// SPDX-License-Identifier: GPL-2.0
/*
 *      linux/arch/alpha/kernel/core_marvel.c
 *
 * Code common to all Marvel based systems.
 */

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

#include <linux/types.h>
#include <linux/pci.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/memblock.h>

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

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


/*
 * Debug helpers
 */
#define DEBUG_CONFIG 0

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


/*
 * Private data
 */
static struct io7 *io7_head = NULL;


/*
 * Helper functions
 */
static unsigned long __attribute__ ((unused))
read_ev7_csr(int pe, unsigned long offset)
{
        ev7_csr *ev7csr = EV7_CSR_KERN(pe, offset);
        unsigned long q;

        mb();
        q = ev7csr->csr;
        mb();

        return q;
}

static void __attribute__ ((unused))
write_ev7_csr(int pe, unsigned long offset, unsigned long q)
{
        ev7_csr *ev7csr = EV7_CSR_KERN(pe, offset);

        mb();
        ev7csr->csr = q;
        mb();
}

static char * __init
mk_resource_name(int pe, int port, char *str)
{
        char tmp[80];
        char *name;
        size_t sz;

        sz = scnprintf(tmp, sizeof(tmp), "PCI %s PE %d PORT %d", str, pe, port);
        sz += 1; /* NUL terminator */
        name = memblock_alloc_or_panic(sz, SMP_CACHE_BYTES);
        strscpy(name, tmp, sz);

        return name;
}

inline struct io7 *
marvel_next_io7(struct io7 *prev)
{
        return (prev ? prev->next : io7_head);
}

struct io7 *
marvel_find_io7(int pe)
{
        struct io7 *io7;

        for (io7 = io7_head; io7 && io7->pe != pe; io7 = io7->next)
                continue;

        return io7;
}

static struct io7 * __init
alloc_io7(unsigned int pe)
{
        struct io7 *io7;
        struct io7 *insp;
        int h;

        if (marvel_find_io7(pe)) {
                printk(KERN_WARNING "IO7 at PE %d already allocated!\n", pe);
                return NULL;
        }

        io7 = memblock_alloc_or_panic(sizeof(*io7), SMP_CACHE_BYTES);
        io7->pe = pe;
        raw_spin_lock_init(&io7->irq_lock);

        for (h = 0; h < 4; h++) {
                io7->ports[h].io7 = io7;
                io7->ports[h].port = h;
                io7->ports[h].enabled = 0; /* default to disabled */
        }

        /*
         * Insert in pe sorted order.
         */
        if (NULL == io7_head)                   /* empty list */
                io7_head = io7; 
        else if (io7_head->pe > io7->pe) {      /* insert at head */
                io7->next = io7_head;
                io7_head = io7;
        } else {                                /* insert at position */
                for (insp = io7_head; insp; insp = insp->next) {
                        if (insp->pe == io7->pe) {
                                printk(KERN_ERR "Too many IO7s at PE %d\n", 
                                       io7->pe);
                                return NULL;
                        }

                        if (NULL == insp->next || 
                            insp->next->pe > io7->pe) { /* insert here */
                                io7->next = insp->next;
                                insp->next = io7;
                                break;
                        }
                }

                if (NULL == insp) { /* couldn't insert ?!? */
                        printk(KERN_WARNING "Failed to insert IO7 at PE %d "
                               " - adding at head of list\n", io7->pe);
                        io7->next = io7_head;
                        io7_head = io7;
                }
        }
        
        return io7;
}

void
io7_clear_errors(struct io7 *io7)
{
        io7_port7_csrs *p7csrs;
        io7_ioport_csrs *csrs;
        int port;


        /*
         * First the IO ports.
         */
        for (port = 0; port < 4; port++) {
                csrs = IO7_CSRS_KERN(io7->pe, port);

                csrs->POx_ERR_SUM.csr = -1UL;
                csrs->POx_TLB_ERR.csr = -1UL;
                csrs->POx_SPL_COMPLT.csr = -1UL;
                csrs->POx_TRANS_SUM.csr = -1UL;
        }

