diff mbox

[v14,5/9] clocksource/drivers/arm_arch_timer: Simplify ACPI support code.

Message ID 1475086637-1914-6-git-send-email-fu.wei@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

fu.wei@linaro.org Sept. 28, 2016, 6:17 p.m. UTC 
From: Fu Wei <fu.wei@linaro.org>

The patch update arm_arch_timer driver to use the function
provided by the new GTDT driver of ACPI.
By this way, arm_arch_timer.c can be simplified, and separate
all the ACPI GTDT knowledge from this timer driver.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 drivers/clocksource/Kconfig          |  1 +
 drivers/clocksource/arm_arch_timer.c | 50 +++++++++---------------------------
 2 files changed, 13 insertions(+), 38 deletions(-)

Comments

Mark Rutland Oct. 20, 2016, 4:58 p.m. UTC | #1 
On Thu, Sep 29, 2016 at 02:17:13AM +0800, fu.wei@linaro.org wrote:
> From: Fu Wei <fu.wei@linaro.org>
> 
> The patch update arm_arch_timer driver to use the function
> provided by the new GTDT driver of ACPI.
> By this way, arm_arch_timer.c can be simplified, and separate
> all the ACPI GTDT knowledge from this timer driver.
> 
> Signed-off-by: Fu Wei <fu.wei@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>

This generally looks fine, but:

> +	arch_timer_ppi[PHYS_SECURE_PPI] = acpi_gtdt_map_ppi(PHYS_SECURE_PPI);

As mentioned on the prior patch, I think we shouldn't bother parsing the
secure interrupt, given the problem with the GSIV, and the fact that we
shouldn't need it in Linux.

> +	arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
> +	arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
> +	arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
> +	/* Always-on capability */
> +	arch_timer_c3stop = acpi_gtdt_c3stop();

... I think we should check the flag on the relevant interrupt, though
that's worth clarifying.

>  
> -	/* Always-on capability */
> -	arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
> +	if (timer_count < 0)
> +		pr_err("Failed to get platform timer info.\n");

Why don't we log this in the code that would try to initialise the MMIO
timer? We can still fail after this.

Thanks,
Mark.
Mark Rutland Oct. 21, 2016, 11:14 a.m. UTC | #2 
On Thu, Oct 20, 2016 at 05:58:17PM +0100, Mark Rutland wrote:
> On Thu, Sep 29, 2016 at 02:17:13AM +0800, fu.wei@linaro.org wrote:
> > +	arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
> > +	arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
> > +	arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
> > +	/* Always-on capability */
> > +	arch_timer_c3stop = acpi_gtdt_c3stop();
> 
> ... I think we should check the flag on the relevant interrupt, though
> that's worth clarifying.

I see I misread the spec; this is part of the common flags.

Please ignore this point; sorry for the noise.

Thanks,
Mark.
Mark Rutland Oct. 21, 2016, 11:21 a.m. UTC | #3 
On Fri, Oct 21, 2016 at 12:14:01PM +0100, Mark Rutland wrote:
> On Thu, Oct 20, 2016 at 05:58:17PM +0100, Mark Rutland wrote:
> > On Thu, Sep 29, 2016 at 02:17:13AM +0800, fu.wei@linaro.org wrote:
> > > +	arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
> > > +	arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
> > > +	arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
> > > +	/* Always-on capability */
> > > +	arch_timer_c3stop = acpi_gtdt_c3stop();
> > 
> > ... I think we should check the flag on the relevant interrupt, though
> > that's worth clarifying.
> 
> I see I misread the spec; this is part of the common flags.
> 
> Please ignore this point; sorry for the noise.

Actually, I misread the spec this time around; the flag *can* differ per
interrupt for the sysreg/cp15 timer, but not for the MMIO timers where
the flag is in a common field.

So please *do* consider the above.

Thanks,
Mark.
fu.wei@linaro.org Oct. 26, 2016, 8:54 a.m. UTC | #4 
Hi Mark,

On 21 October 2016 at 19:21, Mark Rutland <mark.rutland@arm.com> wrote:
> On Fri, Oct 21, 2016 at 12:14:01PM +0100, Mark Rutland wrote:
>> On Thu, Oct 20, 2016 at 05:58:17PM +0100, Mark Rutland wrote:
>> > On Thu, Sep 29, 2016 at 02:17:13AM +0800, fu.wei@linaro.org wrote:
>> > > + arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
>> > > + arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
>> > > + arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
>> > > + /* Always-on capability */
>> > > + arch_timer_c3stop = acpi_gtdt_c3stop();
>> >
>> > ... I think we should check the flag on the relevant interrupt, though
>> > that's worth clarifying.
>>
>> I see I misread the spec; this is part of the common flags.
>>
>> Please ignore this point; sorry for the noise.
>
> Actually, I misread the spec this time around; the flag *can* differ per
> interrupt for the sysreg/cp15 timer, but not for the MMIO timers where
> the flag is in a common field.
>
> So please *do* consider the above.

