// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/core_tsunami.c
 *
 * Based on code written by David A. Rusling (david.rusling@reo.mts.dec.com).
 *
 * Code common to all TSUNAMI core logic chips.
 */

#define __EXTERN_INLINE inline
#include <asm/io.h>
#include <asm/core_tsunami.h>
#undef __EXTERN_INLINE

#include <linux/module.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/memblock.h>

#include <asm/ptrace.h>
#include <asm/smp.h>
#include <asm/vga.h>

#include "proto.h"
#include "pci_impl.h"

/* Save Tsunami configuration data as the console had it set up.  */

struct 
{
        unsigned long wsba[4];
        unsigned long wsm[4];
        unsigned long tba[4];
} saved_config[2] __attribute__((common));

/*
 * NOTE: Herein lie back-to-back mb instructions.  They are magic. 
 * One plausible explanation is that the I/O controller does not properly
 * handle the system transaction.  Another involves timing.  Ho hum.
 */

/*
 * BIOS32-style PCI interface:
 */

#define DEBUG_CONFIG 0

#if DEBUG_CONFIG
# define DBG_CFG(args)  printk args
#else
# define DBG_CFG(args)
#endif


/*
 * Given a bus, device, and function number, compute resulting
 * configuration space address
 * accordingly.  It is therefore not safe to have concurrent
 * invocations to configuration space access routines, but there
 * really shouldn't be any need for this.
 *
 * Note that all config space accesses use Type 1 address format.
 *
 * Note also that type 1 is determined by non-zero bus number.
 *
 * Type 1:
 *
 *  3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1 
 *  3 2|1 0 9 8|7 6 5 4|3 2 1 0|9 8 7 6|5 4 3 2|1 0 9 8|7 6 5 4|3 2 1 0
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * | | | | | | | | | | |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|0|1|
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *      31:24   reserved
 *      23:16   bus number (8 bits = 128 possible buses)
 *      15:11   Device number (5 bits)
 *      10:8    function number
 *       7:2    register number
 *  
 * Notes:
 *      The function number selects which function of a multi-function device 
 *      (e.g., SCSI and Ethernet).
 * 
 *      The register selects a DWORD (32 bit) register offset.  Hence it
 *      doesn't get shifted by 2 bits as we want to "drop" the bottom two
 *      bits.
 */

static int
mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
             unsigned long *pci_addr, unsigned char *type1)
{
        struct pci_controller *hose = pbus->sysdata;
        unsigned long addr;
        u8 bus = pbus->number;

        DBG_CFG(("mk_conf_addr(bus=%d ,device_fn=0x%x, where=0x%x, "
                 "pci_addr=0x%p, type1=0x%p)\n",
                 bus, device_fn, where, pci_addr, type1));
        
        if (!pbus->parent) /* No parent means peer PCI bus. */
                bus = 0;
        *type1 = (bus != 0);

        addr = (bus << 16) | (device_fn << 8) | where;
        addr |= hose->config_space_base;
                
        *pci_addr = addr;
        DBG_CFG(("mk_conf_addr: returning pci_addr 0x%lx\n", addr));
        return 0;
}

static int 
tsunami_read_config(struct pci_bus *bus, unsigned int devfn, int where,
                    int size, u32 *value)
{
        unsigned long addr;
        unsigned char type1;

        if (mk_conf_addr(bus, devfn, where, &addr, &type1))
                return PCIBIOS_DEVICE_NOT_FOUND;

        switch (size) {
        case 1:
                *value = __kernel_ldbu(*(vucp)addr);
                break;
        case 2:
                *value = __kernel_ldwu(*(vusp)addr);
                break;
        case 4:
                *value = *(vuip)addr;
                break;
        }

        return PCIBIOS_SUCCESSFUL;
}

static int 
tsunami_write_config(struct pci_bus *bus, unsigned int devfn, int where,
                     int size, u32 value)
{
        unsigned long addr;
        unsigned char type1;

        if (mk_conf_addr(bus, devfn, where, &addr, &type1))
                return PCIBIOS_DEVICE_NOT_FOUND;

        switch (size) {
        case 1:
                __kernel_stb(value, *(vucp)addr);
                mb();
                __kernel_ldbu(*(vucp)addr);
                break;
        case 2:
                __kernel_stw(value, *(vusp)addr);
                mb();
                __kernel_ldwu(*(vusp)addr);
                break;
        case 4:
                *(vuip)addr = value;
                mb();
                *(vuip)addr;
                break;
        }

        return PCIBIOS_SUCCESSFUL;
}

struct pci_ops tsunami_pci_ops = 
{
        .read =         tsunami_read_config,
        .write =        tsunami_write_config,
};

void
tsunami_pci_tbi(struct pci_controller *hose, dma_addr_t start, dma_addr_t end)
{
        tsunami_pchip *pchip = hose->index ? TSUNAMI_pchip1 : TSUNAMI_pchip0;
        volatile unsigned long *csr;
        unsigned long value;

