Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On 06/14/2013 02:54 AM, Alexandre Courbot wrote:
> On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren wrote:
>> On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
>>> Use a firmware operation to set the CPU reset handler and only resort to
>>> doing it ourselves if there is none defined.
>>>
>>> This supports the booting of secondary CPUs on devices using a TrustZone
>>> secure monitor.
>>
>>> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
>>
>>> + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
>>> + switch (err) {
>>> + case -ENOSYS:
>>> + tegra_cpu_reset_handler_set(reset_address);
>>> + /* pass-through */
>>
>> Rather than detecting -ENOSYS and falling back to the custom
>> tegra_cpu_reset_handler_set(), does it make sense to plug in
>> tegra_cpu_reset_handler_set as the firmware op when there is no secure
>> firmware detected? That way, this code wouldn't need the special case;
>> that would be isolated to firmware.c.
>
> Mmmm I admit I just followed what Exynos did without thinking much
> about it. I don't see any reason why your suggestion wouldn't work,
> but on second thought tegra_cpu_reset_handler_set() is not a firmware
> operation - wouldn't it be unexpected (and maybe confusing) to have it
> called through call_firmware_op()?
I would see call_firmware_op() as an abstraction that performs certain
operations, which in some cases are performed by firmware. If the
operation doesn't actually need to call into firmware in some
situations, that seems fine to me. But you're right, others may object.
Perhaps get a ruling from whoever created firmware_ops and/or some main
ARM maintainers.
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Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren wrote:
> On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
>> Use a firmware operation to set the CPU reset handler and only resort to
>> doing it ourselves if there is none defined.
>>
>> This supports the booting of secondary CPUs on devices using a TrustZone
>> secure monitor.
>
>> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
>
>> + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
>> + switch (err) {
>> + case -ENOSYS:
>> + tegra_cpu_reset_handler_set(reset_address);
>> + /* pass-through */
>
> Rather than detecting -ENOSYS and falling back to the custom
> tegra_cpu_reset_handler_set(), does it make sense to plug in
> tegra_cpu_reset_handler_set as the firmware op when there is no secure
> firmware detected? That way, this code wouldn't need the special case;
> that would be isolated to firmware.c.
Mmmm I admit I just followed what Exynos did without thinking much
about it. I don't see any reason why your suggestion wouldn't work,
but on second thought tegra_cpu_reset_handler_set() is not a firmware
operation - wouldn't it be unexpected (and maybe confusing) to have it
called through call_firmware_op()?
Alex.
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Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren swar...@wwwdotorg.org wrote:
On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
Use a firmware operation to set the CPU reset handler and only resort to
doing it ourselves if there is none defined.
This supports the booting of secondary CPUs on devices using a TrustZone
secure monitor.
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
+ err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
+ switch (err) {
+ case -ENOSYS:
+ tegra_cpu_reset_handler_set(reset_address);
+ /* pass-through */
Rather than detecting -ENOSYS and falling back to the custom
tegra_cpu_reset_handler_set(), does it make sense to plug in
tegra_cpu_reset_handler_set as the firmware op when there is no secure
firmware detected? That way, this code wouldn't need the special case;
that would be isolated to firmware.c.
Mmmm I admit I just followed what Exynos did without thinking much
about it. I don't see any reason why your suggestion wouldn't work,
but on second thought tegra_cpu_reset_handler_set() is not a firmware
operation - wouldn't it be unexpected (and maybe confusing) to have it
called through call_firmware_op()?
Alex.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On 06/14/2013 02:54 AM, Alexandre Courbot wrote:
On Fri, Jun 14, 2013 at 4:23 AM, Stephen Warren swar...@wwwdotorg.org wrote:
On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
Use a firmware operation to set the CPU reset handler and only resort to
doing it ourselves if there is none defined.
This supports the booting of secondary CPUs on devices using a TrustZone
secure monitor.
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
+ err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
+ switch (err) {
+ case -ENOSYS:
+ tegra_cpu_reset_handler_set(reset_address);
+ /* pass-through */
Rather than detecting -ENOSYS and falling back to the custom
tegra_cpu_reset_handler_set(), does it make sense to plug in
tegra_cpu_reset_handler_set as the firmware op when there is no secure
firmware detected? That way, this code wouldn't need the special case;
that would be isolated to firmware.c.
Mmmm I admit I just followed what Exynos did without thinking much
about it. I don't see any reason why your suggestion wouldn't work,
but on second thought tegra_cpu_reset_handler_set() is not a firmware
operation - wouldn't it be unexpected (and maybe confusing) to have it
called through call_firmware_op()?
I would see call_firmware_op() as an abstraction that performs certain
operations, which in some cases are performed by firmware. If the
operation doesn't actually need to call into firmware in some
situations, that seems fine to me. But you're right, others may object.
Perhaps get a ruling from whoever created firmware_ops and/or some main
ARM maintainers.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
> Use a firmware operation to set the CPU reset handler and only resort to
> doing it ourselves if there is none defined.
>
> This supports the booting of secondary CPUs on devices using a TrustZone
> secure monitor.
> diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
> + err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
> + switch (err) {
> + case -ENOSYS:
> + tegra_cpu_reset_handler_set(reset_address);
> + /* pass-through */
Rather than detecting -ENOSYS and falling back to the custom
tegra_cpu_reset_handler_set(), does it make sense to plug in
tegra_cpu_reset_handler_set as the firmware op when there is no secure
firmware detected? That way, this code wouldn't need the special case;
that would be isolated to firmware.c.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 3/3] ARM: tegra: set CPU reset handler with firmware op
On 06/13/2013 03:12 AM, Alexandre Courbot wrote:
Use a firmware operation to set the CPU reset handler and only resort to
doing it ourselves if there is none defined.
This supports the booting of secondary CPUs on devices using a TrustZone
secure monitor.
diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c
+ err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
+ switch (err) {
+ case -ENOSYS:
+ tegra_cpu_reset_handler_set(reset_address);
+ /* pass-through */
Rather than detecting -ENOSYS and falling back to the custom
tegra_cpu_reset_handler_set(), does it make sense to plug in
tegra_cpu_reset_handler_set as the firmware op when there is no secure
firmware detected? That way, this code wouldn't need the special case;
that would be isolated to firmware.c.
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
