Merge tag 'usb-5.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

[linux/fpc-iii.git] / arch / mips / cavium-octeon / executive / cvmx-l2c.c

/***********************license start***************
 * Author: Cavium Networks
 *
 * Contact: support@caviumnetworks.com
 * This file is part of the OCTEON SDK
 *
 * Copyright (c) 2003-2017 Cavium, Inc.
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, Version 2, as
 * published by the Free Software Foundation.
 *
 * This file is distributed in the hope that it will be useful, but
 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
 * NONINFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this file; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * or visit http://www.gnu.org/licenses/.
 *
 * This file may also be available under a different license from Cavium.
 * Contact Cavium Networks for more information
 ***********************license end**************************************/

/*
 * Implementation of the Level 2 Cache (L2C) control,
 * measurement, and debugging facilities.
 */

#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <asm/octeon/cvmx.h>
#include <asm/octeon/cvmx-l2c.h>
#include <asm/octeon/cvmx-spinlock.h>

/*
 * This spinlock is used internally to ensure that only one core is
 * performing certain L2 operations at a time.
 *
 * NOTE: This only protects calls from within a single application -
 * if multiple applications or operating systems are running, then it
 * is up to the user program to coordinate between them.
 */
static cvmx_spinlock_t cvmx_l2c_spinlock;

int cvmx_l2c_get_core_way_partition(uint32_t core)
{
        uint32_t field;

        /* Validate the core number */
        if (core >= cvmx_octeon_num_cores())
                return -1;

        if (OCTEON_IS_MODEL(OCTEON_CN63XX))
                return cvmx_read_csr(CVMX_L2C_WPAR_PPX(core)) & 0xffff;

        /*
         * Use the lower two bits of the coreNumber to determine the
         * bit offset of the UMSK[] field in the L2C_SPAR register.
         */
        field = (core & 0x3) * 8;

        /*
         * Return the UMSK[] field from the appropriate L2C_SPAR
         * register based on the coreNumber.
         */

        switch (core & 0xC) {
        case 0x0:
                return (cvmx_read_csr(CVMX_L2C_SPAR0) & (0xFF << field)) >> field;
        case 0x4:
                return (cvmx_read_csr(CVMX_L2C_SPAR1) & (0xFF << field)) >> field;
        case 0x8:
                return (cvmx_read_csr(CVMX_L2C_SPAR2) & (0xFF << field)) >> field;
        case 0xC:
                return (cvmx_read_csr(CVMX_L2C_SPAR3) & (0xFF << field)) >> field;
        }
        return 0;
}

int cvmx_l2c_set_core_way_partition(uint32_t core, uint32_t mask)
{
        uint32_t field;
        uint32_t valid_mask;

        valid_mask = (0x1 << cvmx_l2c_get_num_assoc()) - 1;

        mask &= valid_mask;

        /* A UMSK setting which blocks all L2C Ways is an error on some chips */
        if (mask == valid_mask && !OCTEON_IS_MODEL(OCTEON_CN63XX))
                return -1;

        /* Validate the core number */
        if (core >= cvmx_octeon_num_cores())
                return -1;

        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                cvmx_write_csr(CVMX_L2C_WPAR_PPX(core), mask);
                return 0;
        }

        /*
         * Use the lower two bits of core to determine the bit offset of the
         * UMSK[] field in the L2C_SPAR register.
         */
        field = (core & 0x3) * 8;

        /*
         * Assign the new mask setting to the UMSK[] field in the appropriate
         * L2C_SPAR register based on the core_num.
         *
         */
        switch (core & 0xC) {
        case 0x0:
                cvmx_write_csr(CVMX_L2C_SPAR0,
                               (cvmx_read_csr(CVMX_L2C_SPAR0) & ~(0xFF << field)) |
                               mask << field);
                break;
        case 0x4:
                cvmx_write_csr(CVMX_L2C_SPAR1,
                               (cvmx_read_csr(CVMX_L2C_SPAR1) & ~(0xFF << field)) |
                               mask << field);
                break;
        case 0x8:
                cvmx_write_csr(CVMX_L2C_SPAR2,
                               (cvmx_read_csr(CVMX_L2C_SPAR2) & ~(0xFF << field)) |
                               mask << field);
                break;
        case 0xC:
                cvmx_write_csr(CVMX_L2C_SPAR3,
                               (cvmx_read_csr(CVMX_L2C_SPAR3) & ~(0xFF << field)) |
                               mask << field);
                break;
        }
        return 0;
}

int cvmx_l2c_set_hw_way_partition(uint32_t mask)
{
        uint32_t valid_mask;

        valid_mask = (0x1 << cvmx_l2c_get_num_assoc()) - 1;
        mask &= valid_mask;