        /* We can invalidate up to 8 tlb entries in a go.  The flush
           matches against <31:16> in the pci address.  */
        csr = &pchip->tlbia.csr;
        if (((start ^ end) & 0xffff0000) == 0)
                csr = &pchip->tlbiv.csr;

        /* For TBIA, it doesn't matter what value we write.  For TBI, 
           it's the shifted tag bits.  */
        value = (start & 0xffff0000) >> 12;

        *csr = value;
        mb();
        *csr;
}

#ifdef NXM_MACHINE_CHECKS_ON_TSUNAMI
static long __init
tsunami_probe_read(volatile unsigned long *vaddr)
{
        long dont_care, probe_result;
        int cpu = smp_processor_id();
        int s = swpipl(IPL_MCHECK - 1);

        mcheck_taken(cpu) = 0;
        mcheck_expected(cpu) = 1;
        mb();
        dont_care = *vaddr;
        draina();
        mcheck_expected(cpu) = 0;
        probe_result = !mcheck_taken(cpu);
        mcheck_taken(cpu) = 0;
        setipl(s);

        printk("dont_care == 0x%lx\n", dont_care);

        return probe_result;
}

static long __init
tsunami_probe_write(volatile unsigned long *vaddr)
{
        long true_contents, probe_result = 1;

        TSUNAMI_cchip->misc.csr |= (1L << 28); /* clear NXM... */
        true_contents = *vaddr;
        *vaddr = 0;
        draina();
        if (TSUNAMI_cchip->misc.csr & (1L << 28)) {
                int source = (TSUNAMI_cchip->misc.csr >> 29) & 7;
                TSUNAMI_cchip->misc.csr |= (1L << 28); /* ...and unlock NXS. */
                probe_result = 0;
                printk("tsunami_probe_write: unit %d at 0x%016lx\n", source,
                       (unsigned long)vaddr);
        }
        if (probe_result)
                *vaddr = true_contents;
        return probe_result;
}
#else
#define tsunami_probe_read(ADDR) 1
#endif /* NXM_MACHINE_CHECKS_ON_TSUNAMI */

static void __init
tsunami_init_one_pchip(tsunami_pchip *pchip, int index)
{
        struct pci_controller *hose;

        if (tsunami_probe_read(&pchip->pctl.csr) == 0)
                return;

        hose = alloc_pci_controller();
        if (index == 0)
                pci_isa_hose = hose;
        hose->io_space = alloc_resource();
        hose->mem_space = alloc_resource();

        /* This is for userland consumption.  For some reason, the 40-bit
           PIO bias that we use in the kernel through KSEG didn't work for
           the page table based user mappings.  So make sure we get the
           43-bit PIO bias.  */
        hose->sparse_mem_base = 0;
        hose->sparse_io_base = 0;
        hose->dense_mem_base
          = (TSUNAMI_MEM(index) & 0xffffffffffL) | 0x80000000000L;
        hose->dense_io_base
          = (TSUNAMI_IO(index) & 0xffffffffffL) | 0x80000000000L;

        hose->config_space_base = TSUNAMI_CONF(index);
        hose->index = index;

        hose->io_space->start = TSUNAMI_IO(index) - TSUNAMI_IO_BIAS;
        hose->io_space->end = hose->io_space->start + TSUNAMI_IO_SPACE - 1;
        hose->io_space->name = pci_io_names[index];
        hose->io_space->flags = IORESOURCE_IO;

        hose->mem_space->start = TSUNAMI_MEM(index) - TSUNAMI_MEM_BIAS;
        hose->mem_space->end = hose->mem_space->start + 0xffffffff;
        hose->mem_space->name = pci_mem_names[index];
        hose->mem_space->flags = IORESOURCE_MEM;

        if (request_resource(&ioport_resource, hose->io_space) < 0)
                printk(KERN_ERR "Failed to request IO on hose %d\n", index);
        if (request_resource(&iomem_resource, hose->mem_space) < 0)
                printk(KERN_ERR "Failed to request MEM on hose %d\n", index);

