lib: Add platform features in boot time print

We have now clear distinction between platform and hart features.
Modify the boot print messages to print platform features in a string
format. In the process, this patch moved relatively larger functions
to its own file from platform.h header file.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>

include/sbi/sbi_platform.h

@@ -56,6 +56,9 @@ enum sbi_platform_features {
 	SBI_PLATFORM_HAS_MFAULTS_DELEGATION = (1 << 2),
 	/** Platform has custom secondary hart booting support */
 	SBI_PLATFORM_HAS_HART_SECONDARY_BOOT = (1 << 3),
+
+	/** Last index of Platform features*/
+	SBI_PLATFORM_HAS_LAST_FEATURE = SBI_PLATFORM_HAS_HART_SECONDARY_BOOT,
 };
 
 /** Default feature set for a platform */
@@ -223,6 +226,29 @@ struct sbi_platform {
 #define sbi_platform_has_hart_secondary_boot(__p) \
 	((__p)->features & SBI_PLATFORM_HAS_HART_SECONDARY_BOOT)
 
+/**
+ * Get HART index for the given HART
+ *
+ * @param plat pointer to struct sbi_platform
+ * @param hartid HART ID
+ *
+ * @return 0 <= value < hart_count for valid HART otherwise -1U
+ */
+u32 sbi_platform_hart_index(const struct sbi_platform *plat, u32 hartid);
+
+/**
+ * Get the platform features in string format
+ *
+ * @param plat pointer to struct sbi_platform
+ * @param features_str pointer to a char array where the features string will be
+ *		       updated
+ * @param nfstr length of the features_str. The feature string will be truncated
+ *		if nfstr is not long enough.
+ * @return the features value currently set for the given platform
+ */
+int sbi_platform_get_features_str(const struct sbi_platform *plat,
+				  char *features_str, int nfstr);
+
 /**
  * Get name of the platform
  *
@@ -237,6 +263,21 @@ static inline const char *sbi_platform_name(const struct sbi_platform *plat)
 	return "Unknown";
 }
 
+/**
+ * Get the platform features
+ *
+ * @param plat pointer to struct sbi_platform
+ *
+ * @return the features value currently set for the given platform
+ */
+static inline unsigned long sbi_platform_get_features(
+						const struct sbi_platform *plat)
+{
+	if (plat)
+		return plat->features;
+	return 0;
+}
+
 /**
  * Get platform specific tlb range flush maximum value. Any request with size
  * higher than this is upgraded to a full flush.
@@ -281,32 +322,6 @@ static inline u32 sbi_platform_hart_stack_size(const struct sbi_platform *plat)
 	return 0;
 }
 
-/**
- * Get HART index for the given HART
- *
- * @param plat pointer to struct sbi_platform
- * @param hartid HART ID
- *
- * @return 0 <= value < hart_count for valid HART otherwise -1U
- */
-static inline u32 sbi_platform_hart_index(const struct sbi_platform *plat,
-					  u32 hartid)
-{
-	u32 i;
-
-	if (!plat)
-		return -1U;
-	if (plat->hart_index2id) {
-		for (i = 0; i < plat->hart_count; i++) {
-			if (plat->hart_index2id[i] == hartid)
-				return i;
-		}
-		return -1U;
-	}
-
-	return hartid;
-}
-
 /**
  * Check whether given HART is invalid
  *

lib/sbi/objects.mk

@@ -31,6 +31,7 @@ libsbi-objs-y += sbi_illegal_insn.o
 libsbi-objs-y += sbi_init.o
 libsbi-objs-y += sbi_ipi.o
 libsbi-objs-y += sbi_misaligned_ldst.o
+libsbi-objs-y += sbi_platform.o
 libsbi-objs-y += sbi_scratch.o
 libsbi-objs-y += sbi_string.o
 libsbi-objs-y += sbi_system.o

lib/sbi/sbi_init.c

@@ -18,6 +18,7 @@
 #include <sbi/sbi_ipi.h>
 #include <sbi/sbi_platform.h>
 #include <sbi/sbi_system.h>
+#include <sbi/sbi_string.h>
 #include <sbi/sbi_timer.h>
 #include <sbi/sbi_tlb.h>
 #include <sbi/sbi_version.h>
@@ -34,8 +35,10 @@
 
 static void sbi_boot_prints(struct sbi_scratch *scratch, u32 hartid)
 {
-	int xlen;
+	int xlen, ret;
 	char str[64];
+	int max_fstr_len = 128;
+	char features[128];
 	const struct sbi_platform *plat = sbi_platform_ptr(scratch);
 
