rt-thread-official/libcpu/arm/am335x/mmu.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2012-01-10     bernard      porting to AM1808
 */

#include <rtthread.h>
#include "am33xx.h"
#include <mmu.h>

extern void rt_cpu_dcache_disable(void);
extern void rt_hw_cpu_dcache_enable(void);
extern void rt_cpu_icache_disable(void);
extern void rt_hw_cpu_icache_enable(void);
extern void rt_cpu_mmu_disable(void);
extern void rt_cpu_mmu_enable(void);
extern void rt_cpu_tlb_set(register rt_uint32_t i);

void mmu_disable_dcache()
{
    rt_cpu_dcache_disable();
}

void mmu_enable_dcache()
{
    rt_hw_cpu_dcache_enable();
}

void mmu_disable_icache()
{
    rt_cpu_icache_disable();
}

void mmu_enable_icache()
{
    rt_hw_cpu_icache_enable();
}

void mmu_disable()
{
    rt_cpu_mmu_disable();
}

void mmu_enable()
{
    rt_cpu_mmu_enable();
}

void mmu_setttbase(register rt_uint32_t i)
{
    register rt_uint32_t value;

   /* Invalidates all TLBs.Domain access is selected as
    * client by configuring domain access register,
    * in that case access controlled by permission value
    * set by page table entry
    */
    value = 0;
    asm volatile ("mcr p15, 0, %0, c8, c7, 0"::"r"(value));

    value = 0x55555555;
    asm volatile ("mcr p15, 0, %0, c3, c0, 0"::"r"(value));

    rt_cpu_tlb_set(i);
}

void mmu_set_domain(register rt_uint32_t i)
{
    asm volatile ("mcr p15,0, %0, c3, c0,  0": :"r" (i));
}

void mmu_enable_alignfault()
{
    register rt_uint32_t i;

    /* read control register */
    asm volatile ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

    i |= (1 << 1);

    /* write back to control register */
    asm volatile ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void mmu_disable_alignfault()
{
    register rt_uint32_t i;

    /* read control register */
    asm volatile ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

    i &= ~(1 << 1);

    /* write back to control register */
    asm volatile ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void mmu_clean_invalidated_cache_index(int index)
{
    asm volatile ("mcr p15, 0, %0, c7, c14, 2": :"r" (index));
}

void mmu_clean_dcache(rt_uint32_t buffer, rt_uint32_t size)
{
    unsigned int ptr;

    ptr = buffer & ~0x1f;

    while (ptr < buffer + size)
    {
        asm volatile ("mcr p15, 0, %0, c7, c10, 1": :"r" (ptr));
        ptr += 32;
    }
}

void mmu_invalidate_dcache(rt_uint32_t buffer, rt_uint32_t size)
{
    unsigned int ptr;

    ptr = buffer & ~0x1f;

    while (ptr < buffer + size)
    {
        asm volatile ("mcr p15, 0, %0, c7, c6, 1": :"r" (ptr));
        ptr += 32;
    }
}

void mmu_invalidate_tlb()
{
    asm volatile ("mcr p15, 0, %0, c8, c7, 0": :"r" (0));
}

void mmu_invalidate_icache()
{
    asm volatile ("mcr p15, 0, %0, c7, c5, 0": :"r" (0));
}

/* level1 page table */
static volatile unsigned int _page_table[4*1024] __attribute__((aligned(16*1024)));
void mmu_setmtt(rt_uint32_t vaddrStart, rt_uint32_t vaddrEnd, rt_uint32_t paddrStart, rt_uint32_t attr)
{
    volatile rt_uint32_t *pTT;
    volatile int i,nSec;
    pTT=(rt_uint32_t *)_page_table+(vaddrStart>>20);
    nSec=(vaddrEnd>>20)-(vaddrStart>>20);
    for(i=0;i<=nSec;i++)
    {
        *pTT = attr |(((paddrStart>>20)+i)<<20);
        pTT++;
    }
}

/* set page table */
RT_WEAK void mmu_setmtts(void)
{
    mmu_setmtt(0x00000000, 0xFFFFFFFF,     0x00000000, RW_NCNB);  /* None cached for 4G memory   */
    mmu_setmtt(0x80200000, 0x80800000 - 1, 0x80200000, RW_CB);    /* 126M cached DDR memory      */
    mmu_setmtt(0x80000000, 0x80200000 - 1, 0x80000000, RW_NCNB);  /* 2M none-cached DDR memory   */
    mmu_setmtt(0x402F0000, 0x40300000 - 1, 0x402F0000, RW_CB);    /* 63K OnChip memory           */
}

void rt_hw_mmu_init(void)
{
    /* disable I/D cache */
    mmu_disable_dcache();
    mmu_disable_icache();
    mmu_disable();
    mmu_invalidate_tlb();

    mmu_setmtts();

    /* set MMU table address */
    mmu_setttbase((rt_uint32_t)_page_table);

    /* enables MMU */
    mmu_enable();

    /* enable Instruction Cache */
    mmu_enable_icache();

    /* enable Data Cache */
    mmu_enable_dcache();
}