Avoid un-intended DCTI Couples. Use of DCTI couples is deprecated. Also address the "Programming Note" for optimal performance. Here is the complete text from Oracle SPARC Architecture Specs. 6.3.4.7 DCTI Couples "A delayed control transfer instruction (DCTI) in the delay slot of another DCTI is referred to as a “DCTI couple”. The use of DCTI couples is deprecated in the Oracle SPARC Architecture; no new software should place a DCTI in the delay slot of another DCTI, because on future Oracle SPARC Architecture implementations DCTI couples may execute either slowly or differently than the programmer assumes it will. SPARC V8 and SPARC V9 Compatibility Note The SPARC V8 architecture left behavior undefined for a DCTI couple. The SPARC V9 architecture defined behavior in that case, but as of UltraSPARC Architecture 2005, use of DCTI couples was deprecated. Software should not expect high performance from DCTI couples, and performance of DCTI couples should be expected to decline further in future processors. Programming Note As noted in TABLE 6-5 on page 115, an annulled branch-always (branch-always with a = 1) instruction is not architecturally a DCTI. However, since not all implementations make that distinction, for optimal performance, a DCTI should not be placed in the instruction word immediately following an annulled branch-always instruction (BA,A or BPA,A)." Signed-off-by: Babu Moger <babu.moger@xxxxxxxxxx> Reviewed-by: Rob Gardner <rob.gardner@xxxxxxxxxx> --- arch/sparc/kernel/head_64.S | 4 ++++ arch/sparc/kernel/misctrap.S | 1 + arch/sparc/kernel/rtrap_64.S | 1 + arch/sparc/kernel/spiterrs.S | 1 + arch/sparc/kernel/sun4v_tlb_miss.S | 1 + arch/sparc/kernel/urtt_fill.S | 1 + arch/sparc/kernel/winfixup.S | 2 ++ arch/sparc/lib/NG2memcpy.S | 4 ++++ arch/sparc/lib/NG4memcpy.S | 1 + arch/sparc/lib/NG4memset.S | 1 + arch/sparc/lib/NGmemcpy.S | 1 + 11 files changed, 18 insertions(+), 0 deletions(-) diff --git a/arch/sparc/kernel/head_64.S b/arch/sparc/kernel/head_64.S index 6aa3da1..4410119 100644 --- a/arch/sparc/kernel/head_64.S +++ b/arch/sparc/kernel/head_64.S @@ -96,6 +96,7 @@ sparc64_boot: andn %g1, PSTATE_AM, %g1 wrpr %g1, 0x0, %pstate ba,a,pt %xcc, 1f + nop .globl prom_finddev_name, prom_chosen_path, prom_root_node .globl prom_getprop_name, prom_mmu_name, prom_peer_name @@ -613,6 +614,7 @@ niagara_tlb_fixup: nop ba,a,pt %xcc, 80f + nop niagara4_patch: call niagara4_patch_copyops nop @@ -622,6 +624,7 @@ niagara4_patch: nop ba,a,pt %xcc, 80f + nop niagara2_patch: call niagara2_patch_copyops @@ -632,6 +635,7 @@ niagara2_patch: nop ba,a,pt %xcc, 80f + nop niagara_patch: call niagara_patch_copyops diff --git a/arch/sparc/kernel/misctrap.S b/arch/sparc/kernel/misctrap.S index 34b4933..9276d2f 100644 --- a/arch/sparc/kernel/misctrap.S +++ b/arch/sparc/kernel/misctrap.S @@ -82,6 +82,7 @@ do_stdfmna: call handle_stdfmna add %sp, PTREGS_OFF, %o0 ba,a,pt %xcc, rtrap + nop .size do_stdfmna,.