        /*
         * Save the existing PCI window translations.  SRM will 
         * need them when we go to reboot.
         */

        saved_config[index].wsba[0] = pchip->wsba[0].csr;
        saved_config[index].wsm[0] = pchip->wsm[0].csr;
        saved_config[index].tba[0] = pchip->tba[0].csr;

        saved_config[index].wsba[1] = pchip->wsba[1].csr;
        saved_config[index].wsm[1] = pchip->wsm[1].csr;
        saved_config[index].tba[1] = pchip->tba[1].csr;

        saved_config[index].wsba[2] = pchip->wsba[2].csr;
        saved_config[index].wsm[2] = pchip->wsm[2].csr;
        saved_config[index].tba[2] = pchip->tba[2].csr;

        saved_config[index].wsba[3] = pchip->wsba[3].csr;
        saved_config[index].wsm[3] = pchip->wsm[3].csr;
        saved_config[index].tba[3] = pchip->tba[3].csr;

        /*
         * Set up the PCI to main memory translation windows.
         *
         * Note: Window 3 is scatter-gather only
         * 
         * Window 0 is scatter-gather 8MB at 8MB (for isa)
         * Window 1 is scatter-gather (up to) 1GB at 1GB
         * Window 2 is direct access 2GB at 2GB
         *
         * NOTE: we need the align_entry settings for Acer devices on ES40,
         * specifically floppy and IDE when memory is larger than 2GB.
         */
        hose->sg_isa = iommu_arena_new(hose, 0x00800000, 0x00800000,
                                       SMP_CACHE_BYTES);
        /* Initially set for 4 PTEs, but will be overridden to 64K for ISA. */
        hose->sg_isa->align_entry = 4;

        hose->sg_pci = iommu_arena_new(hose, 0x40000000,
                                       size_for_memory(0x40000000),
                                       SMP_CACHE_BYTES);
        hose->sg_pci->align_entry = 4; /* Tsunami caches 4 PTEs at a time */

        __direct_map_base = 0x80000000;
        __direct_map_size = 0x80000000;

        pchip->wsba[0].csr = hose->sg_isa->dma_base | 3;
        pchip->wsm[0].csr  = (hose->sg_isa->size - 1) & 0xfff00000;
        pchip->tba[0].csr  = virt_to_phys(hose->sg_isa->ptes);

        pchip->wsba[1].csr = hose->sg_pci->dma_base | 3;
        pchip->wsm[1].csr  = (hose->sg_pci->size - 1) & 0xfff00000;
        pchip->tba[1].csr  = virt_to_phys(hose->sg_pci->ptes);

        pchip->wsba[2].csr = 0x80000000 | 1;
        pchip->wsm[2].csr  = (0x80000000 - 1) & 0xfff00000;
        pchip->tba[2].csr  = 0;

        pchip->wsba[3].csr = 0;

        /* Enable the Monster Window to make DAC pci64 possible. */
        pchip->pctl.csr |= pctl_m_mwin;

        tsunami_pci_tbi(hose, 0, -1);
}


void __iomem *
tsunami_ioportmap(unsigned long addr)
{
        FIXUP_IOADDR_VGA(addr);
        return (void __iomem *)(addr + TSUNAMI_IO_BIAS);
}

void __iomem *
tsunami_ioremap(unsigned long addr, unsigned long size)
{
        FIXUP_MEMADDR_VGA(addr);
        return (void __iomem *)(addr + TSUNAMI_MEM_BIAS);
}

#ifndef CONFIG_ALPHA_GENERIC
EXPORT_SYMBOL(tsunami_ioportmap);
EXPORT_SYMBOL(tsunami_ioremap);
#endif

void __init
tsunami_init_arch(void)
{
#ifdef NXM_MACHINE_CHECKS_ON_TSUNAMI
        unsigned long tmp;
        
        /* Ho hum.. init_arch is called before init_IRQ, but we need to be
           able to handle machine checks.  So install the handler now.  */
        wrent(entInt, 0);

