12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 2bfa9a2ebSMichael Ellerman /* 3bfa9a2ebSMichael Ellerman * MSI support for PPC4xx SoCs using High Speed Transfer Assist (HSTA) for 4bfa9a2ebSMichael Ellerman * generation of the interrupt. 5bfa9a2ebSMichael Ellerman * 6bfa9a2ebSMichael Ellerman * Copyright © 2013 Alistair Popple <alistair@popple.id.au> IBM Corporation 7bfa9a2ebSMichael Ellerman */ 8bfa9a2ebSMichael Ellerman 9bfa9a2ebSMichael Ellerman #include <linux/kernel.h> 10bfa9a2ebSMichael Ellerman #include <linux/interrupt.h> 11bfa9a2ebSMichael Ellerman #include <linux/msi.h> 12bfa9a2ebSMichael Ellerman #include <linux/of.h> 13bfa9a2ebSMichael Ellerman #include <linux/of_platform.h> 14bfa9a2ebSMichael Ellerman #include <linux/pci.h> 15bfa9a2ebSMichael Ellerman #include <linux/semaphore.h> 16bfa9a2ebSMichael Ellerman #include <asm/msi_bitmap.h> 17bfa9a2ebSMichael Ellerman #include <asm/ppc-pci.h> 18bfa9a2ebSMichael Ellerman 19bfa9a2ebSMichael Ellerman struct ppc4xx_hsta_msi { 20bfa9a2ebSMichael Ellerman struct device *dev; 21bfa9a2ebSMichael Ellerman 22bfa9a2ebSMichael Ellerman /* The ioremapped HSTA MSI IO space */ 23bfa9a2ebSMichael Ellerman u32 __iomem *data; 24bfa9a2ebSMichael Ellerman 25bfa9a2ebSMichael Ellerman /* Physical address of HSTA MSI IO space */ 26bfa9a2ebSMichael Ellerman u64 address; 27bfa9a2ebSMichael Ellerman struct msi_bitmap bmp; 28bfa9a2ebSMichael Ellerman 29bfa9a2ebSMichael Ellerman /* An array mapping offsets to hardware IRQs */ 30bfa9a2ebSMichael Ellerman int *irq_map; 31bfa9a2ebSMichael Ellerman 32bfa9a2ebSMichael Ellerman /* Number of hwirqs supported */ 33bfa9a2ebSMichael Ellerman int irq_count; 34bfa9a2ebSMichael Ellerman }; 35bfa9a2ebSMichael Ellerman static struct ppc4xx_hsta_msi ppc4xx_hsta_msi; 36bfa9a2ebSMichael Ellerman 37bfa9a2ebSMichael Ellerman static int hsta_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) 38bfa9a2ebSMichael Ellerman { 39bfa9a2ebSMichael Ellerman struct msi_msg msg; 40bfa9a2ebSMichael Ellerman struct msi_desc *entry; 41bfa9a2ebSMichael Ellerman int irq, hwirq; 42bfa9a2ebSMichael Ellerman u64 addr; 43bfa9a2ebSMichael Ellerman 44bfa9a2ebSMichael Ellerman /* We don't support MSI-X */ 45bfa9a2ebSMichael Ellerman if (type == PCI_CAP_ID_MSIX) { 46bfa9a2ebSMichael Ellerman pr_debug("%s: MSI-X not supported.\n", __func__); 47bfa9a2ebSMichael Ellerman return -EINVAL; 48bfa9a2ebSMichael Ellerman } 49bfa9a2ebSMichael Ellerman 50*85dabc2fSThomas Gleixner msi_for_each_desc(entry, &dev->dev, MSI_DESC_NOTASSOCIATED) { 51bfa9a2ebSMichael Ellerman irq = msi_bitmap_alloc_hwirqs(&ppc4xx_hsta_msi.bmp, 1); 52bfa9a2ebSMichael Ellerman if (irq < 0) { 53bfa9a2ebSMichael Ellerman pr_debug("%s: Failed to allocate msi interrupt\n", 54bfa9a2ebSMichael Ellerman __func__); 55bfa9a2ebSMichael Ellerman return irq; 56bfa9a2ebSMichael Ellerman } 57bfa9a2ebSMichael Ellerman 58bfa9a2ebSMichael Ellerman hwirq = ppc4xx_hsta_msi.irq_map[irq]; 59bfa9a2ebSMichael Ellerman if (!hwirq) { 60bfa9a2ebSMichael Ellerman pr_err("%s: Failed mapping irq %d\n", __func__, irq); 61bfa9a2ebSMichael Ellerman return -EINVAL; 62bfa9a2ebSMichael Ellerman } 63bfa9a2ebSMichael Ellerman 64bfa9a2ebSMichael Ellerman /* 65bfa9a2ebSMichael Ellerman * HSTA generates interrupts on writes to 128-bit aligned 66bfa9a2ebSMichael Ellerman * addresses. 