coreboot-kgpe-d16/payloads/libpayload/arch/arm64/mmu.c

619 lines
16 KiB
C

/*
* This file is part of the coreboot project.
*
* Copyright 2014 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 <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <arch/mmu.h>
#include <arch/lib_helpers.h>
#include <arch/cache.h>
/* Maximum number of XLAT Tables available based on ttb buffer size */
static unsigned int max_tables;
/* Address of ttb buffer */
static uint64_t *xlat_addr;
static int free_idx;
static uint8_t ttb_buffer[TTB_DEFAULT_SIZE] __attribute__((aligned(GRANULE_SIZE)));
/*
* The usedmem_ranges is used to describe all the memory ranges that are
* actually used by payload i.e. _start -> _end in linker script and the
* coreboot tables. This is required for two purposes:
* 1) During the pre_sysinfo_scan_mmu_setup, these are the only ranges
* initialized in the page table as we do not know the entire memory map.
* 2) During the post_sysinfo_scan_mmu_setup, these ranges are used to check if
* the DMA buffer is being placed in a sane location and does not overlap any of
* the used mem ranges.
*/
struct mmu_ranges usedmem_ranges;
static const uint64_t level_to_addr_mask[] = {
L1_ADDR_MASK,
L2_ADDR_MASK,
L3_ADDR_MASK,
};
static const uint64_t level_to_addr_shift[] = {
L1_ADDR_SHIFT,
L2_ADDR_SHIFT,
L3_ADDR_SHIFT,
};
static void __attribute__((noreturn)) mmu_error(void)
{
halt();
}
/*
* Func : get_block_attr
* Desc : Get block descriptor attributes based on the value of tag in memrange
* region
*/
static uint64_t get_block_attr(unsigned long tag)
{
uint64_t attr;
/* We should be in EL2(which is non-secure only) or EL1(non-secure) */
attr = BLOCK_NS;
/* Assuming whole memory is read-write */
attr |= BLOCK_AP_RW;
attr |= BLOCK_ACCESS;
switch (tag) {
case TYPE_NORMAL_MEM:
attr |= (BLOCK_INDEX_MEM_NORMAL << BLOCK_INDEX_SHIFT);
break;
case TYPE_DEV_MEM:
attr |= BLOCK_INDEX_MEM_DEV_NGNRNE << BLOCK_INDEX_SHIFT;
break;
case TYPE_DMA_MEM:
attr |= BLOCK_INDEX_MEM_NORMAL_NC << BLOCK_INDEX_SHIFT;
break;
}
return attr;
}
/*
* Func : get_index_from_addr
* Desc : Get index into table at a given level using appropriate bits from the
* base address
*/
static uint64_t get_index_from_addr(uint64_t addr, uint8_t level)
{
uint64_t mask = level_to_addr_mask[level-1];
uint8_t shift = level_to_addr_shift[level-1];
return ((addr & mask) >> shift);
}
/*
* Func : table_desc_valid
* Desc : Check if a table entry contains valid desc
*/
static uint64_t table_desc_valid(uint64_t desc)
{
return((desc & TABLE_DESC) == TABLE_DESC);
}
/*
* Func : get_new_table
* Desc : Return the next free XLAT table from ttb buffer
*/
static uint64_t *get_new_table(void)
{
uint64_t *new;
if (free_idx >= max_tables) {
printf("ARM64 MMU: No free table\n");
return NULL;
}
new = (uint64_t*)((unsigned char *)xlat_addr + free_idx * GRANULE_SIZE);
free_idx++;
memset(new, 0, GRANULE_SIZE);
return new;
}
/*
* Func : get_table_from_desc
* Desc : Get next level table address from table descriptor
*/
static uint64_t *get_table_from_desc(uint64_t desc)
{
uint64_t *ptr = (uint64_t*)(desc & XLAT_TABLE_MASK);
return ptr;
}
/*
* Func: get_next_level_table
* Desc: Check if the table entry is a valid descriptor. If not, allocate new
* table, update the entry and return the table addr. If valid, return the addr.
*/
static uint64_t *get_next_level_table(uint64_t *ptr)
{
uint64_t desc = *ptr;
if (!table_desc_valid(desc)) {
uint64_t *new_table = get_new_table();
if (new_table == NULL)
return NULL;
desc = ((uint64_t)new_table) | TABLE_DESC;
*ptr = desc;
}
return get_table_from_desc(desc);
}
/*
* Func : init_xlat_table
* Desc : Given a base address and size, it identifies the indices within
* different level XLAT tables which map the given base addr. Similar to table
* walk, except that all invalid entries during the walk are updated
* accordingly. On success, it returns the size of the block/page addressed by
* the final table.
