thunderbolt / net: Let the service drivers configure interrupt throttling

Instead of the core driver programming fixed value for throttling let
the service drivers to specify the interval if they need this.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index 495f7fe366e69681b150c6e84526bcaf1d39e891..f8f97e8e2226cfa2989f86194721cce288b43d44 100644 (file)
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -34,6 +34,7 @@
 #define TBNET_RING_SIZE                256
 #define TBNET_LOGIN_RETRIES    60
 #define TBNET_LOGOUT_RETRIES   10
+#define TBNET_THROTTLING       128000
 #define TBNET_E2E              BIT(0)
 #define TBNET_MATCH_FRAGS_ID   BIT(1)
 #define TBNET_64K_FRAMES       BIT(2)
@@ -956,6 +957,9 @@ static int tbnet_open(struct net_device *dev)
        }
        net->rx_ring.ring = ring;
 
+       tb_ring_throttling(net->tx_ring.ring, TBNET_THROTTLING);
+       tb_ring_throttling(net->rx_ring.ring, TBNET_THROTTLING);
+
        napi_enable(&net->napi);
        start_login(net);
 

diff --git a/drivers/thunderbolt/dma_test.c b/drivers/thunderbolt/dma_test.c
index af1e6bc9c7cdbac291d8d31fa5f6151bdd376d19..7877319b1b03a8d54453cf7851e5eade264d4008 100644 (file)
--- a/drivers/thunderbolt/dma_test.c
+++ b/drivers/thunderbolt/dma_test.c
@@ -155,6 +155,8 @@ static int dma_test_start_rings(struct dma_test *dt)
                dt->tx_ring = ring;
                e2e_tx_hop = ring->hop;
 
+               tb_ring_throttling(ring, 128000);
+
                ret = tb_xdomain_alloc_out_hopid(xd, -1);
                if (ret < 0) {
                        dma_test_free_rings(dt);
@@ -162,6 +164,7 @@ static int dma_test_start_rings(struct dma_test *dt)
                }
 
                dt->tx_hopid = ret;
+
        }
 
        if (dt->packets_to_receive) {
@@ -180,6 +183,8 @@ static int dma_test_start_rings(struct dma_test *dt)
 
                dt->rx_ring = ring;
 
+               tb_ring_throttling(ring, 128000);
+
                ret = tb_xdomain_alloc_in_hopid(xd, -1);
                if (ret < 0) {
                        dma_test_free_rings(dt);

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index 1a20516730677f1b0206e71b7cc2586a35c6ea43..13009246e617613996c4bae06350a9e82fc32f68 100644 (file)
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -93,7 +93,7 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
        u32 old, new;
 
        if (ring->irq > 0) {
-               u32 step, shift, ivr, misc;
+               u32 step, shift, ivr, misc, itr;
                void __iomem *ivr_base;
                int auto_clear_bit;
                int index;
@@ -131,6 +131,12 @@ static void ring_interrupt_active(struct tb_ring *ring, bool active)
                if (active)
                        ivr |= ring->vector << shift;
                iowrite32(ivr, ivr_base + step);
+
+               /* Throttling is specified in 256ns increments */
+               itr = DIV_ROUND_UP(ring->interval_nsec, 256);
+               itr &= REG_INT_THROTTLING_RATE_INTERVAL_MASK;
+               iowrite32(itr, ring->nhi->iobase + REG_INT_THROTTLING_RATE +
+                         ring->vector * 4);
        }
 
        old = ioread32(ring->nhi->iobase + reg);
@@ -854,6 +860,26 @@ void tb_ring_free(struct tb_ring *ring)
 }
 EXPORT_SYMBOL_GPL(tb_ring_free);
 
+/**
+ * tb_ring_throttling() - Configure throttling for ring interrupt
+ * @ring: Ring to configure
+ * @interval_nsec: Interval counter for moderation (in ns), %0 disables
+ *
+ * Enables or disables ring interrupt throttling. The ring must be
+ * stopped for this to be called. Granularity is 256 ns.
+ *
+ * Return: %0 on success, negative errno otherwise.
+ */
+int tb_ring_throttling(struct tb_ring *ring, unsigned int interval_nsec)
+{
+       guard(spinlock_irqsave)(&ring->lock);
+       if (WARN_ON_ONCE(ring->running))
+               return -EBUSY;
+       ring->interval_nsec = interval_nsec;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(tb_ring_throttling);
+
 /**
  * nhi_mailbox_cmd() - Send a command through NHI mailbox
  * @nhi: Pointer to the NHI structure
@@ -1035,22 +1061,6 @@ static int nhi_poweroff_noirq(struct device *dev)
        return __nhi_suspend_noirq(dev, wakeup);
 }
 
