1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/alpha/kernel/sys_eiger.c 4 * 5 * Copyright (C) 1995 David A Rusling 6 * Copyright (C) 1996, 1999 Jay A Estabrook 7 * Copyright (C) 1998, 1999 Richard Henderson 8 * Copyright (C) 1999 Iain Grant 9 * 10 * Code supporting the EIGER (EV6+TSUNAMI). 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/types.h> 15 #include <linux/mm.h> 16 #include <linux/sched.h> 17 #include <linux/pci.h> 18 #include <linux/init.h> 19 #include <linux/bitops.h> 20 21 #include <asm/ptrace.h> 22 #include <asm/dma.h> 23 #include <asm/irq.h> 24 #include <asm/mmu_context.h> 25 #include <asm/io.h> 26 #include <asm/core_tsunami.h> 27 #include <asm/hwrpb.h> 28 #include <asm/tlbflush.h> 29 30 #include "proto.h" 31 #include "irq_impl.h" 32 #include "pci_impl.h" 33 #include "machvec_impl.h" 34 35 36 /* Note that this interrupt code is identical to TAKARA. */ 37 38 /* Note mask bit is true for DISABLED irqs. */ 39 static unsigned long cached_irq_mask[2] = { -1, -1 }; 40 41 static inline void 42 eiger_update_irq_hw(unsigned long irq, unsigned long mask) 43 { 44 int regaddr; 45 46 mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30)); 47 regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c); 48 outl(mask & 0xffff0000UL, regaddr); 49 } 50 51 static inline void 52 eiger_enable_irq(struct irq_data *d) 53 { 54 unsigned int irq = d->irq; 55 unsigned long mask; 56 mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63))); 57 eiger_update_irq_hw(irq, mask); 58 } 59 60 static void 61 eiger_disable_irq(struct irq_data *d) 62 { 63 unsigned int irq = d->irq; 64 unsigned long mask; 65 mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63)); 66 eiger_update_irq_hw(irq, mask); 67 } 68 69 static struct irq_chip eiger_irq_type = { 70 .name = "EIGER", 71 .irq_unmask = eiger_enable_irq, 72 .irq_mask = eiger_disable_irq, 73 .irq_mask_ack = eiger_disable_irq, 74 }; 75 76 static void 77 eiger_device_interrupt(unsigned long vector) 78 { 79 unsigned intstatus; 80 81 /* 82 * The PALcode will have passed us vectors 0x800 or 0x810, 83 * which are fairly arbitrary values and serve only to tell 84 * us whether an interrupt has come in on IRQ0 or IRQ1. If 85 * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's 86 * probably ISA, but PCI interrupts can come through IRQ0 87 * as well if the interrupt controller isn't in accelerated 88 * mode. 89 * 90 * OTOH, the accelerator thing doesn't seem to be working 91 * overly well, so what we'll do instead is try directly 92 * examining the Master Interrupt Register to see if it's a 93 * PCI interrupt, and if _not_ then we'll pass it on to the 94 * ISA handler. 95 */ 96 97 intstatus = inw(0x500) & 15; 98 if (intstatus) { 99 /* 100 * This is a PCI interrupt. Check each bit and 101 * despatch an interrupt if it's set. 102 */ 103 104 if (intstatus & 8) handle_irq(16+3); 105 if (intstatus & 4) handle_irq(16+2); 106 if (intstatus & 2) handle_irq(16+1); 107 if (intstatus & 1) handle_irq(16+0); 108 } else { 109 isa_device_interrupt(vector); 110 } 111 } 112 113 static void 114 eiger_srm_device_interrupt(unsigned long vector) 115 { 116 int irq = (vector - 0x800) >> 4; 117 handle_irq(irq); 118 } 119 120 static void __init 121 eiger_init_irq(void) 122 { 123 long i; 124 125 outb(0, DMA1_RESET_REG); 126 outb(0, DMA2_RESET_REG); 127 outb(DMA_MODE_CASCADE, DMA2_MODE_REG); 128 outb(0, DMA2_MASK_REG); 129 130 if (alpha_using_srm) 131 alpha_mv.device_interrupt = eiger_srm_device_interrupt; 132 133 for (i = 16; i < 128; i += 16) 134 eiger_update_irq_hw(i, -1); 135 136 init_i8259a_irqs(); 137 138 for (i = 16; i < 128; ++i) { 139 irq_set_chip_and_handler(i, &eiger_irq_type, handle_level_irq); 140 irq_set_status_flags(i, IRQ_LEVEL); 141 } 142 } 143 144 static int 145 eiger_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) 146 { 147 u8 irq_orig; 148 149 /* The SRM console has already calculated out the IRQ value's for 150 option cards. As this works lets just read in the value already 151 set and change it to a useable value by Linux. 152 153 All the IRQ values generated by the console are greater than 90, 154 so we subtract 80 because it is (90 - allocated ISA IRQ's). */ 155 156 pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig); 157 158 return irq_orig - 0x80; 159 } 160 161 static u8 162 eiger_swizzle(struct pci_dev *dev, u8 *pinp) 163 { 164 struct pci_controller *hose = dev->sysdata; 165 int slot, pin = *pinp; 166 int bridge_count = 0; 167 168 /* Find the number of backplane bridges. */ 169 int backplane = inw(0x502) & 0x0f; 170 171 switch (backplane) 172 { 173 case 0x00: bridge_count = 0; break; /* No bridges */ 174 case 0x01: bridge_count = 1; break; /* 1 */ 175 case 0x03: bridge_count = 2; break; /* 2 */ 176 case 0x07: bridge_count = 3; break; /* 3 */ 177 case 0x0f: bridge_count = 4; break; /* 4 */ 178 } 179 180 slot = PCI_SLOT(dev->devfn); 181 while (dev->bus->self) { 182 /* Check for built-in bridges on hose 0. */ 183 if (hose->index == 0 184 && (PCI_SLOT(dev->bus->self->devfn) 185 > 20 - bridge_count)) { 186 slot = PCI_SLOT(dev->devfn); 187 break; 188 } 189 /* Must be a card-based bridge. */ 190 pin = pci_swizzle_interrupt_pin(dev, pin); 191 192 /* Move up the chain of bridges. */ 193 dev = dev->bus->self; 194 } 195 *pinp = pin; 196 return slot; 197 } 198 199 /* 200 * The System Vectors 201 */ 202 203 struct alpha_machine_vector eiger_mv __initmv = { 204 .vector_name = "Eiger", 205 DO_EV6_MMU, 206 DO_DEFAULT_RTC, 207 DO_TSUNAMI_IO, 208 .machine_check = tsunami_machine_check, 209 .max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS, 210 .min_io_address = DEFAULT_IO_BASE, 211 .min_mem_address = DEFAULT_MEM_BASE, 212 .pci_dac_offset = TSUNAMI_DAC_OFFSET, 213 214 .nr_irqs = 128, 215 .device_interrupt = eiger_device_interrupt, 216 217 .init_arch = tsunami_init_arch, 218 .init_irq = eiger_init_irq, 219 .init_rtc = common_init_rtc, 220 .init_pci = common_init_pci, 221 .kill_arch = tsunami_kill_arch, 222 .pci_map_irq = eiger_map_irq, 223 .pci_swizzle = eiger_swizzle, 224 }; 225 ALIAS_MV(eiger) 226