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authorShelley Chen <shchen@google.com>2020-05-01 17:00:31 -0700
committerShelley Chen <shchen@google.com>2020-10-02 23:11:39 +0000
commitb4a4f59dd2cbec1cb891ea1e537591e9800df02b (patch)
tree718dd24cb47d2ec6596e73dd86e8712c23e19eae /src/drivers
parent156bc6f47a7c4536649f79ee037c7eed063d1805 (diff)
downloadcoreboot-b4a4f59dd2cbec1cb891ea1e537591e9800df02b.tar.xz
mrc_cache: Update mrc_cache data in romstage
Previously, we were writing to cbmem after memory training and then writing the training data from cbmem to mrc_cache in ramstage. We were doing this because we were unable to read/write to SPI simultaneously on older x86 chips. Now that newer chips allow for simultaneously reads and writes, we can move the mrc_cache update into romstage. This is beneficial if there is a reboot for some reason after memory training but before the previous mrc_cache_stash_data call originally in ramstage. If this happens, we would lose all the mrc_cache training data in the next boot even though we've already performed the memory training. Added new config BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES to accomodate older x86 platforms that don't do mmapping but still want to use the cbmem to store the mrc_cache data in order to write the mrc_cache data back at a later time. We are maintaining the use of cbmem for these older platforms because we have no way of validating the earlier write back to mrc_cache at this time. BUG=b:150502246 BRANCH=None TEST=reboot from ec console. Make sure memory training happens. reboot from ec console. Make sure that we don't do training again. Signed-off-by: Shelley Chen <shchen@google.com> Change-Id: I3430bda45484cb8c2b01ab9614508039dfaac9a3 Reviewed-on: https://review.coreboot.org/c/coreboot/+/44196 Reviewed-by: Furquan Shaikh <furquan@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/drivers')
-rw-r--r--src/drivers/mrc_cache/Kconfig14
-rw-r--r--src/drivers/mrc_cache/mrc_cache.c151
2 files changed, 119 insertions, 46 deletions
diff --git a/src/drivers/mrc_cache/Kconfig b/src/drivers/mrc_cache/Kconfig
index 79cc205a9d..e09c5d8859 100644
--- a/src/drivers/mrc_cache/Kconfig
+++ b/src/drivers/mrc_cache/Kconfig
@@ -35,4 +35,18 @@ config MRC_WRITE_NV_LATE
normal, select this item. This will cause the write to occur at
BS_OS_RESUME_CHECK-ENTRY.
+config MRC_STASH_TO_CBMEM
+ bool
+ default y if MRC_WRITE_NV_LATE || BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES
+ default n
+ help
+ Instead of writing back MRC_CACHE training data back to the
+ MRC_CACHE right away, stash the data into cbmem. This data
+ will be written back later to MRC_CACHE. This is selected
+ for platforms which either do not support writes to SPI
+ flash in early stages
+ (BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES) or the platforms
+ that need to write back the MRC data in late ramstage boot
+ states (MRC_WRITE_NV_LATE).
+
endif # CACHE_MRC_SETTINGS
diff --git a/src/drivers/mrc_cache/mrc_cache.c b/src/drivers/mrc_cache/mrc_cache.c
index 00652acde6..d2991ac917 100644
--- a/src/drivers/mrc_cache/mrc_cache.c
+++ b/src/drivers/mrc_cache/mrc_cache.c
@@ -117,7 +117,7 @@ static const struct cache_region *lookup_region(struct region *r, int type)
if (cr == NULL) {
printk(BIOS_ERR, "MRC: failed to locate region type %d.\n",
- type);
+ type);
return NULL;
}
@@ -311,18 +311,30 @@ void *mrc_cache_current_mmap_leak(int type, uint32_t version,
}
static bool mrc_cache_needs_update(const struct region_device *rdev,
