coreboot-kgpe-d16/src/lib/cbmem.c
Aaron Durbin df3a109b72 cbmem: dynamic cbmem support
This patch adds a parallel implementation of cbmem that supports
dynamic sizing. The original implementation relied on reserving
a fixed-size block of memory for adding cbmem entries. In order to
allow for more flexibility for adding cbmem allocations the dynamic
cbmem infrastructure was developed as an alternative to the fixed block
approach. Also, the amount of memory to reserve for cbmem allocations
does not need to be known prior to the first allocation.

The dynamic cbmem code implements the same API as the existing cbmem
code except for cbmem_init() and cbmem_reinit(). The add and find
routines behave the same way. The dynamic cbmem infrastructure
uses a top down allocator that starts allocating from a board/chipset
defined function cbmem_top(). A root pointer lives just below
cbmem_top(). In turn that pointer points to the root block which
contains the entries for all the large alloctations. The corresponding
block for each large allocation falls just below the previous entry.

It should be noted that this implementation rounds all allocations
up to a 4096 byte granularity. Though a packing allocator could
be written for small allocations it was deemed OK to just fragment
the memory as there shouldn't be that many small allocations. The
result is less code with a tradeoff of some wasted memory.

           +----------------------+ <- cbmem_top()
  |   +----|   root pointer       |
  |   |    +----------------------+
  |   |    |                      |--------+
  |   +--->|   root block         |-----+  |
  |        +----------------------+     |  |
  |        |                      |     |  |
  |        |                      |     |  |
  |        |   alloc N            |<----+  |
  |        +----------------------+        |
  |        |                      |        |
  |        |                      |        |
 \|/       |   alloc N + 1        |<-------+
  v        +----------------------+

In addition to preserving the previous cbmem API, the dynamic
cbmem API allows for removing blocks from cbmem. This allows for
the boot process to allocate memory that can be discarded after
it's been used for performing more complex boot tasks in romstage.

In order to plumb this support in there were some issues to work
around regarding writing of coreboot tables. There were a few
assumptions to how cbmem was layed out which dictated some ifdef
guarding and other runtime checks so as not to incorrectly
tag the e820 and coreboot memory tables.

The example shown below is using dynamic cbmem infrastructure.
The reserved memory for cbmem is less than 512KiB.

coreboot memory table:
 0. 0000000000000000-0000000000000fff: CONFIGURATION TABLES
 1. 0000000000001000-000000000002ffff: RAM
 2. 0000000000030000-000000000003ffff: RESERVED
 3. 0000000000040000-000000000009ffff: RAM
 4. 00000000000a0000-00000000000fffff: RESERVED
 5. 0000000000100000-0000000000efffff: RAM
 6. 0000000000f00000-0000000000ffffff: RESERVED
 7. 0000000001000000-000000007bf80fff: RAM
 8. 000000007bf81000-000000007bffffff: CONFIGURATION TABLES
 9. 000000007c000000-000000007e9fffff: RESERVED
10. 00000000f0000000-00000000f3ffffff: RESERVED
11. 00000000fed10000-00000000fed19fff: RESERVED
12. 00000000fed84000-00000000fed84fff: RESERVED
13. 0000000100000000-00000001005fffff: RAM
Wrote coreboot table at: 7bf81000, 0x39c bytes, checksum f5bf
coreboot table: 948 bytes.
CBMEM ROOT  0. 7bfff000 00001000
MRC DATA    1. 7bffe000 00001000
ROMSTAGE    2. 7bffd000 00001000
TIME STAMP  3. 7bffc000 00001000
ROMSTG STCK 4. 7bff7000 00005000
CONSOLE     5. 7bfe7000 00010000
VBOOT       6. 7bfe6000 00001000
RAMSTAGE    7. 7bf98000 0004e000
GDT         8. 7bf97000 00001000
ACPI        9. 7bf8b000 0000c000
ACPI GNVS  10. 7bf8a000 00001000
SMBIOS     11. 7bf89000 00001000
COREBOOT   12. 7bf81000 00008000

