| Message ID | alpine.LFD.2.03.1308121125420.14472@syhkavp.arg (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Aug 12, 2013 at 12:55:23PM -0400, Nicolas Pitre wrote: > On Mon, 12 Aug 2013, Dave Martin wrote: > > > On Mon, Aug 12, 2013 at 11:28:04AM +0100, Russell King - ARM Linux wrote: > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down.clone.0': > > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > > > This is caused by the assembly code in this file clobbering R11, which > > > is incompatible with having CONFIG_FRAME_POINTER=y. > > > > Is there any reason not to fix this just by pushing/popping r11 inside > > the asm and removing it from the clobber list? > > That's most likely the best fix. What about this? > > ---- >8 > > From: Nicolas Pitre <nicolas.pitre@linaro.org> > Date: Mon, 12 Aug 2013 12:47:13 -0400 > Subject: [PATCH] ARM: vexpress/MCPM: fix cache disable sequence when > CONFIG_FRAME_POINTER=y > > If CONFIG_FRAME_POINTER=y we hget the following error: > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down': > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > Let's fix that by explicitly preserving r11 on the stack and removing it > from the clobber list. > > Reported-by: Russell King <linux@arm.linux.org.uk> ^^^^^^^^^^^^^^^^^^^^^^ rmk+kernel@arm.linux.org.uk please
On Mon, 12 Aug 2013, Russell King - ARM Linux wrote: > On Mon, Aug 12, 2013 at 12:55:23PM -0400, Nicolas Pitre wrote: > > On Mon, 12 Aug 2013, Dave Martin wrote: > > > > > On Mon, Aug 12, 2013 at 11:28:04AM +0100, Russell King - ARM Linux wrote: > > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down.clone.0': > > > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > > > > > This is caused by the assembly code in this file clobbering R11, which > > > > is incompatible with having CONFIG_FRAME_POINTER=y. > > > > > > Is there any reason not to fix this just by pushing/popping r11 inside > > > the asm and removing it from the clobber list? > > > > That's most likely the best fix. What about this? > > > > ---- >8 > > > > From: Nicolas Pitre <nicolas.pitre@linaro.org> > > Date: Mon, 12 Aug 2013 12:47:13 -0400 > > Subject: [PATCH] ARM: vexpress/MCPM: fix cache disable sequence when > > CONFIG_FRAME_POINTER=y > > > > If CONFIG_FRAME_POINTER=y we hget the following error: > > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down': > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > Let's fix that by explicitly preserving r11 on the stack and removing it > > from the clobber list. > > > > Reported-by: Russell King <linux@arm.linux.org.uk> > ^^^^^^^^^^^^^^^^^^^^^^ > rmk+kernel@arm.linux.org.uk please Sure. By default I simply picked up the email address the report was sent with. Nicolas
On Mon, Aug 12, 2013 at 12:55:23PM -0400, Nicolas Pitre wrote: > On Mon, 12 Aug 2013, Dave Martin wrote: > > > On Mon, Aug 12, 2013 at 11:28:04AM +0100, Russell King - ARM Linux wrote: > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down.clone.0': > > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > > > This is caused by the assembly code in this file clobbering R11, which > > > is incompatible with having CONFIG_FRAME_POINTER=y. > > > > Is there any reason not to fix this just by pushing/popping r11 inside > > the asm and removing it from the clobber list? > > That's most likely the best fix. What about this? Were we replacing these instances with the macro, or is that still in flight? Anyway, if useful: Reviewed-by: Dave Martin <Dave.Martin@arm.com> Cheers ---Dave > > ---- >8 > > From: Nicolas Pitre <nicolas.pitre@linaro.org> > Date: Mon, 12 Aug 2013 12:47:13 -0400 > Subject: [PATCH] ARM: vexpress/MCPM: fix cache disable sequence when > CONFIG_FRAME_POINTER=y > > If CONFIG_FRAME_POINTER=y we hget the following error: > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down': > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > Let's fix that by explicitly preserving r11 on the stack and removing it > from the clobber list. > > Reported-by: Russell King <linux@arm.linux.org.uk> > Signed-off-by: Nicolas Pitre <nico@linaro.org> > > diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c > index 85fffa702f..3a6384c6c4 100644 > --- a/arch/arm/mach-vexpress/dcscb.c > +++ b/arch/arm/mach-vexpress/dcscb.c > @@ -144,8 +144,13 @@ static void dcscb_power_down(void) > * Let's do it in the safest possible way i.e. with > * no memory access within the following sequence > * including to the stack. > + * > + * Note: fp is preserved to the stack explicitly prior doing > + * this since adding it to the clobber list is