        /* A UMSK setting which blocks all L2C Ways is an error on some chips */
        if (mask == valid_mask  && !OCTEON_IS_MODEL(OCTEON_CN63XX))
                return -1;

        if (OCTEON_IS_MODEL(OCTEON_CN63XX))
                cvmx_write_csr(CVMX_L2C_WPAR_IOBX(0), mask);
        else
                cvmx_write_csr(CVMX_L2C_SPAR4,
                               (cvmx_read_csr(CVMX_L2C_SPAR4) & ~0xFF) | mask);
        return 0;
}

int cvmx_l2c_get_hw_way_partition(void)
{
        if (OCTEON_IS_MODEL(OCTEON_CN63XX))
                return cvmx_read_csr(CVMX_L2C_WPAR_IOBX(0)) & 0xffff;
        else
                return cvmx_read_csr(CVMX_L2C_SPAR4) & (0xFF);
}

void cvmx_l2c_config_perf(uint32_t counter, enum cvmx_l2c_event event,
                          uint32_t clear_on_read)
{
        if (OCTEON_IS_MODEL(OCTEON_CN5XXX) || OCTEON_IS_MODEL(OCTEON_CN3XXX)) {
                union cvmx_l2c_pfctl pfctl;

                pfctl.u64 = cvmx_read_csr(CVMX_L2C_PFCTL);

                switch (counter) {
                case 0:
                        pfctl.s.cnt0sel = event;
                        pfctl.s.cnt0ena = 1;
                        pfctl.s.cnt0rdclr = clear_on_read;
                        break;
                case 1:
                        pfctl.s.cnt1sel = event;
                        pfctl.s.cnt1ena = 1;
                        pfctl.s.cnt1rdclr = clear_on_read;
                        break;
                case 2:
                        pfctl.s.cnt2sel = event;
                        pfctl.s.cnt2ena = 1;
                        pfctl.s.cnt2rdclr = clear_on_read;
                        break;
                case 3:
                default:
                        pfctl.s.cnt3sel = event;
                        pfctl.s.cnt3ena = 1;
                        pfctl.s.cnt3rdclr = clear_on_read;
                        break;
                }

                cvmx_write_csr(CVMX_L2C_PFCTL, pfctl.u64);
        } else {
                union cvmx_l2c_tadx_prf l2c_tadx_prf;
                int tad;

                cvmx_dprintf("L2C performance counter events are different for this chip, mapping 'event' to cvmx_l2c_tad_event_t\n");
                if (clear_on_read)
                        cvmx_dprintf("L2C counters don't support clear on read for this chip\n");

                l2c_tadx_prf.u64 = cvmx_read_csr(CVMX_L2C_TADX_PRF(0));

                switch (counter) {
                case 0:
                        l2c_tadx_prf.s.cnt0sel = event;
                        break;
                case 1:
                        l2c_tadx_prf.s.cnt1sel = event;
                        break;
                case 2:
                        l2c_tadx_prf.s.cnt2sel = event;
                        break;
                default:
                case 3:
                        l2c_tadx_prf.s.cnt3sel = event;
                        break;
                }
                for (tad = 0; tad < CVMX_L2C_TADS; tad++)
                        cvmx_write_csr(CVMX_L2C_TADX_PRF(tad),
                                       l2c_tadx_prf.u64);
        }
}

uint64_t cvmx_l2c_read_perf(uint32_t counter)
{
        switch (counter) {
        case 0:
                if (OCTEON_IS_MODEL(OCTEON_CN5XXX) || OCTEON_IS_MODEL(OCTEON_CN3XXX))
                        return cvmx_read_csr(CVMX_L2C_PFC0);
                else {
                        uint64_t counter = 0;
                        int tad;

                        for (tad = 0; tad < CVMX_L2C_TADS; tad++)
                                counter += cvmx_read_csr(CVMX_L2C_TADX_PFC0(tad));
                        return counter;
                }
        case 1:
                if (OCTEON_IS_MODEL(OCTEON_CN5XXX) || OCTEON_IS_MODEL(OCTEON_CN3XXX))
                        return cvmx_read_csr(CVMX_L2C_PFC1);
                else {
                        uint64_t counter = 0;
                        int tad;

                        for (tad = 0; tad < CVMX_L2C_TADS; tad++)
                                counter += cvmx_read_csr(CVMX_L2C_TADX_PFC1(tad));
                        return counter;
                }
        case 2:
                if (OCTEON_IS_MODEL(OCTEON_CN5XXX) || OCTEON_IS_MODEL(OCTEON_CN3XXX))
                        return cvmx_read_csr(CVMX_L2C_PFC2);
                else {
                        uint64_t counter = 0;
                        int tad;

