Remove CACHE_ROM.

With the recent improvement 3d6ffe76f8,
speedup by CACHE_ROM is reduced a lot.
On the other hand this makes coreboot run out of MTRRs depending on
system configuration, hence screwing up I/O access and cache
coherency in worst cases.

CACHE_ROM requires the user to sanity check their boot output because
the feature is brittle. The working configuration is dependent on I/O
hole size, ram size, and chipset. Because of this the current
implementation can leave a system configured in an inconsistent state
leading to unexpected results such as poor performance and/or
inconsistent cache-coherency

Remove this as a buggy feature until we figure out how to do it properly
if necessary.

Change-Id: I858d78a907bf042fcc21fdf7a2bf899e9f6b591d
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/5146
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>
This commit is contained in:
Vladimir Serbinenko 2014-02-05 19:46:45 +01:00
parent 20f83d5656
commit 4337020b95
16 changed files with 0 additions and 163 deletions

View File

@ -789,9 +789,6 @@ void bsp_init_and_start_aps(struct bus *cpu_bus)
/* Restore the default SMM region. */
restore_default_smm_area(smm_save_area);
/* Enable ROM caching if option was selected. */
x86_mtrr_enable_rom_caching();
}
static struct device_operations cpu_dev_ops = {

View File

@ -143,14 +143,6 @@ void release_aps_for_smm_relocation(int do_parallel)
printk(BIOS_DEBUG, "Timed out waiting for AP SMM relocation\n");
}
/* The mtrr code sets up ROM caching on the BSP, but not the others. However,
* the boot loader payload disables this. In order for Linux not to complain
* ensure the caching is disabled for the APs before going to sleep. */
static void cleanup_rom_caching(void)
{
x86_mtrr_disable_rom_caching();
}
/* By the time APs call ap_init() caching has been setup, and microcode has
* been loaded. */
static void asmlinkage ap_init(unsigned int cpu, void *microcode_ptr)
@ -184,13 +176,6 @@ static void asmlinkage ap_init(unsigned int cpu, void *microcode_ptr)
/* After SMM relocation a 2nd microcode load is required. */
intel_microcode_load_unlocked(microcode_ptr);
/* The MTRR resources are core scoped. Therefore, there is no need
* to do the same work twice. Additionally, this check keeps the
* ROM cache enabled on the BSP since its hyperthread sibling won't
* call cleanup_rom_caching(). */
if ((lapicid() & 1) == 0)
cleanup_rom_caching();
/* FIXME(adurbin): park CPUs properly -- preferably somewhere in a
* reserved part of memory that the OS cannot get to. */
stop_this_cpu();

View File

@ -76,13 +76,6 @@ config LOGICAL_CPUS
bool
default y
config CACHE_ROM
bool "Allow for caching system ROM."
default n
help
When selected a variable range MTRR is allocated for coreboot and
the bootloader enables caching of the system ROM for faster access.
config SMM_TSEG
bool
default n

