// SPDX-License-Identifier: GPL-2.0
/*
 * linux/arch/alpha/kernel/sys_marvel.c
 *
 * Marvel / IO7 support
 */

#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_marvel.h>
#include <asm/hwrpb.h>
#include <asm/tlbflush.h>
#include <asm/vga.h>

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

#if NR_IRQS < MARVEL_NR_IRQS
# error NR_IRQS < MARVEL_NR_IRQS !!!
#endif


/*
 * Interrupt handling.
 */
static void 
io7_device_interrupt(unsigned long vector)
{
        unsigned int pid;
        unsigned int irq;

        /*
         * Vector is 0x800 + (interrupt)
         *
         * where (interrupt) is:
         *
         *      ...16|15 14|13     4|3 0
         *      -----+-----+--------+---
         *        PE |  0  |   irq  | 0
         *
         * where (irq) is 
         *
         *       0x0800 - 0x0ff0         - 0x0800 + (LSI id << 4)
         *       0x1000 - 0x2ff0         - 0x1000 + (MSI_DAT<8:0> << 4)
         */
        pid = vector >> 16;
        irq = ((vector & 0xffff) - 0x800) >> 4;

        irq += 16;                              /* offset for legacy */
        irq &= MARVEL_IRQ_VEC_IRQ_MASK;         /* not too many bits */
        irq |= pid << MARVEL_IRQ_VEC_PE_SHIFT;  /* merge the pid     */

        handle_irq(irq);
}

static volatile unsigned long *
io7_get_irq_ctl(unsigned int irq, struct io7 **pio7)
{
        volatile unsigned long *ctl;
        unsigned int pid;
        struct io7 *io7;

        pid = irq >> MARVEL_IRQ_VEC_PE_SHIFT;

        if (!(io7 = marvel_find_io7(pid))) {
                printk(KERN_ERR 
                       "%s for nonexistent io7 -- vec %x, pid %d\n",
                       __func__, irq, pid);
                return NULL;
        }

        irq &= MARVEL_IRQ_VEC_IRQ_MASK; /* isolate the vector    */
        irq -= 16;                      /* subtract legacy bias  */

        if (irq >= 0x180) {
                printk(KERN_ERR 
                       "%s for invalid irq -- pid %d adjusted irq %x\n",
                       __func__, pid, irq);
                return NULL;
        }

        ctl = &io7->csrs->PO7_LSI_CTL[irq & 0xff].csr; /* assume LSI */
        if (irq >= 0x80)                /* MSI */
                ctl = &io7->csrs->PO7_MSI_CTL[((irq - 0x80) >> 5) & 0x0f].csr;

        if (pio7) *pio7 = io7;
        return ctl;
}

static void
io7_enable_irq(struct irq_data *d)
{
        volatile unsigned long *ctl;
        unsigned int irq = d->irq;
        struct io7 *io7;

        ctl = io7_get_irq_ctl(irq, &io7);
        if (!ctl || !io7) {
                printk(KERN_ERR "%s: get_ctl failed for irq %x\n",
                       __func__, irq);
                return;
        }

        raw_spin_lock(&io7->irq_lock);
        *ctl |= 1UL << 24;
        mb();
        *ctl;
        raw_spin_unlock(&io7->irq_lock);
}

static void
io7_disable_irq(struct irq_data *d)
{
        volatile unsigned long *ctl;
        unsigned int irq = d->irq;
        struct io7 *io7;

        ctl = io7_get_irq_ctl(irq, &io7);
        if (!ctl || !io7) {
                printk(KERN_ERR "%s: get_ctl failed for irq %x\n",
                       __func__, irq);
                return;
        }

        raw_spin_lock(&io7->irq_lock);
        *ctl &= ~(1UL << 24);
        mb();
        *ctl;
        raw_spin_unlock(&io7->irq_lock);
}

static void
marvel_irq_noop(struct irq_data *d)
{
        return;
}

static struct irq_chip marvel_legacy_irq_type = {
        .name           = "LEGACY",
        .irq_mask       = marvel_irq_noop,
        .irq_unmask     = marvel_irq_noop,
};

static struct irq_chip io7_lsi_irq_type = {
        .name           = "LSI",
        .irq_unmask     = io7_enable_irq,
        .irq_mask       = io7_disable_irq,
        .irq_mask_ack   = io7_disable_irq,
};

static struct irq_chip io7_msi_irq_type = {
        .name           = "MSI",
        .irq_unmask     = io7_enable_irq,
        .irq_mask       = io7_disable_irq,
        .irq_ack        = marvel_irq_noop,
};

static void
io7_redirect_irq(struct io7 *io7, 
                 volatile unsigned long *csr, 
                 unsigned int where)
{
        unsigned long val;
        
        val = *csr;
        val &= ~(0x1ffUL << 24);                /* clear the target pid   */
        val |= ((unsigned long)where << 24);    /* set the new target pid */
        
        *csr = val;
        mb();
        *csr;
}

static void 
io7_redirect_one_lsi(struct io7 *io7, unsigned int which, unsigned int where)
{
        unsigned long val;

