Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
On Thu, May 28, 2015 at 07:55:16PM +0100, Arnd Bergmann wrote: On Thursday 28 May 2015 09:36:05 Tony Lindgren wrote: * Dave Martin dave.mar...@arm.com [150528 09:19]: On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* -* The kernel doesn't interwork: v7_flush_dcache_all in particluar will -* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. -* This sequence switches back to ARM. Note that .align may insert a -* nop: bx pc needs to be word-aligned in order to work. -*/ - THUMB(.thumb ) - THUMB(.align ) - THUMB(bx pc ) - THUMB(nop ) - .arm - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the ret macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. Thanks, I've updated the description with the commit info above. I'll keep the removal of the duplicate code in this patch, as it's all related to the mode switching and we don't want to do it twice. I would have thought that the change is actually necessary after 6ebbf2ce43, because it now returns in ARM mode, which will cause the bx pc; nop thumb instruction sequence be misinterpreted as an ARM instruction. Arnd You're right. The THUMB2_KERNEL indeed won't work without deleting this code. Cheers ---Dave -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
* Dave P Martin dave.mar...@arm.com [150529 04:08]: On Thu, May 28, 2015 at 07:55:16PM +0100, Arnd Bergmann wrote: On Thursday 28 May 2015 09:36:05 Tony Lindgren wrote: * Dave Martin dave.mar...@arm.com [150528 09:19]: On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* -* The kernel doesn't interwork: v7_flush_dcache_all in particluar will -* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. -* This sequence switches back to ARM. Note that .align may insert a -* nop: bx pc needs to be word-aligned in order to work. -*/ - THUMB(.thumb ) - THUMB(.align ) - THUMB(bx pc ) - THUMB(nop ) - .arm - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the ret macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. Thanks, I've updated the description with the commit info above. I'll keep the removal of the duplicate code in this patch, as it's all related to the mode switching and we don't want to do it twice. I would have thought that the change is actually necessary after 6ebbf2ce43, because it now returns in ARM mode, which will cause the bx pc; nop thumb instruction sequence be misinterpreted as an ARM instruction. Arnd You're right. The THUMB2_KERNEL indeed won't work without deleting this code. OK thanks for checking. Regards, Tony -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
* Arnd Bergmann a...@arndb.de [150528 11:57]: On Thursday 28 May 2015 09:36:05 Tony Lindgren wrote: * Dave Martin dave.mar...@arm.com [150528 09:19]: On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* -* The kernel doesn't interwork: v7_flush_dcache_all in particluar will -* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. -* This sequence switches back to ARM. Note that .align may insert a -* nop: bx pc needs to be word-aligned in order to work. -*/ - THUMB(.thumb ) - THUMB(.align ) - THUMB(bx pc ) - THUMB(nop ) - .arm - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the ret macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. Thanks, I've updated the description with the commit info above. I'll keep the removal of the duplicate code in this patch, as it's all related to the mode switching and we don't want to do it twice. I would have thought that the change is actually necessary after 6ebbf2ce43, because it now returns in ARM mode, which will cause the bx pc; nop thumb instruction sequence be misinterpreted as an ARM instruction. Could be it's necessary.. But alone that change is not enough. Regards, Tony -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
On Thursday 28 May 2015 09:36:05 Tony Lindgren wrote: * Dave Martin dave.mar...@arm.com [150528 09:19]: On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* -* The kernel doesn't interwork: v7_flush_dcache_all in particluar will -* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. -* This sequence switches back to ARM. Note that .align may insert a -* nop: bx pc needs to be word-aligned in order to work. -*/ - THUMB(.thumb ) - THUMB(.align ) - THUMB(bx pc ) - THUMB(nop ) - .arm - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the ret macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. Thanks, I've updated the description with the commit info above. I'll keep the removal of the duplicate code in this patch, as it's all related to the mode switching and we don't want to do it twice. I would have thought that the change is actually necessary after 6ebbf2ce43, because it now returns in ARM mode, which will cause the bx pc; nop thumb instruction sequence be misinterpreted as an ARM instruction. Arnd -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
