#define RING_ENTRY_SIZE sizeof(struct dma64dd)
/* # entries in PDC dma ring */
-#define PDC_RING_ENTRIES 128
+#define PDC_RING_ENTRIES 512
+/*
+ * Minimum number of ring descriptor entries that must be free to tell mailbox
+ * framework that it can submit another request
+ */
+#define PDC_RING_SPACE_MIN 15
+
#define PDC_RING_SIZE (PDC_RING_ENTRIES * RING_ENTRY_SIZE)
/* Rings are 8k aligned */
#define RING_ALIGN_ORDER 13
* Interrupt mask and status definitions. Enable interrupts for tx and rx on
* ring 0
*/
-#define PDC_XMTINT_0 (24 + PDC_RINGSET)
#define PDC_RCVINT_0 (16 + PDC_RINGSET)
-#define PDC_XMTINTEN_0 BIT(PDC_XMTINT_0)
#define PDC_RCVINTEN_0 BIT(PDC_RCVINT_0)
-#define PDC_INTMASK (PDC_XMTINTEN_0 | PDC_RCVINTEN_0)
+#define PDC_INTMASK (PDC_RCVINTEN_0)
#define PDC_LAZY_FRAMECOUNT 1
#define PDC_LAZY_TIMEOUT 10000
#define PDC_LAZY_INT (PDC_LAZY_TIMEOUT | (PDC_LAZY_FRAMECOUNT << 24))
/* PDC state structure */
struct pdc_state {
- /* synchronize access to this PDC state structure */
- spinlock_t pdc_lock;
-
/* Index of the PDC whose state is in this structure instance */
u8 pdc_idx;
struct dentry *debugfs_stats; /* debug FS stats file for this PDC */
/* counters */
- u32 pdc_requests; /* number of request messages submitted */
- u32 pdc_replies; /* number of reply messages received */
- u32 txnobuf; /* count of tx ring full */
- u32 rxnobuf; /* count of rx ring full */
- u32 rx_oflow; /* count of rx overflows */
+ u32 pdc_requests; /* number of request messages submitted */
+ u32 pdc_replies; /* number of reply messages received */
+ u32 last_tx_not_done; /* too few tx descriptors to indicate done */
+ u32 tx_ring_full; /* unable to accept msg because tx ring full */
+ u32 rx_ring_full; /* unable to accept msg because rx ring full */
+ u32 txnobuf; /* unable to create tx descriptor */
+ u32 rxnobuf; /* unable to create rx descriptor */
+ u32 rx_oflow; /* count of rx overflows */
};
/* Global variables */
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"SPU %u stats:\n", pdcs->pdc_idx);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "PDC requests............%u\n",
+ "PDC requests....................%u\n",
pdcs->pdc_requests);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "PDC responses...........%u\n",
+ "PDC responses...................%u\n",
pdcs->pdc_replies);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "Tx err ring full........%u\n",
+ "Tx not done.....................%u\n",
+ pdcs->last_tx_not_done);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Tx ring full....................%u\n",
+ pdcs->tx_ring_full);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Rx ring full....................%u\n",
+ pdcs->rx_ring_full);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Tx desc write fail. Ring full...%u\n",
pdcs->txnobuf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "Rx err ring full........%u\n",
+ "Rx desc write fail. Ring full...%u\n",
pdcs->rxnobuf);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "Receive overflow........%u\n",
+ "Receive overflow................%u\n",
pdcs->rx_oflow);
+ out_offset += snprintf(buf + out_offset, out_count - out_offset,
+ "Num frags in rx ring............%u\n",
+ NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr,
+ pdcs->nrxpost));
if (out_offset > out_count)
out_offset = out_count;
u32 rx_idx; /* ring index of start of receive frame */
dma_addr_t resp_hdr_daddr;
- spin_lock(&pdcs->pdc_lock);
-
/*
* return if a complete response message is not yet ready.
