From 2f8704b6c8c3ce65cdf2b589a98de1d1d9dc8ffa Mon Sep 17 00:00:00 2001
From: Daniel Cederman <cederman@gaisler.com>
Date: Thu, 13 Jul 2017 09:26:50 +0200
Subject: sparc: Add assembly workaround for LEON3FT B2BST errata

This patch adds NOP instructions to prevent instruction sequences
that are sensitive to the LEON3FT B2BST errata. See GRLIB-TN-0009:
"LEON3FT Stale Cache Entry After Store with Data Tag Parity Error"
for more information.

The sequences are only modified if __FIX_LEON3FT_B2BST is defined.

The patch works in conjunction with the -mfix-ut700, -mfix-gr712rc,
and -mfix-ut699 GCC flags that prevents the sensitive sequences from
being generated.

Update #3057.
---
 c/src/lib/libcpu/sparc/access/access.S | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'c/src/lib/libcpu/sparc/access/access.S')

diff --git a/c/src/lib/libcpu/sparc/access/access.S b/c/src/lib/libcpu/sparc/access/access.S
index cb8693b776..9397cb815b 100644
--- a/c/src/lib/libcpu/sparc/access/access.S
+++ b/c/src/lib/libcpu/sparc/access/access.S
@@ -59,6 +59,33 @@ SYM(_ld64):
 	retl
 	 ldd [%o0], %o0
 
+#if defined(__FIX_LEON3FT_B2BST)
+
+SYM(_st8):
+	stub %o1, [%o0]
+	retl
+	 nop
+
+SYM(_st_be16):
+SYM(_st16):
+	stuh %o1, [%o0]
+	retl
+	 nop
+
+SYM(_st_be32):
+SYM(_st32):
+	st %o1, [%o0]
+	retl
+	 nop
+
+SYM(_st_be64):
+SYM(_st64):
+	std %o1, [%o0]
+	retl
+	 nop
+
+#else
+
 SYM(_st8):
 	retl
 	 stb %o1, [%o0]
@@ -79,3 +106,4 @@ SYM(_st64):
 	mov %o1, %o2
 	retl
 	 std %o2, [%o0]
+#endif
-- 
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