lib/xlat_tables/aarch64/xlat_tables.c

/*
 * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <cassert.h>
#include <platform_def.h>
#include <xlat_tables.h>
#include "../xlat_tables_private.h"

#define IS_POWER_OF_TWO(x)	(((x) & ((x) - 1)) == 0)

/*
 * The virtual address space size must be a power of two (as set in TCR.T0SZ).
 * As we start the initial lookup at level 1, it must also be between 2 GB and
 * 512 GB (with the virtual address size therefore 31 to 39 bits). See section
 * D4.2.5 in the ARMv8-A Architecture Reference Manual (DDI 0487A.i) for more
 * information.
 */
CASSERT(ADDR_SPACE_SIZE >= (1ull << 31) && ADDR_SPACE_SIZE <= (1ull << 39) &&
	IS_POWER_OF_TWO(ADDR_SPACE_SIZE), assert_valid_addr_space_size);

#define UNSET_DESC	~0ul
#define NUM_L1_ENTRIES (ADDR_SPACE_SIZE >> L1_XLAT_ADDRESS_SHIFT)

static uint64_t l1_xlation_table[NUM_L1_ENTRIES]
		__aligned(NUM_L1_ENTRIES * sizeof(uint64_t));

static unsigned long long tcr_ps_bits;

static unsigned long long calc_physical_addr_size_bits(
					unsigned long long max_addr)
{
	/* Physical address can't exceed 48 bits */
	assert((max_addr & ADDR_MASK_48_TO_63) == 0);

	/* 48 bits address */
	if (max_addr & ADDR_MASK_44_TO_47)
		return TCR_PS_BITS_256TB;

	/* 44 bits address */
	if (max_addr & ADDR_MASK_42_TO_43)
		return TCR_PS_BITS_16TB;

	/* 42 bits address */
	if (max_addr & ADDR_MASK_40_TO_41)
		return TCR_PS_BITS_4TB;

	/* 40 bits address */
	if (max_addr & ADDR_MASK_36_TO_39)
		return TCR_PS_BITS_1TB;

	/* 36 bits address */
	if (max_addr & ADDR_MASK_32_TO_35)
		return TCR_PS_BITS_64GB;

	return TCR_PS_BITS_4GB;
}

void init_xlat_tables(void)
{
	unsigned long long max_pa;
	uintptr_t max_va;
	print_mmap();
	init_xlation_table(0, l1_xlation_table, 1, &max_va, &max_pa);
	tcr_ps_bits = calc_physical_addr_size_bits(max_pa);
	assert(max_va < ADDR_SPACE_SIZE);
}

/*******************************************************************************
 * Macro generating the code for the function enabling the MMU in the given
 * exception level, assuming that the pagetables have already been created.
 *
 *   _el:		Exception level at which the function will run
 *   _tcr_extra:	Extra bits to set in the TCR register. This mask will
 *			be OR'ed with the default TCR value.
 *   _tlbi_fct:		Function to invalidate the TLBs at the current
 *			exception level
 ******************************************************************************/
#define DEFINE_ENABLE_MMU_EL(_el, _tcr_extra, _tlbi_fct)		\
	void enable_mmu_el##_el(unsigned int flags)				\
	{								\
		uint64_t mair, tcr, ttbr;				\
		uint32_t sctlr;						\
									\
		assert(IS_IN_EL(_el));					\
		assert((read_sctlr_el##_el() & SCTLR_M_BIT) == 0);	\
									\
		/* Set attributes in the right indices of the MAIR */	\
		mair = MAIR_ATTR_SET(ATTR_DEVICE, ATTR_DEVICE_INDEX);	\
		mair |= MAIR_ATTR_SET(ATTR_IWBWA_OWBWA_NTR,		\
				ATTR_IWBWA_OWBWA_NTR_INDEX);		\
		mair |= MAIR_ATTR_SET(ATTR_NON_CACHEABLE,		\
				ATTR_NON_CACHEABLE_INDEX);		\
		write_mair_el##_el(mair);				\
									\
		/* Invalidate TLBs at the current exception level */	\
		_tlbi_fct();						\
									\
		/* Set TCR bits as well. */				\
		/* Inner & outer WBWA & shareable + T0SZ = 32 */	\
		tcr = TCR_SH_INNER_SHAREABLE | TCR_RGN_OUTER_WBA |	\
			TCR_RGN_INNER_WBA |				\
			(64 - __builtin_ctzl(ADDR_SPACE_SIZE));		\
		tcr |= _tcr_extra;					\
		write_tcr_el##_el(tcr);					\
									\
		/* Set TTBR bits as well */				\
		ttbr = (uint64_t) l1_xlation_table;			\
		write_ttbr0_el##_el(ttbr);				\
									\
		/* Ensure all translation table writes have drained */	\
		/* into memory, the TLB invalidation is complete, */	\
		/* and translation register writes are committed */	\
		/* before enabling the MMU */				\
		dsb();							\
		isb();							\
									\
		sctlr = read_sctlr_el##_el();				\
		sctlr |= SCTLR_WXN_BIT | SCTLR_M_BIT;			\
									\
		if (flags & DISABLE_DCACHE)				\
			sctlr &= ~SCTLR_C_BIT;				\
		else							\
			sctlr |= SCTLR_C_BIT;				\
									\
		write_sctlr_el##_el(sctlr);				\
									\
		/* Ensure the MMU enable takes effect immediately */	\
		isb();							\
	}

/* Define EL1 and EL3 variants of the function enabling the MMU */
DEFINE_ENABLE_MMU_EL(1,
		(tcr_ps_bits << TCR_EL1_IPS_SHIFT),
		tlbivmalle1)
DEFINE_ENABLE_MMU_EL(3,
		TCR_EL3_RES1 | (tcr_ps_bits << TCR_EL3_PS_SHIFT),
		tlbialle3)