        /*
         * Then the common ones.
         */
        p7csrs = IO7_PORT7_CSRS_KERN(io7->pe);

        p7csrs->PO7_ERROR_SUM.csr = -1UL;
        p7csrs->PO7_UNCRR_SYM.csr = -1UL;
        p7csrs->PO7_CRRCT_SYM.csr = -1UL;
}


/*
 * IO7 PCI, PCI/X, AGP configuration.
 */
static void __init
io7_init_hose(struct io7 *io7, int port)
{
        static int hose_index = 0;

        struct pci_controller *hose = alloc_pci_controller();
        struct io7_port *io7_port = &io7->ports[port];
        io7_ioport_csrs *csrs = IO7_CSRS_KERN(io7->pe, port);
        int i;

        hose->index = hose_index++;     /* arbitrary */
        
        /*
         * We don't have an isa or legacy hose, but glibc expects to be
         * able to use the bus == 0 / dev == 0 form of the iobase syscall
         * to determine information about the i/o system. Since XFree86 
         * relies on glibc's determination to tell whether or not to use
         * sparse access, we need to point the pci_isa_hose at a real hose
         * so at least that determination is correct.
         */
        if (hose->index == 0)
                pci_isa_hose = hose;

        io7_port->csrs = csrs;
        io7_port->hose = hose;
        hose->sysdata = io7_port;

        hose->io_space = alloc_resource();
        hose->mem_space = alloc_resource();

        /*
         * Base addresses for userland consumption. Since these are going
         * to be mapped, they are pure physical addresses.
         */
        hose->sparse_mem_base = hose->sparse_io_base = 0;
        hose->dense_mem_base = IO7_MEM_PHYS(io7->pe, port);
        hose->dense_io_base = IO7_IO_PHYS(io7->pe, port);

        /*
         * Base addresses and resource ranges for kernel consumption.
         */
        hose->config_space_base = (unsigned long)IO7_CONF_KERN(io7->pe, port);

        hose->io_space->start = (unsigned long)IO7_IO_KERN(io7->pe, port);
        hose->io_space->end = hose->io_space->start + IO7_IO_SPACE - 1;
        hose->io_space->name = mk_resource_name(io7->pe, port, "IO");
        hose->io_space->flags = IORESOURCE_IO;

        hose->mem_space->start = (unsigned long)IO7_MEM_KERN(io7->pe, port);
        hose->mem_space->end = hose->mem_space->start + IO7_MEM_SPACE - 1;
        hose->mem_space->name = mk_resource_name(io7->pe, port, "MEM");
        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", 
                       hose->index);
        if (request_resource(&iomem_resource, hose->mem_space) < 0)
                printk(KERN_ERR "Failed to request MEM on hose %d\n", 
                       hose->index);

        /*
         * Save the existing DMA window settings for later restoration.
         */
        for (i = 0; i < 4; i++) {
                io7_port->saved_wbase[i] = csrs->POx_WBASE[i].csr;
                io7_port->saved_wmask[i] = csrs->POx_WMASK[i].csr;
                io7_port->saved_tbase[i] = csrs->POx_TBASE[i].csr;
        }

        /*
         * Set up the PCI to main memory translation windows.
         *
         * Window 0 is scatter-gather 8MB at 8MB
         * Window 1 is direct access 1GB at 2GB
         * Window 2 is scatter-gather (up-to) 1GB at 3GB
         * Window 3 is disabled
         */

        /*
         * TBIA before modifying windows.
         */
        marvel_pci_tbi(hose, 0, -1);

