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authorMark Rutland <mark.rutland@arm.com>2016-09-07 11:07:09 +0100
committerWill Deacon <will.deacon@arm.com>2016-09-12 10:46:07 +0100
commit6ba3b554f5b9b53cb99c0edb93f0ea855fbc712a (patch)
treee9dc583beb65d3deb66fa72184afe4ed8550f9af
parent792d47379f4d4c76692f1795f33d38582f8907fa (diff)
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 <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/kernel/entry.S10
-rw-r--r--arch/arm64/lib/copy_page.S13
-rw-r--r--arch/arm64/mm/proc.S9
3 files changed, 8 insertions, 24 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 6880dcc3b465..223d54a4d66b 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 4c1e700840b6..c3cd65e31814 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 5eb35964ab8e..1b11dcd7e851 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"