View File

@ -199,16 +199,6 @@ static struct memranges *get_physical_address_space(void)
memranges_add_resources_filter(addr_space, mask, match, MTRR_TYPE_WRCOMB,
filter_vga_wrcomb);
#if CONFIG_CACHE_ROM
/* Add a write-protect region covering the ROM size
* when CONFIG_CACHE_ROM is enabled. The ROM is assumed
* to be located at 4GiB - rom size. */
resource_t rom_base = RANGE_TO_PHYS_ADDR(
RANGE_4GB - PHYS_TO_RANGE_ADDR(CACHE_ROM_SIZE));
memranges_insert(addr_space, rom_base, CACHE_ROM_SIZE,
MTRR_TYPE_WRPROT);
#endif
/* The address space below 4GiB is special. It needs to be
* covered entirly by range entries so that MTRR calculations
* can be properly done for the full 32-bit address space.
@ -380,61 +370,6 @@ void x86_setup_fixed_mtrrs(void)
enable_fixed_mtrr();
}
/* Keep track of the MTRR that covers the ROM for caching purposes. */
#if CONFIG_CACHE_ROM
static long rom_cache_mtrr = -1;
long x86_mtrr_rom_cache_var_index(void)
{
return rom_cache_mtrr;
}
void x86_mtrr_enable_rom_caching(void)
{
msr_t msr_val;
unsigned long index;
if (rom_cache_mtrr < 0)
return;
index = rom_cache_mtrr;
disable_cache();
msr_val = rdmsr(MTRRphysBase_MSR(index));
msr_val.lo &= ~0xff;
msr_val.lo |= MTRR_TYPE_WRPROT;
wrmsr(MTRRphysBase_MSR(index), msr_val);
enable_cache();
}
void x86_mtrr_disable_rom_caching(void)
{
msr_t msr_val;
unsigned long index;
if (rom_cache_mtrr < 0)
return;
index = rom_cache_mtrr;
disable_cache();
msr_val = rdmsr(MTRRphysBase_MSR(index));
msr_val.lo &= ~0xff;
wrmsr(MTRRphysBase_MSR(index), msr_val);
enable_cache();
}
static void disable_cache_rom(void *unused)
{
x86_mtrr_disable_rom_caching();
}
BOOT_STATE_INIT_ENTRIES(disable_rom_cache_bscb) = {
BOOT_STATE_INIT_ENTRY(BS_OS_RESUME, BS_ON_ENTRY,
disable_cache_rom, NULL),
BOOT_STATE_INIT_ENTRY(BS_PAYLOAD_LOAD, BS_ON_EXIT,
disable_cache_rom, NULL),
};
#endif
struct var_mtrr_state {
struct memranges *addr_space;
int above4gb;
@ -482,17 +417,6 @@ static void write_var_mtrr(struct var_mtrr_state *var_state,
mask = (1ULL << var_state->address_bits) - 1;
rsize = rsize & mask;
#if CONFIG_CACHE_ROM
/* CONFIG_CACHE_ROM allocates an MTRR specifically for allowing
* one to turn on caching for faster ROM access. However, it is
* left to the MTRR callers to enable it. */
if (mtrr_type == MTRR_TYPE_WRPROT) {
mtrr_type = MTRR_TYPE_UNCACHEABLE;
if (rom_cache_mtrr < 0)
rom_cache_mtrr = var_state->mtrr_index;
}
#endif
printk(BIOS_DEBUG, "MTRR: %d base 0x%016llx mask 0x%016llx type %d\n",
var_state->mtrr_index, rbase, rsize, mtrr_type);

View File

@ -52,10 +52,6 @@
* of the nature of the global MTRR enable flag. Therefore, all direct
* or indirect callers of enable_fixed_mtrr() should ensure that the
* variable MTRR MSRs do not contain bad ranges.
* 3. If CONFIG_CACHE_ROM is selected an MTRR is allocated for enabling
* the caching of the ROM. However, it is set to uncacheable (UC). It
* is the responsibility of the caller to enable it by calling
* x86_mtrr_enable_rom_caching().
*/
void x86_setup_mtrrs(void);
/*
@ -71,25 +67,6 @@ void x86_setup_fixed_mtrrs(void);
/* Set up fixed MTRRs but do not enable them. */
void x86_setup_fixed_mtrrs_no_enable(void);
int x86_mtrr_check(void);
/* ROM caching can be used after variable MTRRs are set up. Beware that
* enabling CONFIG_CACHE_ROM will eat through quite a few MTRRs based on
* one's IO hole size and WRCOMB resources. Be sure to check the console
* log when enabling CONFIG_CACHE_ROM or adding WRCOMB resources. Beware that
* on CPUs with core-scoped MTRR registers such as hyperthreaded CPUs the
* rom caching will be disabled if all threads run the MTRR code. Therefore,
* one needs to call x86_mtrr_enable_rom_caching() after all threads of the
* same core have run the MTRR code. */
#if CONFIG_CACHE_ROM
void x86_mtrr_enable_rom_caching(void);
void x86_mtrr_disable_rom_caching(void);
/* Return the variable range MTRR index of the ROM cache. */
long x86_mtrr_rom_cache_var_index(void);
#else
static inline void x86_mtrr_enable_rom_caching(void) {}
static inline void x86_mtrr_disable_rom_caching(void) {}
static inline long x86_mtrr_rom_cache_var_index(void) { return -1; }
#endif /* CONFIG_CACHE_ROM */
#endif
#if !defined(__ASSEMBLER__) && defined(__PRE_RAM__) && !defined(__ROMCC__)

