1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_irq.c b/drivers/net/ethernet/meta/fbnic/fbnic_irq.c
new file mode 100644
index 000000000000..1c88a2bf3a7a
--- /dev/null
+++ b/drivers/net/ethernet/meta/fbnic/fbnic_irq.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include <linux/pci.h>
+#include <linux/types.h>
+
+#include "fbnic.h"
+#include "fbnic_netdev.h"
+#include "fbnic_txrx.h"
+
+static irqreturn_t fbnic_fw_msix_intr(int __always_unused irq, void *data)
+{
+	struct fbnic_dev *fbd = (struct fbnic_dev *)data;
+
+	fbnic_mbx_poll(fbd);
+
+	fbnic_wr32(fbd, FBNIC_INTR_MASK_CLEAR(0), 1u << FBNIC_FW_MSIX_ENTRY);
+
+	return IRQ_HANDLED;
+}
+
+static int __fbnic_fw_enable_mbx(struct fbnic_dev *fbd, int vector)
+{
+	int err;
+
+	/* Initialize mailbox and attempt to poll it into ready state */
+	fbnic_mbx_init(fbd);
+	err = fbnic_mbx_poll_tx_ready(fbd);
+	if (err) {
+		dev_warn(fbd->dev, "FW mailbox did not enter ready state\n");
+		return err;
+	}
+
+	/* Enable interrupt and unmask the vector */
+	enable_irq(vector);
+	fbnic_wr32(fbd, FBNIC_INTR_MASK_CLEAR(0), 1u << FBNIC_FW_MSIX_ENTRY);
+
+	return 0;
+}
+
+/**
+ * fbnic_fw_request_mbx - Configure and initialize Firmware Mailbox
+ * @fbd: Pointer to device to initialize
+ *
+ * This function will allocate the IRQ and then reinitialize the mailbox
+ * starting communication between the host and firmware.
+ *
+ * Return: non-zero on failure.
+ **/
+int fbnic_fw_request_mbx(struct fbnic_dev *fbd)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int vector, err;
+
+	WARN_ON(fbd->fw_msix_vector);
+
+	vector = pci_irq_vector(pdev, FBNIC_FW_MSIX_ENTRY);
+	if (vector < 0)
+		return vector;
+
+	/* Request the IRQ for FW Mailbox vector. */
+	err = request_threaded_irq(vector, NULL, &fbnic_fw_msix_intr,
+				   IRQF_ONESHOT | IRQF_NO_AUTOEN,
+				   dev_name(fbd->dev), fbd);
+	if (err)
+		return err;
+
+	/* Initialize mailbox and attempt to poll it into ready state */
+	err = __fbnic_fw_enable_mbx(fbd, vector);
+	if (err)
+		free_irq(vector, fbd);
+
+	fbd->fw_msix_vector = vector;
+
+	return err;
+}
+
+/**
+ * fbnic_fw_disable_mbx - Temporarily place mailbox in standby state
+ * @fbd: Pointer to device
+ *
+ * Shutdown the mailbox by notifying the firmware to stop sending us logs, mask
+ * and synchronize the IRQ, and then clean up the rings.
+ **/
+static void fbnic_fw_disable_mbx(struct fbnic_dev *fbd)
+{
+	/* Disable interrupt and synchronize the IRQ */
+	disable_irq(fbd->fw_msix_vector);
+
+	/* Mask the vector */
+	fbnic_wr32(fbd, FBNIC_INTR_MASK_SET(0), 1u << FBNIC_FW_MSIX_ENTRY);
+
+	/* Make sure disabling logs message is sent, must be done here to
+	 * avoid risk of completing without a running interrupt.
+	 */
+	fbnic_mbx_flush_tx(fbd);
+	fbnic_mbx_clean(fbd);
+}
+
+/**
+ * fbnic_fw_free_mbx - Disable mailbox and place it in standby state
+ * @fbd: Pointer to device to disable
+ *
+ * This function will disable the mailbox interrupt, free any messages still
+ * in the mailbox and place it into a disabled state. The firmware is
+ * expected to see the update and assume that the host is in the reset state.
+ **/
+void fbnic_fw_free_mbx(struct fbnic_dev *fbd)
+{
+	/* Vector has already been freed */
+	if (!fbd->fw_msix_vector)
+		return;
+
+	fbnic_fw_disable_mbx(fbd);
+
+	/* Free the vector */
+	free_irq(fbd->fw_msix_vector, fbd);
+	fbd->fw_msix_vector = 0;
+}
+
+static irqreturn_t fbnic_pcs_msix_intr(int __always_unused irq, void *data)
+{
+	struct fbnic_dev *fbd = data;
+	struct fbnic_net *fbn;
+
+	if (fbd->mac->pcs_get_link_event(fbd) == FBNIC_LINK_EVENT_NONE) {
+		fbnic_wr32(fbd, FBNIC_INTR_MASK_CLEAR(0),
+			   1u << FBNIC_PCS_MSIX_ENTRY);
+		return IRQ_HANDLED;
+	}
+
+	fbn = netdev_priv(fbd->netdev);
+
+	phylink_pcs_change(&fbn->phylink_pcs, false);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * fbnic_pcs_request_irq - Configure the PCS to enable it to advertise link
+ * @fbd: Pointer to device to initialize
+ *
+ * This function provides basic bringup for the MAC/PCS IRQ. For now the IRQ
+ * will remain disabled until we start the MAC/PCS/PHY logic via phylink.
+ *
+ * Return: non-zero on failure.
