1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MSI framework for platform devices
4 *
5 * Copyright (C) 2015 ARM Limited, All Rights Reserved.
6 * Author: Marc Zyngier <marc.zyngier@arm.com>
7 * Copyright (C) 2022 Linutronix GmbH
8 */
9
10 #include <linux/device.h>
11 #include <linux/irqdomain.h>
12 #include <linux/msi.h>
13
14 /*
15 * This indirection can go when platform_device_msi_init_and_alloc_irqs()
16 * is switched to a proper irq_chip::irq_write_msi_msg() callback. Keep it
17 * simple for now.
18 */
platform_msi_write_msi_msg(struct irq_data * d,struct msi_msg * msg)19 static void platform_msi_write_msi_msg(struct irq_data *d, struct msi_msg *msg)
20 {
21 irq_write_msi_msg_t cb = d->chip_data;
22
23 cb(irq_data_get_msi_desc(d), msg);
24 }
25
platform_msi_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)26 static void platform_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
27 {
28 arg->desc = desc;
29 arg->hwirq = desc->msi_index;
30 }
31
32 static const struct msi_domain_template platform_msi_template = {
33 .chip = {
34 .name = "pMSI",
35 .irq_mask = irq_chip_mask_parent,
36 .irq_unmask = irq_chip_unmask_parent,
37 .irq_write_msi_msg = platform_msi_write_msi_msg,
38 /* The rest is filled in by the platform MSI parent */
39 },
40
41 .ops = {
42 .set_desc = platform_msi_set_desc,
43 },
44
45 .info = {
46 .bus_token = DOMAIN_BUS_DEVICE_MSI,
47 },
48 };
49
50 /**
51 * platform_device_msi_init_and_alloc_irqs - Initialize platform device MSI
52 * and allocate interrupts for @dev
53 * @dev: The device for which to allocate interrupts
54 * @nvec: The number of interrupts to allocate
55 * @write_msi_msg: Callback to write an interrupt message for @dev
56 *
57 * Returns:
58 * Zero for success, or an error code in case of failure
59 *
60 * This creates a MSI domain on @dev which has @dev->msi.domain as
61 * parent. The parent domain sets up the new domain. The domain has
62 * a fixed size of @nvec. The domain is managed by devres and will
63 * be removed when the device is removed.
64 *
65 * Note: For migration purposes this falls back to the original platform_msi code
66 * up to the point where all platforms have been converted to the MSI
67 * parent model.
68 */
platform_device_msi_init_and_alloc_irqs(struct device * dev,unsigned int nvec,irq_write_msi_msg_t write_msi_msg)69 int platform_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec,
70 irq_write_msi_msg_t write_msi_msg)
71 {
72 struct irq_domain *domain = dev->msi.domain;
73
74 if (!domain || !write_msi_msg)
75 return -EINVAL;
76
77 /*
78 * @write_msi_msg is stored in the resulting msi_domain_info::data.
79 * The underlying domain creation mechanism will assign that
80 * callback to the resulting irq chip.
81 */
82 if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN,
83 &platform_msi_template,
84 nvec, NULL, write_msi_msg))
85 return -ENODEV;
86
87 return msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
88 }
89 EXPORT_SYMBOL_GPL(platform_device_msi_init_and_alloc_irqs);
90
91 /**
92 * platform_device_msi_free_irqs_all - Free all interrupts for @dev
93 * @dev: The device for which to free interrupts
94 */
platform_device_msi_free_irqs_all(struct device * dev)95 void platform_device_msi_free_irqs_all(struct device *dev)
96 {
97 msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
98 }
99 EXPORT_SYMBOL_GPL(platform_device_msi_free_irqs_all);
100