[v3,32/62] arm/acpi: Parse GTDT to initialize timer

Commit Message

Shannon Zhao Nov. 17, 2015, 9:40 a.m. UTC

From: Parth Dixit <[e-mail]>

Parse GTDT (Generic Timer Descriptor Table) to initialize timer. Using
the information presented by GTDT to initialize the arch timer (not
memory-mapped).

Signed-off-by: Naresh Bhat <[e-mail]>
Signed-off-by: Parth Dixit <[e-mail]>
Signed-off-by: Shannon Zhao <[e-mail]>
---
 xen/arch/arm/time.c | 73 +++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 62 insertions(+), 11 deletions(-)

Comments

Stefano Stabellini Nov. 26, 2015, 12:54 p.m. UTC | #1

On Tue, 17 Nov 2015, [e-mail] wrote:
> From: Parth Dixit <[e-mail]>
> 
> Parse GTDT (Generic Timer Descriptor Table) to initialize timer. Using
> the information presented by GTDT to initialize the arch timer (not
> memory-mapped).
> 
> Signed-off-by: Naresh Bhat <[e-mail]>
> Signed-off-by: Parth Dixit <[e-mail]>
> Signed-off-by: Shannon Zhao <[e-mail]>
> ---
>  xen/arch/arm/time.c | 73 +++++++++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 62 insertions(+), 11 deletions(-)
> 
> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> index 5ded30c..adbfc2a 100644
> --- a/xen/arch/arm/time.c
> +++ b/xen/arch/arm/time.c
> @@ -29,6 +29,7 @@
>  #include <xen/time.h>
>  #include <xen/sched.h>
>  #include <xen/event.h>
> +#include <xen/acpi.h>
>  #include <asm/system.h>
>  #include <asm/time.h>
>  #include <asm/gic.h>
> @@ -65,8 +66,45 @@ unsigned int timer_get_irq(enum timer_ppi ppi)
>  
>  static __initdata struct dt_device_node *timer;
>  
> +#ifdef CONFIG_ACPI
> +/* Initialize per-processor generic timer */
> +static int __init arch_timer_acpi_init(struct acpi_table_header *table)
> +{
> +    unsigned int irq_type;
> +    struct acpi_table_gtdt *gtdt;
> +
> +    gtdt = container_of(table, struct acpi_table_gtdt, header);
> +
> +    /* Initialize all the generic timer IRQ variable from GTDT table */
> +    irq_type = acpi_get_irq_type(gtdt->non_secure_el1_flags);
> +    irq_set_type(gtdt->non_secure_el1_interrupt, irq_type);
> +    timer_irq[TIMER_PHYS_NONSECURE_PPI] = gtdt->non_secure_el1_interrupt;
> +
> +    irq_type = acpi_get_irq_type(gtdt->secure_el1_flags);
> +    irq_set_type(gtdt->secure_el1_interrupt, irq_type);
> +    timer_irq[TIMER_PHYS_SECURE_PPI] = gtdt->secure_el1_interrupt;
> +
> +    irq_type = acpi_get_irq_type(gtdt->virtual_timer_flags);
> +    irq_set_type(gtdt->virtual_timer_interrupt, irq_type);
> +    timer_irq[TIMER_VIRT_PPI] = gtdt->virtual_timer_interrupt;
> +
> +    irq_type = acpi_get_irq_type(gtdt->non_secure_el2_flags);
> +    irq_set_type(gtdt->non_secure_el2_interrupt, irq_type);
> +    timer_irq[TIMER_HYP_PPI] = gtdt->non_secure_el2_interrupt;
> +
> +    return 0;
> +}
> +
> +void __init acpi_preinit_xen_time(void)

static?


> +{
> +	acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
> +}
> +#else
> +static inline void acpi_preinit_xen_time(void) { }
> +#endif
> +
>  /* Set up the timer on the boot CPU (early init function) */
> -void __init preinit_xen_time(void)
> +static void __init dt_preinit_xen_time(void)
>  {
>      static const struct dt_device_match timer_ids[] __initconst =
>      {
> @@ -74,7 +112,6 @@ void __init preinit_xen_time(void)
>          { /* sentinel */ },
>      };
>      int res;
> -    u32 rate;
>  
>      timer = dt_find_matching_node(NULL, timer_ids);
>      if ( !timer )
> @@ -86,8 +123,19 @@ void __init preinit_xen_time(void)
>      if ( res )
>          panic("Timer: Cannot initialize platform timer");

Don't we want to call platform_init_time on ARM too? It doesn't look
like something DT specific. I guess we should move the call to the
generic init function?


> -    res = dt_property_read_u32(timer, "clock-frequency", &rate);
> -    if ( res )

I think we should keep the clock-frequency DT read in
dt_preinit_xen_time.


> +}
> +
> +void __init preinit_xen_time(void)
> +{
> +    u32 rate;
> +
> +    /* Initialize all the generic timers presented in GTDT */
> +    if ( acpi_disabled )
> +        dt_preinit_xen_time();
> +    else
> +        acpi_preinit_xen_time();
> +
> +    if( acpi_disabled && dt_property_read_u32(timer, "clock-frequency", &rate) )
>      {
>          cpu_khz = rate / 1000;
>          timer_dt_clock_frequency = rate;

I don't think we want to read a DT property from a generic
initialization function.