        /*
         * Set up window 0 for scatter-gather 8MB at 8MB.
         */
        hose->sg_isa = iommu_arena_new_node(0, hose, 0x00800000, 0x00800000, 0);
        hose->sg_isa->align_entry = 8;  /* cache line boundary */
        csrs->POx_WBASE[0].csr = 
                hose->sg_isa->dma_base | wbase_m_ena | wbase_m_sg;
        csrs->POx_WMASK[0].csr = (hose->sg_isa->size - 1) & wbase_m_addr;
        csrs->POx_TBASE[0].csr = virt_to_phys(hose->sg_isa->ptes);

        /*
         * Set up window 1 for direct-mapped 1GB at 2GB.
         */
        csrs->POx_WBASE[1].csr = __direct_map_base | wbase_m_ena;
        csrs->POx_WMASK[1].csr = (__direct_map_size - 1) & wbase_m_addr;
        csrs->POx_TBASE[1].csr = 0;

        /*
         * Set up window 2 for scatter-gather (up-to) 1GB at 3GB.
         */
        hose->sg_pci = iommu_arena_new_node(0, hose, 0xc0000000, 0x40000000, 0);
        hose->sg_pci->align_entry = 8;  /* cache line boundary */
        csrs->POx_WBASE[2].csr = 
                hose->sg_pci->dma_base | wbase_m_ena | wbase_m_sg;
        csrs->POx_WMASK[2].csr = (hose->sg_pci->size - 1) & wbase_m_addr;
        csrs->POx_TBASE[2].csr = virt_to_phys(hose->sg_pci->ptes);

        /*
         * Disable window 3.
         */
        csrs->POx_WBASE[3].csr = 0;

        /*
         * Make sure that the AGP Monster Window is disabled.
         */
        csrs->POx_CTRL.csr &= ~(1UL << 61);

#if 1
        printk("FIXME: disabling master aborts\n");
        csrs->POx_MSK_HEI.csr &= ~(3UL << 14);
#endif
        /*
         * TBIA after modifying windows.
         */
        marvel_pci_tbi(hose, 0, -1);
}

static void __init
marvel_init_io7(struct io7 *io7)
{
        int i;

        printk("Initializing IO7 at PID %d\n", io7->pe);

        /*
         * Get the Port 7 CSR pointer.
         */
        io7->csrs = IO7_PORT7_CSRS_KERN(io7->pe);

        /*
         * Init this IO7's hoses.
         */
        for (i = 0; i < IO7_NUM_PORTS; i++) {
                io7_ioport_csrs *csrs = IO7_CSRS_KERN(io7->pe, i);
                if (csrs->POx_CACHE_CTL.csr == 8) {
                        io7->ports[i].enabled = 1;
                        io7_init_hose(io7, i);
                }
        }
}

static void __init
marvel_io7_present(gct6_node *node)
{
        int pe;

        if (node->type != GCT_TYPE_HOSE ||
            node->subtype != GCT_SUBTYPE_IO_PORT_MODULE) 
                return;

        pe = (node->id >> 8) & 0xff;
        printk("Found an IO7 at PID %d\n", pe);

        alloc_io7(pe);
}

static void __init
marvel_find_console_vga_hose(void)
{
#ifdef CONFIG_VGA_HOSE
        u64 *pu64 = (u64 *)((u64)hwrpb + hwrpb->ctbt_offset);

        if (pu64[7] == 3) {     /* TERM_TYPE == graphics */
                struct pci_controller *hose = NULL;
                int h = (pu64[30] >> 24) & 0xff; /* TERM_OUT_LOC, hose # */
                struct io7 *io7;
                int pid, port;

                /* FIXME - encoding is going to have to change for Marvel
                 *         since hose will be able to overflow a byte...
                 *         need to fix this decode when the console 
                 *         changes its encoding
                 */
                printk("console graphics is on hose %d (console)\n", h);