- const struct cbmem_entry *to_be_updated)
+ const struct mrc_metadata *new_md,
+ const void *new_data, size_t new_data_size)
{
- void *mapping;
+ void *mapping, *data_mapping;
size_t size = region_device_sz(rdev);
bool need_update = false;
- if (cbmem_entry_size(to_be_updated) != size)
+ if (new_data_size != size)
return true;
mapping = rdev_mmap_full(rdev);
+ if (mapping == NULL) {
+ printk(BIOS_ERR, "MRC: cannot mmap existing cache.\n");
+ return true;
+ }
+ data_mapping = mapping + sizeof(struct mrc_metadata);
+
+ /* we need to compare the md and the data separately */
+ /* check the mrc_metadata */
+ if (memcmp(new_md, mapping, sizeof(struct mrc_metadata)))
+ need_update = true;
- if (memcmp(cbmem_entry_start(to_be_updated), mapping, size))
+ /* check the data */
+ if (!need_update && memcmp(new_data, data_mapping, new_data_size))
need_update = true;
rdev_munmap(rdev, mapping);
@@ -357,7 +369,10 @@ static void log_event_cache_update(uint8_t slot, enum result res)
* read and write. The read assumes a memory-mapped boot device that can be used
* to quickly locate and compare the up-to-date data. However, when an update
* is required it uses the writeable region access to perform the update. */
-static void update_mrc_cache_by_type(int type)
+static void update_mrc_cache_by_type(int type,
+ struct mrc_metadata *new_md,
+ const void *new_data,
+ size_t new_data_size)
{
const struct cache_region *cr;
struct region region;
@@ -365,7 +380,6 @@ static void update_mrc_cache_by_type(int type)
struct region_device write_rdev;
struct region_file cache_file;
struct mrc_metadata md;
- const struct cbmem_entry *to_be_updated;
struct incoherent_rdev backing_irdev;
const struct region_device *backing_rdev;
struct region_device latest_rdev;
@@ -376,13 +390,6 @@ static void update_mrc_cache_by_type(int type)
if (cr == NULL)
return;
- to_be_updated = cbmem_entry_find(cr->cbmem_id);
- if (to_be_updated == NULL) {
- printk(BIOS_ERR, "MRC: No data in cbmem for '%s'.\n",
- cr->name);
- return;
- }
-
printk(BIOS_DEBUG, "MRC: Checking cached data update for '%s'.\n",
cr->name);
@@ -411,7 +418,8 @@ static void update_mrc_cache_by_type(int type)
return;
- if (!mrc_cache_needs_update(&latest_rdev, to_be_updated)) {
+ if (!mrc_cache_needs_update(&latest_rdev,
+ new_md, new_data, new_data_size)) {
printk(BIOS_DEBUG, "MRC: '%s' does not need update.\n", cr->name);
log_event_cache_update(cr->elog_slot, ALREADY_UPTODATE);
return;
@@ -419,10 +427,18 @@ static void update_mrc_cache_by_type(int type)
printk(BIOS_DEBUG, "MRC: cache data '%s' needs update.\n", cr->name);
- if (region_file_update_data(&cache_file,
- cbmem_entry_start(to_be_updated),
- cbmem_entry_size(to_be_updated)) < 0) {
- printk(BIOS_DEBUG, "MRC: failed to update '%s'.\n", cr->name);
+ struct update_region_file_entry entries[] = {
+ [0] = {
+ .size = sizeof(struct mrc_metadata),
+ .data = new_md,
+ },
+ [1] = {
+ .size = new_data_size,
+ .data = new_data,
+ },
+ };
+ if (region_file_update_data_arr(&cache_file, entries, ARRAY_SIZE(entries)) < 0) {
+ printk(BIOS_ERR, "MRC: failed to update '%s'.\n", cr->name);
log_event_cache_update(cr->elog_slot, UPDATE_FAILURE);
} else {
printk(BIOS_DEBUG, "MRC: updated '%s'.\n", cr->name);
@@ -548,12 +564,46 @@ static void invalidate_normal_cache(void)
printk(BIOS_ERR, "MRC: invalidation failed for '%s'.\n", name);
}
-static void update_mrc_cache(void *unused)
+static void update_mrc_cache_from_cbmem(int type)
+{
+ const struct cache_region *cr;
