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authorJohan Almbladh <johan.almbladh@anyfinetworks.com>2021-10-05 18:54:03 +0200
committerAndrii Nakryiko <andrii@kernel.org>2021-10-06 21:28:09 +0200
commitf7c036c15b5388749bc8de208fb7b19d69c4f6fa (patch)
treec055560c6ab84e6fa3dd3dd842c89d6887021987 /arch/mips/include
parentmips, uasm: Enable muhu opcode for MIPS R6 (diff)
downloadlinux-f7c036c15b5388749bc8de208fb7b19d69c4f6fa.tar.xz
linux-f7c036c15b5388749bc8de208fb7b19d69c4f6fa.zip
mips, uasm: Add workaround for Loongson-2F nop CPU errata
This patch implements a workaround for the Loongson-2F nop in generated, code, if the existing option CONFIG_CPU_NOP_WORKAROUND is set. Before, the binutils option -mfix-loongson2f-nop was enabled, but no workaround was done when emitting MIPS code. Now, the nop pseudo instruction is emitted as "or ax,ax,zero" instead of the default "sll zero,zero,0". This is consistent with the workaround implemented by binutils. Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Link: https://sourceware.org/legacy-ml/binutils/2009-11/msg00387.html Link: https://lore.kernel.org/bpf/20211005165408.2305108-3-johan.almbladh@anyfinetworks.com
Diffstat (limited to 'arch/mips/include')
-rw-r--r--arch/mips/include/asm/uasm.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/mips/include/asm/uasm.h b/arch/mips/include/asm/uasm.h
index 5efa4e2dc9ab..296bcf31abb5 100644
--- a/arch/mips/include/asm/uasm.h
+++ b/arch/mips/include/asm/uasm.h
@@ -249,7 +249,11 @@ static inline void uasm_l##lb(struct uasm_label **lab, u32 *addr) \
#define uasm_i_bnezl(buf, rs, off) uasm_i_bnel(buf, rs, 0, off)
#define uasm_i_ehb(buf) uasm_i_sll(buf, 0, 0, 3)
#define uasm_i_move(buf, a, b) UASM_i_ADDU(buf, a, 0, b)
+#ifdef CONFIG_CPU_NOP_WORKAROUNDS
+#define uasm_i_nop(buf) uasm_i_or(buf, 1, 1, 0)
+#else
#define uasm_i_nop(buf) uasm_i_sll(buf, 0, 0, 0)
+#endif
#define uasm_i_ssnop(buf) uasm_i_sll(buf, 0, 0, 1)
static inline void uasm_i_drotr_safe(u32 **p, unsigned int a1,