1 /* 2 * Copyright 2006, Segher Boessenkool, IBM Corporation. 3 * Copyright 2006-2007, Michael Ellerman, IBM Corporation. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License 7 * as published by the Free Software Foundation; version 2 of the 8 * License. 9 * 10 */ 11 12 #include <linux/irq.h> 13 #include <linux/bootmem.h> 14 #include <linux/msi.h> 15 #include <asm/mpic.h> 16 #include <asm/prom.h> 17 #include <asm/hw_irq.h> 18 #include <asm/ppc-pci.h> 19 20 #include "mpic.h" 21 22 /* A bit ugly, can we get this from the pci_dev somehow? */ 23 static struct mpic *msi_mpic; 24 25 static void mpic_u3msi_mask_irq(unsigned int irq) 26 { 27 mask_msi_irq(irq); 28 mpic_mask_irq(irq); 29 } 30 31 static void mpic_u3msi_unmask_irq(unsigned int irq) 32 { 33 mpic_unmask_irq(irq); 34 unmask_msi_irq(irq); 35 } 36 37 static struct irq_chip mpic_u3msi_chip = { 38 .shutdown = mpic_u3msi_mask_irq, 39 .mask = mpic_u3msi_mask_irq, 40 .unmask = mpic_u3msi_unmask_irq, 41 .eoi = mpic_end_irq, 42 .set_type = mpic_set_irq_type, 43 .set_affinity = mpic_set_affinity, 44 .typename = "MPIC-U3MSI", 45 }; 46 47 static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos) 48 { 49 u8 flags; 50 u32 tmp; 51 u64 addr; 52 53 pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags); 54 55 if (flags & HT_MSI_FLAGS_FIXED) 56 return HT_MSI_FIXED_ADDR; 57 58 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp); 59 addr = tmp & HT_MSI_ADDR_LO_MASK; 60 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp); 61 addr = addr | ((u64)tmp << 32); 62 63 return addr; 64 } 65 66 static u64 find_ht_magic_addr(struct pci_dev *pdev) 67 { 68 struct pci_bus *bus; 69 unsigned int pos; 70 71 for (bus = pdev->bus; bus; bus = bus->parent) { 72 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING); 73 if (pos) 74 return read_ht_magic_addr(bus->self, pos); 75 } 76 77 return 0; 78 } 79 80 static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type) 81 { 82 if (type == PCI_CAP_ID_MSIX) 83 pr_debug("u3msi: MSI-X untested, trying anyway.\n"); 84 85 /* If we can't find a magic address then MSI ain't gonna work */ 86 if (find_ht_magic_addr(pdev) == 0) { 87 pr_debug("u3msi: no magic address found for %s\n", 88 pci_name(pdev)); 89 return -ENXIO; 90 } 91 92 return 0; 93 } 94 95 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev) 96 { 97 struct msi_desc *entry; 98 99 list_for_each_entry(entry, &pdev->msi_list, list) { 100 if (entry->irq == NO_IRQ) 101 continue; 102 103 set_irq_msi(entry->irq, NULL); 104 mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1); 105 irq_dispose_mapping(entry->irq); 106 } 107 108 return; 109 } 110 111 static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) 112 { 113 irq_hw_number_t hwirq; 114 unsigned int virq; 115 struct msi_desc *entry; 116 struct msi_msg msg; 117 u64 addr; 118 119 addr = find_ht_magic_addr(pdev); 120 msg.address_lo = addr & 0xFFFFFFFF; 121 msg.address_hi = addr >> 32; 122 123 list_for_each_entry(entry, &pdev->msi_list, list) { 124 hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1); 125 if (hwirq < 0) { 126 pr_debug("u3msi: failed allocating hwirq\n"); 127 return hwirq; 128 } 129 130 virq = irq_create_mapping(msi_mpic->irqhost, hwirq); 131 if (virq == NO_IRQ) { 132 pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq); 133 mpic_msi_free_hwirqs(msi_mpic, hwirq, 1); 134 return -ENOSPC; 135 } 136 137 set_irq_msi(virq, entry); 138 set_irq_chip(virq, &mpic_u3msi_chip); 139 set_irq_type(virq, IRQ_TYPE_EDGE_RISING); 140 141 pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) addr 0x%lx\n", 142 virq, hwirq, addr); 143 144 msg.data = hwirq; 145 write_msi_msg(virq, &msg); 146 147 hwirq++; 148 } 149 150 return 0; 151 } 152 153 int mpic_u3msi_init(struct mpic *mpic) 154 { 155 int rc; 156 157 rc = mpic_msi_init_allocator(mpic); 158 if (rc) { 159 pr_debug("u3msi: Error allocating bitmap!\n"); 160 return rc; 161 } 162 163 pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n"); 164 165 BUG_ON(msi_mpic); 166 msi_mpic = mpic; 167 168 WARN_ON(ppc_md.setup_msi_irqs); 169 ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs; 170 ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs; 171 ppc_md.msi_check_device = u3msi_msi_check_device; 172 173 return 0; 174 } 175