View File

@ -235,24 +235,6 @@ static inline void lb_vboot_handoff(struct lb_header *header) {}
#endif /* CONFIG_VBOOT_VERIFY_FIRMWARE */
#endif /* CONFIG_CHROMEOS */
static void lb_x86_rom_cache(struct lb_header *header)
{
#if CONFIG_ARCH_X86
long mtrr_index;
struct lb_x86_rom_mtrr *lb_x86_rom_mtrr;
mtrr_index = x86_mtrr_rom_cache_var_index();
if (mtrr_index < 0)
return;
lb_x86_rom_mtrr = (struct lb_x86_rom_mtrr *)lb_new_record(header);
lb_x86_rom_mtrr->tag = LB_TAG_X86_ROM_MTRR;
lb_x86_rom_mtrr->size = sizeof(struct lb_x86_rom_mtrr);
lb_x86_rom_mtrr->index = mtrr_index;
#endif
}
static void add_cbmem_pointers(struct lb_header *header)
{
/*
@ -529,8 +511,6 @@ unsigned long write_coreboot_table(
lb_strings(head);
/* Record our framebuffer */
lb_framebuffer(head);
/* Communicate x86 variable MTRR ROM cache information. */
lb_x86_rom_cache(head);
#if CONFIG_CHROMEOS
/* Record our GPIO settings (ChromeOS specific) */

View File

@ -18,11 +18,6 @@
##
if VENDOR_GOOGLE
# Auto select common options
config VENDOR_SPECIFIC_OPTIONS
def_bool y
select CACHE_ROM
choice
prompt "Mainboard model"

View File

@ -18,7 +18,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
select HAVE_SMI_HANDLER
select MAINBOARD_HAS_CHROMEOS
select EXTERNAL_MRC_BLOB
select CACHE_ROM
select MONOTONIC_TIMER_MSR
config VBOOT_RAMSTAGE_INDEX

View File

@ -18,7 +18,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
select HAVE_SMI_HANDLER
select MAINBOARD_HAS_CHROMEOS
select EXTERNAL_MRC_BLOB
select CACHE_ROM
select MONOTONIC_TIMER_MSR
select DRIVERS_I2C_RTD2132

View File

@ -18,7 +18,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
select HAVE_SMI_HANDLER
select MAINBOARD_HAS_CHROMEOS
select EXTERNAL_MRC_BLOB
select CACHE_ROM
select MONOTONIC_TIMER_MSR
config VBOOT_RAMSTAGE_INDEX

View File

@ -18,7 +18,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
select HAVE_SMI_HANDLER
select MAINBOARD_HAS_CHROMEOS
select EXTERNAL_MRC_BLOB
select CACHE_ROM
select MONOTONIC_TIMER_MSR
select MAINBOARD_HAS_NATIVE_VGA_INIT
select MAINBOARD_DO_NATIVE_VGA_INIT

View File

@ -13,7 +13,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
select HAVE_ACPI_RESUME
select HAVE_SMI_HANDLER
select MAINBOARD_HAS_CHROMEOS
select CACHE_ROM
select MAINBOARD_HAS_NATIVE_VGA_INIT
select MONOTONIC_TIMER_MSR

View File

@ -87,14 +87,10 @@ config CBFS_SIZE
config ENABLE_FAST_BOOT
bool "Enable Fast Boot"
default y if CPU_INTEL_FSP_MODEL_306AX && SOUTHBRIDGE_INTEL_FSP_BD82X6X
depends on !CACHE_ROM
help
Enabling this feature will cause MRC data to be cached in NV storage
which will speed up boot time on future reboots and/or power cycles.
WARNING: This feature combined with the CACHE_ROM may result in undefined
behavior.
config MRC_CACHE_SIZE
hex "MRC Data Cache Size"
default 0x10000

View File

@ -340,8 +340,6 @@ static const struct pci_driver mc_driver_44 __pci_driver = {
static void cpu_bus_init(device_t dev)
{
initialize_cpus(dev->link_list);
/* Enable ROM caching if option was selected. */
x86_mtrr_enable_rom_caching();
}
static void cpu_bus_noop(device_t dev)

View File

@ -476,8 +476,6 @@ static const struct pci_driver mc_driver_1 __pci_driver = {
static void cpu_bus_init(device_t dev)
{
initialize_cpus(dev->link_list);
/* Enable ROM caching if option was selected. */
x86_mtrr_enable_rom_caching();
}
static void cpu_bus_noop(device_t dev)

View File

@ -9,7 +9,6 @@ if SOC_INTEL_BAYTRAIL
config CPU_SPECIFIC_OPTIONS
def_bool y
select CACHE_MRC_SETTINGS
select CACHE_ROM
select CAR_MIGRATION
select COLLECT_TIMESTAMPS
select CPU_MICROCODE_IN_CBFS