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 #include <asm/msi_bitmap.h> 20 21 #include "mpic.h" 22 23 /* A bit ugly, can we get this from the pci_dev somehow? */ 24 static struct mpic *msi_mpic; 25 26 static void mpic_u3msi_mask_irq(unsigned int irq) 27 { 28 mask_msi_irq(irq); 29 mpic_mask_irq(irq); 30 } 31 32 static void mpic_u3msi_unmask_irq(unsigned int irq) 33 { 34 mpic_unmask_irq(irq); 35 unmask_msi_irq(irq); 36 } 37 38 static struct irq_chip mpic_u3msi_chip = { 39 .shutdown = mpic_u3msi_mask_irq, 40 .mask = mpic_u3msi_mask_irq, 41 .unmask = mpic_u3msi_unmask_irq, 42 .eoi = mpic_end_irq, 43 .set_type = mpic_set_irq_type, 44 .set_affinity = mpic_set_affinity, 45 .typename = "MPIC-U3MSI", 46 }; 47 48 static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos) 49 { 50 u8 flags; 51 u32 tmp; 52 u64 addr; 53 54 pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags); 55 56 if (flags & HT_MSI_FLAGS_FIXED) 57 return HT_MSI_FIXED_ADDR; 58 59 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp); 60 addr = tmp & HT_MSI_ADDR_LO_MASK; 61 pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp); 62 addr = addr | ((u64)tmp << 32); 63 64 return addr; 65 } 66 67 static u64 find_ht_magic_addr(struct pci_dev *pdev) 68 { 69 struct pci_bus *bus; 70 unsigned int pos; 71 72 for (bus = pdev->bus; bus; bus = bus->parent) { 73 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING); 74 if (pos) 75 return read_ht_magic_addr(bus->self, pos); 76 } 77 78 return 0; 79 } 80 81 static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type) 82 { 83 if (type == PCI_CAP_ID_MSIX) 84 pr_debug("u3msi: MSI-X untested, trying anyway.\n"); 85 86 /* If we can't find a magic address then MSI ain't gonna work */ 87 if (find_ht_magic_addr(pdev) == 0) { 88 pr_debug("u3msi: no magic address found for %s\n", 89 pci_name(pdev)); 90 return -ENXIO; 91 } 92 93 return 0; 94 } 95 96 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev) 97 { 98 struct msi_desc *entry; 99 100 list_for_each_entry(entry, &pdev->msi_list, list) { 101 if (entry->irq == NO_IRQ) 102 continue; 103 104 set_irq_msi(entry->irq, NULL); 105 msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, 106 virq_to_hw(entry->irq), 1); 107 irq_dispose_mapping(entry->irq); 108 } 109 110 return; 111 } 112 113 static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) 114 { 115 unsigned int virq; 116 struct msi_desc *entry; 117 struct msi_msg msg; 118 u64 addr; 119 int hwirq; 120 121 addr = find_ht_magic_addr(pdev); 122 msg.address_lo = addr & 0xFFFFFFFF; 123 msg.address_hi = addr >> 32; 124 125 list_for_each_entry(entry, &pdev->msi_list, list) { 126 hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1); 127 if (hwirq < 0) { 128 pr_debug("u3msi: failed allocating hwirq\n"); 129 return hwirq; 130 } 131 132 virq = irq_create_mapping(msi_mpic->irqhost, hwirq); 133 if (virq == NO_IRQ) { 134 pr_debug("u3msi: failed mapping hwirq 0x%x\n", hwirq); 135 msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1); 136 return -ENOSPC; 137 } 138 139 set_irq_msi(virq, entry); 140 set_irq_chip(virq, &mpic_u3msi_chip); 141 set_irq_type(virq, IRQ_TYPE_EDGE_RISING); 142 143 pr_debug("u3msi: allocated virq 0x%x (hw 0x%x) addr 0x%lx\n", 144 virq, hwirq, (unsigned long)addr); 145 146 msg.data = hwirq; 147 write_msi_msg(virq, &msg); 148 149 hwirq++; 150 } 151 152 return 0; 153 } 154 155 int mpic_u3msi_init(struct mpic *mpic) 156 { 157 int rc; 158 159 rc = mpic_msi_init_allocator(mpic); 160 if (rc) { 161 pr_debug("u3msi: Error allocating bitmap!\n"); 162 return rc; 163 } 164 165 pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n"); 166 167 BUG_ON(msi_mpic); 168 msi_mpic = mpic; 169 170 WARN_ON(ppc_md.setup_msi_irqs); 171 ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs; 172 ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs; 173 ppc_md.msi_check_device = u3msi_msi_check_device; 174 175 return 0; 176 } 177