*/
static uint64_t init_xlat_table(uint64_t base_addr,
uint64_t size,
uint64_t tag)
{
uint64_t l1_index = get_index_from_addr(base_addr,1);
uint64_t l2_index = get_index_from_addr(base_addr,2);
uint64_t l3_index = get_index_from_addr(base_addr,3);
uint64_t *table = xlat_addr;
uint64_t desc;
uint64_t attr = get_block_attr(tag);
/*
* L1 table lookup
* If VA has bits more than 41, lookup starts at L1
*/
if (l1_index) {
table = get_next_level_table(&table[l1_index]);
if (!table)
return 0;
}
/*
* L2 table lookup
* If lookup was performed at L1, L2 table addr is obtained from L1 desc
* else, lookup starts at ttbr address
*/
if (!l3_index && (size >= L2_XLAT_SIZE)) {
/*
* If block address is aligned and size is greater than or equal
* to 512MiB i.e. size addressed by each L2 entry, we can
* directly store a block desc
*/
desc = base_addr | BLOCK_DESC | attr;
table[l2_index] = desc;
/* L3 lookup is not required */
return L2_XLAT_SIZE;
} else {
/* L2 entry stores a table descriptor */
table = get_next_level_table(&table[l2_index]);
if (!table)
return 0;
}
/* L3 table lookup */
desc = base_addr | PAGE_DESC | attr;
table[l3_index] = desc;
return L3_XLAT_SIZE;
}
/*
* Func : sanity_check
* Desc : Check if the address is aligned and size is atleast the granule size
*/
static uint64_t sanity_check(uint64_t addr,
uint64_t size)
{
/* Address should be atleast 64 KiB aligned */
if (addr & GRANULE_SIZE_MASK)
return 1;
/* Size should be atleast granule size */
if (size < GRANULE_SIZE)
return 1;
return 0;
}
/*
* Func : init_mmap_entry
* Desc : For each mmap entry, this function calls init_xlat_table with the base
* address. Based on size returned from init_xlat_table, base_addr is updated
* and subsequent calls are made for initializing the xlat table until the whole
* region is initialized.
*/
static void init_mmap_entry(struct mmu_memrange *r)
{
uint64_t base_addr = r->base;
uint64_t size = r->size;
uint64_t tag = r->type;
uint64_t temp_size = size;
while (temp_size) {
uint64_t ret;
if (sanity_check(base_addr,temp_size)) {
printf("Libpayload: ARM64 MMU: sanity check failed\n");
return;
}
ret = init_xlat_table(base_addr + (size - temp_size),
temp_size, tag);
if (ret == 0)
return;
temp_size -= ret;
}
}
/*
* Func : mmu_init
* Desc : Initialize mmu based on the mmu_memrange passed. ttb_buffer is used as
* the base address for xlat tables. TTB_DEFAULT_SIZE defines the max number of
* tables that can be used
* Assuming that memory 0-2GiB is device memory.