On Thu, May 28, 2015 at 09:36:05AM -0700, Tony Lindgren wrote: * Dave Martin dave.mar...@arm.com [150528 09:19]: On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote: --- a/arch/arm/mach-omap2/sleep34xx.S +++ b/arch/arm/mach-omap2/sleep34xx.S @@ -203,23 +203,8 @@ save_context_wfi: */ ldr r1, kernel_flush blx r1 - /* - * The kernel doesn't interwork: v7_flush_dcache_all in particluar will - * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled. - * This sequence switches back to ARM. Note that .align may insert a - * nop: bx pc needs to be word-aligned in order to work. - */ - THUMB( .thumb ) - THUMB( .align ) - THUMB( bx pc ) - THUMB( nop ) - .arm - ^ This looks unrelated to the issue? This code is simply unnecessary after Russell introduced the ret macro in commit 6ebbf2ce43. That made v7_flush_dcache_all do a proper interworking return. It should probably be in a separate commit, or at least mentioned explicitly in the commit log. Thanks, I've updated the description with the commit info above. I'll keep the removal of the duplicate code in this patch, as it's all related to the mode switching and we don't want to do it twice. b omap3_do_wfi - -/* - * Local variables - */ ^ Likewise this is just tidyup, not bug fixing. Will keep that too, the local variables comments are now just too confusing while reading the code after adding the ENDPROC. And that too is just removal. I have no objection to tidyups ;) So long as the commit message is clear about which parts are bugfix and which parts are tidyup, I'm fine with that. Cheers ---Dave -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
On Thu, May 28, 2015 at 1:55 AM, Tony Lindgren t...@atomide.com wrote: 8 -- From: Tony Lindgren t...@atomide.com Date: Wed, 27 May 2015 15:33:57 -0700 Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: Internal error: Oops: 8005 [#1] SMP THUMB2 ... [c046497b] (_raw_spin_unlock_irqrestore) from [c0024375] (omap3_enter_idle_bm+0xc5/0x178) [c0024375] (omap3_enter_idle_bm) from [c0374e63] (cpuidle_enter_state+0x77/0x27c) [c0374e63] (cpuidle_enter_state) from [c00627f1] (cpu_startup_entry+0x155/0x23c) [c00627f1] (cpu_startup_entry) from [c06b9a47] (start_kernel+0x32f/0x338) [c06b9a47] (start_kernel) from [8000807f] (0x8000807f) The power management related assembly on moaps needs to interact with moaps - omaps GraÅžvydas -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
* Grazvydas Ignotas nota...@gmail.com [150528 04:45]:
On Thu, May 28, 2015 at 1:55 AM, Tony Lindgren t...@atomide.com wrote:
8 --
From: Tony Lindgren t...@atomide.com
Date: Wed, 27 May 2015 15:33:57 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on moaps needs to interact with
moaps - omaps
Thanks, fixed now. I also added a link for why ENDPROC is needed to the
description. I'll apply the patch below into fixes today.
Regards,
Tony
8 --
From: Tony Lindgren t...@atomide.com
Date: Wed, 27 May 2015 15:33:57 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on omaps needs to interact with
ARM mode bootrom code, so we need to keep most of the related assembly
in ARM mode.
Turns out this error is because of missing ENDPROC for assembly code
as suggested by Stephen Boyd sb...@codeaurora.org. Let's add the
missing ENDPROC in two places to sleep34xx.S, and also remove the
earlier mystery code that was probably also caused by missing ENDPROC
for earlier kernels.
The reason why ENDPROC makes a difference is it sets .type and then
the compiler knows what to do with the thumb bit as explained at:
https://wiki.ubuntu.com/ARM/Thumb2PortingHowto
Reported-by: Kevin Hilman khil...@kernel.org
Tested-by: Kevin Hilman khil...@linaro.org
Signed-off-by: Tony Lindgren t...@atomide.com
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -203,23 +203,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
-* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
-* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
-* This sequence switches back to ARM. Note that .align may insert a
-* nop: bx pc needs to be word-aligned in order to work.
-*/
- THUMB(.thumb )
- THUMB(.align )
- THUMB(bx pc )
- THUMB(nop )
- .arm
-
b omap3_do_wfi
-
-/*
- * Local variables
- */
+ENDPROC(omap34xx_cpu_suspend)
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
@@ -364,10 +349,7 @@ exit_nonoff_modes:
* ===
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
-
-/*
- * Local variables
- */
+ENDPROC(omap3_do_wfi)
sdrc_power:
.word SDRC_POWER_V
cm_idlest1_core:
--
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Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote:
* Grazvydas Ignotas nota...@gmail.com [150528 04:45]:
On Thu, May 28, 2015 at 1:55 AM, Tony Lindgren t...@atomide.com wrote:
8 --
From: Tony Lindgren t...@atomide.com
Date: Wed, 27 May 2015 15:33:57 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on moaps needs to interact with
moaps - omaps
Thanks, fixed now. I also added a link for why ENDPROC is needed to the
description. I'll apply the patch below into fixes today.