67bfa9a2ebSMichael Ellerman */ 68bfa9a2ebSMichael Ellerman addr = ppc4xx_hsta_msi.address + irq*0x10; 69bfa9a2ebSMichael Ellerman msg.address_hi = upper_32_bits(addr); 70bfa9a2ebSMichael Ellerman msg.address_lo = lower_32_bits(addr); 71bfa9a2ebSMichael Ellerman 72bfa9a2ebSMichael Ellerman /* Data is not used by the HSTA. */ 73bfa9a2ebSMichael Ellerman msg.data = 0; 74bfa9a2ebSMichael Ellerman 75bfa9a2ebSMichael Ellerman pr_debug("%s: Setup irq %d (0x%0llx)\n", __func__, hwirq, 76bfa9a2ebSMichael Ellerman (((u64) msg.address_hi) << 32) | msg.address_lo); 77bfa9a2ebSMichael Ellerman 78bfa9a2ebSMichael Ellerman if (irq_set_msi_desc(hwirq, entry)) { 79bfa9a2ebSMichael Ellerman pr_err( 80bfa9a2ebSMichael Ellerman "%s: Invalid hwirq %d specified in device tree\n", 81bfa9a2ebSMichael Ellerman __func__, hwirq); 82bfa9a2ebSMichael Ellerman msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); 83bfa9a2ebSMichael Ellerman return -EINVAL; 84bfa9a2ebSMichael Ellerman } 85bfa9a2ebSMichael Ellerman pci_write_msi_msg(hwirq, &msg); 86bfa9a2ebSMichael Ellerman } 87bfa9a2ebSMichael Ellerman 88bfa9a2ebSMichael Ellerman return 0; 89bfa9a2ebSMichael Ellerman } 90bfa9a2ebSMichael Ellerman 91bfa9a2ebSMichael Ellerman static int hsta_find_hwirq_offset(int hwirq) 92bfa9a2ebSMichael Ellerman { 93bfa9a2ebSMichael Ellerman int irq; 94bfa9a2ebSMichael Ellerman 95bfa9a2ebSMichael Ellerman /* Find the offset given the hwirq */ 96bfa9a2ebSMichael Ellerman for (irq = 0; irq < ppc4xx_hsta_msi.irq_count; irq++) 97bfa9a2ebSMichael Ellerman if (ppc4xx_hsta_msi.irq_map[irq] == hwirq) 98bfa9a2ebSMichael Ellerman return irq; 99bfa9a2ebSMichael Ellerman 100bfa9a2ebSMichael Ellerman return -EINVAL; 101bfa9a2ebSMichael Ellerman } 102bfa9a2ebSMichael Ellerman 103bfa9a2ebSMichael Ellerman static void hsta_teardown_msi_irqs(struct pci_dev *dev) 104bfa9a2ebSMichael Ellerman { 105bfa9a2ebSMichael Ellerman struct msi_desc *entry; 106bfa9a2ebSMichael Ellerman int irq; 107bfa9a2ebSMichael Ellerman 108*85dabc2fSThomas Gleixner msi_for_each_desc(entry, &dev->dev, MSI_DESC_ASSOCIATED) { 109bfa9a2ebSMichael Ellerman irq = hsta_find_hwirq_offset(entry->irq); 110bfa9a2ebSMichael Ellerman 111bfa9a2ebSMichael Ellerman /* entry->irq should always be in irq_map */ 112bfa9a2ebSMichael Ellerman BUG_ON(irq < 0); 113bfa9a2ebSMichael Ellerman irq_set_msi_desc(entry->irq, NULL); 114bfa9a2ebSMichael Ellerman msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1); 115bfa9a2ebSMichael Ellerman pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__, 116bfa9a2ebSMichael Ellerman entry->irq, irq); 117bfa9a2ebSMichael Ellerman } 118bfa9a2ebSMichael Ellerman } 119bfa9a2ebSMichael Ellerman 120bfa9a2ebSMichael Ellerman static int hsta_msi_probe(struct platform_device *pdev) 121bfa9a2ebSMichael Ellerman { 122bfa9a2ebSMichael Ellerman struct device *dev = &pdev->dev; 123bfa9a2ebSMichael Ellerman struct resource *mem; 124bfa9a2ebSMichael Ellerman int irq, ret, irq_count; 125bfa9a2ebSMichael Ellerman struct pci_controller *phb; 126bfa9a2ebSMichael Ellerman 127bfa9a2ebSMichael Ellerman mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 128bfa9a2ebSMichael Ellerman if (!mem) { 129bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to get mmio space\n"); 130bfa9a2ebSMichael Ellerman return -EINVAL; 131bfa9a2ebSMichael Ellerman } 132bfa9a2ebSMichael Ellerman 133bfa9a2ebSMichael Ellerman irq_count = of_irq_count(dev->of_node); 134bfa9a2ebSMichael Ellerman if (!irq_count) { 135bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to find IRQ range\n"); 136bfa9a2ebSMichael Ellerman return -EINVAL; 137bfa9a2ebSMichael Ellerman } 138bfa9a2ebSMichael