                /*
                 * The console's hose numbering is:
                 *
                 *      hose<n:2>: PID
                 *      hose<1:0>: PORT
                 *
                 * We need to find the hose at that pid and port
                 */
                pid = h >> 2;
                port = h & 3;
                if ((io7 = marvel_find_io7(pid)))
                        hose = io7->ports[port].hose;

                if (hose) {
                        printk("Console graphics on hose %d\n", hose->index);
                        pci_vga_hose = hose;
                }
        }
#endif
}

gct6_search_struct gct_wanted_node_list[] __initdata = {
        { GCT_TYPE_HOSE, GCT_SUBTYPE_IO_PORT_MODULE, marvel_io7_present },
        { 0, 0, NULL }
};

/*
 * In case the GCT is not complete, let the user specify PIDs with IO7s
 * at boot time. Syntax is 'io7=a,b,c,...,n' where a-n are the PIDs (decimal)
 * where IO7s are connected
 */
static int __init
marvel_specify_io7(char *str)
{
        unsigned long pid;
        struct io7 *io7;
        char *pchar;

        do {
                pid = simple_strtoul(str, &pchar, 0);
                if (pchar != str) {
                        printk("User-specified IO7 at PID %lu\n", pid);
                        io7 = alloc_io7(pid);
                        if (io7) marvel_init_io7(io7);
                }

                if (pchar == str) pchar++;
                str = pchar;
        } while(*str);

        return 1;
}
__setup("io7=", marvel_specify_io7);

void __init
marvel_init_arch(void)
{
        struct io7 *io7;

        /* With multiple PCI busses, we play with I/O as physical addrs.  */
        ioport_resource.end = ~0UL;

        /* PCI DMA Direct Mapping is 1GB at 2GB.  */
        __direct_map_base = 0x80000000;
        __direct_map_size = 0x40000000;

        /* Parse the config tree.  */
        gct6_find_nodes(GCT_NODE_PTR(0), gct_wanted_node_list);

        /* Init the io7s.  */
        for (io7 = NULL; NULL != (io7 = marvel_next_io7(io7)); ) 
                marvel_init_io7(io7);

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

void
marvel_kill_arch(int mode)
{
}


/*
 * PCI Configuration Space access functions
 *
 * Configuration space addresses have the following format:
 *
 *      |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
 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *      |B|B|B|B|B|B|B|B|D|D|D|D|D|F|F|F|R|R|R|R|R|R|R|R|
 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *       n:24   reserved for hose base
 *      23:16   bus number (8 bits = 128 possible buses)
 *      15:11   Device number (5 bits)
 *      10:8    function number
 *       7:2    register number
 *  
 * Notes:
 *      IO7 determines whether to use a type 0 or type 1 config cycle
 *      based on the bus number. Therefore the bus number must be set 
 *      to 0 for the root bus on any hose.
 *      
 *      The function number selects which function of a multi-function device 
 *      (e.g., SCSI and Ethernet).
 * 
 */

static inline unsigned long
build_conf_addr(struct pci_controller *hose, u8 bus, 
                unsigned int devfn, int where)
{
        return (hose->config_space_base | (bus << 16) | (devfn << 8) | where);
}

static unsigned long
mk_conf_addr(struct pci_bus *pbus, unsigned int devfn, int where)
{
        struct pci_controller *hose = pbus->sysdata;
        struct io7_port *io7_port;
        unsigned long addr = 0;
        u8 bus = pbus->number;

        if (!hose)
                return addr;

        /* Check for enabled.  */
        io7_port = hose->sysdata;
        if (!io7_port->enabled)
                return addr;

        if (!pbus->parent) { /* No parent means peer PCI bus. */
                /* Don't support idsel > 20 on primary bus.  */
                if (devfn >= PCI_DEVFN(21, 0))
                        return addr;
                bus = 0;
        }

        addr = build_conf_addr(hose, bus, devfn, where);

