/*
 * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
 * Copyright (C) 1997, 2001 Ralf Baechle (ralf@gnu.org)
 * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
 * Copyright (C) 2004  Maciej W. Rozycki
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <linux/config.h>
#include <linux/init.h>
#include <asm/mmu_context.h>
#include <asm/bootinfo.h>
#include <asm/cacheops.h>
#include <asm/cpu.h>
#include <asm/uaccess.h>

extern void sb1_dma_init(void);

/* These are probed at ld_mmu time */
static unsigned long icache_size;
static unsigned long dcache_size;

static unsigned short icache_line_size;
static unsigned short dcache_line_size;

static unsigned int icache_index_mask;
static unsigned int dcache_index_mask;

static unsigned short icache_assoc;
static unsigned short dcache_assoc;

static unsigned short icache_sets;
static unsigned short dcache_sets;

static unsigned int icache_range_cutoff;
static unsigned int dcache_range_cutoff;

/*
 * The dcache is fully coherent to the system, with one
 * big caveat:  the instruction stream.  In other words,
 * if we miss in the icache, and have dirty data in the
 * L1 dcache, then we'll go out to memory (or the L2) and
 * get the not-as-recent data.
 *
 * So the only time we have to flush the dcache is when
 * we're flushing the icache.  Since the L2 is fully
 * coherent to everything, including I/O, we never have
 * to flush it
 */

/*
 * Writeback and invalidate the entire dcache
 */
static inline void __sb1_writeback_inv_dcache_all(void)
{
        __asm__ __volatile__ (
                ".set push                  \n"
                ".set noreorder             \n"
                ".set noat                  \n"
                ".set mips4                 \n"
                "     move   $1, $0         \n" /* Start at index 0 */
                "1:   cache  %2, 0($1)      \n" /* Invalidate this index */
                "     cache  %2, (1<<13)($1)\n" /* Invalidate this index */
                "     cache  %2, (2<<13)($1)\n" /* Invalidate this index */
                "     cache  %2, (3<<13)($1)\n" /* Invalidate this index */
                "     addiu  %1, %1, -1     \n" /* Decrement loop count */
                "     bnez   %1, 1b         \n" /* loop test */
                "      addu  $1, $1, %0     \n" /* Next address */
                ".set pop                   \n"
                :
                : "r" (dcache_line_size), "r" (dcache_sets),
                  "i" (Index_Writeback_Inv_D));
}

/*
 * Writeback and invalidate a range of the dcache.  The addresses are
 * virtual, and since we're using index ops and bit 12 is part of both
 * the virtual frame and physical index, we have to clear both sets
 * (bit 12 set and cleared).
 */
static inline void __sb1_writeback_inv_dcache_range(unsigned long start,
        unsigned long end)
{
        __asm__ __volatile__ (
        "       .set    push            \n"
        "       .set    noreorder       \n"
        "       .set    noat            \n"
        "       .set    mips4           \n"
        "       and     $1, %0, %3      \n" /* mask non-index bits */
        "1:     cache   %4, (0<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (1<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (2<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (3<<13)($1) \n" /* Index-WB-inval this address */
        "       xori    $1, $1, 1<<12   \n" /* flip bit 12 (va/pa alias) */
        "       cache   %4, (0<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (1<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (2<<13)($1) \n" /* Index-WB-inval this address */
        "       cache   %4, (3<<13)($1) \n" /* Index-WB-inval this address */
        "       addu    %0, %0, %2      \n" /* next line */
        "       bne     %0, %1, 1b      \n" /* loop test */
        "        and    $1, %0, %3      \n" /* mask non-index bits */
        "       sync                    \n"
        "       .set pop                \n"
        :
        : "r" (start & ~(dcache_line_size - 1)),
          "r" ((end + dcache_line_size - 1) & ~(dcache_line_size - 1)),
          "r" (dcache_line_size),
          "r" (dcache_index_mask),
          "i" (Index_Writeback_Inv_D));
}