Ellerman 139bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.dev = dev; 140bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.address = mem->start; 141bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.data = ioremap(mem->start, resource_size(mem)); 142bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.irq_count = irq_count; 143bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.data) { 144bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to map memory\n"); 145bfa9a2ebSMichael Ellerman return -ENOMEM; 146bfa9a2ebSMichael Ellerman } 147bfa9a2ebSMichael Ellerman 148bfa9a2ebSMichael Ellerman ret = msi_bitmap_alloc(&ppc4xx_hsta_msi.bmp, irq_count, dev->of_node); 149bfa9a2ebSMichael Ellerman if (ret) 150bfa9a2ebSMichael Ellerman goto out; 151bfa9a2ebSMichael Ellerman 1526da2ec56SKees Cook ppc4xx_hsta_msi.irq_map = kmalloc_array(irq_count, sizeof(int), 1536da2ec56SKees Cook GFP_KERNEL); 154bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.irq_map) { 155bfa9a2ebSMichael Ellerman ret = -ENOMEM; 156bfa9a2ebSMichael Ellerman goto out1; 157bfa9a2ebSMichael Ellerman } 158bfa9a2ebSMichael Ellerman 159bfa9a2ebSMichael Ellerman /* Setup a mapping from irq offsets to hardware irq numbers */ 160bfa9a2ebSMichael Ellerman for (irq = 0; irq < irq_count; irq++) { 161bfa9a2ebSMichael Ellerman ppc4xx_hsta_msi.irq_map[irq] = 162bfa9a2ebSMichael Ellerman irq_of_parse_and_map(dev->of_node, irq); 163bfa9a2ebSMichael Ellerman if (!ppc4xx_hsta_msi.irq_map[irq]) { 164bfa9a2ebSMichael Ellerman dev_err(dev, "Unable to map IRQ\n"); 165bfa9a2ebSMichael Ellerman ret = -EINVAL; 166bfa9a2ebSMichael Ellerman goto out2; 167bfa9a2ebSMichael Ellerman } 168bfa9a2ebSMichael Ellerman } 169bfa9a2ebSMichael Ellerman 170bfa9a2ebSMichael Ellerman list_for_each_entry(phb, &hose_list, list_node) { 171bfa9a2ebSMichael Ellerman phb->controller_ops.setup_msi_irqs = hsta_setup_msi_irqs; 172bfa9a2ebSMichael Ellerman phb->controller_ops.teardown_msi_irqs = hsta_teardown_msi_irqs; 173bfa9a2ebSMichael Ellerman } 174bfa9a2ebSMichael Ellerman return 0; 175bfa9a2ebSMichael Ellerman 176bfa9a2ebSMichael Ellerman out2: 177bfa9a2ebSMichael Ellerman kfree(ppc4xx_hsta_msi.irq_map); 178bfa9a2ebSMichael Ellerman 179bfa9a2ebSMichael Ellerman out1: 180bfa9a2ebSMichael Ellerman msi_bitmap_free(&ppc4xx_hsta_msi.bmp); 181bfa9a2ebSMichael Ellerman 182bfa9a2ebSMichael Ellerman out: 183bfa9a2ebSMichael Ellerman iounmap(ppc4xx_hsta_msi.data); 184bfa9a2ebSMichael Ellerman return ret; 185bfa9a2ebSMichael Ellerman } 186bfa9a2ebSMichael Ellerman 187bfa9a2ebSMichael Ellerman static const struct of_device_id hsta_msi_ids[] = { 188bfa9a2ebSMichael Ellerman { 189bfa9a2ebSMichael Ellerman .compatible = "ibm,hsta-msi", 190bfa9a2ebSMichael Ellerman }, 191bfa9a2ebSMichael Ellerman {} 192bfa9a2ebSMichael Ellerman }; 193bfa9a2ebSMichael Ellerman 194bfa9a2ebSMichael Ellerman static struct platform_driver hsta_msi_driver = { 195bfa9a2ebSMichael Ellerman .probe = hsta_msi_probe, 196bfa9a2ebSMichael Ellerman .driver = { 197bfa9a2ebSMichael Ellerman .name = "hsta-msi", 198bfa9a2ebSMichael Ellerman .of_match_table = hsta_msi_ids, 199bfa9a2ebSMichael Ellerman }, 200bfa9a2ebSMichael Ellerman }; 201bfa9a2ebSMichael Ellerman 202bfa9a2ebSMichael Ellerman static int hsta_msi_init(void) 203bfa9a2ebSMichael Ellerman { 204bfa9a2ebSMichael Ellerman return platform_driver_register(&hsta_msi_driver); 205bfa9a2ebSMichael Ellerman } 206bfa9a2ebSMichael Ellerman subsys_initcall(hsta_msi_init); 207