        DBG_CFG(("mk_conf_addr: returning pci_addr 0x%lx\n", addr));
        return addr;
}

static int
marvel_read_config(struct pci_bus *bus, unsigned int devfn, int where,
                   int size, u32 *value)
{
        unsigned long addr;
        
        if (0 == (addr = mk_conf_addr(bus, devfn, where)))
                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;
        default:
                return PCIBIOS_FUNC_NOT_SUPPORTED;
        }

        return PCIBIOS_SUCCESSFUL;
}

static int
marvel_write_config(struct pci_bus *bus, unsigned int devfn, int where,
                    int size, u32 value)
{
        unsigned long addr;
        
        if (0 == (addr = mk_conf_addr(bus, devfn, where)))
                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;
        default:
                return PCIBIOS_FUNC_NOT_SUPPORTED;
        }

        return PCIBIOS_SUCCESSFUL;
}

struct pci_ops marvel_pci_ops =
{
        .read =         marvel_read_config,
        .write =        marvel_write_config,
};


/*
 * Other PCI helper functions.
 */
void
marvel_pci_tbi(struct pci_controller *hose, dma_addr_t start, dma_addr_t end)
{
        io7_ioport_csrs *csrs = ((struct io7_port *)hose->sysdata)->csrs;

        wmb();
        csrs->POx_SG_TBIA.csr = 0;
        mb();
        csrs->POx_SG_TBIA.csr;
}



/*
 * RTC Support
 */
struct marvel_rtc_access_info {
        unsigned long function;
        unsigned long index;
        unsigned long data;
};

static void
__marvel_access_rtc(void *info)
{
        struct marvel_rtc_access_info *rtc_access = info;

        register unsigned long __r0 __asm__("$0");
        register unsigned long __r16 __asm__("$16") = rtc_access->function;
        register unsigned long __r17 __asm__("$17") = rtc_access->index;
        register unsigned long __r18 __asm__("$18") = rtc_access->data;
        
        __asm__ __volatile__(
                "call_pal %4 # cserve rtc"
                : "=r"(__r16), "=r"(__r17), "=r"(__r18), "=r"(__r0)
                : "i"(PAL_cserve), "0"(__r16), "1"(__r17), "2"(__r18)
                : "$1", "$22", "$23", "$24", "$25");

        rtc_access->data = __r0;
}

static u8
__marvel_rtc_io(u8 b, unsigned long addr, int write)
{
        static u8 index = 0;

        struct marvel_rtc_access_info rtc_access;
        u8 ret = 0;

        switch(addr) {
        case 0x70:                                      /* RTC_PORT(0) */
                if (write) index = b;
                ret = index;
                break;

        case 0x71:                                      /* RTC_PORT(1) */
                rtc_access.index = index;
                rtc_access.data = bcd2bin(b);
                rtc_access.function = 0x48 + !write;    /* GET/PUT_TOY */

                __marvel_access_rtc(&rtc_access);

                ret = bin2bcd(rtc_access.data);
                break;

        default:
                printk(KERN_WARNING "Illegal RTC port %lx\n", addr);
                break;
        }

        return ret;
}


/*
 * IO map support.
 */
void __iomem *
marvel_ioremap(unsigned long addr, unsigned long size)
{
        struct pci_controller *hose;
        unsigned long baddr, last;
        struct vm_struct *area;
        unsigned long vaddr;
        unsigned long *ptes;
        unsigned long pfn;

        /*
         * Adjust the address.
         */ 
        FIXUP_MEMADDR_VGA(addr);

        /*
         * Find the hose.
         */
        for (hose = hose_head; hose; hose = hose->next) {
                if ((addr >> 32) == (hose->mem_space->start >> 32))
                        break; 
        }
        if (!hose)
                return NULL;

        /*
         * We have the hose - calculate the bus limits.
         */
        baddr = addr - hose->mem_space->start;
        last = baddr + size - 1;

        /*
         * Is it direct-mapped?
         */
        if ((baddr >= __direct_map_base) && 
            ((baddr + size - 1) < __direct_map_base + __direct_map_size)) {
                addr = IDENT_ADDR | (baddr - __direct_map_base);
                return (void __iomem *) addr;
        }

