X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fopenwrt.git;a=blobdiff_plain;f=target%2Flinux%2Fgeneric%2Fbackport-5.4%2F071-v5.16-01-mips-uasm-Add-workaround-for-Loongson-2F-nop-CPU-err.patch;fp=target%2Flinux%2Fgeneric%2Fbackport-5.4%2F071-v5.16-01-mips-uasm-Add-workaround-for-Loongson-2F-nop-CPU-err.patch;h=3a4d573f80af285d80407ff981c47dd4e5cf50c7;hp=0000000000000000000000000000000000000000;hb=f2e1e156c0b64b7fae72940c0895b30266729b1e;hpb=0eed96ca5d86bdc4158c8ef6814893bc2a3dc467 diff --git a/target/linux/generic/backport-5.4/071-v5.16-01-mips-uasm-Add-workaround-for-Loongson-2F-nop-CPU-err.patch b/target/linux/generic/backport-5.4/071-v5.16-01-mips-uasm-Add-workaround-for-Loongson-2F-nop-CPU-err.patch new file mode 100644 index 0000000000..3a4d573f80 --- /dev/null +++ b/target/linux/generic/backport-5.4/071-v5.16-01-mips-uasm-Add-workaround-for-Loongson-2F-nop-CPU-err.patch @@ -0,0 +1,31 @@ +From: Johan Almbladh +Date: Tue, 5 Oct 2021 18:54:03 +0200 +Subject: [PATCH] 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. + +Link: https://sourceware.org/legacy-ml/binutils/2009-11/msg00387.html + +Signed-off-by: Johan Almbladh +Reviewed-by: Jiaxun Yang +--- + +--- 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 uas + #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,