> @@ -104,14 +152,17 @@ int __init init_xen_time(void)
>      int res;
>      unsigned int i;
>  
> -    /* Retrieve all IRQs for the timer */
> -    for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
> +    if( acpi_disabled )
>      {
> -        res = platform_get_irq(timer, i);
> -
> -        if ( res < 0 )
> -            panic("Timer: Unable to retrieve IRQ %u from the device tree", i);
> -        timer_irq[i] = res;
> +        /* Retrieve all IRQs for the timer */
> +        for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
> +        {
> +            res = platform_get_irq(timer, i);
> +
> +            if ( res < 0 )
> +                panic("Timer: Unable to retrieve IRQ %u from the device tree", i);
> +            timer_irq[i] = res;
> +        }
>      }

Can't be just move this into the DT specific init function?


>  
>      /* Check that this CPU supports the Generic Timer interface */
> -- 
> 2.1.0
> 
> 
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> Xen-devel mailing list
> [e-mail]
> http://lists.xen.org/xen-devel
>

Patch

diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index 5ded30c..adbfc2a 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -29,6 +29,7 @@ 
 #include <xen/time.h>
 #include <xen/sched.h>
 #include <xen/event.h>
+#include <xen/acpi.h>
 #include <asm/system.h>
 #include <asm/time.h>
 #include <asm/gic.h>
@@ -65,8 +66,45 @@  unsigned int timer_get_irq(enum timer_ppi ppi)
 
 static __initdata struct dt_device_node *timer;
 
+#ifdef CONFIG_ACPI
+/* Initialize per-processor generic timer */
+static int __init arch_timer_acpi_init(struct acpi_table_header *table)
+{
+    unsigned int irq_type;
+    struct acpi_table_gtdt *gtdt;
+
+    gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+    /* Initialize all the generic timer IRQ variable from GTDT table */
+    irq_type = acpi_get_irq_type(gtdt->non_secure_el1_flags);
+    irq_set_type(gtdt->non_secure_el1_interrupt, irq_type);
+    timer_irq[TIMER_PHYS_NONSECURE_PPI] = gtdt->non_secure_el1_interrupt;
+
+    irq_type = acpi_get_irq_type(gtdt->secure_el1_flags);
+    irq_set_type(gtdt->secure_el1_interrupt, irq_type);
+    timer_irq[TIMER_PHYS_SECURE_PPI] = gtdt->secure_el1_interrupt;
+
+    irq_type = acpi_get_irq_type(gtdt->virtual_timer_flags);
+    irq_set_type(gtdt->virtual_timer_interrupt, irq_type);
+    timer_irq[TIMER_VIRT_PPI] = gtdt->virtual_timer_interrupt;
+
+    irq_type = acpi_get_irq_type(gtdt->non_secure_el2_flags);
+    irq_set_type(gtdt->non_secure_el2_interrupt, irq_type);
+    timer_irq[TIMER_HYP_PPI] = gtdt->non_secure_el2_interrupt;
+
+    return 0;
+}
+
+void __init acpi_preinit_xen_time(void)
+{
+	acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
+}
+#else
+static inline void acpi_preinit_xen_time(void) { }
+#endif
+
 /* Set up the timer on the boot CPU (early init function) */
-void __init preinit_xen_time(void)
+static void __init dt_preinit_xen_time(void)
 {
     static const struct dt_device_match timer_ids[] __initconst =
     {
@@ -74,7 +112,6 @@  void __init preinit_xen_time(void)
         { /* sentinel */ },
     };
     int res;
-    u32 rate;
 
     timer = dt_find_matching_node(NULL, timer_ids);
     if ( !timer )
@@ -86,8 +123,19 @@  void __init preinit_xen_time(void)
     if ( res )
         panic("Timer: Cannot initialize platform timer");
 
-    res = dt_property_read_u32(timer, "clock-frequency", &rate);
-    if ( res )
+}
+
+void __init preinit_xen_time(void)
+{
+    u32 rate;
+
+    /* Initialize all the generic timers presented in GTDT */
+    if ( acpi_disabled )
+        dt_preinit_xen_time();
+    else
+        acpi_preinit_xen_time();
+
+    if( acpi_disabled && dt_property_read_u32(timer, "clock-frequency", &rate) )
     {
         cpu_khz = rate / 1000;
         timer_dt_clock_frequency = rate;
@@ -104,14 +152,17 @@  int __init init_xen_time(void)
     int res;
     unsigned int i;
 
-    /* Retrieve all IRQs for the timer */
-    for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
+    if( acpi_disabled )
     {
-        res = platform_get_irq(timer, i);
-
-        if ( res < 0 )
-            panic("Timer: Unable to retrieve IRQ %u from the device tree", i);
-        timer_irq[i] = res;
+        /* Retrieve all IRQs for the timer */
+        for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
+        {
+            res = platform_get_irq(timer, i);
+
+            if ( res < 0 )
+                panic("Timer: Unable to retrieve IRQ %u from the device tree", i);
+            timer_irq[i] = res;
+        }
     }
 
     /* Check that this CPU supports the Generic Timer interface */