                        for (tad = 0; tad < CVMX_L2C_TADS; tad++)
                                counter += cvmx_read_csr(CVMX_L2C_TADX_PFC2(tad));
                        return counter;
                }
        case 3:
        default:
                if (OCTEON_IS_MODEL(OCTEON_CN5XXX) || OCTEON_IS_MODEL(OCTEON_CN3XXX))
                        return cvmx_read_csr(CVMX_L2C_PFC3);
                else {
                        uint64_t counter = 0;
                        int tad;

                        for (tad = 0; tad < CVMX_L2C_TADS; tad++)
                                counter += cvmx_read_csr(CVMX_L2C_TADX_PFC3(tad));
                        return counter;
                }
        }
}

/**
 * @INTERNAL
 * Helper function use to fault in cache lines for L2 cache locking
 *
 * @addr:   Address of base of memory region to read into L2 cache
 * @len:    Length (in bytes) of region to fault in
 */
static void fault_in(uint64_t addr, int len)
{
        char *ptr;

        /*
         * Adjust addr and length so we get all cache lines even for
         * small ranges spanning two cache lines.
         */
        len += addr & CVMX_CACHE_LINE_MASK;
        addr &= ~CVMX_CACHE_LINE_MASK;
        ptr = cvmx_phys_to_ptr(addr);
        /*
         * Invalidate L1 cache to make sure all loads result in data
         * being in L2.
         */
        CVMX_DCACHE_INVALIDATE;
        while (len > 0) {
                READ_ONCE(*ptr);
                len -= CVMX_CACHE_LINE_SIZE;
                ptr += CVMX_CACHE_LINE_SIZE;
        }
}

int cvmx_l2c_lock_line(uint64_t addr)
{
        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                int shift = CVMX_L2C_TAG_ADDR_ALIAS_SHIFT;
                uint64_t assoc = cvmx_l2c_get_num_assoc();
                uint64_t tag = addr >> shift;
                uint64_t index = CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS, cvmx_l2c_address_to_index(addr) << CVMX_L2C_IDX_ADDR_SHIFT);
                uint64_t way;
                union cvmx_l2c_tadx_tag l2c_tadx_tag;

                CVMX_CACHE_LCKL2(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS, addr), 0);

                /* Make sure we were able to lock the line */
                for (way = 0; way < assoc; way++) {
                        CVMX_CACHE_LTGL2I(index | (way << shift), 0);
                        /* make sure CVMX_L2C_TADX_TAG is updated */
                        CVMX_SYNC;
                        l2c_tadx_tag.u64 = cvmx_read_csr(CVMX_L2C_TADX_TAG(0));
                        if (l2c_tadx_tag.s.valid && l2c_tadx_tag.s.tag == tag)
                                break;
                }

                /* Check if a valid line is found */
                if (way >= assoc) {
                        /* cvmx_dprintf("ERROR: cvmx_l2c_lock_line: line not found for locking at 0x%llx address\n", (unsigned long long)addr); */
                        return -1;
                }

                /* Check if lock bit is not set */
                if (!l2c_tadx_tag.s.lock) {
                        /* cvmx_dprintf("ERROR: cvmx_l2c_lock_line: Not able to lock at 0x%llx address\n", (unsigned long long)addr); */
                        return -1;
                }
                return way;
        } else {
                int retval = 0;
                union cvmx_l2c_dbg l2cdbg;
                union cvmx_l2c_lckbase lckbase;
                union cvmx_l2c_lckoff lckoff;
                union cvmx_l2t_err l2t_err;

                cvmx_spinlock_lock(&cvmx_l2c_spinlock);

                l2cdbg.u64 = 0;
                lckbase.u64 = 0;
                lckoff.u64 = 0;

                /* Clear l2t error bits if set */
                l2t_err.u64 = cvmx_read_csr(CVMX_L2T_ERR);
                l2t_err.s.lckerr = 1;
                l2t_err.s.lckerr2 = 1;
                cvmx_write_csr(CVMX_L2T_ERR, l2t_err.u64);

                addr &= ~CVMX_CACHE_LINE_MASK;

                /* Set this core as debug core */
                l2cdbg.s.ppnum = cvmx_get_core_num();
                CVMX_SYNC;
                cvmx_write_csr(CVMX_L2C_DBG, l2cdbg.u64);
                cvmx_read_csr(CVMX_L2C_DBG);

                lckoff.s.lck_offset = 0; /* Only lock 1 line at a time */
                cvmx_write_csr(CVMX_L2C_LCKOFF, lckoff.u64);
                cvmx_read_csr(CVMX_L2C_LCKOFF);

                if (((union cvmx_l2c_cfg)(cvmx_read_csr(CVMX_L2C_CFG))).s.idxalias) {
                        int alias_shift = CVMX_L2C_IDX_ADDR_SHIFT + 2 * CVMX_L2_SET_BITS - 1;
                        uint64_t addr_tmp = addr ^ (addr & ((1 << alias_shift) - 1)) >> CVMX_L2_SET_BITS;