+ struct region region;
+ const struct cbmem_entry *to_be_updated;
+
+ cr = lookup_region(&region, type);
+
+ if (cr == NULL) {
+ printk(BIOS_ERR, "MRC: could not find cache_region type %d\n", type);
+ return;
+ }
+
+ to_be_updated = cbmem_entry_find(cr->cbmem_id);
+
+ if (to_be_updated == NULL) {
+ printk(BIOS_INFO, "MRC: No data in cbmem for '%s'.\n",
+ cr->name);
+ return;
+ }
+
+ update_mrc_cache_by_type(type,
+ /* pointer to mrc_cache entry metadata header */
+ cbmem_entry_start(to_be_updated),
+ /* pointer to start of mrc_cache entry data */
+ cbmem_entry_start(to_be_updated) +
+ sizeof(struct mrc_metadata),
+ /* size of just data portion of the entry */
+ cbmem_entry_size(to_be_updated) -
+ sizeof(struct mrc_metadata));
+}
+
+static void finalize_mrc_cache(void *unused)
{
- update_mrc_cache_by_type(MRC_TRAINING_DATA);
+ if (CONFIG(MRC_STASH_TO_CBMEM)) {
+ update_mrc_cache_from_cbmem(MRC_TRAINING_DATA);
- if (CONFIG(MRC_SETTINGS_VARIABLE_DATA))
- update_mrc_cache_by_type(MRC_VARIABLE_DATA);
+ if (CONFIG(MRC_SETTINGS_VARIABLE_DATA))
+ update_mrc_cache_from_cbmem(MRC_VARIABLE_DATA);
+ }
if (CONFIG(MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN))
invalidate_normal_cache();
@@ -562,11 +612,9 @@ static void update_mrc_cache(void *unused)
}
int mrc_cache_stash_data(int type, uint32_t version, const void *data,
- size_t size)
+ size_t size)
{
const struct cache_region *cr;
- size_t cbmem_size;
- struct mrc_metadata *md;
cr = lookup_region_type(type);
if (cr == NULL) {
@@ -575,24 +623,36 @@ int mrc_cache_stash_data(int type, uint32_t version, const void *data,
return -1;
}
- cbmem_size = sizeof(*md) + size;
-
- md = cbmem_add(cr->cbmem_id, cbmem_size);
-
- if (md == NULL) {
- printk(BIOS_ERR, "MRC: failed to add '%s' to cbmem.\n",
- cr->name);
- return -1;
+ struct mrc_metadata md = {
+ .signature = MRC_DATA_SIGNATURE,
+ .data_size = size,
+ .version = version,
+ .data_checksum = compute_ip_checksum(data, size),
+ };
+ md.header_checksum =
+ compute_ip_checksum(&md, sizeof(struct mrc_metadata));
+
+ if (CONFIG(MRC_STASH_TO_CBMEM)) {
+ /* Store data in cbmem for use in ramstage */
+ struct mrc_metadata *cbmem_md;
+ size_t cbmem_size;
+ cbmem_size = sizeof(*cbmem_md) + size;
+
+ cbmem_md = cbmem_add(cr->cbmem_id, cbmem_size);
+
+ if (cbmem_md == NULL) {
+ printk(BIOS_ERR, "MRC: failed to add '%s' to cbmem.\n",
+ cr->name);
+ return -1;
+ }
+
+ memcpy(cbmem_md, &md, sizeof(*cbmem_md));
+ /* cbmem_md + 1 is the pointer to the mrc_cache data */
+ memcpy(cbmem_md + 1, data, size);
+ } else {
+ /* Otherwise store to mrc_cache right away */
+ update_mrc_cache_by_type(type, &md, data, size);
}
-
- memset(md, 0, sizeof(*md));
- md->signature = MRC_DATA_SIGNATURE;
- md->data_size = size;
- md->version = version;
- md->data_checksum = compute_ip_checksum(data, size);
- md->header_checksum = compute_ip_checksum(md, sizeof(*md));
- memcpy(&md[1], data, size);
-
return 0;
}
@@ -600,9 +660,8 @@ int mrc_cache_stash_data(int type, uint32_t version, const void *data,
* Ensures MRC training data is stored into SPI after PCI enumeration is done.
* Some implementations may require this to be later than others.
*/
-
#if CONFIG(MRC_WRITE_NV_LATE)
-BOOT_STATE_INIT_ENTRY(BS_OS_RESUME_CHECK, BS_ON_ENTRY, update_mrc_cache, NULL);
+BOOT_STATE_INIT_ENTRY(BS_OS_RESUME_CHECK, BS_ON_ENTRY, finalize_mrc_cache, NULL);
#else
-BOOT_STATE_INIT_ENTRY(BS_DEV_ENUMERATE, BS_ON_EXIT, update_mrc_cache, NULL);
+BOOT_STATE_INIT_ENTRY(BS_DEV_ENUMERATE, BS_ON_EXIT, finalize_mrc_cache, NULL);
#endif