// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/sys_titan.c
 *
 *      Copyright (C) 1995 David A Rusling
 *      Copyright (C) 1996, 1999 Jay A Estabrook
 *      Copyright (C) 1998, 1999 Richard Henderson
 *      Copyright (C) 1999, 2000 Jeff Wiedemeier
 *
 * Code supporting TITAN systems (EV6+TITAN), currently:
 *      Privateer
 *      Falcon
 *      Granite
 */

#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/core_titan.h>
#include <asm/hwrpb.h>
#include <asm/tlbflush.h>

#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"
#include "err_impl.h"


/*
 * Titan generic
 */

/*
 * Titan supports up to 4 CPUs
 */
static unsigned long titan_cpu_irq_affinity[4] = { ~0UL, ~0UL, ~0UL, ~0UL };

/*
 * Mask is set (1) if enabled
 */
static unsigned long titan_cached_irq_mask;

/*
 * Need SMP-safe access to interrupt CSRs
 */
DEFINE_SPINLOCK(titan_irq_lock);

static void
titan_update_irq_hw(unsigned long mask)
{
        register titan_cchip *cchip = TITAN_cchip;
        unsigned long isa_enable = 1UL << 55;
        register int bcpu = boot_cpuid;

#ifdef CONFIG_SMP
        cpumask_t cpm;
        volatile unsigned long *dim0, *dim1, *dim2, *dim3;
        unsigned long mask0, mask1, mask2, mask3, dummy;

        cpumask_copy(&cpm, cpu_present_mask);
        mask &= ~isa_enable;
        mask0 = mask & titan_cpu_irq_affinity[0];
        mask1 = mask & titan_cpu_irq_affinity[1];
        mask2 = mask & titan_cpu_irq_affinity[2];
        mask3 = mask & titan_cpu_irq_affinity[3];

        if (bcpu == 0) mask0 |= isa_enable;
        else if (bcpu == 1) mask1 |= isa_enable;
        else if (bcpu == 2) mask2 |= isa_enable;
        else mask3 |= isa_enable;

        dim0 = &cchip->dim0.csr;
        dim1 = &cchip->dim1.csr;
        dim2 = &cchip->dim2.csr;
        dim3 = &cchip->dim3.csr;
        if (!cpumask_test_cpu(0, &cpm)) dim0 = &dummy;
        if (!cpumask_test_cpu(1, &cpm)) dim1 = &dummy;
        if (!cpumask_test_cpu(2, &cpm)) dim2 = &dummy;
        if (!cpumask_test_cpu(3, &cpm)) dim3 = &dummy;

        *dim0 = mask0;
        *dim1 = mask1;
        *dim2 = mask2;
        *dim3 = mask3;
        mb();
        *dim0;
        *dim1;
        *dim2;
        *dim3;
#else
        volatile unsigned long *dimB;
        dimB = &cchip->dim0.csr;
        if (bcpu == 1) dimB = &cchip->dim1.csr;
        else if (bcpu == 2) dimB = &cchip->dim2.csr;
        else if (bcpu == 3) dimB = &cchip->dim3.csr;

        *dimB = mask | isa_enable;
        mb();
        *dimB;
#endif
}

static inline void
titan_enable_irq(struct irq_data *d)
{
        unsigned int irq = d->irq;
        spin_lock(&titan_irq_lock);
        titan_cached_irq_mask |= 1UL << (irq - 16);
        titan_update_irq_hw(titan_cached_irq_mask);
        spin_unlock(&titan_irq_lock);
}

static inline void
titan_disable_irq(struct irq_data *d)
{
        unsigned int irq = d->irq;
        spin_lock(&titan_irq_lock);
        titan_cached_irq_mask &= ~(1UL << (irq - 16));
        titan_update_irq_hw(titan_cached_irq_mask);
        spin_unlock(&titan_irq_lock);
}

static void
titan_cpu_set_irq_affinity(unsigned int irq, cpumask_t affinity)
{
        int cpu;

        for (cpu = 0; cpu < 4; cpu++) {
                if (cpumask_test_cpu(cpu, &affinity))
                        titan_cpu_irq_affinity[cpu] |= 1UL << irq;
                else
                        titan_cpu_irq_affinity[cpu] &= ~(1UL << irq);
        }

}

static int
titan_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity,
                       bool force)
{ 
        unsigned int irq = d->irq;
        spin_lock(&titan_irq_lock);
        titan_cpu_set_irq_affinity(irq - 16, *affinity);
        titan_update_irq_hw(titan_cached_irq_mask);
        spin_unlock(&titan_irq_lock);

        return 0;
}

static void
titan_device_interrupt(unsigned long vector)
{
        printk("titan_device_interrupt: NOT IMPLEMENTED YET!!\n");
}

static void 
titan_srm_device_interrupt(unsigned long vector)
{
        int irq;

        irq = (vector - 0x800) >> 4;
        handle_irq(irq);
}


static void __init
init_titan_irqs(struct irq_chip * ops, int imin, int imax)
{
        long i;
        for (i = imin; i <= imax; ++i) {
                irq_set_chip_and_handler(i, ops, handle_level_irq);
                irq_set_status_flags(i, IRQ_LEVEL);
        }
}

static struct irq_chip titan_irq_type = {
       .name                    = "TITAN",
       .irq_unmask              = titan_enable_irq,
       .irq_mask                = titan_disable_irq,
       .irq_mask_ack            = titan_disable_irq,
       .irq_set_affinity        = titan_set_irq_affinity,
};

static irqreturn_t
titan_intr_nop(int irq, void *dev_id)
{
      /*
       * This is a NOP interrupt handler for the purposes of
       * event counting -- just return.
       */                                                                     
       return IRQ_HANDLED;
}

static void __init
titan_init_irq(void)
{
        if (alpha_using_srm && !alpha_mv.device_interrupt)
                alpha_mv.device_interrupt = titan_srm_device_interrupt;
        if (!alpha_mv.device_interrupt)
                alpha_mv.device_interrupt = titan_device_interrupt;

        titan_update_irq_hw(0);

        init_titan_irqs(&titan_irq_type, 16, 63 + 16);
}
  
static void __init
titan_legacy_init_irq(void)
{
        /* init the legacy dma controller */
        outb(0, DMA1_RESET_REG);
        outb(0, DMA2_RESET_REG);
        outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
        outb(0, DMA2_MASK_REG);