/*
 * Writeback and invalidate a range of the dcache.  With physical
 * addresseses, we don't have to worry about possible bit 12 aliasing.
 * XXXKW is it worth turning on KX and using hit ops with xkphys?
 */
static inline void __sb1_writeback_inv_dcache_phys_range(unsigned long start,
        unsigned long end)
{
        __asm__ __volatile__ (
                "       .set    push            \n"
                "       .set    noreorder       \n"
                "       .set    noat            \n"
                "       .set    mips4           \n"
                "       and     $1, %0, %3      \n" /* mask non-index bits */
                "1:     cache   %4, (0<<13)($1) \n" /* Index-WB-inval this address */
                "       cache   %4, (1<<13)($1) \n" /* Index-WB-inval this address */
                "       cache   %4, (2<<13)($1) \n" /* Index-WB-inval this address */
                "       cache   %4, (3<<13)($1) \n" /* Index-WB-inval this address */
                "       addu    %0, %0, %2      \n" /* next line */
                "       bne     %0, %1, 1b      \n" /* loop test */
                "        and    $1, %0, %3      \n" /* mask non-index bits */
                "       sync                    \n"
                "       .set pop                \n"
                :
                : "r" (start  & ~(dcache_line_size - 1)),
                  "r" ((end + dcache_line_size - 1) & ~(dcache_line_size - 1)),
                  "r" (dcache_line_size),
                  "r" (dcache_index_mask),
                  "i" (Index_Writeback_Inv_D));
}


/*
 * Invalidate the entire icache
 */
static inline void __sb1_flush_icache_all(void)
{
        __asm__ __volatile__ (
                ".set push                  \n"
                ".set noreorder             \n"
                ".set noat                  \n"
                ".set mips4                 \n"
                "     move   $1, $0         \n" /* Start at index 0 */
                "1:   cache  %2, 0($1)      \n" /* Invalidate this index */
                "     cache  %2, (1<<13)($1)\n" /* Invalidate this index */
                "     cache  %2, (2<<13)($1)\n" /* Invalidate this index */
                "     cache  %2, (3<<13)($1)\n" /* Invalidate this index */
                "     addiu  %1, %1, -1     \n" /* Decrement loop count */
                "     bnez   %1, 1b         \n" /* loop test */
                "      addu  $1, $1, %0     \n" /* Next address */
                "     bnezl  $0, 2f         \n" /* Force mispredict */
                "      nop                  \n"
                "2:   sync                  \n"
                ".set pop                   \n"
                :
                : "r" (icache_line_size), "r" (icache_sets),
                  "i" (Index_Invalidate_I));
}

/*
 * Flush the icache for a given physical page.  Need to writeback the
 * dcache first, then invalidate the icache.  If the page isn't
 * executable, nothing is required.
 */
static void local_sb1_flush_cache_page(struct vm_area_struct *vma,
        unsigned long addr)
{
        int cpu = smp_processor_id();

#ifndef CONFIG_SMP
        if (!(vma->vm_flags & VM_EXEC))
                return;
#endif

        __sb1_writeback_inv_dcache_range(addr, addr + PAGE_SIZE);

        /*
         * Bumping the ASID is probably cheaper than the flush ...
         */
        if (cpu_context(cpu, vma->vm_mm) != 0)
                drop_mmu_context(vma->vm_mm, cpu);
}

#ifdef CONFIG_SMP
struct flush_cache_page_args {
        struct vm_area_struct *vma;
        unsigned long addr;
};

static void sb1_flush_cache_page_ipi(void *info)
{
        struct flush_cache_page_args *args = info;

        local_sb1_flush_cache_page(args->vma, args->addr);
}

/* Dirty dcache could be on another CPU, so do the IPIs */
static void sb1_flush_cache_page(struct vm_area_struct *vma, unsigned long addr)
{
        struct flush_cache_page_args args;

        if (!(vma->vm_flags & VM_EXEC))
                return;

        addr &= PAGE_MASK;
        args.vma = vma;
        args.addr = addr;
        smp_call_function(sb1_flush_cache_page_ipi, (void *) &args, 1, 1);
        local_sb1_flush_cache_page(vma, addr);
}
#else
void sb1_flush_cache_page(struct vm_area_struct *vma, unsigned long addr)
        __attribute__((alias("local_sb1_flush_cache_page")));
#endif

