xref: /nrf52832-nimble/rt-thread/libcpu/arm/armv6/mmu.c (revision 104654410c56c573564690304ae786df310c91fc)

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 */

#include "mmu.h"

#ifdef __CC_ARM
void mmu_setttbase(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, value, c8, c7, 0
	}

	value = 0x55555555;
	__asm volatile
	{
		mcr p15, 0, value, c3, c0, 0
			mcr p15, 0, i, c2, c0, 0
	}
}

void mmu_set_domain(rt_uint32_t i)
{
	__asm volatile
	{
		mcr p15,0, i, c3, c0,  0
	}
}

void mmu_enable()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			orr value, value, #0x01
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_disable()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			bic value, value, #0x01
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_enable_icache()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			orr value, value, #0x1000
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_enable_dcache()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			orr value, value, #0x04
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_disable_icache()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			bic value, value, #0x1000
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_disable_dcache()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			bic value, value, #0x04
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_enable_alignfault()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			orr value, value, #0x02
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_disable_alignfault()
{
	register rt_uint32_t value;

	__asm volatile
	{
		mrc p15, 0, value, c1, c0, 0
			bic value, value, #0x02
			mcr p15, 0, value, c1, c0, 0
	}
}

void mmu_clean_invalidated_cache_index(int index)
{
	__asm volatile
	{
		mcr p15, 0, index, c7, c14, 2
	}
}

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

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

	while(ptr < buffer + size)
	{
		__asm volatile
		{
			MCR p15, 0, ptr, c7, c14, 1
		}
		ptr += CACHE_LINE_SIZE;
	}
}

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

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

	while (ptr < buffer + size)
	{
		__asm volatile
		{
			MCR p15, 0, ptr, c7, c10, 1
		}
		ptr += CACHE_LINE_SIZE;
	}
}

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

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

	while (ptr < buffer + size)
	{
		__asm volatile
		{
			MCR p15, 0, ptr, c7, c6, 1
		}
		ptr += CACHE_LINE_SIZE;
	}
}

void mmu_invalidate_tlb()
{
	register rt_uint32_t value;

	value = 0;
	__asm volatile
	{
		mcr p15, 0, value, c8, c7, 0
	}
}

void mmu_invalidate_icache()
{
	register rt_uint32_t value;

	value = 0;

	__asm volatile
	{
		mcr p15, 0, value, c7, c5, 0
	}
}


void mmu_invalidate_dcache_all()
{
	register rt_uint32_t value;

	value = 0;

	__asm volatile
	{
		mcr p15, 0, value, c7, c6, 0
	}
}
#elif defined(__GNUC__)
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));
	asm volatile ("mcr p15, 0, %0, c2, c0, 0"::"r"(i));
}

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

void mmu_enable()
{
	register rt_uint32_t i;

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

	i |= 0x1;
	/* Enables the extended page tables to be configured for
	   the hardware page translation mechanism, Subpage AP bits disabled */
	i |= (1 << 23); /* support for ARMv6 MMU features */
	i |= (1 << 13); /* High exception vectors selected, address range = 0xFFFF0000-0xFFFF001C */

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

void mmu_disable()
{
	register rt_uint32_t i;

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

	i &= ~0x1;

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

void mmu_enable_icache()
{
	register rt_uint32_t i;

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

	i |= (1 << 12);

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

void mmu_enable_dcache()
{
	register rt_uint32_t i;

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

	i |= (1 << 2);

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

void mmu_disable_icache()
{
	register rt_uint32_t i;

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

	i &= ~(1 << 12);

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

void mmu_disable_dcache()
{
	register rt_uint32_t i;

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

	i &= ~(1 << 2);

	/* write back to control register */
	asm volatile ("mcr p15, 0, %0, c1, 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_invalidated_dcache(rt_uint32_t buffer, rt_uint32_t size)
{
	unsigned int ptr;

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

	while(ptr < buffer + size)
	{
		asm volatile ("mcr p15, 0, %0, c7, c14, 1": :"r" (ptr));
		ptr += CACHE_LINE_SIZE;
	}
}


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

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

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

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

	ptr = buffer & ~(CACHE_LINE_SIZE - 1);

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

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));
}

void mmu_invalidate_dcache_all()
{
	asm volatile ("mcr p15, 0, %0, c7, c6, 0": :"r" (0));
}
#endif

