Add generic functions for setting up aarch64 MMU translation tables

Change-Id: I5b8d040ebc6672e40e4f13925e2fd5bc124103f4 Signed-off-by: Jon Medhurst <tixy@linaro.org>
11 years ago · c481c26987
3 changed files with 314 additions and 1 deletions
--- a/include/aarch64/arch.h
+++ b/include/aarch64/arch.h
@ -259,7 +259,26 @@
 #define OSH			(0x2 << 6)
 #define ISH			(0x3 << 6)

-#define IS_PAGE_ALIGNED(addr)	(((addr) & 0xFFF) == 0)
+#define PAGE_SIZE_SHIFT		FOUR_KB_SHIFT
+#define PAGE_SIZE		(1 << PAGE_SIZE_SHIFT)
+#define PAGE_SIZE_MASK		(PAGE_SIZE - 1)
+#define IS_PAGE_ALIGNED(addr)	(((addr) & PAGE_SIZE_MASK) == 0)
+
+#define XLAT_ENTRY_SIZE_SHIFT	3 /* Each MMU table entry is 8 bytes (1 << 3) */
+#define XLAT_ENTRY_SIZE		(1 << XLAT_ENTRY_SIZE_SHIFT)
+
+#define XLAT_TABLE_SIZE_SHIFT	PAGE_SIZE_SHIFT
+#define XLAT_TABLE_SIZE		(1 << XLAT_TABLE_SIZE_SHIFT)
+
+/* Values for number of entries in each MMU translation table */
+#define XLAT_TABLE_ENTRIES_SHIFT (XLAT_TABLE_SIZE_SHIFT - XLAT_ENTRY_SIZE_SHIFT)
+#define XLAT_TABLE_ENTRIES	(1 << XLAT_TABLE_ENTRIES_SHIFT)
+#define XLAT_TABLE_ENTRIES_MASK	(XLAT_TABLE_ENTRIES - 1)
+
+/* Values to convert a memory address to an index into a translation table */
+#define L3_XLAT_ADDRESS_SHIFT	PAGE_SIZE_SHIFT
+#define L2_XLAT_ADDRESS_SHIFT	(L3_XLAT_ADDRESS_SHIFT + XLAT_TABLE_ENTRIES_SHIFT)
+#define L1_XLAT_ADDRESS_SHIFT	(L2_XLAT_ADDRESS_SHIFT + XLAT_TABLE_ENTRIES_SHIFT)