                        lckbase.s.lck_base = addr_tmp >> 7;

                } else {
                        lckbase.s.lck_base = addr >> 7;
                }

                lckbase.s.lck_ena = 1;
                cvmx_write_csr(CVMX_L2C_LCKBASE, lckbase.u64);
                /* Make sure it gets there */
                cvmx_read_csr(CVMX_L2C_LCKBASE);

                fault_in(addr, CVMX_CACHE_LINE_SIZE);

                lckbase.s.lck_ena = 0;
                cvmx_write_csr(CVMX_L2C_LCKBASE, lckbase.u64);
                /* Make sure it gets there */
                cvmx_read_csr(CVMX_L2C_LCKBASE);

                /* Stop being debug core */
                cvmx_write_csr(CVMX_L2C_DBG, 0);
                cvmx_read_csr(CVMX_L2C_DBG);

                l2t_err.u64 = cvmx_read_csr(CVMX_L2T_ERR);
                if (l2t_err.s.lckerr || l2t_err.s.lckerr2)
                        retval = 1;  /* We were unable to lock the line */

                cvmx_spinlock_unlock(&cvmx_l2c_spinlock);
                return retval;
        }
}

int cvmx_l2c_lock_mem_region(uint64_t start, uint64_t len)
{
        int retval = 0;

        /* Round start/end to cache line boundaries */
        len += start & CVMX_CACHE_LINE_MASK;
        start &= ~CVMX_CACHE_LINE_MASK;
        len = (len + CVMX_CACHE_LINE_MASK) & ~CVMX_CACHE_LINE_MASK;

        while (len) {
                retval += cvmx_l2c_lock_line(start);
                start += CVMX_CACHE_LINE_SIZE;
                len -= CVMX_CACHE_LINE_SIZE;
        }
        return retval;
}

void cvmx_l2c_flush(void)
{
        uint64_t assoc, set;
        uint64_t n_assoc, n_set;

        n_set = cvmx_l2c_get_num_sets();
        n_assoc = cvmx_l2c_get_num_assoc();

        if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                uint64_t address;
                /* These may look like constants, but they aren't... */
                int assoc_shift = CVMX_L2C_TAG_ADDR_ALIAS_SHIFT;
                int set_shift = CVMX_L2C_IDX_ADDR_SHIFT;

                for (set = 0; set < n_set; set++) {
                        for (assoc = 0; assoc < n_assoc; assoc++) {
                                address = CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
                                                       (assoc << assoc_shift) | (set << set_shift));
                                CVMX_CACHE_WBIL2I(address, 0);
                        }
                }
        } else {
                for (set = 0; set < n_set; set++)
                        for (assoc = 0; assoc < n_assoc; assoc++)
                                cvmx_l2c_flush_line(assoc, set);
        }
}


int cvmx_l2c_unlock_line(uint64_t address)
{

        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                int assoc;
                union cvmx_l2c_tag tag;
                uint32_t tag_addr;
                uint32_t index = cvmx_l2c_address_to_index(address);

                tag_addr = ((address >> CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) & ((1 << CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) - 1));

                /*
                 * For 63XX, we can flush a line by using the physical
                 * address directly, so finding the cache line used by
                 * the address is only required to provide the proper
                 * return value for the function.
                 */
                for (assoc = 0; assoc < CVMX_L2_ASSOC; assoc++) {
                        tag = cvmx_l2c_get_tag(assoc, index);

                        if (tag.s.V && (tag.s.addr == tag_addr)) {
                                CVMX_CACHE_WBIL2(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS, address), 0);
                                return tag.s.L;
                        }
                }
        } else {
                int assoc;
                union cvmx_l2c_tag tag;
                uint32_t tag_addr;

                uint32_t index = cvmx_l2c_address_to_index(address);

                /* Compute portion of address that is stored in tag */
                tag_addr = ((address >> CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) & ((1 << CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) - 1));
                for (assoc = 0; assoc < CVMX_L2_ASSOC; assoc++) {
                        tag = cvmx_l2c_get_tag(assoc, index);

