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authorRussell King <rmk+kernel@arm.linux.org.uk>2014-06-30 19:29:12 +0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2014-07-18 15:29:04 +0400
commit6ebbf2ce437b33022d30badd49dc94d33ecfa498 (patch)
treebc015e35b456a28bb0e501803a454dc0c0d3291a /arch/arm/mach-tegra/sleep-tegra20.S
parentaf040ffc9ba1e079ee4c0748aff64fa3d4716fa5 (diff)
downloadlinux-6ebbf2ce437b33022d30badd49dc94d33ecfa498.tar.xz
ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+
ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-tegra/sleep-tegra20.S')
-rw-r--r--arch/arm/mach-tegra/sleep-tegra20.S24
1 files changed, 12 insertions, 12 deletions
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index aaaf3abd2688..be4bc5f853f5 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -78,7 +78,7 @@ ENTRY(tegra20_hotplug_shutdown)
/* Put this CPU down */
cpu_id r0
bl tegra20_cpu_shutdown
- mov pc, lr @ should never get here
+ ret lr @ should never get here
ENDPROC(tegra20_hotplug_shutdown)
/*
@@ -96,7 +96,7 @@ ENDPROC(tegra20_hotplug_shutdown)
*/
ENTRY(tegra20_cpu_shutdown)
cmp r0, #0
- moveq pc, lr @ must not be called for CPU 0
+ reteq lr @ must not be called for CPU 0
mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
mov r12, #CPU_RESETTABLE
str r12, [r1]
@@ -117,7 +117,7 @@ ENTRY(tegra20_cpu_shutdown)
cpu_id r3
cmp r3, r0
beq .
- mov pc, lr
+ ret lr
ENDPROC(tegra20_cpu_shutdown)
#endif
@@ -164,7 +164,7 @@ ENTRY(tegra_pen_lock)
cmpeq r12, r0 @ !turn == cpu?
beq 1b @ while !turn == cpu && flag[!cpu] == 1
- mov pc, lr @ locked
+ ret lr @ locked
ENDPROC(tegra_pen_lock)
ENTRY(tegra_pen_unlock)
@@ -176,7 +176,7 @@ ENTRY(tegra_pen_unlock)
addne r2, r3, #PMC_SCRATCH39
mov r12, #0
str r12, [r2]
- mov pc, lr
+ ret lr
ENDPROC(tegra_pen_unlock)
/*
@@ -189,7 +189,7 @@ ENTRY(tegra20_cpu_clear_resettable)
mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
mov r12, #CPU_NOT_RESETTABLE
str r12, [r1]
- mov pc, lr
+ ret lr
ENDPROC(tegra20_cpu_clear_resettable)
/*
@@ -202,7 +202,7 @@ ENTRY(tegra20_cpu_set_resettable_soon)
mov32 r1, TEGRA_PMC_VIRT + PMC_SCRATCH41
mov r12, #CPU_RESETTABLE_SOON
str r12, [r1]
- mov pc, lr
+ ret lr
ENDPROC(tegra20_cpu_set_resettable_soon)
/*
@@ -217,7 +217,7 @@ ENTRY(tegra20_cpu_is_resettable_soon)
cmp r12, #CPU_RESETTABLE_SOON
moveq r0, #1
movne r0, #0
- mov pc, lr
+ ret lr
ENDPROC(tegra20_cpu_is_resettable_soon)
/*
@@ -239,7 +239,7 @@ ENTRY(tegra20_sleep_core_finish)
mov32 r1, TEGRA_IRAM_LPx_RESUME_AREA
add r0, r0, r1
- mov pc, r3
+ ret r3
ENDPROC(tegra20_sleep_core_finish)
/*
@@ -402,7 +402,7 @@ exit_selfrefresh_loop:
mov32 r0, TEGRA_PMC_BASE
ldr r0, [r0, #PMC_SCRATCH41]
- mov pc, r0 @ jump to tegra_resume
+ ret r0 @ jump to tegra_resume
ENDPROC(tegra20_lp1_reset)
/*
@@ -455,7 +455,7 @@ tegra20_switch_cpu_to_clk32k:
mov r0, #0 /* brust policy = 32KHz */
str r0, [r5, #CLK_RESET_SCLK_BURST]
- mov pc, lr
+ ret lr
/*
* tegra20_enter_sleep
@@ -535,7 +535,7 @@ padsave_done:
adr r2, tegra20_sclk_save
str r0, [r2]
dsb
- mov pc, lr
+ ret lr
tegra20_sdram_pad_address:
.word TEGRA_APB_MISC_BASE + APB_MISC_XM2CFGCPADCTRL