-do_stdfmna .type breakpoint_trap,#function diff --git a/arch/sparc/kernel/rtrap_64.S b/arch/sparc/kernel/rtrap_64.S index 216948c..709a82e 100644 --- a/arch/sparc/kernel/rtrap_64.S +++ b/arch/sparc/kernel/rtrap_64.S @@ -237,6 +237,7 @@ rt_continue: ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1 bne,pt %xcc, user_rtt_fill_32bit wrpr %g1, %cwp ba,a,pt %xcc, user_rtt_fill_64bit + nop user_rtt_fill_fixup_dax: ba,pt %xcc, user_rtt_fill_fixup_common diff --git a/arch/sparc/kernel/spiterrs.S b/arch/sparc/kernel/spiterrs.S index 4a73009..d7e5408 100644 --- a/arch/sparc/kernel/spiterrs.S +++ b/arch/sparc/kernel/spiterrs.S @@ -86,6 +86,7 @@ __spitfire_cee_trap_continue: rd %pc, %g7 ba,a,pt %xcc, 2f + nop 1: ba,pt %xcc, etrap_irq rd %pc, %g7 diff --git a/arch/sparc/kernel/sun4v_tlb_miss.S b/arch/sparc/kernel/sun4v_tlb_miss.S index 6179e19..c19f352 100644 --- a/arch/sparc/kernel/sun4v_tlb_miss.S +++ b/arch/sparc/kernel/sun4v_tlb_miss.S @@ -352,6 +352,7 @@ sun4v_mna: call sun4v_do_mna add %sp, PTREGS_OFF, %o0 ba,a,pt %xcc, rtrap + nop /* Privileged Action. */ sun4v_privact: diff --git a/arch/sparc/kernel/urtt_fill.S b/arch/sparc/kernel/urtt_fill.S index 5604a2b..364af32 100644 --- a/arch/sparc/kernel/urtt_fill.S +++ b/arch/sparc/kernel/urtt_fill.S @@ -92,6 +92,7 @@ user_rtt_fill_fixup_common: call sun4v_data_access_exception nop ba,a,pt %xcc, rtrap + nop 1: call spitfire_data_access_exception nop diff --git a/arch/sparc/kernel/winfixup.S b/arch/sparc/kernel/winfixup.S index 855019a..1ee173c 100644 --- a/arch/sparc/kernel/winfixup.S +++ b/arch/sparc/kernel/winfixup.S @@ -152,6 +152,8 @@ fill_fixup_dax: call sun4v_data_access_exception nop ba,a,pt %xcc, rtrap + nop 1: call spitfire_data_access_exception nop ba,a,pt %xcc, rtrap + nop diff --git a/arch/sparc/lib/NG2memcpy.S b/arch/sparc/lib/NG2memcpy.S index c629dbd..64dcd6c 100644 --- a/arch/sparc/lib/NG2memcpy.S +++ b/arch/sparc/lib/NG2memcpy.S @@ -326,11 +326,13 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */ blu 170f nop ba,a,pt %xcc, 180f + nop 4: /* 32 <= low bits < 48 */ blu 150f nop ba,a,pt %xcc, 160f + nop 5: /* 0 < low bits < 32 */ blu,a 6f cmp %g2, 8 @@ -338,6 +340,7 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */ blu 130f nop ba,a,pt %xcc, 140f + nop 6: /* 0 < low bits < 16 */ bgeu 120f nop @@ -475,6 +478,7 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */ brz,pt %o2, 85f sub %o0, %o1, GLOBAL_SPARE ba,a,pt %XCC, 90f + nop .align 64 75: /* 16 < len <= 64 */ diff --git a/arch/sparc/lib/NG4memcpy.S b/arch/sparc/lib/NG4memcpy.S index 75bb93b..78ea962 100644 --- a/arch/sparc/lib/NG4memcpy.S +++ b/arch/sparc/lib/NG4memcpy.S @@ -530,4 +530,5 @@ FUNC_NAME: /* %o0=dst, %o1=src, %o2=len */ bne,pt %icc, 1b EX_ST(STORE(stb, %g1, %o0 - 0x01), NG4_retl_o2_plus_1) ba,a,pt %icc, .Lexit + nop .size FUNC_NAME, .-FUNC_NAME diff --git a/arch/sparc/lib/NG4memset.S b/arch/sparc/lib/NG4memset.S index 41da4bd..7c0c81f 100644 --- a/arch/sparc/lib/NG4memset.S +++ b/arch/sparc/lib/NG4memset.S @@ -102,4 +102,5 @@ NG4bzero: bne,pt %icc, 1b add %o0, 0x30, %o0 ba,a,pt %icc, .Lpostloop + nop .size NG4bzero,.-NG4bzero diff --git a/arch/sparc/lib/NGmemcpy.S b/arch/sparc/lib/NGmemcpy.S index d88c4ed..cd654a7 100644 --- a/arch/sparc/lib/NGmemcpy.S +++ b/arch/sparc/lib/NGmemcpy.S @@ -394,6 +394,7 @@ FUNC_NAME: /* %i0=dst, %i1=src, %i2=len */ brz,pt %i2, 85f sub %o0, %i1, %i3 ba,a,pt %XCC, 90f + nop .align 64 70: /* 16 < len <= 64 */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
