* [ARM:PATCH v3 1/1] Pass the timer clock-frequency to DOM0 xen/arm: Pass the timer "clock-frequency" to DOM0 in make_timer_node()
@ 2014-04-14 8:14 Suriyan Ramasami
2014-04-15 19:30 ` Julien Grall
0 siblings, 1 reply; 3+ messages in thread
From: Suriyan Ramasami @ 2014-04-14 8:14 UTC (permalink / raw)
To: julien.grall
Cc: Suriyan Ramasami, xen-devel, tim, Ian.Campbell, stefano.stabellini
If the DT representing the ARM generic timer mentions a clock-frequency,
propragate it to the DT that is built for DOM0.
This is necessary as a workaround for boards (Odroid-XU) where CNTFRQ is
not set or returns a wrong value.
Ideally CNTFRQ should be set by the boot loader. The bootloader should
respect the ARM ARM (see B.8.1.1):
"The CNTFRQ register is UNKNOWN at reset, and therefore the counter
frequency must written to CNTFRQ as part of the system boot process."
For the Odroid-XU the SPL BL2 code is entered in NS HYP mode which
prevents the execution of the mcr call to set CNTFRQ.
Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
---
Changed since v2:
* Gather all changes in one place.
* Added additional comments
Changed since v1:
* Fix typo for quotes around clock-frequency.
---
xen/arch/arm/domain_build.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 502db84..a86d756 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -622,6 +622,8 @@ static int make_timer_node(const struct domain *d, void *fdt,
int res;
const struct dt_irq *irq;
gic_interrupt_t intrs[3];
+ u32 clock_frequency;
+ bool_t clock_valid;
DPRINT("Create timer node\n");
@@ -663,6 +665,15 @@ static int make_timer_node(const struct domain *d, void *fdt,
if ( res )
return res;
+ clock_valid = dt_property_read_u32(dev, "clock-frequency",
+ &clock_frequency);
+ if (clock_valid)
+ {
+ res = fdt_property_cell(fdt, "clock-frequency", clock_frequency);
+ if ( res )
+ return res;
+ }
+
res = fdt_end_node(fdt);
return res;
--
1.8.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [ARM:PATCH v3 1/1] Pass the timer clock-frequency to DOM0 xen/arm: Pass the timer "clock-frequency" to DOM0 in make_timer_node()
2014-04-14 8:14 [ARM:PATCH v3 1/1] Pass the timer clock-frequency to DOM0 xen/arm: Pass the timer "clock-frequency" to DOM0 in make_timer_node() Suriyan Ramasami
@ 2014-04-15 19:30 ` Julien Grall
2014-04-16 16:32 ` Ian Campbell
0 siblings, 1 reply; 3+ messages in thread
From: Julien Grall @ 2014-04-15 19:30 UTC (permalink / raw)
To: Suriyan Ramasami; +Cc: xen-devel, tim, Ian.Campbell, stefano.stabellini
Hello Suriyan,
Thank you for the patch.
On 04/14/2014 09:14 AM, Suriyan Ramasami wrote:
> If the DT representing the ARM generic timer mentions a clock-frequency,
> propragate it to the DT that is built for DOM0.
>
> This is necessary as a workaround for boards (Odroid-XU) where CNTFRQ is
> not set or returns a wrong value.
>
> Ideally CNTFRQ should be set by the boot loader. The bootloader should
> respect the ARM ARM (see B.8.1.1):
> "The CNTFRQ register is UNKNOWN at reset, and therefore the counter
> frequency must written to CNTFRQ as part of the system boot process."
>
> For the Odroid-XU the SPL BL2 code is entered in NS HYP mode which
> prevents the execution of the mcr call to set CNTFRQ.
>
> Signed-off-by: Suriyan Ramasami <suriyan.r@gmail.com>
>
> ---
> Changed since v2:
> * Gather all changes in one place.
> * Added additional comments
>
> Changed since v1:
> * Fix typo for quotes around clock-frequency.
> ---
> xen/arch/arm/domain_build.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 502db84..a86d756 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -622,6 +622,8 @@ static int make_timer_node(const struct domain *d, void *fdt,
> int res;
> const struct dt_irq *irq;
> gic_interrupt_t intrs[3];
> + u32 clock_frequency;
> + bool_t clock_valid;
>
> DPRINT("Create timer node\n");
>
> @@ -663,6 +665,15 @@ static int make_timer_node(const struct domain *d, void *fdt,
> if ( res )
> return res;
>
> + clock_valid = dt_property_read_u32(dev, "clock-frequency",
> + &clock_frequency);
> + if (clock_valid)
On Xen, the coding style request if to be:
if ( clock_valid )
With this change:
Reviewed-by: Julien Grall <julien.grall@linaro.org>
Regards,
--
Julien Grall
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [ARM:PATCH v3 1/1] Pass the timer clock-frequency to DOM0 xen/arm: Pass the timer "clock-frequency" to DOM0 in make_timer_node()
2014-04-15 19:30 ` Julien Grall
@ 2014-04-16 16:32 ` Ian Campbell
0 siblings, 0 replies; 3+ messages in thread
From: Ian Campbell @ 2014-04-16 16:32 UTC (permalink / raw)
To: Julien Grall; +Cc: Suriyan Ramasami, xen-devel, tim, stefano.stabellini
On Tue, 2014-04-15 at 20:30 +0100, Julien Grall wrote:
>
> > + clock_valid = dt_property_read_u32(dev, "clock-frequency",
> > + &clock_frequency);
> > + if (clock_valid)
>
> On Xen, the coding style request if to be:
>
> if ( clock_valid )
>
> With this change:
>
> Reviewed-by: Julien Grall <julien.grall@linaro.org>
Acked + applied with the coding style fix.
Ian.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-04-14 8:14 [ARM:PATCH v3 1/1] Pass the timer clock-frequency to DOM0 xen/arm: Pass the timer "clock-frequency" to DOM0 in make_timer_node() Suriyan Ramasami
2014-04-15 19:30 ` Julien Grall
2014-04-16 16:32 ` Ian Campbell
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