc_irq_handler(int irq, void *cookie)
}
/**
- * pdc_irq_thread() - Function invoked on deferred thread when a DMA tx has
- * completed or data is available to receive.
+ * pdc_irq_thread() - Function invoked on deferred thread when data is available
+ * to receive.
* @irq: Interrupt number
* @cookie: PDC state for PDC that generated the interrupt
*
- * On DMA tx complete, notify the mailbox client. On DMA rx complete, process
- * as many SPU response messages as are available and send each to the mailbox
- * client.
+ * On DMA rx complete, process as many SPU response messages as are available
+ * and send each to the mailbox client.
*
* Return: IRQ_HANDLED if we recognized and handled the interrupt
* IRQ_NONE otherwise
@@ -961,39 +973,15 @@ static irqreturn_t pdc_irq_handler(int irq, void *cookie)
static irqreturn_t pdc_irq_thread(int irq, void *cookie)
{
struct pdc_state *pdcs = cookie;
- struct mbox_controller *mbc;
- struct mbox_chan *chan;
bool rx_int;
- int rx_status;
- struct brcm_message mssg;
rx_int = test_and_clear_bit(PDC_RCVINT_0, &pdcs->intstatus);
-
if (pdcs && rx_int) {
dev_dbg(&pdcs->pdev->dev,
"%s() got irq %d with rx_int %s",
__func__, irq, rx_int ? "set" : "clear");
- mbc = &pdcs->mbc;
- chan = &mbc->chans[0];
-
- while (1) {
- /* Could be many frames ready */
- memset(&mssg, 0, sizeof(mssg));
- mssg.type = BRCM_MESSAGE_SPU;
- rx_status = pdc_receive(pdcs, &mssg);
- if (rx_status >= 0) {
- dev_dbg(&pdcs->pdev->dev,
- "%s(): invoking client rx cb",
- __func__);
- mbox_chan_received_data(chan, &mssg);
- } else {
- dev_dbg(&pdcs->pdev->dev,
- "%s(): no SPU response available",
- __func__);
- break;
- }
- }
+ pdc_receive(pdcs);
return IRQ_HANDLED;
}
return IRQ_NONE;
--
2.1.0