/* level1 page table */
static volatile unsigned int _pgd_table[4*1024] ALIGN(16*1024);
/*
 * level2 page table
 * RT_MMU_PTE_SIZE must be 1024*n
 */
#define RT_MMU_PTE_SIZE		4096
static volatile unsigned int _pte_table[RT_MMU_PTE_SIZE] ALIGN(1*1024);

void mmu_create_pgd(struct mem_desc *mdesc)
{
	volatile rt_uint32_t *pTT;
	volatile int i, nSec;
	pTT = (rt_uint32_t *)_pgd_table + (mdesc->vaddr_start >> 20);
	nSec = (mdesc->vaddr_end >> 20) - (mdesc->vaddr_start >> 20);
	for(i = 0; i <= nSec; i++)
	{
		*pTT = mdesc->sect_attr | (((mdesc->paddr_start >> 20) + i) << 20);
		pTT++;
	}
}

void mmu_create_pte(struct mem_desc *mdesc)
{
	volatile rt_uint32_t *pTT;
	volatile rt_uint32_t *p_pteentry;
	int i;
	rt_uint32_t vaddr;
	rt_uint32_t total_page = 0;
	rt_uint32_t pte_offset = 0;
	rt_uint32_t sect_attr = 0;

	total_page = (mdesc->vaddr_end >> 12) - (mdesc->vaddr_start >> 12) + 1;
	pte_offset = mdesc->sect_attr & 0xfffffc00;
	sect_attr = mdesc->sect_attr & 0x3ff;
	vaddr = mdesc->vaddr_start;

	for(i = 0; i < total_page; i++)
	{
		pTT = (rt_uint32_t *)_pgd_table + (vaddr >> 20);
		if (*pTT == 0) /* Level 1 page table item not used, now update pgd item */
		{
			*pTT = pte_offset | sect_attr;
			p_pteentry = (rt_uint32_t *)pte_offset +
				((vaddr & 0x000ff000) >> 12);
			pte_offset += 1024;
		}
		else /* using old Level 1 page table item */
		{
			p_pteentry = (rt_uint32_t *)(*pTT & 0xfffffc00) +
				((vaddr & 0x000ff000) >> 12);
		}


		*p_pteentry = mdesc->page_attr | (((mdesc->paddr_start >> 12) + i) << 12);
		vaddr += 0x1000;
	}
}

static void build_pte_mem_desc(struct mem_desc *mdesc, rt_uint32_t size)
{
	rt_uint32_t pte_offset = 0;
	rt_uint32_t nsec = 0;
	/* set page table */
	for (; size > 0; size--)
	{
		if (mdesc->mapped_mode == PAGE_MAPPED)
		{
			nsec = (RT_ALIGN(mdesc->vaddr_end, 0x100000) - RT_ALIGN_DOWN(mdesc->vaddr_start, 0x100000)) >> 20;
			mdesc->sect_attr |= (((rt_uint32_t)_pte_table)& 0xfffffc00) + pte_offset;
			pte_offset += nsec << 10;
		}
		if (pte_offset >= RT_MMU_PTE_SIZE)
		{
			rt_kprintf("PTE table size too little\n");
			RT_ASSERT(0);
		}

		mdesc++;
	}
}


void rt_hw_mmu_init(struct mem_desc *mdesc, rt_uint32_t size)
{
	/* disable I/D cache */
	mmu_disable_dcache();
	mmu_disable_icache();
	mmu_disable();
	mmu_invalidate_tlb();

	/* clear pgd and pte table */
	rt_memset((void *)_pgd_table, 0, 16*1024);
	rt_memset((void *)_pte_table, 0, RT_MMU_PTE_SIZE);
	build_pte_mem_desc(mdesc, size);
	/* set page table */
	for (; size > 0; size--)
	{
		if (mdesc->mapped_mode == SECT_MAPPED)
		{
			mmu_create_pgd(mdesc);
		}
		else
		{
			mmu_create_pte(mdesc);
		}

		mdesc++;
	}

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

	/* enables MMU */
	mmu_enable();

	/* enable Instruction Cache */
	mmu_enable_icache();

	/* enable Data Cache */
	mmu_enable_dcache();

	mmu_invalidate_icache();
	mmu_invalidate_dcache_all();
}