                        if (tag.s.V && (tag.s.addr == tag_addr)) {
                                cvmx_l2c_flush_line(assoc, index);
                                return tag.s.L;
                        }
                }
        }
        return 0;
}

int cvmx_l2c_unlock_mem_region(uint64_t start, uint64_t len)
{
        int num_unlocked = 0;
        /* Round start/end to cache line boundaries */
        len += start & CVMX_CACHE_LINE_MASK;
        start &= ~CVMX_CACHE_LINE_MASK;
        len = (len + CVMX_CACHE_LINE_MASK) & ~CVMX_CACHE_LINE_MASK;
        while (len > 0) {
                num_unlocked += cvmx_l2c_unlock_line(start);
                start += CVMX_CACHE_LINE_SIZE;
                len -= CVMX_CACHE_LINE_SIZE;
        }

        return num_unlocked;
}

/*
 * Internal l2c tag types.  These are converted to a generic structure
 * that can be used on all chips.
 */
union __cvmx_l2c_tag {
        uint64_t u64;
        struct cvmx_l2c_tag_cn50xx {
                __BITFIELD_FIELD(uint64_t reserved:40,
                __BITFIELD_FIELD(uint64_t V:1,          /* Line valid */
                __BITFIELD_FIELD(uint64_t D:1,          /* Line dirty */
                __BITFIELD_FIELD(uint64_t L:1,          /* Line locked */
                __BITFIELD_FIELD(uint64_t U:1,          /* Use, LRU eviction */
                __BITFIELD_FIELD(uint64_t addr:20,      /* Phys addr (33..14) */
                ;))))))
        } cn50xx;
        struct cvmx_l2c_tag_cn30xx {
                __BITFIELD_FIELD(uint64_t reserved:41,
                __BITFIELD_FIELD(uint64_t V:1,          /* Line valid */
                __BITFIELD_FIELD(uint64_t D:1,          /* Line dirty */
                __BITFIELD_FIELD(uint64_t L:1,          /* Line locked */
                __BITFIELD_FIELD(uint64_t U:1,          /* Use, LRU eviction */
                __BITFIELD_FIELD(uint64_t addr:19,      /* Phys addr (33..15) */
                ;))))))
        } cn30xx;
        struct cvmx_l2c_tag_cn31xx {
                __BITFIELD_FIELD(uint64_t reserved:42,
                __BITFIELD_FIELD(uint64_t V:1,          /* Line valid */
                __BITFIELD_FIELD(uint64_t D:1,          /* Line dirty */
                __BITFIELD_FIELD(uint64_t L:1,          /* Line locked */
                __BITFIELD_FIELD(uint64_t U:1,          /* Use, LRU eviction */
                __BITFIELD_FIELD(uint64_t addr:18,      /* Phys addr (33..16) */
                ;))))))
        } cn31xx;
        struct cvmx_l2c_tag_cn38xx {
                __BITFIELD_FIELD(uint64_t reserved:43,
                __BITFIELD_FIELD(uint64_t V:1,          /* Line valid */
                __BITFIELD_FIELD(uint64_t D:1,          /* Line dirty */
                __BITFIELD_FIELD(uint64_t L:1,          /* Line locked */
                __BITFIELD_FIELD(uint64_t U:1,          /* Use, LRU eviction */
                __BITFIELD_FIELD(uint64_t addr:17,      /* Phys addr (33..17) */
                ;))))))
        } cn38xx;
        struct cvmx_l2c_tag_cn58xx {
                __BITFIELD_FIELD(uint64_t reserved:44,
                __BITFIELD_FIELD(uint64_t V:1,          /* Line valid */
                __BITFIELD_FIELD(uint64_t D:1,          /* Line dirty */
                __BITFIELD_FIELD(uint64_t L:1,          /* Line locked */
                __BITFIELD_FIELD(uint64_t U:1,          /* Use, LRU eviction */
                __BITFIELD_FIELD(uint64_t addr:16,      /* Phys addr (33..18) */
                ;))))))
        } cn58xx;
        struct cvmx_l2c_tag_cn58xx cn56xx;      /* 2048 sets */
        struct cvmx_l2c_tag_cn31xx cn52xx;      /* 512 sets */
};


/**
 * @INTERNAL
 * Function to read a L2C tag.  This code make the current core
 * the 'debug core' for the L2.  This code must only be executed by
 * 1 core at a time.
 *
 * @assoc:  Association (way) of the tag to dump
 * @index:  Index of the cacheline
 *
 * Returns The Octeon model specific tag structure.  This is
 *         translated by a wrapper function to a generic form that is
 *         easier for applications to use.
 */
static union __cvmx_l2c_tag __read_l2_tag(uint64_t assoc, uint64_t index)
{

        uint64_t debug_tag_addr = CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS, (index << 7) + 96);
        uint64_t core = cvmx_get_core_num();
        union __cvmx_l2c_tag tag_val;
        uint64_t dbg_addr = CVMX_L2C_DBG;
        unsigned long flags;
        union cvmx_l2c_dbg debug_val;

        debug_val.u64 = 0;
        /*
         * For low core count parts, the core number is always small
         * enough to stay in the correct field and not set any
         * reserved bits.
         */
        debug_val.s.ppnum = core;
        debug_val.s.l2t = 1;
        debug_val.s.set = assoc;

        local_irq_save(flags);
        /*
         * Make sure core is quiet (no prefetches, etc.) before
         * entering debug mode.
         */
        CVMX_SYNC;
        /* Flush L1 to make sure debug load misses L1 */
        CVMX_DCACHE_INVALIDATE;