Regards,
Tony
8 --
From: Tony Lindgren t...@atomide.com
Date: Wed, 27 May 2015 15:33:57 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on omaps needs to interact with
ARM mode bootrom code, so we need to keep most of the related assembly
in ARM mode.
Turns out this error is because of missing ENDPROC for assembly code
as suggested by Stephen Boyd sb...@codeaurora.org. Let's add the
missing ENDPROC in two places to sleep34xx.S, and also remove the
earlier mystery code that was probably also caused by missing ENDPROC
for earlier kernels.
The reason why ENDPROC makes a difference is it sets .type and then
the compiler knows what to do with the thumb bit as explained at:
https://wiki.ubuntu.com/ARM/Thumb2PortingHowto
Reported-by: Kevin Hilman khil...@kernel.org
Tested-by: Kevin Hilman khil...@linaro.org
Signed-off-by: Tony Lindgren t...@atomide.com
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -203,23 +203,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
- * The kernel doesn't interwork: v7_flush_dcache_all in particluar will
- * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
- * This sequence switches back to ARM. Note that .align may insert a
- * nop: bx pc needs to be word-aligned in order to work.
- */
- THUMB( .thumb )
- THUMB( .align )
- THUMB( bx pc )
- THUMB( nop )
- .arm
-
^ This looks unrelated to the issue? This code is simply unnecessary
after Russell introduced the ret macro in commit 6ebbf2ce43. That
made v7_flush_dcache_all do a proper interworking return.
It should probably be in a separate commit, or at least mentioned
explicitly in the commit log.
b omap3_do_wfi
-
-/*
- * Local variables
- */
^ Likewise this is just tidyup, not bug fixing.
+ENDPROC(omap34xx_cpu_suspend)
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
@@ -364,10 +349,7 @@ exit_nonoff_modes:
* ===
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
-
-/*
- * Local variables
- */
+ENDPROC(omap3_do_wfi)
The ENDPROC()s look appropriate here.
[...]
Cheers
---Dave
--
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Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
* Dave Martin dave.mar...@arm.com [150528 09:19]:
On Thu, May 28, 2015 at 07:21:25AM -0700, Tony Lindgren wrote:
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -203,23 +203,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
-* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
-* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
-* This sequence switches back to ARM. Note that .align may insert a
-* nop: bx pc needs to be word-aligned in order to work.
-*/
- THUMB(.thumb )
- THUMB(.align )
- THUMB(bx pc )
- THUMB(nop )
- .arm
-
^ This looks unrelated to the issue? This code is simply unnecessary
after Russell introduced the ret macro in commit 6ebbf2ce43. That
made v7_flush_dcache_all do a proper interworking return.
It should probably be in a separate commit, or at least mentioned
explicitly in the commit log.
Thanks, I've updated the description with the commit info above.
I'll keep the removal of the duplicate code in this patch, as it's
all related to the mode switching and we don't want to do it twice.
b omap3_do_wfi
-
-/*
- * Local variables
- */
^ Likewise this is just tidyup, not bug fixing.
Will keep that too, the local variables comments are now just too
confusing while reading the code after adding the ENDPROC. And that
too is just removal.
+ENDPROC(omap34xx_cpu_suspend)
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
@@ -364,10 +349,7 @@ exit_nonoff_modes:
* ===
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
-
-/*
- * Local variables
- */
+ENDPROC(omap3_do_wfi)
The ENDPROC()s look appropriate here.
OK thanks for looking, I was hoping you'd check it as you did the
original thumb2 changes for this file :) Updated patch below.
Regards,
Tony
8
From: Tony Lindgren t...@atomide.com
Date: Thu, 28 May 2015 07:22:08 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on omaps needs to interact with
ARM mode bootrom code, so we need to keep most of the related assembly
in ARM mode.
Turns out this error is because of missing ENDPROC for assembly code
as suggested by Stephen Boyd sb...@codeaurora.org. Let's fix the
problem by adding ENDPROC in two places to sleep34xx.S.
Let's also remove the now duplicate custom code for mode switching.
This has been unnecessary since commit 6ebbf2ce437b (ARM: convert
all mov.* pc, reg to bx reg for ARMv6+).
And let's also remove the comments about local variables, they are
now just confusing after the ENDPROC.
The reason why ENDPROC makes a difference is it sets .type and then
the compiler knows what to do with the thumb bit as explained at:
https://wiki.ubuntu.com/ARM/Thumb2PortingHowto
Reported-by: Kevin Hilman khil...@kernel.org
Tested-by: Kevin Hilman khil...@linaro.org
Signed-off-by: Tony Lindgren t...@atomide.com
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -203,23 +203,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
-* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
-* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
-* This sequence switches back to ARM. Note that .align may insert a
-* nop: bx pc needs to be word-aligned in order to work.
