AArch32: Add translation table library support

This patch adds translation library supports for AArch32 platforms.
The library only supports long descriptor formats for AArch32.
The `enable_mmu_secure()` enables the MMU for secure world with
`TTBR0` pointing to the populated translation tables.

Change-Id: I061345b1779391d098e35e7fe0c76e3ebf850e08

include/lib/xlat_tables.h

@@ -188,9 +188,14 @@ void mmap_add_region(unsigned long long base_pa, uintptr_t base_va,
 				size_t size, unsigned int attr);
 void mmap_add(const mmap_region_t *mm);
 
+#ifdef AARCH32
+/* AArch32 specific translation table API */
+void enable_mmu_secure(uint32_t flags);
+#else
 /* AArch64 specific translation table APIs */
 void enable_mmu_el1(unsigned int flags);
 void enable_mmu_el3(unsigned int flags);
+#endif /* AARCH32 */
 
 #endif /*__ASSEMBLY__*/
 #endif /* __XLAT_TABLES_H__ */

lib/xlat_tables/aarch32/xlat_tables.c

+/*
+ * Copyright (c) 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 <utils.h>
+#include <xlat_tables.h>
+#include "../xlat_tables_private.h"
+
+/*
+ * The virtual address space size must be a power of two. As we start the initial
+ * lookup at level 1, it must also be between 2 GB and 4 GB. See section
+ * G4.6.5 in the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
+ * information.
+ */
+CASSERT(ADDR_SPACE_SIZE >= (1ull << 31) && ADDR_SPACE_SIZE <= (1ull << 32) &&
+	IS_POWER_OF_TWO(ADDR_SPACE_SIZE), assert_valid_addr_space_size);
+
+#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));
+
+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);
+	assert(max_va < ADDR_SPACE_SIZE);
+}
+
+/*******************************************************************************
+ * Function for enabling the MMU in Secure PL1, assuming that the
+ * page-tables have already been created.
+ ******************************************************************************/
+void enable_mmu_secure(unsigned int flags)
+{
+	unsigned int mair0, ttbcr, sctlr;
+	uint64_t ttbr0;
+
+	assert(IS_IN_SECURE());
+	assert((read_sctlr() & SCTLR_M_BIT) == 0);
+
+	/* Set attributes in the right indices of the MAIR */
+	mair0 = MAIR0_ATTR_SET(ATTR_DEVICE, ATTR_DEVICE_INDEX);
+	mair0 |= MAIR0_ATTR_SET(ATTR_IWBWA_OWBWA_NTR,
+			ATTR_IWBWA_OWBWA_NTR_INDEX);
+	mair0 |= MAIR0_ATTR_SET(ATTR_NON_CACHEABLE,
+			ATTR_NON_CACHEABLE_INDEX);
+	write_mair0(mair0);
+
+	/* Invalidate TLBs at the current exception level */
+	tlbiall();
+
+	/*
+	 * Set TTBCR bits as well. Set TTBR0 table properties as Inner
+	 * & outer WBWA & shareable. Disable TTBR1.
+	 */
+	ttbcr = TTBCR_EAE_BIT |
+		TTBCR_SH0_INNER_SHAREABLE | TTBCR_RGN0_OUTER_WBA |
+		TTBCR_RGN0_INNER_WBA |
+		(32 - __builtin_ctzl((uintptr_t)ADDR_SPACE_SIZE));
+	ttbcr |= TTBCR_EPD1_BIT;
+	write_ttbcr(ttbcr);
+
+	/* Set TTBR0 bits as well */
+	ttbr0 = (uintptr_t) l1_xlation_table;
+	write64_ttbr0(ttbr0);
+	write64_ttbr1(0);
+
+	/*
+	 * 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();
+	sctlr |= SCTLR_WXN_BIT | SCTLR_M_BIT;
+
+	if (flags & DISABLE_DCACHE)
+		sctlr &= ~SCTLR_C_BIT;
+	else
+		sctlr |= SCTLR_C_BIT;
+
+	write_sctlr(sctlr);
+
+	/* Ensure the MMU enable takes effect immediately */
+	isb();
+}