        /*
         * The following must be done in assembly as when in debug
         * mode all data loads from L2 return special debug data, not
         * normal memory contents.  Also, interrupts must be disabled,
         * since if an interrupt occurs while in debug mode the ISR
         * will get debug data from all its memory * reads instead of
         * the contents of memory.
         */

        asm volatile (
                ".set push\n\t"
                ".set mips64\n\t"
                ".set noreorder\n\t"
                "sd    %[dbg_val], 0(%[dbg_addr])\n\t"   /* Enter debug mode, wait for store */
                "ld    $0, 0(%[dbg_addr])\n\t"
                "ld    %[tag_val], 0(%[tag_addr])\n\t"   /* Read L2C tag data */
                "sd    $0, 0(%[dbg_addr])\n\t"          /* Exit debug mode, wait for store */
                "ld    $0, 0(%[dbg_addr])\n\t"
                "cache 9, 0($0)\n\t"             /* Invalidate dcache to discard debug data */
                ".set pop"
                : [tag_val] "=r" (tag_val)
                : [dbg_addr] "r" (dbg_addr), [dbg_val] "r" (debug_val), [tag_addr] "r" (debug_tag_addr)
                : "memory");

        local_irq_restore(flags);

        return tag_val;
}


union cvmx_l2c_tag cvmx_l2c_get_tag(uint32_t association, uint32_t index)
{
        union cvmx_l2c_tag tag;

        tag.u64 = 0;
        if ((int)association >= cvmx_l2c_get_num_assoc()) {
                cvmx_dprintf("ERROR: cvmx_l2c_get_tag association out of range\n");
                return tag;
        }
        if ((int)index >= cvmx_l2c_get_num_sets()) {
                cvmx_dprintf("ERROR: cvmx_l2c_get_tag index out of range (arg: %d, max: %d)\n",
                             (int)index, cvmx_l2c_get_num_sets());
                return tag;
        }
        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                union cvmx_l2c_tadx_tag l2c_tadx_tag;
                uint64_t address = CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
                                                (association << CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) |
                                                (index << CVMX_L2C_IDX_ADDR_SHIFT));
                /*
                 * Use L2 cache Index load tag cache instruction, as
                 * hardware loads the virtual tag for the L2 cache
                 * block with the contents of L2C_TAD0_TAG
                 * register.
                 */
                CVMX_CACHE_LTGL2I(address, 0);
                CVMX_SYNC;   /* make sure CVMX_L2C_TADX_TAG is updated */
                l2c_tadx_tag.u64 = cvmx_read_csr(CVMX_L2C_TADX_TAG(0));

                tag.s.V     = l2c_tadx_tag.s.valid;
                tag.s.D     = l2c_tadx_tag.s.dirty;
                tag.s.L     = l2c_tadx_tag.s.lock;
                tag.s.U     = l2c_tadx_tag.s.use;
                tag.s.addr  = l2c_tadx_tag.s.tag;
        } else {
                union __cvmx_l2c_tag tmp_tag;
                /* __read_l2_tag is intended for internal use only */
                tmp_tag = __read_l2_tag(association, index);