-*/
- THUMB(.thumb )
- THUMB(.align )
- THUMB(bx pc )
- THUMB(nop )
- .arm
-
b omap3_do_wfi
-
-/*
- * Local variables
- */
+ENDPROC(omap34xx_cpu_suspend)
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
@@ -364,10 +349,7 @@ exit_nonoff_modes:
* ===
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
-
-/*
- * Local variables
- */
+ENDPROC(omap3_do_wfi)
sdrc_power:
.word SDRC_POWER_V
cm_idlest1_core:
--
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Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
* Kevin Hilman khil...@kernel.org [150527 15:20]:
[ fix email for Dave Martin, +Tyler ]
Tony Lindgren t...@atomide.com writes:
The power management related assembly needs to interact with
ARM mode bootrom code, so we need to keep most of the related
assembly in ARM mode.
Currently we are entering into and ARM mode assembly function
from thumb2 mode, so we need to make sure we switch to ARM
mode. And we need to do that again after the cache flush.
---
Kevin told me about this earlier today..
And for full boot log/panics, see the kernelci.org thumb2 kernel boots
that fail: http://kernelci.org/boot/?THUMB2_KERNELfail
Anybody got better ideas for a fix here?
FWIW, a quick test of this patch makes my omap3-beagle-xm pass a simple
boot test, but it fails with off idle.
Thanks to Stephen Boyd's suggestion of checking the missing ENDPROC,
here's a better fix :) Now off idle works too.
Regards,
Tony
8 --
From: Tony Lindgren t...@atomide.com
Date: Wed, 27 May 2015 15:33:57 -0700
Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel
We get a NULL pointer dereference on omap3 for thumb2 compiled kernels:
Internal error: Oops: 8005 [#1] SMP THUMB2
...
[c046497b] (_raw_spin_unlock_irqrestore) from [c0024375]
(omap3_enter_idle_bm+0xc5/0x178)
[c0024375] (omap3_enter_idle_bm) from [c0374e63]
(cpuidle_enter_state+0x77/0x27c)
[c0374e63] (cpuidle_enter_state) from [c00627f1]
(cpu_startup_entry+0x155/0x23c)
[c00627f1] (cpu_startup_entry) from [c06b9a47]
(start_kernel+0x32f/0x338)
[c06b9a47] (start_kernel) from [8000807f] (0x8000807f)
The power management related assembly on moaps needs to interact with
ARM mode bootrom code, so we need to keep most of the related assembly
in ARM mode.
Turns out this error is because of missing ENDPROC for assembly code
as suggested by Stephen Boyd sb...@codeaurora.org. Let's add the
missing ENDPROC in two places to sleep34xx.S, and also remove the
earlier mystery code that was probably also caused by missing ENDPROC
for earlier kernels.
Reported-by: Kevin Hilman khil...@kernel.org
Signed-off-by: Tony Lindgren t...@atomide.com
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -203,23 +203,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
-* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
-* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
-* This sequence switches back to ARM. Note that .align may insert a
-* nop: bx pc needs to be word-aligned in order to work.
-*/
- THUMB(.thumb )
- THUMB(.align )
- THUMB(bx pc )
- THUMB(nop )
- .arm
-
b omap3_do_wfi
-
-/*
- * Local variables
- */
+ENDPROC(omap34xx_cpu_suspend)
omap3_do_wfi_sram_addr:
.word omap3_do_wfi_sram
kernel_flush:
@@ -364,10 +349,7 @@ exit_nonoff_modes:
* ===
*/
ldmfd sp!, {r4 - r11, pc} @ restore regs and return
-
-/*
- * Local variables
- */
+ENDPROC(omap3_do_wfi)
sdrc_power:
.word SDRC_POWER_V
cm_idlest1_core:
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Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
Tony Lindgren t...@atomide.com writes: * Kevin Hilman khil...@kernel.org [150527 15:20]: [ fix email for Dave Martin, +Tyler ] Tony Lindgren t...@atomide.com writes: The power management related assembly needs to interact with ARM mode bootrom code, so we need to keep most of the related assembly in ARM mode. Currently we are entering into and ARM mode assembly function from thumb2 mode, so we need to make sure we switch to ARM mode. And we need to do that again after the cache flush. --- Kevin told me about this earlier today.. And for full boot log/panics, see the kernelci.org thumb2 kernel boots that fail: http://kernelci.org/boot/?THUMB2_KERNELfail Anybody got better ideas for a fix here? FWIW, a quick test of this patch makes my omap3-beagle-xm pass a simple boot test, but it fails with off idle. Thanks to Stephen Boyd's suggestion of checking the missing ENDPROC, here's a better fix :) Now off idle works too. Regards, Tony 8 -- From: Tony Lindgren t...