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/*
* This file is part of the coreboot project.
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <config.h>
#include <stdlib.h>
#include <stdint.h>
#include <symbols.h>
#include <cbmem.h>
#include <console/console.h>
#include <arch/cache.h>
#include <arch/io.h>
#if CONFIG_ARM_LPAE
/* See B3.6.2 of ARMv7 Architecture Reference Manual */
/* TODO: Utilize the contiguous hint flag */
#define ATTR_BASE (\
0ULL << 54 | /* XN. 0:Not restricted */ \
0ULL << 53 | /* PXN. 0:Not restricted */ \
1 << 10 | /* AF. 1:Accessed. This is to prevent access \
* fault when accessed for the first time */ \
0 << 6 | /* AP[2:1]. 0b00:full access from PL1 */ \
0 << 5 | /* NS. 0:Output address is in Secure space */ \
0 << 1 | /* block/table. 0:block entry */ \
1 << 0 /* validity. 1:valid */ \
)
#define ATTR_NC (ATTR_BASE | (MAIR_INDX_NC << 2) | \
(1ULL << 53) | (1ULL << 54))
#define ATTR_WT (ATTR_BASE | (MAIR_INDX_WT << 2))
#define ATTR_WB (ATTR_BASE | (MAIR_INDX_WB << 2))
#define BLOCK_SHIFT 21
typedef uint64_t pgd_t;
typedef uint64_t pmd_t;
static const unsigned int denom = 2;
#else /* CONFIG_ARM_LPAE */
/*
* Section entry bits:
* 31:20 - section base address
* 18 - 0 to indicate normal section (versus supersection)
* 17 - nG, 0 to indicate page is global
* 16 - S, 0 for non-shareable (?)
* 15 - APX, 0 for full access
* 14:12 - TEX, 0b000 for outer and inner write-back
* 11:10 - AP, 0b11 for full access
* 9 - P, ? (FIXME: not described or possibly obsolete?)
* 8: 5 - Domain
* 4 - XN, 1 to set execute-never (and also avoid prefetches)
* 3 - C, 1 for cacheable
* 2 - B, 1 for bufferable
* 1: 0 - 0b10 to indicate section entry
*/
#define ATTR_BASE ((3 << 10) | 0x2)
#define ATTR_NC (ATTR_BASE | (1 << 4))
#define ATTR_WT (ATTR_BASE | (1 << 3))
#define ATTR_WB (ATTR_BASE | (1 << 3) | (1 << 2))
#define BLOCK_SHIFT 20
typedef uint32_t pgd_t;
typedef uint32_t pmd_t;
static const unsigned int denom = 1;
#endif /* CONFIG_ARM_LPAE */
static pmd_t *const ttb_buff = (pmd_t *)_ttb;
/*
* mask/shift/size for pages and blocks
*/
#define PAGE_SHIFT 12
#define PAGE_SIZE (1UL << PAGE_SHIFT)
#define PAGE_MASK ~((1UL << PAGE_SHIFT) - 1)
#define BLOCK_SIZE (1UL << BLOCK_SHIFT)
/*
* MAIR Index
*/
#define MAIR_INDX_NC 0
#define MAIR_INDX_WT 1
#define MAIR_INDX_WB 2
static void mmu_flush_page_table_entry_range(
unsigned long start_mb, unsigned long size_mb)
{
int i;
/* Flush the page table entries from the dcache. */
for (i = start_mb/denom; i*denom < start_mb + size_mb; i++)
dccmvac((uintptr_t)&ttb_buff[i]);
dsb();
/* Invalidate the TLB entries. */
for (i = start_mb/denom; i*denom < start_mb + size_mb; i++)
tlbimvaa(i*denom*MiB);
dsb();
isb();
}
void mmu_disable_range(unsigned long start_mb, unsigned long size_mb)
{
int i;
printk(BIOS_DEBUG, "Disabling: [0x%08lx:0x%08lx)\n",
start_mb*MiB, start_mb*MiB + size_mb*MiB);
