// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
 * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
 */

#include <common.h>
#include <cpu_func.h>
#include <errno.h>
#include <log.h>
#include <asm/armv7m.h>
#include <asm/cache.h>
#include <asm/io.h>
#include <linux/bitops.h>

/* Cache maintenance operation registers */

#define V7M_CACHE_REG_ICIALLU           ((u32 *)(V7M_CACHE_MAINT_BASE + 0x00))
#define INVAL_ICACHE_POU                0
#define V7M_CACHE_REG_ICIMVALU          ((u32 *)(V7M_CACHE_MAINT_BASE + 0x08))
#define V7M_CACHE_REG_DCIMVAC           ((u32 *)(V7M_CACHE_MAINT_BASE + 0x0C))
#define V7M_CACHE_REG_DCISW             ((u32 *)(V7M_CACHE_MAINT_BASE + 0x10))
#define V7M_CACHE_REG_DCCMVAU           ((u32 *)(V7M_CACHE_MAINT_BASE + 0x14))
#define V7M_CACHE_REG_DCCMVAC           ((u32 *)(V7M_CACHE_MAINT_BASE + 0x18))
#define V7M_CACHE_REG_DCCSW             ((u32 *)(V7M_CACHE_MAINT_BASE + 0x1C))
#define V7M_CACHE_REG_DCCIMVAC          ((u32 *)(V7M_CACHE_MAINT_BASE + 0x20))
#define V7M_CACHE_REG_DCCISW            ((u32 *)(V7M_CACHE_MAINT_BASE + 0x24))
#define WAYS_SHIFT                      30
#define SETS_SHIFT                      5

/* armv7m processor feature registers */

#define V7M_PROC_REG_CLIDR              ((u32 *)(V7M_PROC_FTR_BASE + 0x00))
#define V7M_PROC_REG_CTR                ((u32 *)(V7M_PROC_FTR_BASE + 0x04))
#define V7M_PROC_REG_CCSIDR             ((u32 *)(V7M_PROC_FTR_BASE + 0x08))
#define MASK_NUM_WAYS                   GENMASK(12, 3)
#define MASK_NUM_SETS                   GENMASK(27, 13)
#define CLINE_SIZE_MASK                 GENMASK(2, 0)
#define NUM_WAYS_SHIFT                  3
#define NUM_SETS_SHIFT                  13
#define V7M_PROC_REG_CSSELR             ((u32 *)(V7M_PROC_FTR_BASE + 0x0C))
#define SEL_I_OR_D                      BIT(0)

enum cache_type {
        DCACHE,
        ICACHE,
};

/* PoU : Point of Unification, Poc: Point of Coherency */
enum cache_action {
        INVALIDATE_POU,         /* i-cache invalidate by address */
        INVALIDATE_POC,         /* d-cache invalidate by address */
        INVALIDATE_SET_WAY,     /* d-cache invalidate by sets/ways */
        FLUSH_POU,              /* d-cache clean by address to the PoU */
        FLUSH_POC,              /* d-cache clean by address to the PoC */
        FLUSH_SET_WAY,          /* d-cache clean by sets/ways */
        FLUSH_INVAL_POC,        /* d-cache clean & invalidate by addr to PoC */
        FLUSH_INVAL_SET_WAY,    /* d-cache clean & invalidate by set/ways */
};

#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
struct dcache_config {
        u32 ways;
        u32 sets;
};

static void get_cache_ways_sets(struct dcache_config *cache)
{
        u32 cache_size_id = readl(V7M_PROC_REG_CCSIDR);

        cache->ways = (cache_size_id & MASK_NUM_WAYS) >> NUM_WAYS_SHIFT;
        cache->sets = (cache_size_id & MASK_NUM_SETS) >> NUM_SETS_SHIFT;
}

/*
 * Return the io register to perform required cache action like clean or clean
 * & invalidate by sets/ways.
 */
static u32 *get_action_reg_set_ways(enum cache_action action)
{
        switch (action) {
        case INVALIDATE_SET_WAY:
                return V7M_CACHE_REG_DCISW;
        case FLUSH_SET_WAY:
                return V7M_CACHE_REG_DCCSW;
        case FLUSH_INVAL_SET_WAY:
                return V7M_CACHE_REG_DCCISW;
        default:
                break;
        };

        return NULL;
}

/*
 * Return the io register to perform required cache action like clean or clean
 * & invalidate by adddress or range.
 */
static u32 *get_action_reg_range(enum cache_action action)
{
        switch (action) {
        case INVALIDATE_POU:
                return V7M_CACHE_REG_ICIMVALU;
        case INVALIDATE_POC:
                return V7M_CACHE_REG_DCIMVAC;
        case FLUSH_POU:
                return V7M_CACHE_REG_DCCMVAU;
        case FLUSH_POC:
                return V7M_CACHE_REG_DCCMVAC;
        case FLUSH_INVAL_POC:
                return V7M_CACHE_REG_DCCIMVAC;
        default:
                break;
        }

        return NULL;
}

static u32 get_cline_size(enum cache_type type)
{
        u32 size;

        if (type == DCACHE)
                clrbits_le32(V7M_PROC_REG_CSSELR, BIT(SEL_I_OR_D));
        else if (type == ICACHE)
                setbits_le32(V7M_PROC_REG_CSSELR, BIT(SEL_I_OR_D));
        /* Make sure cache selection is effective for next memory access */
        dsb();

        size = readl(V7M_PROC_REG_CCSIDR) & CLINE_SIZE_MASK;
        /* Size enocoded as 2 less than log(no_of_words_in_cache_line) base 2 */
        size = 1 << (size + 2);
        debug("cache line size is %d\n", size);

        return size;
}

/* Perform the action like invalidate/clean on a range of cache addresses */
static int action_cache_range(enum cache_action action, u32 start_addr,
                              int64_t size)
{
        u32 cline_size;
        u32 *action_reg;
        enum cache_type type;

        action_reg = get_action_reg_range(action);
        if (!action_reg)
                return -EINVAL;
        if (action == INVALIDATE_POU)
                type = ICACHE;
        else
                type = DCACHE;

