// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/core_polaris.c
 *
 * POLARIS chip-specific code
 */

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

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

#include <asm/ptrace.h>

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

/*
 * 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.  This is fairly straightforward
 * on POLARIS, since the chip itself generates Type 0 or Type 1
 * cycles automatically depending on the bus number (Bus 0 is
 * hardwired to Type 0, all others are Type 1.  Peer bridges
 * are not supported).
 *
 * All types:
 *
 *  3 3 3 3|3 3 3 3|3 3 2 2|2 2 2 2|2 2 2 2|1 1 1 1|1 1 1 1|1 1 
 *  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 9 8|7 6 5 4|3 2 1 0
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |1|1|1|1|1|0|0|1|1|1|1|1|1|1|1|0|B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|x|x|
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *      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, u8 *type1)
{
        u8 bus = pbus->number;

        *type1 = (bus == 0) ? 0 : 1;
        *pci_addr = (bus << 16) | (device_fn << 8) | (where) |
                    POLARIS_DENSE_CONFIG_BASE;

        DBG_CFG(("mk_conf_addr(bus=%d ,device_fn=0x%x, where=0x%x,"
                 " returning address 0x%p\n"
                 bus, device_fn, where, *pci_addr));

        return 0;
}

static int
polaris_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 
polaris_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 polaris_pci_ops = 
{
        .read =         polaris_read_config,
        .write =        polaris_write_config,
};

void __init
polaris_init_arch(void)
{
        struct pci_controller *hose;

        /* May need to initialize error reporting (see PCICTL0/1), but
         * for now assume that the firmware has done the right thing
         * already.
         */
#if 0
        printk("polaris_init_arch(): trusting firmware for setup\n");
#endif

        /*
         * Create our single hose.
         */

        pci_isa_hose = hose = alloc_pci_controller();
        hose->io_space = &ioport_resource;
        hose->mem_space = &iomem_resource;
        hose->index = 0;

        hose->sparse_mem_base = 0;
        hose->dense_mem_base = POLARIS_DENSE_MEM_BASE - IDENT_ADDR;
        hose->sparse_io_base = 0;
        hose->dense_io_base = POLARIS_DENSE_IO_BASE - IDENT_ADDR;

        hose->sg_isa = hose->sg_pci = NULL;

        /* The I/O window is fixed at 2G @ 2G.  */
        __direct_map_base = 0x80000000;
        __direct_map_size = 0x80000000;
}

static inline void
polaris_pci_clr_err(void)
{
        *(vusp)POLARIS_W_STATUS;
        /* Write 1's to settable bits to clear errors */
        *(vusp)POLARIS_W_STATUS = 0x7800;
        mb();
        *(vusp)POLARIS_W_STATUS;
}

void
polaris_machine_check(unsigned long vector, unsigned long la_ptr)
{
        /* Clear the error before any reporting.  */
        mb();
        mb();
        draina();
        polaris_pci_clr_err();
        wrmces(0x7);
        mb();

        process_mcheck_info(vector, la_ptr, "POLARIS",
                            mcheck_expected(0));
}