 #ifdef OPENSBI_VERSION_GIT
@@ -59,6 +62,14 @@ static void sbi_boot_prints(struct sbi_scratch *scratch, u32 hartid)
 	sbi_printf("Platform Name          : %s\n", sbi_platform_name(plat));
 	sbi_printf("Platform HART Count    : %u\n",
 		   sbi_platform_hart_count(plat));
+
+	sbi_memset(features, 0, max_fstr_len);
+	ret = sbi_platform_get_features_str(plat, features, max_fstr_len);
+	if (!ret)
+		sbi_printf("Platform Features      : %s\n", features);
+	else
+		sbi_printf("Platform Features      : %s\n", "none");
+
 	/* Boot HART details */
 	sbi_printf("Boot HART ID           : %u\n", hartid);
 	sbi_printf("Boot HART ISA          : %s\n", str);

lib/sbi/sbi_platform.c

@@ -0,0 +1,104 @@
+/*
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *   Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <sbi/sbi_console.h>
+#include <sbi/sbi_platform.h>
+#include <sbi/sbi_string.h>
+
+static inline char *sbi_platform_feature_id2string(unsigned long feature)
+{
+	char *fstr = NULL;
+
+	if (!feature)
+		return NULL;
+
+	switch (feature) {
+	case SBI_PLATFORM_HAS_TIMER_VALUE:
+		fstr = "timer";
+		break;
+	case SBI_PLATFORM_HAS_HART_HOTPLUG:
+		fstr = "hotplug";
+		break;
+	case SBI_PLATFORM_HAS_MFAULTS_DELEGATION:
+		fstr = "mfdeleg";
+		break;
+	case SBI_PLATFORM_HAS_HART_SECONDARY_BOOT:
+		fstr = "sec_boot";
+		break;
+	default:
+		break;
+	}
+
+	return fstr;
+}
+
+/**
+ * Get the platform features in string format
+ *
+ * @param plat pointer to struct sbi_platform
+ * @param features_str pointer to a char array where the features string will be
+ *		       updated
+ * @param nfstr length of the features_str. The feature string will be truncated
+ *		if nfstr is not long enough.
+ * @return the features value currently set for the given platform
+ */
+int sbi_platform_get_features_str(const struct sbi_platform *plat,
+						char *features_str, int nfstr)
+{
+	unsigned long features, feat = 1UL;
+	char *temp;
+	int offset = 0;
+
+	if (!plat || !features_str || !nfstr)
+		return SBI_EINVAL;
+
+	features = sbi_platform_get_features(plat);
+
+	do {
+		if (features & feat) {
+			temp = sbi_platform_feature_id2string(feat);
+			if (temp) {
+				sbi_snprintf(features_str + offset, nfstr,
+					     "%s,", temp);
+				offset = offset + sbi_strlen(temp) + 1;
+			}
+		}
+		feat = feat << 1;
+	} while (feat <= SBI_PLATFORM_HAS_LAST_FEATURE);
+
+	features_str[offset - 1] = '\0';
+
+	return 0;
+}
+
+/**
+ * Get HART index for the given HART
+ *
+ * @param plat pointer to struct sbi_platform
+ * @param hartid HART ID
+ *
+ * @return 0 <= value < hart_count for valid HART otherwise -1U
+ */
+u32 sbi_platform_hart_index(const struct sbi_platform *plat,
+					  u32 hartid)
+{
+	u32 i;
+
+	if (!plat)
+		return -1U;
+	if (plat->hart_index2id) {
+		for (i = 0; i < plat->hart_count; i++) {
+			if (plat->hart_index2id[i] == hartid)
+				return i;
+		}
+		return -1U;
+	}
+
+	return hartid;
+}