        /*
         * LSI_CTL has target PID @ 14
         */
        val = io7->csrs->PO7_LSI_CTL[which].csr;
        val &= ~(0x1ffUL << 14);                /* clear the target pid */
        val |= ((unsigned long)where << 14);    /* set the new target pid */

        io7->csrs->PO7_LSI_CTL[which].csr = val;
        mb();
        io7->csrs->PO7_LSI_CTL[which].csr;
}

static void 
io7_redirect_one_msi(struct io7 *io7, unsigned int which, unsigned int where)
{
        unsigned long val;

        /*
         * MSI_CTL has target PID @ 14
         */
        val = io7->csrs->PO7_MSI_CTL[which].csr;
        val &= ~(0x1ffUL << 14);                /* clear the target pid */
        val |= ((unsigned long)where << 14);    /* set the new target pid */

        io7->csrs->PO7_MSI_CTL[which].csr = val;
        mb();
        io7->csrs->PO7_MSI_CTL[which].csr;
}

static void __init
init_one_io7_lsi(struct io7 *io7, unsigned int which, unsigned int where)
{
        /*
         * LSI_CTL has target PID @ 14
         */
        io7->csrs->PO7_LSI_CTL[which].csr = ((unsigned long)where << 14);
        mb();
        io7->csrs->PO7_LSI_CTL[which].csr;
}

static void __init
init_one_io7_msi(struct io7 *io7, unsigned int which, unsigned int where)
{
        /*
         * MSI_CTL has target PID @ 14
         */
        io7->csrs->PO7_MSI_CTL[which].csr = ((unsigned long)where << 14);
        mb();
        io7->csrs->PO7_MSI_CTL[which].csr;
}

static void __init
init_io7_irqs(struct io7 *io7, 
              struct irq_chip *lsi_ops,
              struct irq_chip *msi_ops)
{
        long base = (io7->pe << MARVEL_IRQ_VEC_PE_SHIFT) + 16;
        long i;

        printk("Initializing interrupts for IO7 at PE %u - base %lx\n",
                io7->pe, base);

        /*
         * Where should interrupts from this IO7 go?
         *
         * They really should be sent to the local CPU to avoid having to
         * traverse the mesh, but if it's not an SMP kernel, they have to
         * go to the boot CPU. Send them all to the boot CPU for now,
         * as each secondary starts, it can redirect it's local device 
         * interrupts.
         */
        printk("  Interrupts reported to CPU at PE %u\n", boot_cpuid);

        raw_spin_lock(&io7->irq_lock);

        /* set up the error irqs */
        io7_redirect_irq(io7, &io7->csrs->HLT_CTL.csr, boot_cpuid);
        io7_redirect_irq(io7, &io7->csrs->HPI_CTL.csr, boot_cpuid);
        io7_redirect_irq(io7, &io7->csrs->CRD_CTL.csr, boot_cpuid);
        io7_redirect_irq(io7, &io7->csrs->STV_CTL.csr, boot_cpuid);
        io7_redirect_irq(io7, &io7->csrs->HEI_CTL.csr, boot_cpuid);

        /* Set up the lsi irqs.  */
        for (i = 0; i < 128; ++i) {
                irq_set_chip_and_handler(base + i, lsi_ops, handle_level_irq);
                irq_set_status_flags(i, IRQ_LEVEL);
        }

        /* Disable the implemented irqs in hardware.  */
        for (i = 0; i < 0x60; ++i) 
                init_one_io7_lsi(io7, i, boot_cpuid);

        init_one_io7_lsi(io7, 0x74, boot_cpuid);
        init_one_io7_lsi(io7, 0x75, boot_cpuid);


        /* Set up the msi irqs.  */
        for (i = 128; i < (128 + 512); ++i) {
                irq_set_chip_and_handler(base + i, msi_ops, handle_level_irq);
                irq_set_status_flags(i, IRQ_LEVEL);
        }

        for (i = 0; i < 16; ++i)
                init_one_io7_msi(io7, i, boot_cpuid);

        raw_spin_unlock(&io7->irq_lock);
}

static void __init
marvel_init_irq(void)
{
        int i;
        struct io7 *io7 = NULL;

        /* Reserve the legacy irqs.  */
        for (i = 0; i < 16; ++i) {
                irq_set_chip_and_handler(i, &marvel_legacy_irq_type,
                                         handle_level_irq);
        }

