1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2020-21 Intel Corporation.
 4 */
 5
 6#include "iosm_ipc_pcie.h"
 7#include "iosm_ipc_protocol.h"
 8
 9static void ipc_write_dbell_reg(struct iosm_pcie *ipc_pcie, int irq_n, u32 data)
10{
11	void __iomem *write_reg;
12
13	/* Select the first doorbell register, which is only currently needed
14	 * by CP.
15	 */
16	write_reg = (void __iomem *)((u8 __iomem *)ipc_pcie->ipc_regs +
17				     ipc_pcie->doorbell_write +
18				     (irq_n * ipc_pcie->doorbell_reg_offset));
19
20	/* Fire the doorbell irq by writing data on the doorbell write pointer
21	 * register.
22	 */
23	iowrite32(data, write_reg);
24}
25
26void ipc_doorbell_fire(struct iosm_pcie *ipc_pcie, int irq_n, u32 data)
27{
28	ipc_write_dbell_reg(ipc_pcie, irq_n, data);
29}
30
31/* Threaded Interrupt handler for MSI interrupts */
32static irqreturn_t ipc_msi_interrupt(int irq, void *dev_id)
33{
34	struct iosm_pcie *ipc_pcie = dev_id;
35	int instance = irq - ipc_pcie->pci->irq;
36
37	/* Shift the MSI irq actions to the IPC tasklet. IRQ_NONE means the
38	 * irq was not from the IPC device or could not be served.
39	 */
40	if (instance >= ipc_pcie->nvec)
41		return IRQ_NONE;
42
43	if (!test_bit(0, &ipc_pcie->suspend))
44		ipc_imem_irq_process(ipc_pcie->imem, instance);
45
46	return IRQ_HANDLED;
47}
48
49void ipc_release_irq(struct iosm_pcie *ipc_pcie)
50{
51	struct pci_dev *pdev = ipc_pcie->pci;
52
53	if (pdev->msi_enabled) {
54		while (--ipc_pcie->nvec >= 0)
55			free_irq(pdev->irq + ipc_pcie->nvec, ipc_pcie);
56	}
57	pci_free_irq_vectors(pdev);
58}
59
60int ipc_acquire_irq(struct iosm_pcie *ipc_pcie)
61{
62	struct pci_dev *pdev = ipc_pcie->pci;
63	int i, rc = -EINVAL;
64
65	ipc_pcie->nvec = pci_alloc_irq_vectors(pdev, IPC_MSI_VECTORS,
66					       IPC_MSI_VECTORS, PCI_IRQ_MSI);
67
68	if (ipc_pcie->nvec < 0) {
69		rc = ipc_pcie->nvec;
70		goto error;
71	}
72
73	if (!pdev->msi_enabled)
74		goto error;
75
76	for (i = 0; i < ipc_pcie->nvec; ++i) {
77		rc = request_threaded_irq(pdev->irq + i, NULL,
78					  ipc_msi_interrupt, IRQF_ONESHOT,
79					  KBUILD_MODNAME, ipc_pcie);
80		if (rc) {
81			dev_err(ipc_pcie->dev, "unable to grab IRQ, rc=%d", rc);
82			ipc_pcie->nvec = i;
83			ipc_release_irq(ipc_pcie);
84			goto error;
85		}
86	}
87
88error:
89	return rc;
90}