[PATCH] lib: sbi: Improve hartindex_to_hartid_table

[Xiang W]

Modify hartindex_to_hartid_table point to plat->hart_index2id to
save memory. This slows down sbi_hartindex_to_hartid slightly
because it needs to determine whether hartindex_to_hartid_table is
NULL. This will also improve the speed of sbi_hartid_to_hartindex
when plat->hart_index2id is NULL, since there is no need to iterate
through the array.

Signed-off-by: Xiang W <wxjstz at 126.com>
---
 include/sbi/sbi_scratch.h | 13 ++++++++-----
 lib/sbi/sbi_scratch.c     |  7 +++++--
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/include/sbi/sbi_scratch.h b/include/sbi/sbi_scratch.h
index e6a33ba..02db224 100644
--- a/include/sbi/sbi_scratch.h
+++ b/include/sbi/sbi_scratch.h
@@ -213,13 +213,16 @@ extern u32 last_hartindex_having_scratch;
 (((__hartindex) <= sbi_scratch_last_hartindex()) ? true : false)
 
 /** HART index to HART id table */
-extern u32 hartindex_to_hartid_table[];
+extern const u32* hartindex_to_hartid_table;
 
 /** Get sbi_scratch from HART index */
-#define sbi_hartindex_to_hartid(__hartindex)		\
-({							\
-	((__hartindex) <= sbi_scratch_last_hartindex()) ?\
-	hartindex_to_hartid_table[__hartindex] : -1U;	\
+#define sbi_hartindex_to_hartid(__hartindex)			\
+({								\
+	((__hartindex) <= sbi_scratch_last_hartindex()) ?	\
+		(hartindex_to_hartid_table ?			\
+			hartindex_to_hartid_table[__hartindex] :\
+			__hartindex) :				\
+		-1U;						\
 })
 
 /** HART index to scratch table */
diff --git a/lib/sbi/sbi_scratch.c b/lib/sbi/sbi_scratch.c
index ccbbc68..e097077 100644
--- a/lib/sbi/sbi_scratch.c
+++ b/lib/sbi/sbi_scratch.c
@@ -15,7 +15,7 @@
 #include <sbi/sbi_string.h>
 
 u32 last_hartindex_having_scratch = 0;
-u32 hartindex_to_hartid_table[SBI_HARTMASK_MAX_BITS + 1] = { -1U };
+const u32 *hartindex_to_hartid_table;
 struct sbi_scratch *hartindex_to_scratch_table[SBI_HARTMASK_MAX_BITS + 1] = { 0 };
 
 static spinlock_t extra_lock = SPIN_LOCK_INITIALIZER;
@@ -25,6 +25,9 @@ u32 sbi_hartid_to_hartindex(u32 hartid)
 {
 	u32 i;
 
+	if (hartindex_to_hartid_table == NULL)
+		return hartid;
+
 	for (i = 0; i <= last_hartindex_having_scratch; i++)
 		if (hartindex_to_hartid_table[i] == hartid)
 			return i;
@@ -41,11 +44,11 @@ int sbi_scratch_init(struct sbi_scratch *scratch)
 
 	for (i = 0; i < plat->hart_count; i++) {
 		h = (plat->hart_index2id) ? plat->hart_index2id[i] : i;
-		hartindex_to_hartid_table[i] = h;
 		hartindex_to_scratch_table[i] =
 			((hartid2scratch)scratch->hartid_to_scratch)(h, i);
 	}
 
+	hartindex_to_hartid_table = plat->hart_index2id;
 	last_hartindex_having_scratch = plat->hart_count - 1;
 
 	return 0;
-- 
2.40.1