And the corresponding e820 entries:
BIOS-e820: [mem 0x0000000000000000-0x0000000000000fff] type 16
BIOS-e820: [mem 0x0000000000001000-0x000000000002ffff] usable
BIOS-e820: [mem 0x0000000000030000-0x000000000003ffff] reserved
BIOS-e820: [mem 0x0000000000040000-0x000000000009ffff] usable
BIOS-e820: [mem 0x00000000000a0000-0x00000000000fffff] reserved
BIOS-e820: [mem 0x0000000000100000-0x0000000000efffff] usable
BIOS-e820: [mem 0x0000000000f00000-0x0000000000ffffff] reserved
BIOS-e820: [mem 0x0000000001000000-0x000000007bf80fff] usable
BIOS-e820: [mem 0x000000007bf81000-0x000000007bffffff] type 16
BIOS-e820: [mem 0x000000007c000000-0x000000007e9fffff] reserved
BIOS-e820: [mem 0x00000000f0000000-0x00000000f3ffffff] reserved
BIOS-e820: [mem 0x00000000fed10000-0x00000000fed19fff] reserved
BIOS-e820: [mem 0x00000000fed84000-0x00000000fed84fff] reserved
BIOS-e820: [mem 0x0000000100000000-0x00000001005fffff] usable

Change-Id: Ie3bca52211800a8652a77ca684140cfc9b3b9a6b
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2848
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2013-03-21 23:24:19 +01:00