+ **/
+int fbnic_pcs_request_irq(struct fbnic_dev *fbd)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int vector, err;
+
+	WARN_ON(fbd->pcs_msix_vector);
+
+	vector = pci_irq_vector(pdev, FBNIC_PCS_MSIX_ENTRY);
+	if (vector < 0)
+		return vector;
+
+	/* Request the IRQ for PCS link vector.
+	 * Map PCS cause to it, and unmask it
+	 */
+	err = request_irq(vector, &fbnic_pcs_msix_intr, 0,
+			  fbd->netdev->name, fbd);
+	if (err)
+		return err;
+
+	/* Map and enable interrupt, unmask vector after link is configured */
+	fbnic_wr32(fbd, FBNIC_INTR_MSIX_CTRL(FBNIC_INTR_MSIX_CTRL_PCS_IDX),
+		   FBNIC_PCS_MSIX_ENTRY | FBNIC_INTR_MSIX_CTRL_ENABLE);
+
+	fbd->pcs_msix_vector = vector;
+
+	return 0;
+}
+
+/**
+ * fbnic_pcs_free_irq - Teardown the PCS IRQ to prepare for stopping
+ * @fbd: Pointer to device that is stopping
+ *
+ * This function undoes the work done in fbnic_pcs_request_irq and prepares
+ * the device to no longer receive traffic on the host interface.
+ **/
+void fbnic_pcs_free_irq(struct fbnic_dev *fbd)
+{
+	/* Vector has already been freed */
+	if (!fbd->pcs_msix_vector)
+		return;
+
+	/* Disable interrupt */
+	fbnic_wr32(fbd, FBNIC_INTR_MSIX_CTRL(FBNIC_INTR_MSIX_CTRL_PCS_IDX),
+		   FBNIC_PCS_MSIX_ENTRY);
+	fbnic_wrfl(fbd);
+
+	/* Synchronize IRQ to prevent race that would unmask vector */
+	synchronize_irq(fbd->pcs_msix_vector);
+
+	/* Mask the vector */
+	fbnic_wr32(fbd, FBNIC_INTR_MASK_SET(0), 1u << FBNIC_PCS_MSIX_ENTRY);
+
+	/* Free the vector */
+	free_irq(fbd->pcs_msix_vector, fbd);
+	fbd->pcs_msix_vector = 0;
+}
+
+void fbnic_synchronize_irq(struct fbnic_dev *fbd, int nr)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int irq = pci_irq_vector(pdev, nr);
+
+	if (irq < 0)
+		return;
+
+	synchronize_irq(irq);
+}
+
+int fbnic_request_irq(struct fbnic_dev *fbd, int nr, irq_handler_t handler,
+		      unsigned long flags, const char *name, void *data)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int irq = pci_irq_vector(pdev, nr);
+
+	if (irq < 0)
+		return irq;
+
+	return request_irq(irq, handler, flags, name, data);
+}
+
+void fbnic_free_irq(struct fbnic_dev *fbd, int nr, void *data)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int irq = pci_irq_vector(pdev, nr);
+
+	if (irq < 0)
+		return;
+
+	free_irq(irq, data);
+}
+
+void fbnic_napi_name_irqs(struct fbnic_dev *fbd)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(fbd->napi_irq); i++)
+		snprintf(fbd->napi_irq[i].name,
+			 sizeof(fbd->napi_irq[i].name),
+			 "%s-TxRx-%u", fbd->netdev->name, i);
+}
+
+int fbnic_napi_request_irq(struct fbnic_dev *fbd,
+			   struct fbnic_napi_vector *nv)
+{
+	struct fbnic_net *fbn = netdev_priv(fbd->netdev);
+	int i = fbnic_napi_idx(nv);
+	int err;
+
+	if (!fbd->napi_irq[i].users) {
+		err = fbnic_request_irq(fbd, nv->v_idx,
+					fbnic_msix_clean_rings,	0,
+					fbd->napi_irq[i].name,
+					&fbn->napi[i]);
+		if (err)
+			return err;
+	}
+
+	fbd->napi_irq[i].users++;
+	return 0;
+}
+
+void fbnic_napi_free_irq(struct fbnic_dev *fbd,
+			 struct fbnic_napi_vector *nv)
+{
+	struct fbnic_net *fbn = netdev_priv(fbd->netdev);
+	int i = fbnic_napi_idx(nv);
+
+	if (--fbd->napi_irq[i].users)
+		return;
+
+	fbnic_free_irq(fbd, nv->v_idx, &fbn->napi[i]);
+}
+
+void fbnic_free_irqs(struct fbnic_dev *fbd)
+{
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+
+	fbd->num_irqs = 0;
+
+	pci_free_irq_vectors(pdev);
+}
+
+int fbnic_alloc_irqs(struct fbnic_dev *fbd)
+{
+	unsigned int wanted_irqs = FBNIC_NON_NAPI_VECTORS;
+	struct pci_dev *pdev = to_pci_dev(fbd->dev);
+	int num_irqs;
+
+	wanted_irqs += min_t(unsigned int, num_online_cpus(), FBNIC_MAX_RXQS);
+	num_irqs = pci_alloc_irq_vectors(pdev, FBNIC_NON_NAPI_VECTORS + 1,
+					 wanted_irqs, PCI_IRQ_MSIX);
+	if (num_irqs < 0) {
+		dev_err(fbd->dev, "Failed to allocate MSI-X entries\n");
+		return num_irqs;
+	}
+
+	if (num_irqs < wanted_irqs)
+		dev_warn(fbd->dev, "Allocated %d IRQs, expected %d\n",
+			 num_irqs, wanted_irqs);
+
+	fbd->num_irqs = num_irqs;
+
+	return 0;
+}