mmu.c

Go to the documentation of this file.

/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <arch/cache.h>
#include <soc/soc_services.h>
#include <symbols.h>
#include "mmu.h"
 
/* convenient shorthand (in MB) */
#define RPM_START           ((uintptr_t)_rpm / KiB)
#define RPM_END             ((uintptr_t)_erpm / KiB)
#define RPM_SIZE            (RPM_END - RPM_START)
#define SRAM_START          ((uintptr_t)_sram / KiB)
#define SRAM_END            ((uintptr_t)_esram / KiB)
#define DRAM_START          ((uintptr_t)_dram / MiB)
#define DRAM_SIZE           (CONFIG_DRAM_SIZE_MB)
#define DRAM_END            (DRAM_START + DRAM_SIZE)
 
/* DMA memory for drivers */
#define DMA_START            ((uintptr_t)_dma_coherent / MiB)
#define DMA_SIZE             (REGION_SIZE(dma_coherent) / MiB)
 
void setup_dram_mappings(enum dram_state dram)
{
        if (dram == DRAM_INITIALIZED) {
                mmu_config_range(DRAM_START, DRAM_SIZE, DCACHE_WRITEBACK);
                /* Map DMA memory */
                mmu_config_range(DMA_START, DMA_SIZE, DCACHE_OFF);
                if (ENV_ROMSTAGE)
                        /* Mark cbmem backing store as ready. */
                        ipq_cbmem_backing_store_ready();
        } else {
                mmu_disable_range(DRAM_START, DRAM_SIZE);
                /* Map DMA memory */
                mmu_disable_range(DMA_START, DMA_SIZE);
        }
}
 
void setup_mmu(enum dram_state dram)
{
        dcache_mmu_disable();
 
        /* start with mapping everything as strongly ordered. */
        mmu_config_range(0, 4096, DCACHE_OFF);
 
        /* Map Device memory. */
        mmu_config_range_kb(RPM_START, RPM_SIZE, DCACHE_OFF);
 
        mmu_config_range_kb(SRAM_START, SRAM_END - SRAM_START,
                DCACHE_WRITEBACK);
 
        /* Map DRAM memory */
        setup_dram_mappings(dram);
 
        mmu_disable_range(DRAM_END, 4096 - DRAM_END);
 
        /* disable Page 0 for trapping NULL pointer references. */
        mmu_disable_range_kb(0, 1);
 
        mmu_init();
 
        dcache_mmu_enable();
}