@atomide.com Date: Wed, 27 May 2015 15:33:57 -0700 Subject: [PATCH] ARM: OMAP3: Fix booting with thumb2 kernel We get a NULL pointer dereference on omap3 for thumb2 compiled kernels: Internal error: Oops: 8005 [#1] SMP THUMB2 ... [c046497b] (_raw_spin_unlock_irqrestore) from [c0024375] (omap3_enter_idle_bm+0xc5/0x178) [c0024375] (omap3_enter_idle_bm) from [c0374e63] (cpuidle_enter_state+0x77/0x27c) [c0374e63] (cpuidle_enter_state) from [c00627f1] (cpu_startup_entry+0x155/0x23c) [c00627f1] (cpu_startup_entry) from [c06b9a47] (start_kernel+0x32f/0x338) [c06b9a47] (start_kernel) from [8000807f] (0x8000807f) The power management related assembly on moaps needs to interact with ARM mode bootrom code, so we need to keep most of the related assembly in ARM mode. Turns out this error is because of missing ENDPROC for assembly code as suggested by Stephen Boyd sb...@codeaurora.org. Let's add the missing ENDPROC in two places to sleep34xx.S, and also remove the earlier mystery code that was probably also caused by missing ENDPROC for earlier kernels. Reported-by: Kevin Hilman khil...@kernel.org Signed-off-by: Tony Lindgren t...@atomide.com Yup, boot test is now passing for me on omap3-beagle, omap3-beagle-xm, omap3-n900, omap3-overo-tobi, omap3-overo-storm-tobi. Tested-by: Kevin Hilman khil...@linaro.org Thanks for the quick fix. Next step is to look at the exynos4412-odroidu3 failure which probably has a similar cause. Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[RFC] Fix omap3 booting with thumb2 compiled kernel
The power management related assembly needs to interact with
ARM mode bootrom code, so we need to keep most of the related
assembly in ARM mode.
Currently we are entering into and ARM mode assembly function
from thumb2 mode, so we need to make sure we switch to ARM
mode. And we need to do that again after the cache flush.
---
Kevin told me about this earlier today.. Anybody got better ideas
for a fix here?
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -151,6 +151,17 @@ ENTRY(save_secure_ram_context_sz)
*/
.align 3
ENTRY(omap34xx_cpu_suspend)
+
+ /*
+* This ARM assembly can also be called from thumb2 kernel code.
+* Make sure we switch to ARM mode first.
+*/
+ THUMB(.thumb )
+ THUMB(.align )
+ THUMB(bx pc )
+ THUMB(nop )
+ .arm
+
stmfd sp!, {r4 - r11, lr} @ save registers on stack
/*
@@ -187,6 +198,18 @@ save_context_wfi:
bx r1
/*
+* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
+* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
+* This sequence switches back to ARM. Note that .align may insert a
+* nop: bx pc needs to be word-aligned in order to work.
+*/
+ THUMB(.thumb )
+ THUMB(.align )
+ THUMB(bx pc )
+ THUMB(nop )
+ .arm
+
+ /*
* Clear the SCTLR.C bit to prevent further data cache
* allocation. Clearing SCTLR.C would make all the data accesses
* strongly ordered and would not hit the cache.
@@ -203,12 +226,8 @@ save_context_wfi:
*/
ldr r1, kernel_flush
blx r1
- /*
-* The kernel doesn't interwork: v7_flush_dcache_all in particluar will
-* always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
-* This sequence switches back to ARM. Note that .align may insert a
-* nop: bx pc needs to be word-aligned in order to work.
-*/
+
+ /* See the comments above about v7_flush_dcache_all */
THUMB(.thumb )
THUMB(.align )
THUMB(bx pc )
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Re: [RFC] Fix omap3 booting with thumb2 compiled kernel
[ fix email for Dave Martin, +Tyler ] Tony Lindgren t...@atomide.com writes: The power management related assembly needs to interact with ARM mode bootrom code, so we need to keep most of the related assembly in ARM mode. Currently we are entering into and ARM mode assembly function from thumb2 mode, so we need to make sure we switch to ARM mode. And we need to do that again after the cache flush. --- Kevin told me about this earlier today.. And for full boot log/panics, see the kernelci.org thumb2 kernel boots that fail: http://kernelci.org/boot/?THUMB2_KERNELfail Anybody got better ideas for a fix here? FWIW, a quick test of this patch makes my omap3-beagle-xm pass a simple boot test, but it fails with off idle. Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