*/
uint64_t mmu_init(struct mmu_ranges *mmu_ranges)
{
struct mmu_memrange devrange = { 0, 0x80000000, TYPE_DEV_MEM };
int i = 0;
xlat_addr = (uint64_t *)&ttb_buffer;
memset((void*)xlat_addr, 0, GRANULE_SIZE);
max_tables = (TTB_DEFAULT_SIZE >> GRANULE_SIZE_SHIFT);
free_idx = 1;
printf("Libpayload ARM64: TTB_BUFFER: 0x%p Max Tables: %d\n",
(void*)xlat_addr, max_tables);
init_mmap_entry(&devrange);
for (; i < mmu_ranges->used; i++) {
init_mmap_entry(&mmu_ranges->entries[i]);
}
printf("Libpayload ARM64: MMU init done\n");
return 0;
}
static uint32_t is_mmu_enabled(void)
{
uint32_t sctlr;
sctlr = raw_read_sctlr_current();
return (sctlr & SCTLR_M);
}
/*
* Func: mmu_disable
* Desc: Invalidate caches and disable mmu
*/
void mmu_disable(void)
{
uint32_t sctlr;
sctlr = raw_read_sctlr_current();
sctlr &= ~(SCTLR_C | SCTLR_M | SCTLR_I);
tlbiall_current();
dcache_clean_invalidate_all();
dsb();
isb();
raw_write_sctlr_current(sctlr);
dcache_clean_invalidate_all();
dsb();
isb();
}
/*
* Func: mmu_enable
* Desc: Initialize MAIR, TCR, TTBR and enable MMU by setting appropriate bits
* in SCTLR
*/
void mmu_enable(void)
{
uint32_t sctlr;
/* Initialize MAIR indices */
raw_write_mair_current(MAIR_ATTRIBUTES);
/* Invalidate TLBs */
tlbiall_current();
/* Initialize TCR flags */
raw_write_tcr_current(TCR_TOSZ | TCR_IRGN0_NM_WBWAC | TCR_ORGN0_NM_WBWAC |
TCR_SH0_IS | TCR_TG0_64KB | TCR_PS_64GB |
TCR_TBI_USED);
/* Initialize TTBR */
raw_write_ttbr0_current((uintptr_t)xlat_addr);
/* Ensure all translation table writes are committed before enabling MMU */
dsb();
isb();
/* Enable MMU */
sctlr = raw_read_sctlr_current();
sctlr |= SCTLR_C | SCTLR_M | SCTLR_I;
raw_write_sctlr_current(sctlr);
isb();
if(is_mmu_enabled())
printf("ARM64: MMU enable done\n");
else
printf("ARM64: MMU enable failed\n");
}
/*
* Func: mmu_is_dma_range_valid
* Desc: We need to ensure that the dma buffer being allocated doesnt overlap
* with any used memory range. Basically:
* 1. Memory ranges used by the payload (usedmem_ranges)
* 2. Any area that falls below _end symbol in linker script (Kernel needs to be
* loaded in lower areas of memory, So, the payload linker script can have
* kernel memory below _start and _end. Thus, we want to make sure we do not
* step in those areas as well.
* Returns: 1 on success, 0 on error
* ASSUMPTION: All the memory used by payload resides below the program
* proper. If there is any memory used above the _end symbol, then it should be
* marked as used memory in usedmem_ranges during the presysinfo_scan.
*/
static int mmu_is_dma_range_valid(uint64_t dma_base,
uint64_t dma_end)
{
uint64_t payload_end = (uint64_t)&_end;
uint64_t i = 0;
struct mmu_memrange *r = &usedmem_ranges.entries[0];
if ((dma_base <= payload_end) || (dma_end <= payload_end))
return 0;
for (; i < usedmem_ranges.used; i++) {
uint64_t start = r[i].base;
uint64_t end = start + r[i].size;
if (((dma_base >= start) && (dma_base <= end)) ||
((dma_end >= start) && (dma_end <= end)))
return 0;
}
return 1;
}
/*
* Func: mmu_add_dma_range
* Desc: Add a memrange for dma operations. This is special because we want to
* initialize this memory as non-cacheable. We have a constraint that the DMA
* buffer should be below 4GiB(32-bit only). So, we lookup a TYPE_NORMAL_MEM
* from the lowest available addresses and align it to page size i.e. 64KiB.
*/
static struct mmu_memrange* mmu_add_dma_range(struct mmu_ranges *mmu_ranges)
{
int i = 0;
struct mmu_memrange *r = &mmu_ranges->entries[0];
for (; i < mmu_ranges->used; i++) {
if ((r[i].type != TYPE_NORMAL_MEM) ||
(r[i].size < DMA_DEFAULT_SIZE) ||
(r[i].base >= MIN_64_BIT_ADDR))
continue;
uint64_t base_addr;
uint64_t range_end_addr = r[i].base + r[i].size;
uint64_t size;
uint64_t end_addr = range_end_addr;
/* Make sure we choose only 32-bit address range for DMA */
if (end_addr > MIN_64_BIT_ADDR)
end_addr = MIN_64_BIT_ADDR;
/*
* We need to ensure that we do not step over payload regions or
* the coreboot_table
*/
do {
/*
* If end_addr is aligned to GRANULE_SIZE,
* then base_addr will be too.