        /* 
         * Check the scatter-gather arena.
         */
        if (hose->sg_pci &&
            baddr >= (unsigned long)hose->sg_pci->dma_base &&
            last < (unsigned long)hose->sg_pci->dma_base + hose->sg_pci->size) {

                /*
                 * Adjust the limits (mappings must be page aligned)
                 */
                baddr -= hose->sg_pci->dma_base;
                last -= hose->sg_pci->dma_base;
                baddr &= PAGE_MASK;
                size = PAGE_ALIGN(last) - baddr;

                /*
                 * Map it.
                 */
                area = get_vm_area(size, VM_IOREMAP);
                if (!area)
                        return NULL;

                ptes = hose->sg_pci->ptes;
                for (vaddr = (unsigned long)area->addr; 
                    baddr <= last; 
                    baddr += PAGE_SIZE, vaddr += PAGE_SIZE) {
                        pfn = ptes[baddr >> PAGE_SHIFT];
                        if (!(pfn & 1)) {
                                printk("ioremap failed... pte not valid...\n");
                                vfree(area->addr);
                                return NULL;
                        }
                        pfn >>= 1;      /* make it a true pfn */
                        
                        if (__alpha_remap_area_pages(vaddr,
                                                     pfn << PAGE_SHIFT, 
                                                     PAGE_SIZE, 0)) {
                                printk("FAILED to map...\n");
                                vfree(area->addr);
                                return NULL;
                        }
                }

                flush_tlb_all();

                vaddr = (unsigned long)area->addr + (addr & ~PAGE_MASK);

                return (void __iomem *) vaddr;
        }

        /* Assume it was already a reasonable address */
        vaddr = baddr + hose->mem_space->start;
        return (void __iomem *) vaddr;
}

void
marvel_iounmap(volatile void __iomem *xaddr)
{
        unsigned long addr = (unsigned long) xaddr;
        if (addr >= VMALLOC_START)
                vfree((void *)(PAGE_MASK & addr)); 
}

int
marvel_is_mmio(const volatile void __iomem *xaddr)
{
        unsigned long addr = (unsigned long) xaddr;

        if (addr >= VMALLOC_START)
                return 1;
        else
                return (addr & 0xFF000000UL) == 0;
}

#define __marvel_is_port_kbd(a) (((a) == 0x60) || ((a) == 0x64))
#define __marvel_is_port_rtc(a) (((a) == 0x70) || ((a) == 0x71))

void __iomem *marvel_ioportmap (unsigned long addr)
{
        FIXUP_IOADDR_VGA(addr);
        return (void __iomem *)addr;
}

u8
marvel_ioread8(const void __iomem *xaddr)
{
        unsigned long addr = (unsigned long) xaddr;
        if (__marvel_is_port_kbd(addr))
                return 0;
        else if (__marvel_is_port_rtc(addr))
                return __marvel_rtc_io(0, addr, 0);
        else if (marvel_is_ioaddr(addr))
                return __kernel_ldbu(*(vucp)addr);
        else
                /* this should catch other legacy addresses
                   that would normally fail on MARVEL,
                   because there really is nothing there...
                */
                return ~0;
}

void
marvel_iowrite8(u8 b, void __iomem *xaddr)
{
        unsigned long addr = (unsigned long) xaddr;
        if (__marvel_is_port_kbd(addr))
                return;
        else if (__marvel_is_port_rtc(addr)) 
                __marvel_rtc_io(b, addr, 1);
        else if (marvel_is_ioaddr(addr))
                __kernel_stb(b, *(vucp)addr);
}

#ifndef CONFIG_ALPHA_GENERIC
EXPORT_SYMBOL(marvel_ioremap);
EXPORT_SYMBOL(marvel_iounmap);
EXPORT_SYMBOL(marvel_is_mmio);
EXPORT_SYMBOL(marvel_ioportmap);
EXPORT_SYMBOL(marvel_ioread8);
EXPORT_SYMBOL(marvel_iowrite8);
#endif

