From 6ba3b554f5b9b53cb99c0edb93f0ea855fbc712a Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Wed, 7 Sep 2016 11:07:09 +0100 Subject: [PATCH] arm64: use alternative auto-nop Make use of the new alternative_if and alternative_else_nop_endif and get rid of our homebew NOP sleds, making the code simpler to read. Note that for cpu_do_switch_mm the ret has been moved out of the alternative sequence, and in the default case there will be three additional NOPs executed. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/kernel/entry.S | 10 ++-------- arch/arm64/lib/copy_page.S | 13 ++++--------- arch/arm64/mm/proc.S | 9 ++------- 3 files changed, 8 insertions(+), 24 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 6880dcc..223d54a 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -150,13 +150,7 @@ ldr x23, [sp, #S_SP] // load return stack pointer msr sp_el0, x23 #ifdef CONFIG_ARM64_ERRATUM_845719 -alternative_if_not ARM64_WORKAROUND_845719 - nop - nop -#ifdef CONFIG_PID_IN_CONTEXTIDR - nop -#endif -alternative_else +alternative_if ARM64_WORKAROUND_845719 tbz x22, #4, 1f #ifdef CONFIG_PID_IN_CONTEXTIDR mrs x29, contextidr_el1 @@ -165,7 +159,7 @@ alternative_else msr contextidr_el1, xzr #endif 1: -alternative_endif +alternative_else_nop_endif #endif .endif msr elr_el1, x21 // set up the return data diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S index 4c1e700..c3cd65e 100644 --- a/arch/arm64/lib/copy_page.S +++ b/arch/arm64/lib/copy_page.S @@ -29,14 +29,11 @@ * x1 - src */ ENTRY(copy_page) -alternative_if_not ARM64_HAS_NO_HW_PREFETCH - nop - nop -alternative_else +alternative_if ARM64_HAS_NO_HW_PREFETCH # Prefetch two cache lines ahead. prfm pldl1strm, [x1, #128] prfm pldl1strm, [x1, #256] -alternative_endif +alternative_else_nop_endif ldp x2, x3, [x1] ldp x4, x5, [x1, #16] @@ -52,11 +49,9 @@ alternative_endif 1: subs x18, x18, #128 -alternative_if_not ARM64_HAS_NO_HW_PREFETCH - nop -alternative_else +alternative_if ARM64_HAS_NO_HW_PREFETCH prfm pldl1strm, [x1, #384] -alternative_endif +alternative_else_nop_endif stnp x2, x3, [x0] ldp x2, x3, [x1] diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 5eb3596..1b11dcd 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -127,17 +127,12 @@ ENTRY(cpu_do_switch_mm) bfi x0, x1, #48, #16 // set the ASID msr ttbr0_el1, x0 // set TTBR0 isb -alternative_if_not ARM64_WORKAROUND_CAVIUM_27456 - ret - nop - nop - nop -alternative_else +alternative_if ARM64_WORKAROUND_CAVIUM_27456 ic iallu dsb nsh isb +alternative_else_nop_endif ret -alternative_endif ENDPROC(cpu_do_switch_mm) .pushsection ".idmap.text", "ax" -- 2.7.4