incompatible > + * with having CONFIG_FRAME_POINTER=y. > */ > asm volatile( > + "str fp, [sp, #-4]! \n\t" > "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" > "bic r0, r0, #"__stringify(CR_C)" \n\t" > "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" > @@ -156,9 +161,10 @@ static void dcscb_power_down(void) > "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" > "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" > "isb \n\t" > - "dsb " > + "dsb \n\t" > + "ldr fp, [sp], #4" > : : : "r0","r1","r2","r3","r4","r5","r6","r7", > - "r9","r10","r11","lr","memory"); > + "r9","r10","lr","memory"); > > /* > * This is a harmless no-op. On platforms with a real > @@ -182,6 +188,7 @@ static void dcscb_power_down(void) > * Let's do it in the safest possible way as above. > */ > asm volatile( > + "str fp, [sp, #-4]! \n\t" > "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" > "bic r0, r0, #"__stringify(CR_C)" \n\t" > "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" > @@ -192,9 +199,10 @@ static void dcscb_power_down(void) > "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" > "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" > "isb \n\t" > - "dsb " > + "dsb \n\t" > + "ldr fp, [sp], #4" > : : : "r0","r1","r2","r3","r4","r5","r6","r7", > - "r9","r10","r11","lr","memory"); > + "r9","r10","lr","memory"); > } > > __mcpm_cpu_down(cpu, cluster); > diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c > index dfb55d45b6..9419b1550a 100644 > --- a/arch/arm/mach-vexpress/tc2_pm.c > +++ b/arch/arm/mach-vexpress/tc2_pm.c > @@ -139,8 +139,13 @@ static void tc2_pm_down(u64 residency) > * Let's do it in the safest possible way i.e. with > * no memory access within the following sequence > * including the stack. > + * > + * Note: fp is preserved to the stack explicitly prior doing > + * this since adding it to the clobber list is incompatible > + * with having CONFIG_FRAME_POINTER=y. > */ > asm volatile( > + "str fp, [sp, #-4]! \n\t" > "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" > "bic r0, r0, #"__stringify(CR_C)" \n\t" > "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" > @@ -151,9 +156,10 @@ static void tc2_pm_down(u64 residency) > "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" > "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" > "isb \n\t" > - "dsb " > + "dsb \n\t" > + "ldr fp, [sp], #4" > : : : "r0","r1","r2","r3","r4","r5","r6","r7", > - "r9","r10","r11","lr","memory"); > + "r9","r10","lr","memory"); > > cci_disable_port_by_cpu(mpidr); > > @@ -174,6 +180,7 @@ static void tc2_pm_down(u64 residency) > * Let's do it in the safest possible way as above. > */ > asm volatile( > + "str fp, [sp, #-4]! \n\t" > "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" > "bic r0, r0, #"__stringify(CR_C)" \n\t" > "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" > @@ -184,9 +191,10 @@ static void tc2_pm_down(u64 residency) > "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" > "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" > "isb \n\t" > - "dsb " > + "dsb \n\t" > + "ldr fp, [sp], #4" > : : : "r0","r1","r2","r3","r4","r5","r6","r7", > - "r9","r10","r11","lr","memory"); > + "r9","r10","lr","memory"); > } > > __mcpm_cpu_down(cpu, cluster); > > > > > > Since there are no "m" constraints or similar, there should be no > > implicit references to fp or sp inside the asm which would be disrupted > > by that. > > > > We could #ifdef it on CONFIG_FRAME_POINTER, but that probably just > > uglifies the code for no real benefit. > > > > > > FRAME_POINTER depends on !THUMB2_KERNEL, so we shouldn't hit the same > > issue with r7 in Thumb-2. > > > > Cheers > > ---Dave > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Tue, 13 Aug 2013, Dave Martin wrote: > On Mon, Aug 12, 2013 at 12:55:23PM -0400, Nicolas Pitre wrote: > > On Mon, 12 Aug 2013, Dave Martin wrote: > > > > > On Mon, Aug 12, 2013 at 11:28:04AM +0100, Russell King - ARM Linux wrote: > > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down.clone.0': > > > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > > > > > This is caused by the assembly code in this file clobbering R11, which > > > > is incompatible with having CONFIG_FRAME_POINTER=y. > > > > > > Is there any reason not to fix this just by pushing/popping r11 inside > > > the asm and removing it from the clobber list? > > > > That's most likely the best fix. What about this? > > Were we replacing these instances with the macro, or is that still in > flight? I've updated the macro patch accordingly. I prefer to submit that one separately. > Anyway, if useful: > > Reviewed-by: Dave Martin <Dave.Martin@arm.com> Thanks. Nicolas
