[coreboot-gerrit] Change in coreboot[master]: fw_config: Add caching to successfully probed fields

[Tim Wawrzynczak (Code Review)]

Tim Wawrzynczak has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/44782 )

Change subject: fw_config: Add caching to successfully probed fields
......................................................................

fw_config: Add caching to successfully probed fields

Add a backing cache for all successfully probed fw_config fields. This
allows recall of the `struct fw_config` which was probed.

BUG=b:161963281
TEST=tested with follower patch

Signed-off-by: Tim Wawrzynczak 
Change-Id: I0d014206a4ee6cc7592e12e704a7708652330eaf
---
M src/include/fw_config.h
M src/lib/fw_config.c
2 files changed, 37 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/82/44782/1

diff --git a/src/include/fw_config.h b/src/include/fw_config.h
index d41afd6..ca4e8c6 100644
--- a/src/include/fw_config.h
+++ b/src/include/fw_config.h
@@ -40,6 +40,13 @@
  */
 bool fw_config_probe(const struct fw_config *match);

+/**
+ * fw_config_for_each_found() - Call a callback for each fw_config field found
+ * @cb: The callback function
+ * @arg: A context argument that is passed to the callback
+ */
+void fw_config_for_each_found(void (*cb)(const struct fw_config *config, void *arg), void *arg);
+
 #else

static inline bool fw_config_probe(const struct fw_config *match)
diff --git a/src/lib/fw_config.c b/src/lib/fw_config.c
index e97cfdc..9dea196 100644
--- a/src/lib/fw_config.c
+++ b/src/lib/fw_config.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */

+#include <assert.h>
 #include <bootstate.h>
 #include <cbfs.h>
 #include <console/console.h>
@@ -9,6 +10,17 @@
 #include <stdbool.h>
 #include <stdint.h>

+#if ENV_RAMSTAGE
+/*
+ * The maximum number of fw_config fields is limited by the 32-bit mask that is used to
+ * represent them.
+ */
+#define MAX_CACHE_ELEMENTS	(8 * sizeof(uint32_t))
+
+static struct fw_config cached_configs[MAX_CACHE_ELEMENTS];
+static size_t cache_count;
+#endif
+
 /**
  * fw_config_get() - Provide firmware configuration value.
  *
@@ -59,6 +71,15 @@
    	else
    		printk(BIOS_INFO, "fw_config match found: mask=0x%08x value=0x%08x\n",
    		       match->mask, match->value);
+
+#if ENV_RAMSTAGE
+		if (fw_config_get_cached(match->mask) == NULL) {
+			assert(cache_count < MAX_CACHE_ELEMENTS);
+			memcpy(&cached_configs[cache_count], match, sizeof(struct fw_config));
+			++cache_count;
+		}
+#endif
+
    	return true;
    }

@@ -66,6 +87,15 @@
 }

#if ENV_RAMSTAGE
+
+void fw_config_for_each_found(void (*cb)(const struct fw_config *config, void *arg), void *arg)
+{
+	size_t i;
+
+	for (i = 0; i < cache_count; ++i)
+		cb(&cached_configs[i], arg);
+}
+
 static void fw_config_init(void *unused)
 {
    struct device *dev;