 /*
 * AP[1] bit is ignored by hardware and is
--- a/include/aarch64/xlat_tables.h
+++ b/include/aarch64/xlat_tables.h
@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2014, 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 <stdint.h>
+
+/*
+ * Flags for building up memory mapping attributes.
+ * These are organised so that a clear bit gives a more restrictive  mapping
+ * that a set bit, that way a bitwise-and two sets of attributes will never give
+ * an attribute which has greater access rights that any of the original
+ * attributes.
+ */
+typedef enum  {
+	MT_DEVICE	= 0 << 0,
+	MT_MEMORY	= 1 << 0,
+
+	MT_RO		= 0 << 1,
+	MT_RW		= 1 << 1,
+
+	MT_SECURE	= 0 << 2,
+	MT_NS		= 1 << 2
+} mmap_attr;
+
+/*
+ * Structure for specifying a single region of memory.
+ */
+typedef struct {
+	unsigned long	base;
+	unsigned long	size;
+	mmap_attr	attr;
+} mmap_region;
+
+extern void mmap_add_region(unsigned long base, unsigned long size,
+				unsigned attr);
+extern void mmap_add(const mmap_region *mm);
+
+extern void init_xlat_tables(void);
+
+extern uint64_t l1_xlation_table[];
--- a/lib/arch/aarch64/xlat_tables.c
+++ b/lib/arch/aarch64/xlat_tables.c
@ -0,0 +1,228 @@
+/*
+ * Copyright (c) 2014, 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 <assert.h>
+#include <platform.h>
+#include <string.h>
+#include <xlat_tables.h>
+
+
+#ifndef DEBUG_XLAT_TABLE
+#define DEBUG_XLAT_TABLE 0
+#endif
+
+#if DEBUG_XLAT_TABLE
+#define debug_print(...) printf(__VA_ARGS__)
+#else
+#define debug_print(...) ((void)0)
+#endif
+
+
+#define UNSET_DESC	~0ul
+
+#define NUM_L1_ENTRIES (ADDR_SPACE_SIZE >> L1_XLAT_ADDRESS_SHIFT)
+
+uint64_t l1_xlation_table[NUM_L1_ENTRIES]
+__aligned(NUM_L1_ENTRIES * sizeof(uint64_t));
+
+static uint64_t xlat_tables[MAX_XLAT_TABLES][XLAT_TABLE_ENTRIES]
+__aligned(XLAT_TABLE_SIZE) __attribute__((section("xlat_table")));
+
+static unsigned next_xlat;
+
+/*
+ * Array of all memory regions stored in order of ascending base address.
+ * The list is terminated by the first entry with size == 0.
+ */
+static mmap_region mmap[MAX_MMAP_REGIONS + 1];
+
+
+static void print_mmap(void)
+{
+#if DEBUG_XLAT_TABLE
+	debug_print("mmap:\n");
+	mmap_region *mm = mmap;
+	while (mm->size) {
+		debug_print(" %010lx %10lx %x\n", mm->base, mm->size, mm->attr);
+		++mm;
+	};
+	debug_print("\n");
+#endif
+}
+
+void mmap_add_region(unsigned long base, unsigned long size, unsigned attr)
+{
+	mmap_region *mm = mmap;
+	mmap_region *mm_last = mm + sizeof(mmap) / sizeof(mmap[0]) - 1;
+
+	assert(IS_PAGE_ALIGNED(base));
+	assert(IS_PAGE_ALIGNED(size));
+
+	if (!size)
+		return;
+
+	/* Find correct place in mmap to insert new region */
+	while (mm->base < base && mm->size)
+		++mm;
+
+	/* Make room for new region by moving other regions up by one place */
+	memmove(mm + 1, mm, (uintptr_t)mm_last - (uintptr_t)mm);
+
+	/* Check we haven't lost the empty sentinal from the end of the array */
+	assert(mm_last->size == 0);
+
+	mm->base = base;
+	mm->size = size;
+	mm->attr = attr;
+}
+
+void mmap_add(const mmap_region *mm)
+{
+	while (mm->size) {
+		mmap_add_region(mm->base, mm->size, mm->attr);
+		++mm;
+	}
+}
+
+static unsigned long mmap_desc(unsigned attr, unsigned long addr,
+					unsigned level)
+{
+	unsigned long desc = addr;
+
+	desc |= level == 3 ? TABLE_DESC : BLOCK_DESC;
+
+	desc |= attr & MT_NS ? LOWER_ATTRS(NS) : 0;
+
+	desc |= attr & MT_RW ? LOWER_ATTRS(AP_RW) : LOWER_ATTRS(AP_RO);
+
+	desc |= LOWER_ATTRS(ACCESS_FLAG);
+
+	if (attr & MT_MEMORY) {
+		desc |= LOWER_ATTRS(ATTR_IWBWA_OWBWA_NTR_INDEX | ISH);
+		if (attr & MT_RW)
+			desc |= UPPER_ATTRS(XN);
+	} else {
+		desc |= LOWER_ATTRS(ATTR_DEVICE_INDEX | OSH);
+		desc |= UPPER_ATTRS(XN);
+	}
+
+	debug_print(attr & MT_MEMORY ? "MEM" : "DEV");
+	debug_print(attr & MT_RW ? "-RW" : "-RO");
+	debug_print(attr & MT_NS ? "-NS" : "-S");
+
+	return desc;
+}
+
+static int mmap_region_attr(mmap_region *mm, unsigned long base,
+					unsigned long size)
+{
+	int attr = mm->attr;
+
+	for (;;) {
+		++mm;
+
+		if (!mm->size)
+			return attr; /* Reached end of list */
+
+		if (mm->base >= base + size)
+			return attr; /* Next region is after area so end */
+
+		if (mm->base + mm->size <= base)
+			continue; /* Next region has already been overtaken */
+
+		if ((mm->attr & attr) == attr)
+			continue; /* Region doesn't override attribs so skip */
+
+		attr &= mm->attr;
+
+		if (mm->base > base || mm->base + mm->size < base + size)
+			return -1; /* Region doesn't fully cover our area */
+	}
+}
+
+static mmap_region *init_xlation_table(mmap_region *mm, unsigned long base,
+					unsigned long *table, unsigned level)
+{
+	unsigned level_size_shift = L1_XLAT_ADDRESS_SHIFT - (level - 1) *
+						XLAT_TABLE_ENTRIES_SHIFT;
+	unsigned level_size = 1 << level_size_shift;
+	unsigned level_index_mask = XLAT_TABLE_ENTRIES_MASK << level_size_shift;
+
+	assert(level <= 3);
+
+	debug_print("New xlat table:\n");
+
+	do  {
+		unsigned long desc = UNSET_DESC;
+
+		if (mm->base + mm->size <= base) {
+			/* Area now after the region so skip it */
+			++mm;
+			continue;
+		}
+
+		debug_print("      %010lx %8lx " + 6 - 2 * level, base, level_size);
+
+		if (mm->base >= base + level_size) {
+			/* Next region is after area so nothing to map yet */
+			desc = INVALID_DESC;
+		} else if (mm->base <= base &&
+				mm->base + mm->size >= base + level_size) {
+			/* Next region covers all of area */
+			int attr = mmap_region_attr(mm, base, level_size);
+			if (attr >= 0)
+				desc = mmap_desc(attr, base, level);
+		}
+		/* else Next region only partially covers area, so need */
+
+		if (desc == UNSET_DESC) {
+			/* Area not covered by a region so need finer table */
+			unsigned long *new_table = xlat_tables[next_xlat++];
+			assert(next_xlat <= MAX_XLAT_TABLES);
+			desc = TABLE_DESC | (unsigned long)new_table;
+
+			/* Recurse to fill in new table */
+			mm = init_xlation_table(mm, base, new_table, level+1);
+		}
+
+		debug_print("\n");
+
+		*table++ = desc;
+		base += level_size;
+	} while (mm->size && (base & level_index_mask));
+
+	return mm;
+}
+
+void init_xlat_tables(void)
+{
+	print_mmap();
+	init_xlation_table(mmap, 0, l1_xlation_table, 1);
+}