for (i = start_mb/denom; i*denom < start_mb + size_mb; i++)
ttb_buff[i] = 0;
mmu_flush_page_table_entry_range(start_mb, size_mb);
}
void mmu_config_range(unsigned long start_mb, unsigned long size_mb,
enum dcache_policy policy)
{
const char *str = NULL;
pmd_t attr;
int i;
switch(policy) {
case DCACHE_OFF:
/* XN set to avoid prefetches to uncached/unbuffered regions */
attr = ATTR_NC;
str = "off";
break;
case DCACHE_WRITEBACK:
attr = ATTR_WB;
str = "writeback";
break;
case DCACHE_WRITETHROUGH:
attr = ATTR_WT;
str = "writethrough";
break;
default:
printk(BIOS_ERR, "unknown dcache policy: %02x\n", policy);
return;
}
printk(BIOS_DEBUG, "Setting dcache policy: [0x%08lx:0x%08lx) [%s]\n",
start_mb << 20, ((start_mb + size_mb) << 20), str);
/* Write out page table entries. */
for (i = start_mb/denom; i*denom < start_mb + size_mb; i++)
ttb_buff[i] = ((pmd_t)i << BLOCK_SHIFT) | attr;
mmu_flush_page_table_entry_range(start_mb, size_mb);
}
/*
* For coreboot's purposes, we will create a simple identity map.
*
* If LPAE is disabled, we will create a L1 page
* table in RAM with 1MB section translation entries over the 4GB address space.
* (ref: section 10.2 and example 15-4 in Cortex-A series programmer's guide)
*
* If LPAE is enabled, we do two level translation with one L1 table with 4
* entries, each covering a 1GB space, and four L2 tables with 512 entries, each
* covering a 2MB space.
*/
void mmu_init(void)
{
if (CONFIG_ARM_LPAE) {
pgd_t *const pgd_buff = (pgd_t*)(_ttb + 16*KiB);
pmd_t *pmd = ttb_buff;
int i;
printk(BIOS_DEBUG, "LPAE Translation tables are @ %p\n",
ttb_buff);
ASSERT((read_mmfr0() & 0xf) >= 5);
/*
* Set MAIR
* See B4.1.104 of ARMv7 Architecture Reference Manual
*/
write_mair0(
0x00 << (MAIR_INDX_NC*8) | /* Strongly-ordered,
* Non-Cacheable */
0xaa << (MAIR_INDX_WT*8) | /* Write-Thru,
* Read-Allocate */
0xff << (MAIR_INDX_WB*8) /* Write-Back,
* Read/Write-Allocate */
);
/*
* Set up L1 table
* Once set here, L1 table won't be modified by coreboot.
* See B3.6.1 of ARMv7 Architecture Reference Manual
*/
for (i = 0; i < 4; i++) {
pgd_buff[i] = ((uint32_t)pmd & PAGE_MASK) |
3; /* 0b11: valid table entry */
pmd += BLOCK_SIZE / PAGE_SIZE;
}
/*
* Set TTBR0
*/
write_ttbr0((uintptr_t)pgd_buff);
} else {
printk(BIOS_DEBUG, "Translation table is @ %p\n", ttb_buff);
/*
* Translation table base 0 address is in bits 31:14-N, where N
* is given by bits 2:0 in TTBCR (which we set to 0). All lower
* bits in this register should be zero for coreboot.
*/
write_ttbr0((uintptr_t)ttb_buff);
}
/*
* Set TTBCR
* See B4.1.153 of ARMv7 Architecture Reference Manual
* See B3.5.4 and B3.6.4 for how TTBR0 or TTBR1 is selected.
*/
write_ttbcr(
CONFIG_ARM_LPAE << 31 | /* EAE. 1:Enable LPAE */
0 << 16 | 0 << 0 /* Use TTBR0 for all addresses */
);
/* disable domain-level checking of permissions */
write_dacr(~0);
}
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