yes , you are right , will do
Thanks :-)

>
> Thanks,
> Mark.
Hanjun Guo Nov. 11, 2016, 1:55 p.m. UTC | #5 
On 10/21/2016 07:21 PM, Mark Rutland wrote:
> On Fri, Oct 21, 2016 at 12:14:01PM +0100, Mark Rutland wrote:
>> On Thu, Oct 20, 2016 at 05:58:17PM +0100, Mark Rutland wrote:
>>> On Thu, Sep 29, 2016 at 02:17:13AM +0800, fu.wei@linaro.org wrote:
>>>> +	arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
>>>> +	arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
>>>> +	arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
>>>> +	/* Always-on capability */
>>>> +	arch_timer_c3stop = acpi_gtdt_c3stop();
>>>
>>> ... I think we should check the flag on the relevant interrupt, though
>>> that's worth clarifying.
>>
>> I see I misread the spec; this is part of the common flags.
>>
>> Please ignore this point; sorry for the noise.
>
> Actually, I misread the spec this time around; the flag *can* differ per
> interrupt for the sysreg/cp15 timer, but not for the MMIO timers where
> the flag is in a common field.
>
> So please *do* consider the above.

Sorry, misread the email as well...

Check the spec again and it's per interrupt flag.

Thanks
Hanjun
diff mbox

Patch

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index b58d259..a63bf12 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -8,6 +8,7 @@  config CLKSRC_OF
 config CLKSRC_ACPI
 	bool
 	select CLKSRC_PROBE
+	select ACPI_GTDT if ARM64
 
 config CLKSRC_PROBE
 	bool
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 84be023..c7b0040 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -887,61 +887,35 @@  out:
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 		       arch_timer_mem_init);
 
-#ifdef CONFIG_ACPI
-static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
-{
-	int trigger, polarity;
-
-	if (!interrupt)
-		return 0;
-
-	trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
-			: ACPI_LEVEL_SENSITIVE;
-
-	polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
-			: ACPI_ACTIVE_HIGH;
-
-	return acpi_register_gsi(NULL, interrupt, trigger, polarity);
-}
-
+#ifdef CONFIG_ACPI_GTDT
 /* Initialize per-processor generic timer */
 static int __init arch_timer_acpi_init(struct acpi_table_header *table)
 {
-	struct acpi_table_gtdt *gtdt;
+	int timer_count;
 
 	if (arch_timers_present & ARCH_CP15_TIMER) {
 		pr_warn("already initialized, skipping\n");
 		return -EINVAL;
 	}
 
-	gtdt = container_of(table, struct acpi_table_gtdt, header);
-
 	arch_timers_present |= ARCH_CP15_TIMER;
 
-	arch_timer_ppi[PHYS_SECURE_PPI] =
-		map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
-		gtdt->secure_el1_flags);
-
-	arch_timer_ppi[PHYS_NONSECURE_PPI] =
-		map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
-		gtdt->non_secure_el1_flags);
+	timer_count = acpi_gtdt_init(table);
 
-	arch_timer_ppi[VIRT_PPI] =
-		map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
-		gtdt->virtual_timer_flags);
-
-	arch_timer_ppi[HYP_PPI] =
-		map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
-		gtdt->non_secure_el2_flags);
+	arch_timer_ppi[PHYS_SECURE_PPI] = acpi_gtdt_map_ppi(PHYS_SECURE_PPI);
+	arch_timer_ppi[PHYS_NONSECURE_PPI] = acpi_gtdt_map_ppi(PHYS_NONSECURE_PPI);
+	arch_timer_ppi[VIRT_PPI] = acpi_gtdt_map_ppi(VIRT_PPI);
+	arch_timer_ppi[HYP_PPI] = acpi_gtdt_map_ppi(HYP_PPI);
+	/* Always-on capability */
+	arch_timer_c3stop = acpi_gtdt_c3stop();
 
 	/* Get the frequency from CNTFRQ */
 	arch_timer_detect_rate(NULL, NULL);
 
-	/* Always-on capability */
-	arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+	if (timer_count < 0)
+		pr_err("Failed to get platform timer info.\n");
 
-	arch_timer_init();
-	return 0;
+	return arch_timer_init();
 }
 CLOCKSOURCE_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
 #endif