/*
 * Invalidate a range of the icache.  The addresses are virtual, and
 * the cache is virtually indexed and tagged.  However, we don't
 * necessarily have the right ASID context, so use index ops instead
 * of hit ops.
 */
static inline void __sb1_flush_icache_range(unsigned long start,
        unsigned long end)
{
        __asm__ __volatile__ (
                ".set push                  \n"
                ".set noreorder             \n"
                ".set noat                  \n"
                ".set mips4                 \n"
                "     and    $1, %0, %3     \n" /* mask non-index bits */
                "1:   cache  %4, (0<<13)($1) \n" /* Index-inval this address */
                "     cache  %4, (1<<13)($1) \n" /* Index-inval this address */
                "     cache  %4, (2<<13)($1) \n" /* Index-inval this address */
                "     cache  %4, (3<<13)($1) \n" /* Index-inval this address */
                "     addu   %0, %0, %2     \n" /* next line */
                "     bne    %0, %1, 1b     \n" /* loop test */
                "      and   $1, %0, %3     \n" /* mask non-index bits */
                "     bnezl  $0, 2f         \n" /* Force mispredict */
                "      nop                  \n"
                "2:   sync                  \n"
                ".set pop                   \n"
                :
                : "r" (start  & ~(icache_line_size - 1)),
                  "r" ((end + icache_line_size - 1) & ~(icache_line_size - 1)),
                  "r" (icache_line_size),
                  "r" (icache_index_mask),
                  "i" (Index_Invalidate_I));
}


/*
 * Invalidate all caches on this CPU
 */
static void local_sb1___flush_cache_all(void)
{
        __sb1_writeback_inv_dcache_all();
        __sb1_flush_icache_all();
}

#ifdef CONFIG_SMP
void sb1___flush_cache_all_ipi(void *ignored)
        __attribute__((alias("local_sb1___flush_cache_all")));

static void sb1___flush_cache_all(void)
{
        smp_call_function(sb1___flush_cache_all_ipi, 0, 1, 1);
        local_sb1___flush_cache_all();
}
#else
void sb1___flush_cache_all(void)
        __attribute__((alias("local_sb1___flush_cache_all")));
#endif

/*
 * When flushing a range in the icache, we have to first writeback
 * the dcache for the same range, so new ifetches will see any
 * data that was dirty in the dcache.
 *
 * The start/end arguments are Kseg addresses (possibly mapped Kseg).
 */

static void local_sb1_flush_icache_range(unsigned long start,
        unsigned long end)
{
        /* Just wb-inv the whole dcache if the range is big enough */
        if ((end - start) > dcache_range_cutoff)
                __sb1_writeback_inv_dcache_all();
        else
                __sb1_writeback_inv_dcache_range(start, end);
        
        /* Just flush the whole icache if the range is big enough */
        if ((end - start) > icache_range_cutoff)
                __sb1_flush_icache_all();
        else
                __sb1_flush_icache_range(start, end);
}

#ifdef CONFIG_SMP
struct flush_icache_range_args {
        unsigned long start;
        unsigned long end;
};

static void sb1_flush_icache_range_ipi(void *info)
{
        struct flush_icache_range_args *args = info;

        local_sb1_flush_icache_range(args->start, args->end);
}

void sb1_flush_icache_range(unsigned long start, unsigned long end)
{
        struct flush_icache_range_args args;

        args.start = start;
        args.end = end;
        smp_call_function(sb1_flush_icache_range_ipi, &args, 1, 1);
        local_sb1_flush_icache_range(start, end);
}
#else
void sb1_flush_icache_range(unsigned long start, unsigned long end)
        __attribute__((alias("local_sb1_flush_icache_range")));
#endif

/*
 * Flush the icache for a given physical page.  Need to writeback the
 * dcache first, then invalidate the icache.  If the page isn't
 * executable, nothing is required.
 */
static void local_sb1_flush_icache_page(struct vm_area_struct *vma,
        struct page *page)
{
        unsigned long start;
        int cpu = smp_processor_id();

#ifndef CONFIG_SMP
        if (!(vma->vm_flags & VM_EXEC))
                return;
#endif

        /* Need to writeback any dirty data for that page, we have the PA */
        start = (unsigned long)(page-mem_map) << PAGE_SHIFT;
        __sb1_writeback_inv_dcache_phys_range(start, start + PAGE_SIZE);
        /*
         * If there's a context, bump the ASID (cheaper than a flush,
         * since we don't know VAs!)
         */
        if (cpu_context(cpu, vma->vm_mm) != 0) {
                drop_mmu_context(vma->vm_mm, cpu);
        }
}

#ifdef CONFIG_SMP
struct flush_icache_page_args {
        struct vm_area_struct *vma;
        struct page *page;
};

static void sb1_flush_icache_page_ipi(void *info)
{
        struct flush_icache_page_args *args = info;
        local_sb1_flush_icache_page(args->vma, args->page);
}