        /* Cache line size is minium size for the cache action */
        cline_size = get_cline_size(type);
        /* Align start address to cache line boundary */
        start_addr &= ~(cline_size - 1);
        debug("total size for cache action = %llx\n", size);
        do {
                writel(start_addr, action_reg);
                size -= cline_size;
                start_addr += cline_size;
        } while (size > cline_size);

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */
        debug("cache action on range done\n");

        return 0;
}

/* Perform the action like invalidate/clean on all cached addresses */
static int action_dcache_all(enum cache_action action)
{
        struct dcache_config cache;
        u32 *action_reg;
        int i, j;

        action_reg = get_action_reg_set_ways(action);
        if (!action_reg)
                return -EINVAL;

        clrbits_le32(V7M_PROC_REG_CSSELR, BIT(SEL_I_OR_D));
        /* Make sure cache selection is effective for next memory access */
        dsb();

        get_cache_ways_sets(&cache);    /* Get number of ways & sets */
        debug("cache: ways= %d, sets= %d\n", cache.ways + 1, cache.sets + 1);
        for (i = cache.sets; i >= 0; i--) {
                for (j = cache.ways; j >= 0; j--) {
                        writel((j << WAYS_SHIFT) | (i << SETS_SHIFT),
                               action_reg);
                }
        }

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */

        return 0;
}

void dcache_enable(void)
{
        if (dcache_status())    /* return if cache already enabled */
                return;

        if (action_dcache_all(INVALIDATE_SET_WAY)) {
                printf("ERR: D-cache not enabled\n");
                return;
        }

        setbits_le32(&V7M_SCB->ccr, BIT(V7M_CCR_DCACHE));

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */
}

void dcache_disable(void)
{
        if (!dcache_status())
                return;

        /* if dcache is enabled-> dcache disable & then flush */
        if (action_dcache_all(FLUSH_SET_WAY)) {
                printf("ERR: D-cache not flushed\n");
                return;
        }

        clrbits_le32(&V7M_SCB->ccr, BIT(V7M_CCR_DCACHE));

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */
}

int dcache_status(void)
{
        return (readl(&V7M_SCB->ccr) & BIT(V7M_CCR_DCACHE)) != 0;
}

void invalidate_dcache_range(unsigned long start, unsigned long stop)
{
        if (action_cache_range(INVALIDATE_POC, start, stop - start)) {
                printf("ERR: D-cache not invalidated\n");
                return;
        }
}

void flush_dcache_range(unsigned long start, unsigned long stop)
{
        if (action_cache_range(FLUSH_POC, start, stop - start)) {
                printf("ERR: D-cache not flushed\n");
                return;
        }
}
void flush_dcache_all(void)
{
        if (action_dcache_all(FLUSH_SET_WAY)) {
                printf("ERR: D-cache not flushed\n");
                return;
        }
}

void invalidate_dcache_all(void)
{
        if (action_dcache_all(INVALIDATE_SET_WAY)) {
                printf("ERR: D-cache not invalidated\n");
                return;
        }
}
#else
void dcache_enable(void)
{
        return;
}

void dcache_disable(void)
{
        return;
}

int dcache_status(void)
{
        return 0;
}

void flush_dcache_all(void)
{
}

void invalidate_dcache_all(void)
{
}

void mmu_set_region_dcache_behaviour(phys_addr_t start, size_t size,
                                     enum dcache_option option)
{
}

#endif

#if !CONFIG_IS_ENABLED(SYS_ICACHE_OFF)

void invalidate_icache_all(void)
{
        writel(INVAL_ICACHE_POU, V7M_CACHE_REG_ICIALLU);

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */
}

void icache_enable(void)
{
        if (icache_status())
                return;

        invalidate_icache_all();
        setbits_le32(&V7M_SCB->ccr, BIT(V7M_CCR_ICACHE));

        /* Make sure cache action is effective for next memory access */
        dsb();
        isb();  /* Make sure instruction stream sees it */
}

int icache_status(void)
{
        return (readl(&V7M_SCB->ccr) & BIT(V7M_CCR_ICACHE)) != 0;
}

void icache_disable(void)
{
        if (!icache_status())
                return;

        isb();  /* flush pipeline */
        clrbits_le32(&V7M_SCB->ccr, BIT(V7M_CCR_ICACHE));
        isb();  /* subsequent instructions fetch see cache disable effect */
}
#else
void invalidate_icache_all(void)
{
        return;
}

void icache_enable(void)
{
        return;
}

void icache_disable(void)
{
        return;
}

int icache_status(void)
{
        return 0;
}
#endif

void enable_caches(void)
{
#if !CONFIG_IS_ENABLED(SYS_ICACHE_OFF)
        icache_enable();
#endif
#if !CONFIG_IS_ENABLED(SYS_DCACHE_OFF)
        dcache_enable();
#endif
}