        /* NXMs just don't matter to Tsunami--unless they make it
           choke completely. */
        tmp = (unsigned long)(TSUNAMI_cchip - 1);
        printk("%s: probing bogus address:  0x%016lx\n", __func__, bogus_addr);
        printk("\tprobe %s\n",
               tsunami_probe_write((unsigned long *)bogus_addr)
               ? "succeeded" : "failed");
#endif /* NXM_MACHINE_CHECKS_ON_TSUNAMI */

#if 0
        printk("%s: CChip registers:\n", __func__);
        printk("%s: CSR_CSC 0x%lx\n", __func__, TSUNAMI_cchip->csc.csr);
        printk("%s: CSR_MTR 0x%lx\n", __func__, TSUNAMI_cchip.mtr.csr);
        printk("%s: CSR_MISC 0x%lx\n", __func__, TSUNAMI_cchip->misc.csr);
        printk("%s: CSR_DIM0 0x%lx\n", __func__, TSUNAMI_cchip->dim0.csr);
        printk("%s: CSR_DIM1 0x%lx\n", __func__, TSUNAMI_cchip->dim1.csr);
        printk("%s: CSR_DIR0 0x%lx\n", __func__, TSUNAMI_cchip->dir0.csr);
        printk("%s: CSR_DIR1 0x%lx\n", __func__, TSUNAMI_cchip->dir1.csr);
        printk("%s: CSR_DRIR 0x%lx\n", __func__, TSUNAMI_cchip->drir.csr);

        printk("%s: DChip registers:\n");
        printk("%s: CSR_DSC 0x%lx\n", __func__, TSUNAMI_dchip->dsc.csr);
        printk("%s: CSR_STR 0x%lx\n", __func__, TSUNAMI_dchip->str.csr);
        printk("%s: CSR_DREV 0x%lx\n", __func__, TSUNAMI_dchip->drev.csr);
#endif
        /* With multiple PCI busses, we play with I/O as physical addrs.  */
        ioport_resource.end = ~0UL;

        /* Find how many hoses we have, and initialize them.  TSUNAMI
           and TYPHOON can have 2, but might only have 1 (DS10).  */

        tsunami_init_one_pchip(TSUNAMI_pchip0, 0);
        if (TSUNAMI_cchip->csc.csr & 1L<<14)
                tsunami_init_one_pchip(TSUNAMI_pchip1, 1);

        /* Check for graphic console location (if any).  */
        find_console_vga_hose();
}

static void
tsunami_kill_one_pchip(tsunami_pchip *pchip, int index)
{
        pchip->wsba[0].csr = saved_config[index].wsba[0];
        pchip->wsm[0].csr = saved_config[index].wsm[0];
        pchip->tba[0].csr = saved_config[index].tba[0];

        pchip->wsba[1].csr = saved_config[index].wsba[1];
        pchip->wsm[1].csr = saved_config[index].wsm[1];
        pchip->tba[1].csr = saved_config[index].tba[1];

        pchip->wsba[2].csr = saved_config[index].wsba[2];
        pchip->wsm[2].csr = saved_config[index].wsm[2];
        pchip->tba[2].csr = saved_config[index].tba[2];

        pchip->wsba[3].csr = saved_config[index].wsba[3];
        pchip->wsm[3].csr = saved_config[index].wsm[3];
        pchip->tba[3].csr = saved_config[index].tba[3];
}

void
tsunami_kill_arch(int mode)
{
        tsunami_kill_one_pchip(TSUNAMI_pchip0, 0);
        if (TSUNAMI_cchip->csc.csr & 1L<<14)
                tsunami_kill_one_pchip(TSUNAMI_pchip1, 1);
}

static inline void
tsunami_pci_clr_err_1(tsunami_pchip *pchip)
{
        pchip->perror.csr;
        pchip->perror.csr = 0x040;
        mb();
        pchip->perror.csr;
}

static inline void
tsunami_pci_clr_err(void)
{
        tsunami_pci_clr_err_1(TSUNAMI_pchip0);

        /* TSUNAMI and TYPHOON can have 2, but might only have 1 (DS10) */
        if (TSUNAMI_cchip->csc.csr & 1L<<14)
                tsunami_pci_clr_err_1(TSUNAMI_pchip1);
}

void
tsunami_machine_check(unsigned long vector, unsigned long la_ptr)
{
        /* Clear error before any reporting.  */
        mb();
        mb();  /* magic */
        draina();
        tsunami_pci_clr_err();
        wrmces(0x7);
        mb();

        process_mcheck_info(vector, la_ptr, "TSUNAMI",
                            mcheck_expected(smp_processor_id()));
}