/*
 * AGP GART Support.
 */
#include <linux/agp_backend.h>
#include <asm/agp_backend.h>
#include <linux/slab.h>
#include <linux/delay.h>

struct marvel_agp_aperture {
        struct pci_iommu_arena *arena;
        long pg_start;
        long pg_count;
};

static int
marvel_agp_setup(alpha_agp_info *agp)
{
        struct marvel_agp_aperture *aper;

        if (!alpha_agpgart_size)
                return -ENOMEM;

        aper = kmalloc_obj(*aper);
        if (aper == NULL) return -ENOMEM;

        aper->arena = agp->hose->sg_pci;
        aper->pg_count = alpha_agpgart_size / PAGE_SIZE;
        aper->pg_start = iommu_reserve(aper->arena, aper->pg_count,
                                       aper->pg_count - 1);

        if (aper->pg_start < 0) {
                printk(KERN_ERR "Failed to reserve AGP memory\n");
                kfree(aper);
                return -ENOMEM;
        }

        agp->aperture.bus_base = 
                aper->arena->dma_base + aper->pg_start * PAGE_SIZE;
        agp->aperture.size = aper->pg_count * PAGE_SIZE;
        agp->aperture.sysdata = aper;

        return 0;
}

static void
marvel_agp_cleanup(alpha_agp_info *agp)
{
        struct marvel_agp_aperture *aper = agp->aperture.sysdata;
        int status;

        status = iommu_release(aper->arena, aper->pg_start, aper->pg_count);
        if (status == -EBUSY) {
                printk(KERN_WARNING
                       "Attempted to release bound AGP memory - unbinding\n");
                iommu_unbind(aper->arena, aper->pg_start, aper->pg_count);
                status = iommu_release(aper->arena, aper->pg_start, 
                                       aper->pg_count);
        }
        if (status < 0)
                printk(KERN_ERR "Failed to release AGP memory\n");

        kfree(aper);
        kfree(agp);
}

static int
marvel_agp_configure(alpha_agp_info *agp)
{
        io7_ioport_csrs *csrs = ((struct io7_port *)agp->hose->sysdata)->csrs;
        struct io7 *io7 = ((struct io7_port *)agp->hose->sysdata)->io7;
        unsigned int new_rate = 0;
        unsigned long agp_pll;

        /*
         * Check the requested mode against the PLL setting.
         * The agpgart_be code has not programmed the card yet,
         * so we can still tweak mode here.
         */
        agp_pll = io7->csrs->POx_RST[IO7_AGP_PORT].csr;
        switch(IO7_PLL_RNGB(agp_pll)) {
        case 0x4:                               /* 2x only */
                /* 
                 * The PLL is only programmed for 2x, so adjust the
                 * rate to 2x, if necessary.
                 */
                if (agp->mode.bits.rate != 2) 
                        new_rate = 2;
                break;

        case 0x6:                               /* 1x / 4x */
                /*
                 * The PLL is programmed for 1x or 4x.  Don't go faster
                 * than requested, so if the requested rate is 2x, use 1x.
                 */
                if (agp->mode.bits.rate == 2) 
                        new_rate = 1;
                break;

        default:                                /* ??????? */
                /*
                 * Don't know what this PLL setting is, take the requested
                 * rate, but warn the user.
                 */
                printk("%s: unknown PLL setting RNGB=%lx (PLL6_CTL=%016lx)\n",
                       __func__, IO7_PLL_RNGB(agp_pll), agp_pll);
                break;
        }

