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 */ 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 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 */ 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 */ 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