                /*
                 * Convert all tag structure types to generic version,
                 * as it can represent all models.
                 */
                if (OCTEON_IS_MODEL(OCTEON_CN58XX) || OCTEON_IS_MODEL(OCTEON_CN56XX)) {
                        tag.s.V    = tmp_tag.cn58xx.V;
                        tag.s.D    = tmp_tag.cn58xx.D;
                        tag.s.L    = tmp_tag.cn58xx.L;
                        tag.s.U    = tmp_tag.cn58xx.U;
                        tag.s.addr = tmp_tag.cn58xx.addr;
                } else if (OCTEON_IS_MODEL(OCTEON_CN38XX)) {
                        tag.s.V    = tmp_tag.cn38xx.V;
                        tag.s.D    = tmp_tag.cn38xx.D;
                        tag.s.L    = tmp_tag.cn38xx.L;
                        tag.s.U    = tmp_tag.cn38xx.U;
                        tag.s.addr = tmp_tag.cn38xx.addr;
                } else if (OCTEON_IS_MODEL(OCTEON_CN31XX) || OCTEON_IS_MODEL(OCTEON_CN52XX)) {
                        tag.s.V    = tmp_tag.cn31xx.V;
                        tag.s.D    = tmp_tag.cn31xx.D;
                        tag.s.L    = tmp_tag.cn31xx.L;
                        tag.s.U    = tmp_tag.cn31xx.U;
                        tag.s.addr = tmp_tag.cn31xx.addr;
                } else if (OCTEON_IS_MODEL(OCTEON_CN30XX)) {
                        tag.s.V    = tmp_tag.cn30xx.V;
                        tag.s.D    = tmp_tag.cn30xx.D;
                        tag.s.L    = tmp_tag.cn30xx.L;
                        tag.s.U    = tmp_tag.cn30xx.U;
                        tag.s.addr = tmp_tag.cn30xx.addr;
                } else if (OCTEON_IS_MODEL(OCTEON_CN50XX)) {
                        tag.s.V    = tmp_tag.cn50xx.V;
                        tag.s.D    = tmp_tag.cn50xx.D;
                        tag.s.L    = tmp_tag.cn50xx.L;
                        tag.s.U    = tmp_tag.cn50xx.U;
                        tag.s.addr = tmp_tag.cn50xx.addr;
                } else {
                        cvmx_dprintf("Unsupported OCTEON Model in %s\n", __func__);
                }
        }
        return tag;
}

uint32_t cvmx_l2c_address_to_index(uint64_t addr)
{
        uint64_t idx = addr >> CVMX_L2C_IDX_ADDR_SHIFT;
        int indxalias = 0;

        if (OCTEON_IS_MODEL(OCTEON_CN6XXX)) {
                union cvmx_l2c_ctl l2c_ctl;

                l2c_ctl.u64 = cvmx_read_csr(CVMX_L2C_CTL);
                indxalias = !l2c_ctl.s.disidxalias;
        } else {
                union cvmx_l2c_cfg l2c_cfg;

                l2c_cfg.u64 = cvmx_read_csr(CVMX_L2C_CFG);
                indxalias = l2c_cfg.s.idxalias;
        }

        if (indxalias) {
                if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                        uint32_t a_14_12 = (idx / (CVMX_L2C_MEMBANK_SELECT_SIZE/(1<<CVMX_L2C_IDX_ADDR_SHIFT))) & 0x7;

                        idx ^= idx / cvmx_l2c_get_num_sets();
                        idx ^= a_14_12;
                } else {
                        idx ^= ((addr & CVMX_L2C_ALIAS_MASK) >> CVMX_L2C_TAG_ADDR_ALIAS_SHIFT);
                }
        }
        idx &= CVMX_L2C_IDX_MASK;
        return idx;
}

int cvmx_l2c_get_cache_size_bytes(void)
{
        return cvmx_l2c_get_num_sets() * cvmx_l2c_get_num_assoc() *
                CVMX_CACHE_LINE_SIZE;
}

/**
 * Return log base 2 of the number of sets in the L2 cache
 * Returns
 */
int cvmx_l2c_get_set_bits(void)
{
        int l2_set_bits;

        if (OCTEON_IS_MODEL(OCTEON_CN56XX) || OCTEON_IS_MODEL(OCTEON_CN58XX))
                l2_set_bits = 11;       /* 2048 sets */
        else if (OCTEON_IS_MODEL(OCTEON_CN38XX) || OCTEON_IS_MODEL(OCTEON_CN63XX))
                l2_set_bits = 10;       /* 1024 sets */
        else if (OCTEON_IS_MODEL(OCTEON_CN31XX) || OCTEON_IS_MODEL(OCTEON_CN52XX))
                l2_set_bits = 9;        /* 512 sets */
        else if (OCTEON_IS_MODEL(OCTEON_CN30XX))
                l2_set_bits = 8;        /* 256 sets */
        else if (OCTEON_IS_MODEL(OCTEON_CN50XX))
                l2_set_bits = 7;        /* 128 sets */
        else {
                cvmx_dprintf("Unsupported OCTEON Model in %s\n", __func__);
                l2_set_bits = 11;       /* 2048 sets */
        }
        return l2_set_bits;
}

/* Return the number of sets in the L2 Cache */
int cvmx_l2c_get_num_sets(void)
{
        return 1 << cvmx_l2c_get_set_bits();
}