* rxin_numd[rxin] is the number of fragments in the next msg
if ((frags_rdy == 0) ||
(frags_rdy < pdcs->rxin_numd[pdcs->rxin])) {
/* No response ready */
- spin_unlock(&pdcs->pdc_lock);
return -EAGAIN;
}
/* can't read descriptors/data until write index is read */
for (i = 0; i < num_frags; i++)
pdcs->rxin = NEXTRXD(pdcs->rxin, pdcs->nrxpost);
- spin_unlock(&pdcs->pdc_lock);
-
dev_dbg(dev, "PDC %u reclaimed %d rx descriptors",
pdcs->pdc_idx, num_frags);
struct pdc_state *pdcs = cookie;
u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
- if (intstatus & PDC_XMTINTEN_0)
- set_bit(PDC_XMTINT_0, &pdcs->intstatus);
if (intstatus & PDC_RCVINTEN_0)
set_bit(PDC_RCVINT_0, &pdcs->intstatus);
struct pdc_state *pdcs = cookie;
struct mbox_controller *mbc;
struct mbox_chan *chan;
- bool tx_int;
bool rx_int;
int rx_status;
struct brcm_message mssg;
- tx_int = test_and_clear_bit(PDC_XMTINT_0, &pdcs->intstatus);
rx_int = test_and_clear_bit(PDC_RCVINT_0, &pdcs->intstatus);
- if (pdcs && (tx_int || rx_int)) {
+ if (pdcs && rx_int) {
dev_dbg(&pdcs->pdev->dev,
- "%s() got irq %d with tx_int %s, rx_int %s",
- __func__, irq,
- tx_int ? "set" : "clear", rx_int ? "set" : "clear");
+ "%s() got irq %d with rx_int %s",
+ __func__, irq, rx_int ? "set" : "clear");
mbc = &pdcs->mbc;
chan = &mbc->chans[0];
- if (tx_int) {
- dev_dbg(&pdcs->pdev->dev, "%s(): tx done", __func__);
- /* only one frame in flight at a time */
- mbox_chan_txdone(chan, PDC_SUCCESS);
- }
- if (rx_int) {
- 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;
- }
+ 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;
}
}
return IRQ_HANDLED;
dev_dbg(dev, " - base DMA addr of rx ring %pad", &rx.dmabase);
dev_dbg(dev, " - base virtual addr of rx ring %p", rx.vbase);
- /* lock after ring allocation to avoid scheduling while atomic */
- spin_lock(&pdcs->pdc_lock);
-
memcpy(&pdcs->tx_ring_alloc, &tx, sizeof(tx));
memcpy(&pdcs->rx_ring_alloc, &rx, sizeof(rx));
(void *)&pdcs->rxd_64[i].ctrl1);
}
}
- spin_unlock(&pdcs->pdc_lock);
return PDC_SUCCESS;
fail_dealloc:
}
}
+/**
+ * pdc_desc_count() - Count the number of DMA descriptors that will be required
+ * for a given scatterlist. Account for the max length of a DMA buffer.
+ * @sg: Scatterlist to be DMA'd
+ * Return: Number of descriptors required
+ */
+static u32 pdc_desc_count(struct scatterlist *sg)
+{
+ u32 cnt = 0;
+
+ while (sg) {
+ cnt += ((sg->length / PDC_DMA_BUF_MAX) + 1);
+ sg = sg_next(sg);
+ }
+ return cnt;
+}
+
+/**
+ * pdc_rings_full() - Check whether the tx ring has room for tx_cnt descriptors
+ * and the rx ring has room for rx_cnt descriptors.
