fw_config: Add helper function `fw_config_probe_dev`

This change adds a helper function `fw_config_probe_dev()` that allows
the caller to check if any of the probe conditions are true for any
given device. If device has no probe conditions or a matching probe
condition, then it returns true and provides the matching probe
condition back to caller (if provided with a valid pointer). Else, it
returns false. When fw_config support is disabled, this function
always returns true.

Change-Id: Ic2dae338e6fbd7755feb23ca86c50c42103f349b
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54751
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 47 insertions, 13 deletions

diff --git a/src/include/fw_config.h b/src/include/fw_config.h
index b702871358..7a8ad30482 100644
--- a/src/include/fw_config.h
+++ b/src/include/fw_config.h
@@ -70,6 +70,16 @@ bool fw_config_is_provisioned(void);
 */
 const struct fw_config *fw_config_get_found(uint64_t field_mask);
 
+/**
+ * fw_config_probe_dev() - Check if any of the probe conditions are true for given device.
+ * @dev: Device for which probe conditions are checked
+ * @matching_probe: If any probe condition match, then the matching probe condition is returned
+ * to the caller.
+ * Return %true if device has no probing conditions or if a matching probe condition is
+ * encountered, %false otherwise.
+ */
+bool fw_config_probe_dev(const struct device *dev, const struct fw_config **matching_probe);
+
 #else
 
 static inline bool fw_config_probe(const struct fw_config *match)
@@ -78,6 +88,15 @@ static inline bool fw_config_probe(const struct fw_config *match)
 	return true;
 }
 
+static inline bool fw_config_probe_dev(const struct device *dev,
+				       const struct fw_config **matching_probe)
+{
+	/* Always return true when probing with disabled fw_config. */
+	if (matching_probe)
+		*matching_probe = NULL;
+	return true;
+}
+
 #endif /* CONFIG(FW_CONFIG) */
 
 #endif /* __FW_CONFIG__ */
diff --git a/src/lib/fw_config.c b/src/lib/fw_config.c
index 7412f383e1..8e45c004fb 100644
--- a/src/lib/fw_config.c
+++ b/src/lib/fw_config.c
@@ -74,6 +74,29 @@ bool fw_config_is_provisioned(void)
 	return fw_config_get() != UNDEFINED_FW_CONFIG;
 }
 
+bool fw_config_probe_dev(const struct device *dev, const struct fw_config **matching_probe)
+{
+	const struct fw_config *probe;
+
+	if (matching_probe)
+		*matching_probe = NULL;
+
+	/* If the device does not have a probe list, then probing is not required. */
+	if (!dev->probe_list)
+		return true;
+
+	for (probe = dev->probe_list; probe && probe->mask != 0; probe++) {
+		if (!fw_config_probe(probe))
+			continue;
+
+		if (matching_probe)
+			*matching_probe = probe;
+		return true;
+	}
+
+	return false;
+}
+
 #if ENV_RAMSTAGE
 
 /*
@@ -115,23 +138,15 @@ static void fw_config_init(void *unused)
 
 	for (dev = all_devices; dev; dev = dev->next) {
 		const struct fw_config *probe;
-		bool match = false;
-
-		if (!dev->probe_list)
-			continue;
 
-		for (probe = dev->probe_list; probe && probe->mask != 0; probe++) {
-			if (fw_config_probe(probe)) {
-				match = true;
-				cached_configs[probe_index(probe->mask)] = probe;
-				break;
-			}
-		}
-
-		if (!match) {
+		if (!fw_config_probe_dev(dev, &probe)) {
 			printk(BIOS_INFO, "%s disabled by fw_config\n", dev_path(dev));
 			dev->enabled = 0;
+			continue;
 		}
+
+		if (probe)
+			cached_configs[probe_index(probe->mask)] = probe;
 	}
 }
 BOOT_STATE_INIT_ENTRY(BS_DEV_INIT_CHIPS, BS_ON_ENTRY, fw_config_init, NULL);