/* Dirty dcache could be on another CPU, so do the IPIs */
static void sb1_flush_icache_page(struct vm_area_struct *vma,
        struct page *page)
{
        struct flush_icache_page_args args;

        if (!(vma->vm_flags & VM_EXEC))
                return;
        args.vma = vma;
        args.page = page;
        smp_call_function(sb1_flush_icache_page_ipi, (void *) &args, 1, 1);
        local_sb1_flush_icache_page(vma, page);
}
#else
void sb1_flush_icache_page(struct vm_area_struct *vma, struct page *page)
        __attribute__((alias("local_sb1_flush_icache_page")));
#endif

/*
 * A signal trampoline must fit into a single cacheline.
 */
static void local_sb1_flush_cache_sigtramp(unsigned long addr)
{
        __asm__ __volatile__ (
        "       .set    push            \n"
        "       .set    noreorder       \n"
        "       .set    noat            \n"
        "       .set    mips4           \n"
        "       cache   %2, (0<<13)(%0) \n" /* Index-inval this address */
        "       cache   %2, (1<<13)(%0) \n" /* Index-inval this address */
        "       cache   %2, (2<<13)(%0) \n" /* Index-inval this address */
        "       cache   %2, (3<<13)(%0) \n" /* Index-inval this address */
        "       xori    $1, %0, 1<<12   \n" /* Flip index bit 12        */
        "       cache   %2, (0<<13)($1) \n" /* Index-inval this address */
        "       cache   %2, (1<<13)($1) \n" /* Index-inval this address */
        "       cache   %2, (2<<13)($1) \n" /* Index-inval this address */
        "       cache   %2, (3<<13)($1) \n" /* Index-inval this address */
        "       cache   %3, (0<<13)(%1) \n" /* Index-inval this address */
        "       cache   %3, (1<<13)(%1) \n" /* Index-inval this address */
        "       cache   %3, (2<<13)(%1) \n" /* Index-inval this address */
        "       cache   %3, (3<<13)(%1) \n" /* Index-inval this address */
        "       bnezl   $0, 1f          \n" /* Force mispredict */
        "        nop                    \n"
        "1:                             \n"
        "       .set    pop             \n"
        :
        : "r" (addr & dcache_index_mask), "r" (addr & icache_index_mask),
          "i" (Index_Writeback_Inv_D), "i" (Index_Invalidate_I));
}

#ifdef CONFIG_SMP
static void sb1_flush_cache_sigtramp_ipi(void *info)
{
        unsigned long iaddr = (unsigned long) info;
        local_sb1_flush_cache_sigtramp(iaddr);
}

static void sb1_flush_cache_sigtramp(unsigned long addr)
{
        local_sb1_flush_cache_sigtramp(addr);
        smp_call_function(sb1_flush_cache_sigtramp_ipi, (void *) addr, 1, 1);
}
#else
void sb1_flush_cache_sigtramp(unsigned long addr)
        __attribute__((alias("local_sb1_flush_cache_sigtramp")));
#endif


/*
 * Anything that just flushes dcache state can be ignored, as we're always
 * coherent in dcache space.  This is just a dummy function that all the
 * nop'ed routines point to
 */
static void sb1_nop(void)
{
}

/*
 *  Cache set values (from the mips64 spec)
 * 0 - 64
 * 1 - 128
 * 2 - 256
 * 3 - 512
 * 4 - 1024
 * 5 - 2048
 * 6 - 4096
 * 7 - Reserved
 */

static unsigned int decode_cache_sets(unsigned int config_field)
{
        if (config_field == 7) {
                /* JDCXXX - Find a graceful way to abort. */
                return 0;
        }
        return (1<<(config_field + 6));
}

/*
 *  Cache line size values (from the mips64 spec)
 * 0 - No cache present.
 * 1 - 4 bytes
 * 2 - 8 bytes
 * 3 - 16 bytes
 * 4 - 32 bytes
 * 5 - 64 bytes
 * 6 - 128 bytes
 * 7 - Reserved
 */

static unsigned int decode_cache_line_size(unsigned int config_field)
{
        if (config_field == 0) {
                return 0;
        } else if (config_field == 7) {
                /* JDCXXX - Find a graceful way to abort. */
                return 0;
        }
        return (1<<(config_field + 1));
}