-static void nhi_enable_int_throttling(struct tb_nhi *nhi)
-{
-       /* Throttling is specified in 256ns increments */
-       u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
-       unsigned int i;
-
-       /*
-        * Configure interrupt throttling for all vectors even if we
-        * only use few.
-        */
-       for (i = 0; i < MSIX_MAX_VECS; i++) {
-               u32 reg = REG_INT_THROTTLING_RATE + i * 4;
-               iowrite32(throttle, nhi->iobase + reg);
-       }
-}
-
 static int nhi_resume_noirq(struct device *dev)
 {
        struct pci_dev *pdev = to_pci_dev(dev);
@@ -1065,13 +1075,10 @@ static int nhi_resume_noirq(struct device *dev)
         */
        if (!pci_device_is_present(pdev)) {
                nhi->going_away = true;
-       } else {
-               if (nhi->ops && nhi->ops->resume_noirq) {
-                       ret = nhi->ops->resume_noirq(nhi);
-                       if (ret)
-                               return ret;
-               }
-               nhi_enable_int_throttling(tb->nhi);
+       } else if (nhi->ops && nhi->ops->resume_noirq) {
+               ret = nhi->ops->resume_noirq(nhi);
+               if (ret)
+                       return ret;
        }
 
        return tb_domain_resume_noirq(tb);
@@ -1133,7 +1140,6 @@ static int nhi_runtime_resume(struct device *dev)
                        return ret;
        }
 
-       nhi_enable_int_throttling(nhi);
        return tb_domain_runtime_resume(tb);
 }
 
@@ -1271,8 +1277,6 @@ static int nhi_init_msi(struct tb_nhi *nhi)
        /* In case someone left them on. */
        nhi_disable_interrupts(nhi);
 
-       nhi_enable_int_throttling(nhi);
-
        ida_init(&nhi->msix_ida);
 
        /*

diff --git a/drivers/thunderbolt/nhi_regs.h b/drivers/thunderbolt/nhi_regs.h
index cf5222bee971318a2d4438ccb484901b7d134906..d6a197fabc74a229cd9eb9c4eb405a583105882c 100644 (file)
--- a/drivers/thunderbolt/nhi_regs.h
+++ b/drivers/thunderbolt/nhi_regs.h
@@ -101,7 +101,8 @@ struct ring_desc {
 
 #define REG_RING_INTERRUPT_MASK_CLEAR_BASE     0x38208
 
-#define REG_INT_THROTTLING_RATE        0x38c00
+#define REG_INT_THROTTLING_RATE                        0x38c00
+#define REG_INT_THROTTLING_RATE_INTERVAL_MASK  GENMASK(15, 0)
 
 /* Interrupt Vector Allocation */
 #define REG_INT_VEC_ALLOC_BASE 0x38c40

diff --git a/include/linux/thunderbolt.h b/include/linux/thunderbolt.h
index 1d1bd458b5afbc7ab428148c2152a0a826f51858..1160e0bf5c5b7828d14baf6bafffbf71ba7dda79 100644 (file)
--- a/include/linux/thunderbolt.h
+++ b/include/linux/thunderbolt.h
@@ -554,6 +554,8 @@ struct tb_nhi {
  * @start_poll: Called when ring interrupt is triggered to start
  *             polling. Passing %NULL keeps the ring in interrupt mode.
  * @poll_data: Data passed to @start_poll
+ * @interval_nsec: Interval counter if interrupt throttling is to be
+ *                used with this ring (in ns)
  */
 struct tb_ring {
        spinlock_t lock;
@@ -577,6 +579,7 @@ struct tb_ring {
        u16 eof_mask;
        void (*start_poll)(void *data);
        void *poll_data;
+       unsigned int interval_nsec;
 };
 
 /* Leave ring interrupt enabled on suspend */
@@ -697,6 +700,8 @@ static inline int tb_ring_tx(struct tb_ring *ring, struct ring_frame *frame)
 struct ring_frame *tb_ring_poll(struct tb_ring *ring);
 void tb_ring_poll_complete(struct tb_ring *ring);
 
+int tb_ring_throttling(struct tb_ring *ring, unsigned int interval_nsec);
+
 /**
  * tb_ring_dma_device() - Return device used for DMA mapping
  * @ring: Ring whose DMA device is retrieved