        /* init the legacy irq controller */
        init_i8259a_irqs();

        /* init the titan irqs */
        titan_init_irq();
}

void
titan_dispatch_irqs(u64 mask)
{
        unsigned long vector;

        /*
         * Mask down to those interrupts which are enable on this processor
         */
        mask &= titan_cpu_irq_affinity[smp_processor_id()];

        /*
         * Dispatch all requested interrupts 
         */
        while (mask) {
                /* convert to SRM vector... priority is <63> -> <0> */
                vector = 63 - __kernel_ctlz(mask);
                mask &= ~(1UL << vector);       /* clear it out          */
                vector = 0x900 + (vector << 4); /* convert to SRM vector */
                
                /* dispatch it */
                alpha_mv.device_interrupt(vector);
        }
}
  

/*
 * Titan Family
 */
static void __init
titan_request_irq(unsigned int irq, irq_handler_t handler,
                  unsigned long irqflags, const char *devname,
                  void *dev_id)
{
        int err;
        err = request_irq(irq, handler, irqflags, devname, dev_id);
        if (err) {
                printk("titan_request_irq for IRQ %d returned %d; ignoring\n",
                       irq, err);
        }
}

static void __init
titan_late_init(void)
{
        /*
         * Enable the system error interrupts. These interrupts are 
         * all reported to the kernel as machine checks, so the handler
         * is a nop so it can be called to count the individual events.
         */
        titan_request_irq(63+16, titan_intr_nop, 0,
                    "CChip Error", NULL);
        titan_request_irq(62+16, titan_intr_nop, 0,
                    "PChip 0 H_Error", NULL);
        titan_request_irq(61+16, titan_intr_nop, 0,
                    "PChip 1 H_Error", NULL);
        titan_request_irq(60+16, titan_intr_nop, 0,
                    "PChip 0 C_Error", NULL);
        titan_request_irq(59+16, titan_intr_nop, 0,
                    "PChip 1 C_Error", NULL);

        /* 
         * Register our error handlers.
         */
        titan_register_error_handlers();

        /*
         * Check if the console left us any error logs.
         */
        cdl_check_console_data_log();

}

static int
titan_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
        u8 intline;
        int irq;

        /* Get the current intline.  */
        pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &intline);
        irq = intline;

        /* Is it explicitly routed through ISA?  */
        if ((irq & 0xF0) == 0xE0)
                return irq;
 
        /* Offset by 16 to make room for ISA interrupts 0 - 15.  */
        return irq + 16;
}

static void __init
titan_init_pci(void)
{
        /*
         * This isn't really the right place, but there's some init
         * that needs to be done after everything is basically up.
         */
        titan_late_init();
 
        /* Indicate that we trust the console to configure things properly */
        pci_set_flags(PCI_PROBE_ONLY);
        common_init_pci();
        SMC669_Init(0);
        locate_and_init_vga(NULL);
}


/*
 * Privateer
 */
static void __init
privateer_init_pci(void)
{
        /*
         * Hook a couple of extra err interrupts that the
         * common titan code won't.
         */
        titan_request_irq(53+16, titan_intr_nop, 0,
                    "NMI", NULL);
        titan_request_irq(50+16, titan_intr_nop, 0,
                    "Temperature Warning", NULL);

        /*
         * Finish with the common version.
         */
        return titan_init_pci();
}


/*
 * The System Vectors.
 */
struct alpha_machine_vector titan_mv __initmv = {
        .vector_name            = "TITAN",
        DO_EV6_MMU,
        DO_DEFAULT_RTC,
        DO_TITAN_IO,
        .machine_check          = titan_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         = TITAN_DAC_OFFSET,

        .nr_irqs                = 80,   /* 64 + 16 */
        /* device_interrupt will be filled in by titan_init_irq */

        .agp_info               = titan_agp_info,

        .init_arch              = titan_init_arch,
        .init_irq               = titan_legacy_init_irq,
        .init_rtc               = common_init_rtc,
        .init_pci               = titan_init_pci,

        .kill_arch              = titan_kill_arch,
        .pci_map_irq            = titan_map_irq,
        .pci_swizzle            = common_swizzle,
};
ALIAS_MV(titan)

struct alpha_machine_vector privateer_mv __initmv = {
        .vector_name            = "PRIVATEER",
        DO_EV6_MMU,
        DO_DEFAULT_RTC,
        DO_TITAN_IO,
        .machine_check          = privateer_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         = TITAN_DAC_OFFSET,

        .nr_irqs                = 80,   /* 64 + 16 */
        /* device_interrupt will be filled in by titan_init_irq */

        .agp_info               = titan_agp_info,

        .init_arch              = titan_init_arch,
        .init_irq               = titan_legacy_init_irq,
        .init_rtc               = common_init_rtc,
        .init_pci               = privateer_init_pci,

        .kill_arch              = titan_kill_arch,
        .pci_map_irq            = titan_map_irq,
        .pci_swizzle            = common_swizzle,
};
/* No alpha_mv alias for privateer since we compile it 
   in unconditionally with titan; setup_arch knows how to cope. */