/*
 * Relevant bits of the config1 register format (from the MIPS32/MIPS64 specs)
 *
 * 24:22 Icache sets per way
 * 21:19 Icache line size
 * 18:16 Icache Associativity
 * 15:13 Dcache sets per way
 * 12:10 Dcache line size
 * 9:7   Dcache Associativity
 */

static char *way_string[] = {
        "direct mapped", "2-way", "3-way", "4-way",
        "5-way", "6-way", "7-way", "8-way",
};

static __init void probe_cache_sizes(void)
{
        u32 config1;

        config1 = read_c0_config1();
        icache_line_size = decode_cache_line_size((config1 >> 19) & 0x7);
        dcache_line_size = decode_cache_line_size((config1 >> 10) & 0x7);
        icache_sets = decode_cache_sets((config1 >> 22) & 0x7);
        dcache_sets = decode_cache_sets((config1 >> 13) & 0x7);
        icache_assoc = ((config1 >> 16) & 0x7) + 1;
        dcache_assoc = ((config1 >> 7) & 0x7) + 1;
        icache_size = icache_line_size * icache_sets * icache_assoc;
        dcache_size = dcache_line_size * dcache_sets * dcache_assoc;
        /* Need to remove non-index bits for index ops */
        icache_index_mask = (icache_sets - 1) * icache_line_size;
        dcache_index_mask = (dcache_sets - 1) * dcache_line_size;
        /*
         * These are for choosing range (index ops) versus all.
         * icache flushes all ways for each set, so drop icache_assoc.
         * dcache flushes all ways and each setting of bit 12 for each
         * index, so drop dcache_assoc and halve the dcache_sets.
         */
        icache_range_cutoff = icache_sets * icache_line_size;
        dcache_range_cutoff = (dcache_sets / 2) * icache_line_size;

        printk("Primary instruction cache %ldkB, %s, linesize %d bytes.\n",
               icache_size >> 10, way_string[icache_assoc - 1],
               icache_line_size);
        printk("Primary data cache %ldkB, %s, linesize %d bytes.\n",
               dcache_size >> 10, way_string[dcache_assoc - 1],
               dcache_line_size);
}

/*
 * This is called from loadmmu.c.  We have to set up all the
 * memory management function pointers, as well as initialize
 * the caches and tlbs
 */
void ld_mmu_sb1(void)
{
        extern char except_vec2_sb1;
        extern char handle_vec2_sb1;
        unsigned long temp;

        /* Special cache error handler for SB1 */
        memcpy((void *)(KSEG0 + 0x100), &except_vec2_sb1, 0x80);
        memcpy((void *)(KSEG1 + 0x100), &except_vec2_sb1, 0x80);
        memcpy((void *)KSEG1ADDR(&handle_vec2_sb1), &handle_vec2_sb1, 0x80);

        probe_cache_sizes();

#ifdef CONFIG_SIBYTE_DMA_PAGEOPS
        sb1_dma_init();
#endif

        /*
         * None of these are needed for the SB1 - the Dcache is
         * physically indexed and tagged, so no virtual aliasing can
         * occur
         */
        _flush_cache_range = (void *) sb1_nop;
        _flush_cache_mm = (void (*)(struct mm_struct *))sb1_nop;
        _flush_cache_all = sb1_nop;

        /* These routines are for Icache coherence with the Dcache */
        _flush_icache_range = sb1_flush_icache_range;
        _flush_icache_page = sb1_flush_icache_page;
        _flush_icache_all = __sb1_flush_icache_all; /* local only */

        /* This implies an Icache flush too, so can't be nop'ed */
        _flush_cache_page = sb1_flush_cache_page;

        _flush_cache_sigtramp = sb1_flush_cache_sigtramp;
        _flush_data_cache_page = (void *) sb1_nop;

        /* Full flush */
        ___flush_cache_all = sb1___flush_cache_all;

        change_c0_config(CONF_CM_CMASK, CONF_CM_DEFAULT);
        /*
         * This is the only way to force the update of K0 to complete
         * before subsequent instruction fetch.
         */
        __asm__ __volatile__ (
        "       .set    push            \n"
        "       .set    mips4           \n"
        "       la      %0, 1f          \n"
        "       mtc0    %0, $14         \n"
        "       eret                    \n"
        "1:     .set    pop             \n"
        : "=r" (temp));
        flush_cache_all();
}