        /*
         * Set the new rate, if necessary.
         */
        if (new_rate) {
                printk("Requested AGP Rate %dX not compatible "
                       "with PLL setting - using %dX\n",
                       agp->mode.bits.rate,
                       new_rate);

                agp->mode.bits.rate = new_rate;
        }
                
        printk("Enabling AGP on hose %d: %dX%s RQ %d\n", 
               agp->hose->index, agp->mode.bits.rate, 
               agp->mode.bits.sba ? " - SBA" : "", agp->mode.bits.rq);

        csrs->AGP_CMD.csr = agp->mode.lw;

        return 0;
}

static int 
marvel_agp_bind_memory(alpha_agp_info *agp, off_t pg_start, struct agp_memory *mem)
{
        struct marvel_agp_aperture *aper = agp->aperture.sysdata;
        return iommu_bind(aper->arena, aper->pg_start + pg_start, 
                          mem->page_count, mem->pages);
}

static int 
marvel_agp_unbind_memory(alpha_agp_info *agp, off_t pg_start, struct agp_memory *mem)
{
        struct marvel_agp_aperture *aper = agp->aperture.sysdata;
        return iommu_unbind(aper->arena, aper->pg_start + pg_start,
                            mem->page_count);
}

static unsigned long
marvel_agp_translate(alpha_agp_info *agp, dma_addr_t addr)
{
        struct marvel_agp_aperture *aper = agp->aperture.sysdata;
        unsigned long baddr = addr - aper->arena->dma_base;
        unsigned long pte;

        if (addr < agp->aperture.bus_base ||
            addr >= agp->aperture.bus_base + agp->aperture.size) {
                printk("%s: addr out of range\n", __func__);
                return -EINVAL;
        }

        pte = aper->arena->ptes[baddr >> PAGE_SHIFT];
        if (!(pte & 1)) {
                printk("%s: pte not valid\n", __func__);
                return -EINVAL;
        } 
        return (pte >> 1) << PAGE_SHIFT;
}

struct alpha_agp_ops marvel_agp_ops =
{
        .setup          = marvel_agp_setup,
        .cleanup        = marvel_agp_cleanup,
        .configure      = marvel_agp_configure,
        .bind           = marvel_agp_bind_memory,
        .unbind         = marvel_agp_unbind_memory,
        .translate      = marvel_agp_translate
};

alpha_agp_info *
marvel_agp_info(void)
{
        struct pci_controller *hose;
        io7_ioport_csrs *csrs;
        alpha_agp_info *agp;
        struct io7 *io7;

        /*
         * Find the first IO7 with an AGP card.
         *
         * FIXME -- there should be a better way (we want to be able to
         * specify and what if the agp card is not video???)
         */
        hose = NULL;
        for (io7 = NULL; (io7 = marvel_next_io7(io7)) != NULL; ) {
                struct pci_controller *h;
                vuip addr;

                if (!io7->ports[IO7_AGP_PORT].enabled)
                        continue;

                h = io7->ports[IO7_AGP_PORT].hose;
                addr = (vuip)build_conf_addr(h, 0, PCI_DEVFN(5, 0), 0);

                if (*addr != 0xffffffffu) {
                        hose = h;
                        break;
                }
        }

        if (!hose || !hose->sg_pci)
                return NULL;

        printk("MARVEL - using hose %d as AGP\n", hose->index);

        /* 
         * Get the csrs from the hose.
         */
        csrs = ((struct io7_port *)hose->sysdata)->csrs;

        /*
         * Allocate the info structure.
         */
        agp = kmalloc_obj(*agp);
        if (!agp)
                return NULL;

        /*
         * Fill it in.
         */
        agp->hose = hose;
        agp->private = NULL;
        agp->ops = &marvel_agp_ops;

        /*
         * Aperture - not configured until ops.setup().
         */
        agp->aperture.bus_base = 0;
        agp->aperture.size = 0;
        agp->aperture.sysdata = NULL;

        /*
         * Capabilities.
         *
         * NOTE: IO7 reports through AGP_STAT that it can support a read queue
         *       depth of 17 (rq = 0x10). It actually only supports a depth of
         *       16 (rq = 0xf).
         */
        agp->capability.lw = csrs->AGP_STAT.csr;
        agp->capability.bits.rq = 0xf;
        
        /*
         * Mode.
         */
        agp->mode.lw = csrs->AGP_CMD.csr;

        return agp;
}