MIPS: Octeon: Apply CN63XXP1 errata workarounds.
The CN63XXP1 needs a couple of workarounds to ensure memory is not written
in unexpected ways.
All PREF with hints in the range 0-4,6-24 are replaced with PREF 28. We
pass a flag to the assembler to cover compiler generated code, and patch
uasm for the dynamically generated code.
The write buffer threshold is reduced to 4.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1672/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/uasm.c b/arch/mips/mm/uasm.c
index d2647a4..23afdeb 100644
--- a/arch/mips/mm/uasm.c
+++ b/arch/mips/mm/uasm.c
@@ -405,7 +405,6 @@
I_u1u2u3(_mtc0)
I_u2u1u3(_ori)
I_u3u1u2(_or)
-I_u2s3u1(_pref)
I_0(_rfe)
I_u2s3u1(_sc)
I_u2s3u1(_scd)
@@ -427,6 +426,25 @@
I_u1u2s3(_bbit0);
I_u1u2s3(_bbit1);
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+#include <asm/octeon/octeon.h>
+void __uasminit uasm_i_pref(u32 **buf, unsigned int a, signed int b,
+ unsigned int c)
+{
+ if (OCTEON_IS_MODEL(OCTEON_CN63XX_PASS1_X) && a <= 24 && a != 5)
+ /*
+ * As per erratum Core-14449, replace prefetches 0-4,
+ * 6-24 with 'pref 28'.
+ */
+ build_insn(buf, insn_pref, c, 28, b);
+ else
+ build_insn(buf, insn_pref, c, a, b);
+}
+UASM_EXPORT_SYMBOL(uasm_i_pref);
+#else
+I_u2s3u1(_pref)
+#endif
+
/* Handle labels. */
void __uasminit uasm_build_label(struct uasm_label **lab, u32 *addr, int lid)
{