266 lines
6.2 KiB
C

/*
* This file is part of the coreboot project.
*
* Copyright (C) 2009 coresystems GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
*/
#include <types.h>
#include <string.h>
#include <cbmem.h>
#include <console/console.h>
#if CONFIG_HAVE_ACPI_RESUME && !defined(__PRE_RAM__)
#include <arch/acpi.h>
#endif
// The CBMEM TOC reserves 512 bytes to keep
// the other entries somewhat aligned.
// Increase if MAX_CBMEM_ENTRIES exceeds 21
#define CBMEM_TOC_RESERVED 512
#define MAX_CBMEM_ENTRIES 16
#define CBMEM_MAGIC 0x434f5245
struct cbmem_entry {
u32 magic;
u32 id;
u64 base;
u64 size;
} __attribute__((packed));
#ifndef __PRE_RAM__
static struct cbmem_entry *bss_cbmem_toc;
struct cbmem_entry *__attribute__((weak)) get_cbmem_toc(void)
{
return bss_cbmem_toc;
}
void __attribute__((weak)) set_cbmem_toc(struct cbmem_entry * x)
{
/* do nothing, this should be called by chipset to save TOC in NVRAM */
}
#else
struct cbmem_entry *__attribute__((weak)) get_cbmem_toc(void)
{
printk(BIOS_WARNING, "WARNING: you need to define get_cbmem_toc() for your chipset\n");
return NULL;
}
#endif
/**
* cbmem is a simple mechanism to do some kind of book keeping of the coreboot
* high tables memory. This is a small amount of memory which is "stolen" from
* the system memory for coreboot purposes. Usually this memory is used for
* - the coreboot table
* - legacy tables (PIRQ, MP table)
* - ACPI tables
* - suspend/resume backup memory
*/
void cbmem_init(u64 baseaddr, u64 size)
{
struct cbmem_entry *cbmem_toc;
cbmem_toc = (struct cbmem_entry *)(unsigned long)baseaddr;
#ifndef __PRE_RAM__
bss_cbmem_toc = cbmem_toc;
#endif
printk(BIOS_DEBUG, "Initializing CBMEM area to 0x%llx (%lld bytes)\n",
baseaddr, size);
if (size < (64 * 1024)) {
printk(BIOS_DEBUG, "Increase CBMEM size!\n");
for (;;) ;
}
/* we don't need to call this in romstage, usefull only from ramstage */
#ifndef __PRE_RAM__
set_cbmem_toc((struct cbmem_entry *)(unsigned long)baseaddr);
#endif
memset(cbmem_toc, 0, CBMEM_TOC_RESERVED);
cbmem_toc[0] = (struct cbmem_entry) {
.magic = CBMEM_MAGIC,
.id = CBMEM_ID_FREESPACE,
.base = baseaddr + CBMEM_TOC_RESERVED,
.size = size - CBMEM_TOC_RESERVED
};
}
int cbmem_reinit(u64 baseaddr)
{
struct cbmem_entry *cbmem_toc;
cbmem_toc = (struct cbmem_entry *)(unsigned long)baseaddr;
printk(BIOS_DEBUG, "Re-Initializing CBMEM area to 0x%lx\n",
(unsigned long)baseaddr);
#ifndef __PRE_RAM__
bss_cbmem_toc = cbmem_toc;
#endif
return (cbmem_toc[0].magic == CBMEM_MAGIC);
}
void *cbmem_add(u32 id, u64 size)
{
struct cbmem_entry *cbmem_toc;
int i;
void *p;
/*
* This could be a restart, check if the section is there already. It
* is remotely possible that the dram contents persisted over the
* bootloader upgrade AND the same section now needs more room, but
* this is quite a remote possibility and it is ignored here.
*/
p = cbmem_find(id);
if (p) {
printk(BIOS_NOTICE,
"CBMEM section %x: using existing location at %p.\n",
id, p);
return p;
}
cbmem_toc = get_cbmem_toc();
if (cbmem_toc == NULL) {
return NULL;
}
if (cbmem_toc[0].magic != CBMEM_MAGIC) {
printk(BIOS_ERR, "ERROR: CBMEM was not initialized yet.\n");
return NULL;
}
/* Will the entry fit at all? */
if (size > cbmem_toc[0].size) {
printk(BIOS_ERR, "ERROR: Not enough memory for table %x\n", id);
return NULL;
}
/* Align size to 512 byte blocks */
size = ALIGN(size, 512) < cbmem_toc[0].size ?
ALIGN(size, 512) : cbmem_toc[0].size;
/* Now look for the first free/usable TOC entry */
for (i = 0; i < MAX_CBMEM_ENTRIES; i++) {
if (cbmem_toc[i].id == CBMEM_ID_NONE)
break;
}
if (i >= MAX_CBMEM_ENTRIES) {
printk(BIOS_ERR, "ERROR: No more CBMEM entries available.\n");
return NULL;
}
printk(BIOS_DEBUG, "Adding CBMEM entry as no. %d\n", i);
cbmem_toc[i] = (struct cbmem_entry) {
.magic = CBMEM_MAGIC,
.id = id,
.base = cbmem_toc[0].base,
.size = size
};
cbmem_toc[0].base += size;
cbmem_toc[0].size -= size;
return (void *)(u32)cbmem_toc[i].base;
}
void *cbmem_find(u32 id)
{
struct cbmem_entry *cbmem_toc;
int i;
cbmem_toc = get_cbmem_toc();
if (cbmem_toc == NULL)
return NULL;
for (i = 0; i < MAX_CBMEM_ENTRIES; i++) {
if (cbmem_toc[i].id == id)
return (void *)(unsigned long)cbmem_toc[i].base;
}
return (void *)NULL;
}
#if CONFIG_EARLY_CBMEM_INIT || !defined(__PRE_RAM__)
/* Returns True if it was not intialized before. */
int cbmem_initialize(void)
{
int rv = 0;
#ifdef __PRE_RAM__
extern unsigned long get_top_of_ram(void);
uint64_t high_tables_base = get_top_of_ram() - HIGH_MEMORY_SIZE;
uint64_t high_tables_size = HIGH_MEMORY_SIZE;
#endif
/* We expect the romstage to always initialize it. */
if (!cbmem_reinit(high_tables_base)) {
#if CONFIG_HAVE_ACPI_RESUME && !defined(__PRE_RAM__)
/* Something went wrong, our high memory area got wiped */
if (acpi_slp_type == 3 || acpi_slp_type == 2)
acpi_slp_type = 0;
#endif
cbmem_init(high_tables_base, high_tables_size);
rv = 1;
}
#ifndef __PRE_RAM__
cbmem_arch_init();
#endif
return rv;
}
#endif
#ifndef __PRE_RAM__
/* cbmem cannot be initialized before device drivers, but it can be initialized
* after the drivers have run. */
void init_cbmem_pre_device(void) {}
void init_cbmem_post_device(void)
{
cbmem_initialize();
#if CONFIG_CONSOLE_CBMEM
cbmemc_reinit();
#endif
}
void cbmem_list(void)
{
struct cbmem_entry *cbmem_toc;
int i;
cbmem_toc = get_cbmem_toc();
if (cbmem_toc == NULL)
return;
for (i = 0; i < MAX_CBMEM_ENTRIES; i++) {
if (cbmem_toc[i].magic != CBMEM_MAGIC)
continue;
cbmem_print_entry(i, cbmem_toc[i].id, cbmem_toc[i].base,
cbmem_toc[i].size);
}
}
#endif