// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/alpha/kernel/sys_eiger.c
*
* Copyright (C) 1995 David A Rusling
* Copyright (C) 1996, 1999 Jay A Estabrook
* Copyright (C) 1998, 1999 Richard Henderson
* Copyright (C) 1999 Iain Grant
*
* Code supporting the EIGER (EV6+TSUNAMI).
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/ptrace.h>
#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/core_tsunami.h>
#include <asm/hwrpb.h>
#include <asm/tlbflush.h>
#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"
/* Note that this interrupt code is identical to TAKARA. */
/* Note mask bit is true for DISABLED irqs. */
static unsigned long cached_irq_mask[2] = { -1, -1 };
static inline void
eiger_update_irq_hw(unsigned long irq, unsigned long mask)
{
int regaddr;
mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
outl(mask & 0xffff0000UL, regaddr);
}
static inline void
eiger_enable_irq(struct irq_data *d)
{
unsigned int irq = d->irq;
unsigned long mask;
mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
eiger_update_irq_hw(irq, mask);
}
static void
eiger_disable_irq(struct irq_data *d)
{
unsigned int irq = d->irq;
unsigned long mask;
mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
eiger_update_irq_hw(irq, mask);
}
static struct irq_chip eiger_irq_type = {
.name = "EIGER",
.irq_unmask = eiger_enable_irq,
.irq_mask = eiger_disable_irq,
.irq_mask_ack = eiger_disable_irq,
};
static void
eiger_device_interrupt(unsigned long vector)
{
unsigned intstatus;
/*
* The PALcode will have passed us vectors 0x800 or 0x810,
* which are fairly arbitrary values and serve only to tell
* us whether an interrupt has come in on IRQ0 or IRQ1. If
* it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
* probably ISA, but PCI interrupts can come through IRQ0
* as well if the interrupt controller isn't in accelerated
* mode.
*
* OTOH, the accelerator thing doesn't seem to be working
* overly well, so what we'll do instead is try directly
* examining the Master Interrupt Register to see if it's a
* PCI interrupt, and if _not_ then we'll pass it on to the
* ISA handler.
*/
intstatus = inw(0x500) & 15;
if (intstatus) {
/*
* This is a PCI interrupt. Check each bit and
* despatch an interrupt if it's set.
*/
if (intstatus & 8) handle_irq(16+3);
if (intstatus & 4) handle_irq(16+2);
if (intstatus & 2) handle_irq(16+1);
if (intstatus & 1) handle_irq(16+0);
} else {
isa_device_interrupt(vector);
}
}
static void
eiger_srm_device_interrupt(unsigned long vector)
{
int irq = (vector - 0x800) >> 4;
handle_irq(irq);
}
static void __init
eiger_init_irq(void)
{
long i;
outb(0, DMA1_RESET_REG);
outb(0, DMA2_RESET_REG);
outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
outb(0, DMA2_MASK_REG);
if (alpha_using_srm)
alpha_mv.device_interrupt = eiger_srm_device_interrupt;
for (i = 16; i < 128; i += 16)
eiger_update_irq_hw(i, -1);
init_i8259a_irqs();
for (i = 16; i < 128; ++i) {
irq_set_chip_and_handler(i, &eiger_irq_type, handle_level_irq);
irq_set_status_flags(i, IRQ_LEVEL);
}
}
static int
eiger_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
u8 irq_orig;
/* The SRM console has already calculated out the IRQ value's for
option cards. As this works lets just read in the value already
set and change it to a useable value by Linux.
All the IRQ values generated by the console are greater than 90,
so we subtract 80 because it is (90 - allocated ISA IRQ's). */
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);
return irq_orig - 0x80;
}
static u8
eiger_swizzle(struct pci_dev *dev, u8 *pinp)
{
struct pci_controller *hose = dev->sysdata;
int slot, pin = *pinp;
int bridge_count = 0;
/* Find the number of backplane bridges. */
int backplane = inw(0x502) & 0x0f;
switch (backplane)
{
case 0x00: bridge_count = 0; break; /* No bridges */
case 0x01: bridge_count = 1; break; /* 1 */
case 0x03: bridge_count = 2; break; /* 2 */
case 0x07: bridge_count = 3; break; /* 3 */
case 0x0f: bridge_count = 4; break; /* 4 */
};
slot = PCI_SLOT(dev->devfn);
while (dev->bus->self) {
/* Check for built-in bridges on hose 0. */
if (hose->index == 0
&& (PCI_SLOT(dev->bus->self->devfn)
> 20 - bridge_count)) {
slot = PCI_SLOT(dev->devfn);
break;
}
/* Must be a card-based bridge. */
pin = pci_swizzle_interrupt_pin(dev, pin);
/* Move up the chain of bridges. */
dev = dev->bus->self;
}
*pinp = pin;
return slot;
}
/*
* The System Vectors
*/
struct alpha_machine_vector eiger_mv __initmv = {
.vector_name = "Eiger",
DO_EV6_MMU,
DO_DEFAULT_RTC,
DO_TSUNAMI_IO,
.machine_check = tsunami_machine_check,
.max_isa_dma_address = ALPHA_MAX_ISA_DMA_ADDRESS,
.min_io_address = DEFAULT_IO_BASE,
.min_mem_address = DEFAULT_MEM_BASE,
.pci_dac_offset = TSUNAMI_DAC_OFFSET,
.nr_irqs = 128,
.device_interrupt = eiger_device_interrupt,
.init_arch = tsunami_init_arch,
.init_irq = eiger_init_irq,
.init_rtc = common_init_rtc,
.init_pci = common_init_pci,
.kill_arch = tsunami_kill_arch,
.pci_map_irq = eiger_map_irq,
.pci_swizzle = eiger_swizzle,
};
ALIAS_MV(eiger)