On Tue, Aug 13, 2013 at 11:50:17AM -0400, Nicolas Pitre wrote: > On Tue, 13 Aug 2013, Dave Martin wrote: > > > On Mon, Aug 12, 2013 at 12:55:23PM -0400, Nicolas Pitre wrote: > > > On Mon, 12 Aug 2013, Dave Martin wrote: > > > > > > > On Mon, Aug 12, 2013 at 11:28:04AM +0100, Russell King - ARM Linux wrote: > > > > > arch/arm/mach-vexpress/tc2_pm.c: In function 'tc2_pm_down.clone.0': > > > > > arch/arm/mach-vexpress/tc2_pm.c:200:1: error: fp cannot be used in asm here > > > > > > > > > > This is caused by the assembly code in this file clobbering R11, which > > > > > is incompatible with having CONFIG_FRAME_POINTER=y. > > > > > > > > Is there any reason not to fix this just by pushing/popping r11 inside > > > > the asm and removing it from the clobber list? > > > > > > That's most likely the best fix. What about this? > > > > Were we replacing these instances with the macro, or is that still in > > flight? > > I've updated the macro patch accordingly. I prefer to submit that one > separately. OK, sounds good Cheers ---Dave > > > Anyway, if useful: > > > > Reviewed-by: Dave Martin <Dave.Martin@arm.com> > > Thanks. > > > Nicolas > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm/mach-vexpress/dcscb.c b/arch/arm/mach-vexpress/dcscb.c index 85fffa702f..3a6384c6c4 100644 --- a/arch/arm/mach-vexpress/dcscb.c +++ b/arch/arm/mach-vexpress/dcscb.c @@ -144,8 +144,13 @@ static void dcscb_power_down(void) * Let's do it in the safest possible way i.e. with * no memory access within the following sequence * including to the stack. + * + * Note: fp is preserved to the stack explicitly prior doing + * this since adding it to the clobber list is incompatible + * with having CONFIG_FRAME_POINTER=y. */ asm volatile( + "str fp, [sp, #-4]! \n\t" "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" "bic r0, r0, #"__stringify(CR_C)" \n\t" "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" @@ -156,9 +161,10 @@ static void dcscb_power_down(void) "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" "isb \n\t" - "dsb " + "dsb \n\t" + "ldr fp, [sp], #4" : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","r11","lr","memory"); + "r9","r10","lr","memory"); /* * This is a harmless no-op. On platforms with a real @@ -182,6 +188,7 @@ static void dcscb_power_down(void) * Let's do it in the safest possible way as above. */ asm volatile( + "str fp, [sp, #-4]! \n\t" "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" "bic r0, r0, #"__stringify(CR_C)" \n\t" "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" @@ -192,9 +199,10 @@ static void dcscb_power_down(void) "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" "isb \n\t" - "dsb " + "dsb \n\t" + "ldr fp, [sp], #4" : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","r11","lr","memory"); + "r9","r10","lr","memory"); } __mcpm_cpu_down(cpu, cluster); diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c index dfb55d45b6..9419b1550a 100644 --- a/arch/arm/mach-vexpress/tc2_pm.c +++ b/arch/arm/mach-vexpress/tc2_pm.c @@ -139,8 +139,13 @@ static void tc2_pm_down(u64 residency) * Let's do it in the safest possible way i.e. with * no memory access within the following sequence * including the stack. + * + * Note: fp is preserved to the stack explicitly prior doing + * this since adding it to the clobber list is incompatible + * with having CONFIG_FRAME_POINTER=y. */ asm volatile( + "str fp, [sp, #-4]! \n\t" "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" "bic r0, r0, #"__stringify(CR_C)" \n\t" "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" @@ -151,9 +156,10 @@ static void tc2_pm_down(u64 residency) "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" "isb \n\t" - "dsb " + "dsb \n\t" + "ldr fp, [sp], #4" : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","r11","lr","memory"); + "r9","r10","lr","memory"); cci_disable_port_by_cpu(mpidr); @@ -174,6 +180,7 @@ static void tc2_pm_down(u64 residency) * Let's do it in the safest possible way as above. */ asm volatile( + "str fp, [sp, #-4]! \n\t" "mrc p15, 0, r0, c1, c0, 0 @ get CR \n\t" "bic r0, r0, #"__stringify(CR_C)" \n\t" "mcr p15, 0, r0, c1, c0, 0 @ set CR \n\t" @@ -184,9 +191,10 @@ static void tc2_pm_down(u64 residency) "bic r0, r0, #(1 << 6) @ disable local coherency \n\t" "mcr p15, 0, r0, c1, c0, 1 @ set AUXCR \n\t" "isb \n\t" - "dsb " + "dsb \n\t" + "ldr fp, [sp], #4" : : : "r0","r1","r2","r3","r4","r5","r6","r7", - "r9","r10","r11","lr","memory"); + "r9","r10","lr","memory"); } __mcpm_cpu_down(cpu, cluster);