[PATCH v2 15/41] arm : acpi parse GTDT to initialize timer

[Parth Dixit <parth.dixit@linaro.org>]

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[])
+{
+    int type;
+    struct acpi_table_gtdt *gtdt=NULL;
+    u8 checksum;
+    static const int GTDT_INTRL_TAB[] =
+    {
+        ACPI_IRQ_TYPE_LEVEL_HIGH,
+        ACPI_IRQ_TYPE_EDGE_RISING,
+        ACPI_IRQ_TYPE_LEVEL_LOW,
+        ACPI_IRQ_TYPE_EDGE_FALLING
+    };
+
+    acpi_get_table(ACPI_SIG_GTDT, 0, (struct acpi_table_header **)&gtdt);
+
+    if( gtdt )
+    {
+        /* 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));
+    }
+}
+
 /*
  * 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) )
         cpu_khz = rate / 1000;
     else
         cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
@@ -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;
+        }
     }
 
     /* 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 */
-- 
1.9.1