/* Return the number of associations in the L2 Cache */
int cvmx_l2c_get_num_assoc(void)
{
        int l2_assoc;

        if (OCTEON_IS_MODEL(OCTEON_CN56XX) ||
            OCTEON_IS_MODEL(OCTEON_CN52XX) ||
            OCTEON_IS_MODEL(OCTEON_CN58XX) ||
            OCTEON_IS_MODEL(OCTEON_CN50XX) ||
            OCTEON_IS_MODEL(OCTEON_CN38XX))
                l2_assoc = 8;
        else if (OCTEON_IS_MODEL(OCTEON_CN63XX))
                l2_assoc = 16;
        else if (OCTEON_IS_MODEL(OCTEON_CN31XX) ||
                 OCTEON_IS_MODEL(OCTEON_CN30XX))
                l2_assoc = 4;
        else {
                cvmx_dprintf("Unsupported OCTEON Model in %s\n", __func__);
                l2_assoc = 8;
        }

        /* Check to see if part of the cache is disabled */
        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                union cvmx_mio_fus_dat3 mio_fus_dat3;

                mio_fus_dat3.u64 = cvmx_read_csr(CVMX_MIO_FUS_DAT3);
                /*
                 * cvmx_mio_fus_dat3.s.l2c_crip fuses map as follows
                 * <2> will be not used for 63xx
                 * <1> disables 1/2 ways
                 * <0> disables 1/4 ways
                 * They are cumulative, so for 63xx:
                 * <1> <0>
                 * 0 0 16-way 2MB cache
                 * 0 1 12-way 1.5MB cache
                 * 1 0 8-way 1MB cache
                 * 1 1 4-way 512KB cache
                 */

                if (mio_fus_dat3.s.l2c_crip == 3)
                        l2_assoc = 4;
                else if (mio_fus_dat3.s.l2c_crip == 2)
                        l2_assoc = 8;
                else if (mio_fus_dat3.s.l2c_crip == 1)
                        l2_assoc = 12;
        } else {
                uint64_t l2d_fus3;

                l2d_fus3 = cvmx_read_csr(CVMX_L2D_FUS3);
                /*
                 * Using shifts here, as bit position names are
                 * different for each model but they all mean the
                 * same.
                 */
                if ((l2d_fus3 >> 35) & 0x1)
                        l2_assoc = l2_assoc >> 2;
                else if ((l2d_fus3 >> 34) & 0x1)
                        l2_assoc = l2_assoc >> 1;
        }
        return l2_assoc;
}

/**
 * Flush a line from the L2 cache
 * This should only be called from one core at a time, as this routine
 * sets the core to the 'debug' core in order to flush the line.
 *
 * @assoc:  Association (or way) to flush
 * @index:  Index to flush
 */
void cvmx_l2c_flush_line(uint32_t assoc, uint32_t index)
{
        /* Check the range of the index. */
        if (index > (uint32_t)cvmx_l2c_get_num_sets()) {
                cvmx_dprintf("ERROR: cvmx_l2c_flush_line index out of range.\n");
                return;
        }

        /* Check the range of association. */
        if (assoc > (uint32_t)cvmx_l2c_get_num_assoc()) {
                cvmx_dprintf("ERROR: cvmx_l2c_flush_line association out of range.\n");
                return;
        }

        if (OCTEON_IS_MODEL(OCTEON_CN63XX)) {
                uint64_t address;
                /* Create the address based on index and association.
                 * Bits<20:17> select the way of the cache block involved in
                 *             the operation
                 * Bits<16:7> of the effect address select the index
                 */
                address = CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
                                (assoc << CVMX_L2C_TAG_ADDR_ALIAS_SHIFT) |
                                (index << CVMX_L2C_IDX_ADDR_SHIFT));
                CVMX_CACHE_WBIL2I(address, 0);
        } else {
                union cvmx_l2c_dbg l2cdbg;

                l2cdbg.u64 = 0;
                if (!OCTEON_IS_MODEL(OCTEON_CN30XX))
                        l2cdbg.s.ppnum = cvmx_get_core_num();
                l2cdbg.s.finv = 1;

                l2cdbg.s.set = assoc;
                cvmx_spinlock_lock(&cvmx_l2c_spinlock);
                /*
                 * Enter debug mode, and make sure all other writes
                 * complete before we enter debug mode
                 */
                CVMX_SYNC;
                cvmx_write_csr(CVMX_L2C_DBG, l2cdbg.u64);
                cvmx_read_csr(CVMX_L2C_DBG);

                CVMX_PREPARE_FOR_STORE(CVMX_ADD_SEG(CVMX_MIPS_SPACE_XKPHYS,
                                                    index * CVMX_CACHE_LINE_SIZE),
                                       0);
                /* Exit debug mode */
                CVMX_SYNC;
                cvmx_write_csr(CVMX_L2C_DBG, 0);
                cvmx_read_csr(CVMX_L2C_DBG);
                cvmx_spinlock_unlock(&cvmx_l2c_spinlock);
        }
}