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path: root/drivers/thunderbolt/nhi.c
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Diffstat (limited to 'drivers/thunderbolt/nhi.c')
-rw-r--r--drivers/thunderbolt/nhi.c78
1 files changed, 60 insertions, 18 deletions
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index af0a80ddf594..0e79eebfcbb7 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -26,6 +26,8 @@
* use this ring for anything else.
*/
#define RING_E2E_UNUSED_HOPID 2
+/* HopIDs 0-7 are reserved by the Thunderbolt protocol */
+#define RING_FIRST_USABLE_HOPID 8
/*
* Minimal number of vectors when we use MSI-X. Two for control channel
@@ -411,6 +413,62 @@ static void ring_release_msix(struct tb_ring *ring)
ring->irq = 0;
}
+static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
+{
+ int ret = 0;
+
+ spin_lock_irq(&nhi->lock);
+
+ if (ring->hop < 0) {
+ unsigned int i;
+
+ /*
+ * Automatically allocate HopID from the non-reserved
+ * range 8 .. hop_count - 1.
+ */
+ for (i = RING_FIRST_USABLE_HOPID; i < nhi->hop_count; i++) {
+ if (ring->is_tx) {
+ if (!nhi->tx_rings[i]) {
+ ring->hop = i;
+ break;
+ }
+ } else {
+ if (!nhi->rx_rings[i]) {
+ ring->hop = i;
+ break;
+ }
+ }
+ }
+ }
+
+ if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
+ dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
+ ret = -EINVAL;
+ goto err_unlock;
+ }
+ if (ring->is_tx && nhi->tx_rings[ring->hop]) {
+ dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
+ ring->hop);
+ ret = -EBUSY;
+ goto err_unlock;
+ } else if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
+ dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
+ ring->hop);
+ ret = -EBUSY;
+ goto err_unlock;
+ }
+
+ if (ring->is_tx)
+ nhi->tx_rings[ring->hop] = ring;
+ else
+ nhi->rx_rings[ring->hop] = ring;
+
+err_unlock:
+ spin_unlock_irq(&nhi->lock);
+
+ return ret;
+}
+
static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
bool transmit, unsigned int flags,
u16 sof_mask, u16 eof_mask,
@@ -456,28 +514,12 @@ static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
goto err_free_descs;
- spin_lock_irq(&nhi->lock);
- if (hop >= nhi->hop_count) {
- dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop);
+ if (nhi_alloc_hop(nhi, ring))
goto err_release_msix;
- }
- if (transmit && nhi->tx_rings[hop]) {
- dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop);
- goto err_release_msix;
- } else if (!transmit && nhi->rx_rings[hop]) {
- dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop);
- goto err_release_msix;
- }
- if (transmit)
- nhi->tx_rings[hop] = ring;
- else
- nhi->rx_rings[hop] = ring;
- spin_unlock_irq(&nhi->lock);
return ring;
err_release_msix:
- spin_unlock_irq(&nhi->lock);
ring_release_msix(ring);
err_free_descs:
dma_free_coherent(&ring->nhi->pdev->dev,
@@ -506,7 +548,7 @@ EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
/**
* tb_ring_alloc_rx() - Allocate DMA ring for receive
* @nhi: Pointer to the NHI the ring is to be allocated
- * @hop: HopID (ring) to allocate
+ * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
* @size: Number of entries in the ring
* @flags: Flags for the ring
* @sof_mask: Mask of PDF values that start a frame