2021-05-20 14:07:04

by M Chetan Kumar

[permalink] [raw]
Subject: [PATCH V3 02/16] net: iosm: irq handling

1) Request interrupt vector, frees allocated resource.
2) Registers IRQ handler.

Signed-off-by: M Chetan Kumar <[email protected]>
---
v3:
* Removed inline keyword in .c file.
* Aligned ipc_ prefix for function name to be consistent across file.
v2: Streamline multiple returns using goto.
---
drivers/net/wwan/iosm/iosm_ipc_irq.c | 90 ++++++++++++++++++++++++++++
drivers/net/wwan/iosm/iosm_ipc_irq.h | 33 ++++++++++
2 files changed, 123 insertions(+)
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_irq.c
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_irq.h

diff --git a/drivers/net/wwan/iosm/iosm_ipc_irq.c b/drivers/net/wwan/iosm/iosm_ipc_irq.c
new file mode 100644
index 000000000000..702f50a48151
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_irq.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include "iosm_ipc_pcie.h"
+#include "iosm_ipc_protocol.h"
+
+static void ipc_write_dbell_reg(struct iosm_pcie *ipc_pcie, int irq_n, u32 data)
+{
+ void __iomem *write_reg;
+
+ /* Select the first doorbell register, which is only currently needed
+ * by CP.
+ */
+ write_reg = (void __iomem *)((u8 __iomem *)ipc_pcie->ipc_regs +
+ ipc_pcie->doorbell_write +
+ (irq_n * ipc_pcie->doorbell_reg_offset));
+
+ /* Fire the doorbell irq by writing data on the doorbell write pointer
+ * register.
+ */
+ iowrite32(data, write_reg);
+}
+
+void ipc_doorbell_fire(struct iosm_pcie *ipc_pcie, int irq_n, u32 data)
+{
+ ipc_write_dbell_reg(ipc_pcie, irq_n, data);
+}
+
+/* Threaded Interrupt handler for MSI interrupts */
+static irqreturn_t ipc_msi_interrupt(int irq, void *dev_id)
+{
+ struct iosm_pcie *ipc_pcie = dev_id;
+ int instance = irq - ipc_pcie->pci->irq;
+
+ /* Shift the MSI irq actions to the IPC tasklet. IRQ_NONE means the
+ * irq was not from the IPC device or could not be served.
+ */
+ if (instance >= ipc_pcie->nvec)
+ return IRQ_NONE;
+
+ if (!test_bit(0, &ipc_pcie->suspend))
+ ipc_imem_irq_process(ipc_pcie->imem, instance);
+
+ return IRQ_HANDLED;
+}
+
+void ipc_release_irq(struct iosm_pcie *ipc_pcie)
+{
+ struct pci_dev *pdev = ipc_pcie->pci;
+
+ if (pdev->msi_enabled) {
+ while (--ipc_pcie->nvec >= 0)
+ free_irq(pdev->irq + ipc_pcie->nvec, ipc_pcie);
+ }
+ pci_free_irq_vectors(pdev);
+}
+
+int ipc_acquire_irq(struct iosm_pcie *ipc_pcie)
+{
+ struct pci_dev *pdev = ipc_pcie->pci;
+ int i, rc = -EINVAL;
+
+ ipc_pcie->nvec = pci_alloc_irq_vectors(pdev, IPC_MSI_VECTORS,
+ IPC_MSI_VECTORS, PCI_IRQ_MSI);
+
+ if (ipc_pcie->nvec < 0) {
+ rc = ipc_pcie->nvec;
+ goto error;
+ }
+
+ if (!pdev->msi_enabled)
+ goto error;
+
+ for (i = 0; i < ipc_pcie->nvec; ++i) {
+ rc = request_threaded_irq(pdev->irq + i, NULL,
+ ipc_msi_interrupt, IRQF_ONESHOT,
+ KBUILD_MODNAME, ipc_pcie);
+ if (rc) {
+ dev_err(ipc_pcie->dev, "unable to grab IRQ, rc=%d", rc);
+ ipc_pcie->nvec = i;
+ ipc_release_irq(ipc_pcie);
+ goto error;
+ }
+ }
+
+error:
+ return rc;
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_irq.h b/drivers/net/wwan/iosm/iosm_ipc_irq.h
new file mode 100644
index 000000000000..a8ed596cb6a5
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_irq.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_IRQ_H
+#define IOSM_IPC_IRQ_H
+
+struct iosm_pcie;
+
+/**
+ * ipc_doorbell_fire - fire doorbell to CP
+ * @ipc_pcie: Pointer to iosm_pcie
+ * @irq_n: Doorbell type
+ * @data: ipc state
+ */
+void ipc_doorbell_fire(struct iosm_pcie *ipc_pcie, int irq_n, u32 data);
+
+/**
+ * ipc_release_irq - Release the IRQ handler.
+ * @ipc_pcie: Pointer to iosm_pcie struct
+ */
+void ipc_release_irq(struct iosm_pcie *ipc_pcie);
+
+/**
+ * ipc_acquire_irq - acquire IRQ & register IRQ handler.
+ * @ipc_pcie: Pointer to iosm_pcie struct
+ *
+ * Return: 0 on success and failure value on error
+ */
+int ipc_acquire_irq(struct iosm_pcie *ipc_pcie);
+
+#endif
--
2.25.1