Removing redundant ISB instructions

Replacing ISB instructions in each Errata workaround with a single ISB
instruction before the RET in the reset handler.

Change-Id: I08afabc5b98986a6fe81664cd13822b36cab786f
Signed-off-by: Lauren Wehrmeister <[email protected]>

diff --git a/lib/cpus/aarch64/neoverse_n1.S b/lib/cpus/aarch64/neoverse_n1.S
index cffdf9eb6f768306fe85fb1bb114167026e89714..b143a2e7b318110bfe798e89bf72e845df275f70 100644 (file)
--- a/lib/cpus/aarch64/neoverse_n1.S
+++ b/lib/cpus/aarch64/neoverse_n1.S
@@ -43,7 +43,6 @@ func errata_n1_1043202_wa
        msr     CPUPMR_EL3, x0
        ldr     x0, =0x800200071
        msr     CPUPCR_EL3, x0
-       isb
 1:
        ret     x17
 endfunc errata_n1_1043202_wa
@@ -69,7 +68,6 @@ func neoverse_n1_disable_speculative_loads
 
        /* Disable speculative loads */
        msr     SSBS, xzr
-       isb
 
 1:
        ret
@@ -91,7 +89,6 @@ func errata_n1_1073348_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR_EL1_BIT_6
        msr     NEOVERSE_N1_CPUACTLR_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1073348_wa
@@ -118,7 +115,6 @@ func errata_n1_1130799_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR2_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_59
        msr     NEOVERSE_N1_CPUACTLR2_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1130799_wa
@@ -146,7 +142,6 @@ func errata_n1_1165347_wa
        orr     x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_0
        orr     x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_15
        msr     NEOVERSE_N1_CPUACTLR2_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1165347_wa
@@ -173,7 +168,6 @@ func errata_n1_1207823_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR2_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR2_EL1_BIT_11
        msr     NEOVERSE_N1_CPUACTLR2_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1207823_wa
@@ -200,7 +194,6 @@ func errata_n1_1220197_wa
        mrs     x1, NEOVERSE_N1_CPUECTLR_EL1
        orr     x1, x1, NEOVERSE_N1_WS_THR_L2_MASK
        msr     NEOVERSE_N1_CPUECTLR_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1220197_wa
@@ -227,7 +220,6 @@ func errata_n1_1257314_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR3_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR3_EL1_BIT_10
        msr     NEOVERSE_N1_CPUACTLR3_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1257314_wa
@@ -254,7 +246,6 @@ func errata_n1_1262606_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR_EL1_BIT_13
        msr     NEOVERSE_N1_CPUACTLR_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1262606_wa
@@ -281,7 +272,6 @@ func errata_n1_1262888_wa
        mrs     x1, NEOVERSE_N1_CPUECTLR_EL1
        orr     x1, x1, NEOVERSE_N1_CPUECTLR_EL1_MM_TLBPF_DIS_BIT
        msr     NEOVERSE_N1_CPUECTLR_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1262888_wa
@@ -308,7 +298,6 @@ func errata_n1_1275112_wa
        mrs     x1, NEOVERSE_N1_CPUACTLR_EL1
        orr     x1, x1, NEOVERSE_N1_CPUACTLR_EL1_BIT_13
        msr     NEOVERSE_N1_CPUACTLR_EL1, x1
-       isb
 1:
        ret     x17
 endfunc errata_n1_1275112_wa
@@ -336,7 +325,6 @@ func errata_n1_1315703_wa
        mrs     x0, NEOVERSE_N1_CPUACTLR2_EL1
        orr     x0, x0, #NEOVERSE_N1_CPUACTLR2_EL1_BIT_16
        msr     NEOVERSE_N1_CPUACTLR2_EL1, x0
-       isb
 
 1:
        ret     x17
@@ -422,24 +410,22 @@ func neoverse_n1_reset_func
        mrs     x0, actlr_el3
        orr     x0, x0, #NEOVERSE_N1_ACTLR_AMEN_BIT
        msr     actlr_el3, x0
-       isb
 
        /* Make sure accesses from EL0/EL1 are not trapped to EL2 */
        mrs     x0, actlr_el2
        orr     x0, x0, #NEOVERSE_N1_ACTLR_AMEN_BIT
        msr     actlr_el2, x0
-       isb
 
        /* Enable group0 counters */
        mov     x0, #NEOVERSE_N1_AMU_GROUP0_MASK
        msr     CPUAMCNTENSET_EL0, x0
-       isb
 #endif
 
 #if ERRATA_DSU_936184
        bl      errata_dsu_936184_wa
 #endif
 
+       isb
        ret     x19
 endfunc neoverse_n1_reset_func