* (DMA_DEFAULT_SIZE is multiple of GRANULE_SIZE)
*/
assert((DMA_DEFAULT_SIZE % GRANULE_SIZE) == 0);
end_addr = ALIGN_DOWN(end_addr, GRANULE_SIZE);
base_addr = end_addr - DMA_DEFAULT_SIZE;
size = end_addr - base_addr;
if (base_addr < r[i].base)
break;
} while (mmu_is_dma_range_valid(base_addr, end_addr) == 0);
if (base_addr < r[i].base)
continue;
if (r[i].size == size) {
r[i].type = TYPE_DMA_MEM;
return &r[i];
}
if (end_addr != range_end_addr) {
/* Add a new memrange since we split up one
* range crossing the 4GiB boundary or doing an
* ALIGN_DOWN on end_addr.
*/
r[i].size -= (range_end_addr - end_addr);
if (mmu_add_memrange(mmu_ranges, end_addr,
range_end_addr - end_addr,
TYPE_NORMAL_MEM) == NULL)
mmu_error();
}
r[i].size -= size;
r = mmu_add_memrange(mmu_ranges, base_addr, size, TYPE_DMA_MEM);
if (r == NULL)
mmu_error();
return r;
}
/* Should never reach here if everything went fine */
printf("ARM64 ERROR: No DMA region allocated\n");
return NULL;
}
/*
* Func: mmu_extract_ranges
* Desc: Assumption is that coreboot tables have memranges in sorted
* order. So, if there is an opportunity to combine ranges, we do that as
* well. Memranges are initialized for both CB_MEM_RAM and CB_MEM_TABLE as
* TYPE_NORMAL_MEM.
*/
static void mmu_extract_ranges(struct memrange *cb_ranges,
uint64_t ncb,
struct mmu_ranges *mmu_ranges)
{
int i = 0;
struct mmu_memrange *prev_range = NULL;
/* Extract memory ranges to be mapped */
for (; i < ncb; i++) {
switch (cb_ranges[i].type) {
case CB_MEM_RAM:
case CB_MEM_TABLE:
if (prev_range && (prev_range->base + prev_range->size
== cb_ranges[i].base)) {
prev_range->size += cb_ranges[i].size;
} else {
prev_range = mmu_add_memrange(mmu_ranges,
cb_ranges[i].base,
cb_ranges[i].size,
TYPE_NORMAL_MEM);
if (prev_range == NULL)
mmu_error();
}
break;
default:
break;
}
}
}
/*
* Func: mmu_init_ranges
* Desc: Initialize mmu_memranges based on the memranges obtained from coreboot
* tables. Also, initialize dma memrange and xlat_addr for ttb buffer.
*/
struct mmu_memrange *mmu_init_ranges_from_sysinfo(struct memrange *cb_ranges,
uint64_t ncb,
struct mmu_ranges *mmu_ranges)
{
struct mmu_memrange *dma_range;
/* Extract ranges from memrange in lib_sysinfo */
mmu_extract_ranges(cb_ranges, ncb, mmu_ranges);
/* Get a range for dma */
dma_range = mmu_add_dma_range(mmu_ranges);
if (dma_range == NULL)
mmu_error();
return dma_range;
}
/*
* Func: mmu_add_memrange
* Desc: Adds a new memory range
*/
struct mmu_memrange* mmu_add_memrange(struct mmu_ranges *r, uint64_t base,
uint64_t size, uint64_t type)
{
struct mmu_memrange *curr = NULL;
int i = r->used;
if (i < ARRAY_SIZE(r->entries)) {
curr = &r->entries[i];
curr->base = base;
curr->size = size;
curr->type = type;
r->used = i + 1;
}
return curr;
}
/*
* Func: mmu_presysinfo_memory_used
* Desc: Initializes all the memory used for presysinfo page table
* initialization and enabling of MMU. All these ranges are stored in
* usedmem_ranges. usedmem_ranges plays an important role in selecting the dma
* buffer as well since we check the dma buffer range against the used memory
* ranges to prevent any overstepping.
*/
void mmu_presysinfo_memory_used(uint64_t base, uint64_t size)
{
uint64_t range_base;
range_base = ALIGN_DOWN(base, GRANULE_SIZE);
size += (base - range_base);
size = ALIGN_UP(size, GRANULE_SIZE);
mmu_add_memrange(&usedmem_ranges, range_base, size, TYPE_NORMAL_MEM);
}
void mmu_presysinfo_enable(void)
{
mmu_init(&usedmem_ranges);
mmu_enable();
}