Hi Parth,
acpi/boot.c begin to be a junk room for all ACPI code. It would have
On 17/05/15 21:03, Parth Dixit wrote:
> Parse GTDT (Generic Timer Descriptor Table) to initialize timer.
> Using the information presented by GTDT to initialize the arch
> timer (not memory-mapped).
>
> Clear all el2 fields in GTDT table after initialization
> for passing it to Dom0.
>
> Signed-off-by: Naresh Bhat <naresh.bhat@linaro.org>
> Signed-off-by: Parth Dixit <parth.dixit@linaro.org>
> ---
> xen/arch/arm/acpi/boot.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
> xen/arch/arm/time.c | 38 +++++++++++++++++++++++++----------
> xen/include/asm-arm/acpi.h | 2 ++
> 3 files changed, 79 insertions(+), 11 deletions(-)
>
> diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
> index 7d9758f..a8311ae 100644
> --- a/xen/arch/arm/acpi/boot.c
> +++ b/xen/arch/arm/acpi/boot.c
> @@ -30,6 +30,8 @@
>
> #include <asm/acpi.h>
> #include <asm/smp.h>
> +#include <asm/irq.h>
> +#include <asm/time.h>
>
> /* Processors with enabled flag and sane MPIDR */
> static int enabled_cpus;
> @@ -40,6 +42,54 @@ static bool_t __initdata bootcpu_valid;
> /* arch-optional setting to enable display of offline cpus >= nr_cpu_ids */
> static unsigned int total_cpus = 0;
>
> +/* Initialize per-processor generic timer */
> +void __init acpi_preinit_xen_time(unsigned int generic_timer_irq[])
been more logic to have this code in arch/arm/time.c with proper #ifdef.
This would have drop the generic_timer_irq which is difficult to understand.
> +{
> + int type;
> + struct acpi_table_gtdt *gtdt=NULL;
*gtdt = NULL;
> + u8 checksum;
> + static const int GTDT_INTRL_TAB[] =
all uppercase name are used for define.
> + {
> + ACPI_IRQ_TYPE_LEVEL_HIGH,
> + ACPI_IRQ_TYPE_EDGE_RISING,
> + ACPI_IRQ_TYPE_LEVEL_LOW,
> + ACPI_IRQ_TYPE_EDGE_FALLING
> + };
It took me a while to understand how this work.
I would prefer an helper which check each field and return/set the
correct interrupt type.
> +
> + acpi_get_table(ACPI_SIG_GTDT, 0, (struct acpi_table_header **)>dt);
> +
> + if( gtdt )
> + {
If gtdt is NULL you will continue without any warning and potentially
crash later.
Also please do:
if ( !gtdt ) {
/* handle error */
return;
}
/* setup the timer */
It's easier to understand and remove one indentation.
Similar comment as on the MADT, this function is initializing the timer
> + /* Initialize all the generic timer IRQ variable from GTDT table */
> +
> + type = GTDT_INTRL_TAB[gtdt->non_secure_el1_flags & ACPI_GTDT_INTR_MASK];
> + set_irq_type(gtdt->non_secure_el1_interrupt, type);
> + generic_timer_irq[TIMER_PHYS_NONSECURE_PPI] =
> + gtdt->non_secure_el1_interrupt;
> +
> + type = GTDT_INTRL_TAB[gtdt->secure_el1_flags & ACPI_GTDT_INTR_MASK];
> + set_irq_type(gtdt->secure_el1_interrupt, type);
> + generic_timer_irq[TIMER_PHYS_SECURE_PPI] =
> + gtdt->secure_el1_interrupt;
> +
> + type = GTDT_INTRL_TAB[gtdt->non_secure_el2_flags & ACPI_GTDT_INTR_MASK];
> + set_irq_type(gtdt->non_secure_el2_interrupt, type);
> + generic_timer_irq[TIMER_HYP_PPI] =
> + gtdt->non_secure_el2_interrupt;
> +
> + type = GTDT_INTRL_TAB[gtdt->virtual_timer_flags & ACPI_GTDT_INTR_MASK];
> + set_irq_type(gtdt->virtual_timer_interrupt, type);
> + generic_timer_irq[TIMER_VIRT_PPI] =
> + gtdt->virtual_timer_interrupt;
> +
> + gtdt->non_secure_el2_interrupt = 0;
> + gtdt->non_secure_el2_flags = 0;
> + checksum = acpi_tb_checksum(ACPI_CAST_PTR(u8, gtdt), gtdt->header.length);
> + gtdt->header.checksum -= checksum;
> + clean_dcache_va_range(gtdt, sizeof(struct acpi_table_gtdt));
and not modifying the ACPI table.
I would prefer a separate function which is called during DOM0 building.
It would be easier to know how the ACPI table has been modified for DOM0.
Also, please add a comment to explain this block smth like /* Hide EL2
interrupt to DOM0 */. Maybe explaining that the table is re-used.
Furthermore, are you sure that the ACPI table will always be in R/W
memory? If not, we should duplicate the table and update the field.
Only one blank line is enough.
> + }
> +}
> +
> /*
> * acpi_map_gic_cpu_interface - generates a logical cpu number
> * and map to MPIDR represented by GICC structure
> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> index ce6d3fd..bff95ab 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>
> @@ -64,7 +65,7 @@ unsigned int timer_get_irq(enum timer_ppi ppi)
> static __initdata struct dt_device_node *timer;
>
> /* 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 =
> {
> @@ -72,7 +73,6 @@ void __init preinit_xen_time(void)
> { /* sentinel */ },
> };
> int res;
> - u32 rate;
>
> timer = dt_find_matching_node(NULL, timer_ids);
> if ( !timer )
> @@ -84,8 +84,21 @@ 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(timer_irq);
> +
> + if( acpi_disabled && dt_property_read_u32(timer, "clock-frequency", &rate) )
A such check calls for more refactoring...
> cpu_khz = rate / 1000;
> else
> cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
Duplicating this line wouldn't have been too bad compare to the check.
> @@ -99,14 +112,17 @@ 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;
> + }
Another helper for this device tree code?
> }
>
> /* Check that this CPU supports the Generic Timer interface */
> diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h
> index 1767143..482cc5b 100644
> --- a/xen/include/asm-arm/acpi.h
> +++ b/xen/include/asm-arm/acpi.h
> @@ -36,10 +36,12 @@ bool_t acpi_psci_present(void);
> /* 1 to indicate HVC is present instead of SMC as the PSCI conduit */
> bool_t acpi_psci_hvc_present(void);
> void __init acpi_init_cpus(void);
> +void __init acpi_preinit_xen_time(unsigned int generic_timer_irq[]);
> #else
> static inline bool_t acpi_psci_present(void) { return false; }
> static inline bool_t acpi_psci_hvc_present(void) {return false; }
> static inline void acpi_init_cpus(void) { }
> +static inline void acpi_preinit_xen_time(unsigned int generic_timer_irq[]){ }
> #endif /* CONFIG_ACPI */
>
> /* Basic configuration for ACPI */
>
Regards,
--
Julien Grall