        /* Init the io7 irqs.  */
        for (io7 = NULL; (io7 = marvel_next_io7(io7)) != NULL; )
                init_io7_irqs(io7, &io7_lsi_irq_type, &io7_msi_irq_type);
}

static int 
marvel_map_irq(const struct pci_dev *cdev, u8 slot, u8 pin)
{
        struct pci_dev *dev = (struct pci_dev *)cdev;
        struct pci_controller *hose = dev->sysdata;
        struct io7_port *io7_port = hose->sysdata;
        struct io7 *io7 = io7_port->io7;
        int msi_loc, msi_data_off;
        u16 msg_ctl;
        u16 msg_dat;
        u8 intline; 
        int irq;

        pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &intline);
        irq = intline;

        msi_loc = dev->msi_cap;
        msg_ctl = 0;
        if (msi_loc) 
                pci_read_config_word(dev, msi_loc + PCI_MSI_FLAGS, &msg_ctl);

        if (msg_ctl & PCI_MSI_FLAGS_ENABLE) {
                msi_data_off = PCI_MSI_DATA_32;
                if (msg_ctl & PCI_MSI_FLAGS_64BIT) 
                        msi_data_off = PCI_MSI_DATA_64;
                pci_read_config_word(dev, msi_loc + msi_data_off, &msg_dat);

                irq = msg_dat & 0x1ff;          /* we use msg_data<8:0> */
                irq += 0x80;                    /* offset for lsi       */

#if 1
                printk("PCI:%d:%d:%d (hose %d) is using MSI\n",
                       dev->bus->number, 
                       PCI_SLOT(dev->devfn), 
                       PCI_FUNC(dev->devfn),
                       hose->index);
                printk("  %d message(s) from 0x%04x\n", 
                       1 << ((msg_ctl & PCI_MSI_FLAGS_QSIZE) >> 4),
                       msg_dat);
                printk("  reporting on %d IRQ(s) from %d (0x%x)\n", 
                       1 << ((msg_ctl & PCI_MSI_FLAGS_QSIZE) >> 4),
                       (irq + 16) | (io7->pe << MARVEL_IRQ_VEC_PE_SHIFT),
                       (irq + 16) | (io7->pe << MARVEL_IRQ_VEC_PE_SHIFT));
#endif

#if 0
                pci_write_config_word(dev, msi_loc + PCI_MSI_FLAGS,
                                      msg_ctl & ~PCI_MSI_FLAGS_ENABLE);
                pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &intline);
                irq = intline;

                printk("  forcing LSI interrupt on irq %d [0x%x]\n", irq, irq);
#endif
        }

        irq += 16;                                      /* offset for legacy */
        irq |= io7->pe << MARVEL_IRQ_VEC_PE_SHIFT;      /* merge the pid     */

        return irq; 
}

static void __init
marvel_init_pci(void)
{
        struct io7 *io7;

        marvel_register_error_handlers();

        /* Indicate that we trust the console to configure things properly */
        pci_set_flags(PCI_PROBE_ONLY);
        common_init_pci();
        locate_and_init_vga(NULL);

        /* Clear any io7 errors.  */
        for (io7 = NULL; (io7 = marvel_next_io7(io7)) != NULL; ) 
                io7_clear_errors(io7);
}

static void __init
marvel_init_rtc(void)
{
        init_rtc_irq(NULL);
}

static void
marvel_smp_callin(void)
{
        int cpuid = hard_smp_processor_id();
        struct io7 *io7 = marvel_find_io7(cpuid);
        unsigned int i;

        if (!io7)
                return;

        /* 
         * There is a local IO7 - redirect all of its interrupts here.
         */
        printk("Redirecting IO7 interrupts to local CPU at PE %u\n", cpuid);

        /* Redirect the error IRQS here.  */
        io7_redirect_irq(io7, &io7->csrs->HLT_CTL.csr, cpuid);
        io7_redirect_irq(io7, &io7->csrs->HPI_CTL.csr, cpuid);
        io7_redirect_irq(io7, &io7->csrs->CRD_CTL.csr, cpuid);
        io7_redirect_irq(io7, &io7->csrs->STV_CTL.csr, cpuid);
        io7_redirect_irq(io7, &io7->csrs->HEI_CTL.csr, cpuid);

        /* Redirect the implemented LSIs here.  */
        for (i = 0; i < 0x60; ++i) 
                io7_redirect_one_lsi(io7, i, cpuid);

        io7_redirect_one_lsi(io7, 0x74, cpuid);
        io7_redirect_one_lsi(io7, 0x75, cpuid);

        /* Redirect the MSIs here.  */
        for (i = 0; i < 16; ++i)
                io7_redirect_one_msi(io7, i, cpuid);
}

/*
 * System Vectors
 */
struct alpha_machine_vector marvel_ev7_mv __initmv = {
        .vector_name            = "MARVEL/EV7",
        DO_EV7_MMU,
        .rtc_port               = 0x70,
        .rtc_boot_cpu_only      = 1,
        DO_MARVEL_IO,
        .machine_check          = marvel_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         = IO7_DAC_OFFSET,

        .nr_irqs                = MARVEL_NR_IRQS,
        .device_interrupt       = io7_device_interrupt,

        .agp_info               = marvel_agp_info,

        .smp_callin             = marvel_smp_callin,
        .init_arch              = marvel_init_arch,
        .init_irq               = marvel_init_irq,
        .init_rtc               = marvel_init_rtc,
        .init_pci               = marvel_init_pci,
        .kill_arch              = marvel_kill_arch,
        .pci_map_irq            = marvel_map_irq,
        .pci_swizzle            = common_swizzle,
};
ALIAS_MV(marvel_ev7)