+ * @pdcs: PDC state
+ * @tx_cnt: The number of descriptors required in the tx ring
+ * @rx_cnt: The number of descriptors required i the rx ring
+ *
+ * Return: true if one of the rings does not have enough space
+ * false if sufficient space is available in both rings
+ */
+static bool pdc_rings_full(struct pdc_state *pdcs, int tx_cnt, int rx_cnt)
+{
+ u32 rx_avail;
+ u32 tx_avail;
+ bool full = false;
+
+ /* Check if the tx and rx rings are likely to have enough space */
+ rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+ pdcs->nrxpost);
+ if (unlikely(rx_cnt > rx_avail)) {
+ pdcs->rx_ring_full++;
+ full = true;
+ }
+
+ if (likely(!full)) {
+ tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout,
+ pdcs->ntxpost);
+ if (unlikely(tx_cnt > tx_avail)) {
+ pdcs->tx_ring_full++;
+ full = true;
+ }
+ }
+ return full;
+}
+
+/**
+ * pdc_last_tx_done() - If both the tx and rx rings have at least
+ * PDC_RING_SPACE_MIN descriptors available, then indicate that the mailbox
+ * framework can submit another message.
+ * @chan: mailbox channel to check
+ * Return: true if PDC can accept another message on this channel
+ */
+static bool pdc_last_tx_done(struct mbox_chan *chan)
+{
+ struct pdc_state *pdcs = chan->con_priv;
+ bool ret;
+
+ if (unlikely(pdc_rings_full(pdcs, PDC_RING_SPACE_MIN,
+ PDC_RING_SPACE_MIN))) {
+ pdcs->last_tx_not_done++;
+ ret = false;
+ } else {
+ ret = true;
+ }
+ return ret;
+}
+
/**
* pdc_send_data() - mailbox send_data function
* @chan: The mailbox channel on which the data is sent. The channel
int src_nent;
int dst_nent;
int nent;
+ u32 tx_desc_req;
+ u32 rx_desc_req;
if (mssg->type != BRCM_MESSAGE_SPU)
return -ENOTSUPP;
}
}
- spin_lock(&pdcs->pdc_lock);
+ /*
+ * Check if the tx and rx rings have enough space. Do this prior to
+ * writing any tx or rx descriptors. Need to ensure that we do not write
+ * a partial set of descriptors, or write just rx descriptors but
+ * corresponding tx descriptors don't fit. Note that we want this check
+ * and the entire sequence of descriptor to happen without another
+ * thread getting in. The channel spin lock in the mailbox framework
+ * ensures this.
+ */
+ tx_desc_req = pdc_desc_count(mssg->spu.src);
+ rx_desc_req = pdc_desc_count(mssg->spu.dst);
+ if (pdc_rings_full(pdcs, tx_desc_req, rx_desc_req + 1))
+ return -ENOSPC;
/* Create rx descriptors to SPU catch response */
err = pdc_rx_list_init(pdcs, mssg->spu.dst, mssg->ctx);
err |= pdc_tx_list_sg_add(pdcs, mssg->spu.src);
err |= pdc_tx_list_final(pdcs); /* initiate transfer */
- spin_unlock(&pdcs->pdc_lock);
-
if (err)
dev_err(&pdcs->pdev->dev,
"%s failed with error %d", __func__, err);
static const struct mbox_chan_ops pdc_mbox_chan_ops = {
.send_data = pdc_send_data,
+ .last_tx_done = pdc_last_tx_done,
.startup = pdc_startup,
.shutdown = pdc_shutdown
};
if (!mbc->chans)
return -ENOMEM;
- mbc->txdone_irq = true;
- mbc->txdone_poll = false;
+ mbc->txdone_irq = false;
+ mbc->txdone_poll = true;
+ mbc->txpoll_period = 1;
for (chan_index = 0; chan_index < mbc->num_chans; chan_index++)
mbc->chans[chan_index].con_priv = pdcs;
goto cleanup;
}
- spin_lock_init(&pdcs->pdc_lock);
pdcs->pdev = pdev;
platform_set_drvdata(pdev, pdcs);
pdcs->pdc_idx = pdcg.num_spu;
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