[Minios-devel] [UNIKRAFT PATCH v6 5/7] plat/common: Find and register IRQ for arch_timer

[Jia He <justin.he@xxxxxxx>]

Currently, in unikraft, the timer interrupt hasn't been
used to update ticks periodically. We just mask it in
IRQ handler, and wait for sleep function to set new
match counter and unmask IRQ.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
Signed-off-by: Jianyong Wu <jianyong.wu@xxxxxxx>
Signed-off-by: Jia He <justin.he@xxxxxxx>
---
 plat/common/arm/time.c             | 112 ++++++++++++++++++++++++-----
 plat/drivers/gic/gic-v2.c          |   2 +-
 plat/drivers/include/gic/gic-v2.h  |   2 +-
 plat/drivers/include/ofw/gic_fdt.h |   2 +-
 4 files changed, 99 insertions(+), 19 deletions(-)

diff --git a/plat/common/arm/time.c b/plat/common/arm/time.c
index da93991..afe3663 100644
--- a/plat/common/arm/time.c
+++ b/plat/common/arm/time.c
@@ -36,9 +36,18 @@
 #include <ofw/fdt.h>
 #include <uk/assert.h>
 #include <uk/plat/time.h>
+#include <uk/plat/lcpu.h>
 #include <uk/plat/irq.h>
 #include <uk/bitops.h>
 #include <cpu.h>
+#include <ofw/gic_fdt.h>
+#include <irq.h>
+#include <gic/gic-v2.h>
+
+/* Bits definition of cntv_ctl_el0 register */
+#define GT_TIMER_ENABLE        0x01
+#define GT_TIMER_MASK_IRQ      0x02
+#define GT_TIMER_IRQ_STATUS    0x04
 
 /* TODO: For now this file is KVM dependent. As soon as we have more
  * Arm platforms that are using this file, we need to introduce a
@@ -139,6 +148,50 @@ static void calculate_mult_shift(uint32_t *mult, uint8_t 
*shift,
        *shift = sft;
 }
 
+static inline void generic_timer_enable(void)
+{
+       SYSREG_WRITE32(cntv_ctl_el0,
+                      SYSREG_READ32(cntv_ctl_el0) | GT_TIMER_ENABLE);
+
+       /* Ensure the write of sys register is visible */
+       isb();
+}
+
+static inline void generic_timer_disable(void)
+{
+       SYSREG_WRITE32(cntv_ctl_el0,
+               SYSREG_READ32(cntv_ctl_el0) & ~GT_TIMER_ENABLE);
+
+       /* Ensure the write of sys register is visible */
+       isb();
+}
+
+static inline void generic_timer_mask_irq(void)
+{
+       SYSREG_WRITE32(cntv_ctl_el0,
+               SYSREG_READ32(cntv_ctl_el0) | GT_TIMER_MASK_IRQ);
+
+       /* Ensure the write of sys register is visible */
+       isb();
+}
+
+static inline void generic_timer_unmask_irq(void)
+{
+       SYSREG_WRITE32(cntv_ctl_el0,
+               SYSREG_READ32(cntv_ctl_el0) & (~GT_TIMER_MASK_IRQ));
+
+       /* Ensure the write of sys register is visible */
+       isb();
+}
+
+static inline void generic_timer_update_compare(uint64_t new_val)
+{
+       SYSREG_WRITE64(cntv_cval_el0, new_val);
+
+       /* Ensure the write of sys register is visible */
+       isb();
+}
+
 static uint32_t generic_timer_get_frequency(int fdt_timer)
 {
        int len;
@@ -233,16 +286,28 @@ static int generic_timer_init(int fdt_timer)
        return 0;
 }
 
+static int generic_timer_irq_handler(void *arg __unused)
+{
+       /*
+        * We just mask the IRQ here, the scheduler will call
+        * generic_timer_cpu_block, and then unmask the IRQ.
+        */
+       generic_timer_mask_irq();
+
+       /* Yes, we handled the irq. */
+       return 1;
+}
+
 unsigned long sched_have_pending_events;
 
 void time_block_until(__snsec until)
 {
+       /*
+        * TODO:
+        * As we haven't support interrupt on Arm, so we just
+        * use busy polling for now.
+        */
        while ((__snsec) ukplat_monotonic_clock() < until) {
-               /*
-                * TODO:
-                * As we haven't support interrupt on Arm, so we just
-                * use busy polling for now.
-                */
                if (__uk_test_and_clear_bit(0, &sched_have_pending_events))
                        break;
        }
@@ -260,16 +325,12 @@ __nsec ukplat_wall_clock(void)
        return generic_timer_monotonic() + generic_timer_epochoffset();
 }
 
-static int timer_handler(void *arg __unused)
-{
-       /* Yes, we handled the irq. */
-       return 1;
-}
-
 /* must be called before interrupts are enabled */
 void ukplat_time_init(void)
 {
-       int rc, fdt_timer;
+       int rc, irq, fdt_timer;
+       uint32_t irq_type, hwirq;
+       uint32_t trigger_type;
 
        /*
         * Monotonic time begins at boot_ticks (first read of counter
@@ -283,11 +344,30 @@ void ukplat_time_init(void)
        if (fdt_timer < 0)
                UK_CRASH("Could not find arch timer!\n");
 
-       rc = ukplat_irq_register(0, timer_handler, NULL);
-       if (rc < 0)
-               UK_CRASH("Failed to register timer interrupt handler\n");
-
        rc = generic_timer_init(fdt_timer);
        if (rc < 0)
                UK_CRASH("Failed to initialize platform time\n");
+
+       rc = gic_get_irq_from_dtb(_libkvmplat_cfg.dtb, fdt_timer, 2,
+                       &irq_type, &hwirq, &trigger_type);
+       if (rc < 0)
+               UK_CRASH("Failed to find IRQ number from DTB\n");
+
+       irq = gic_irq_translate(irq_type, hwirq);
+       if (irq < 0 || irq >= __MAX_IRQ)
+               UK_CRASH("Failed to translate IRQ number, type=%u, hwirq=%u\n",
+                       irq_type, hwirq);
+
+       rc = ukplat_irq_register(irq, generic_timer_irq_handler, NULL);
+       if (rc < 0)
+               UK_CRASH("Failed to register timer interrupt handler\n");
+
+       /*
+        * Mask IRQ before scheduler start working. Otherwise we will get
+        * unexpected timer interrupts when system is booting.
+        */
+       generic_timer_mask_irq();
+
+       /* Enable timer */
+       generic_timer_enable();
 }
diff --git a/plat/drivers/gic/gic-v2.c b/plat/drivers/gic/gic-v2.c
index 687714e..c01c92f 100644
--- a/plat/drivers/gic/gic-v2.c
+++ b/plat/drivers/gic/gic-v2.c
@@ -291,7 +291,7 @@ void gic_set_irq_type(uint32_t irq, int trigger)
        write_gicd32(GICD_ICFGR(irq), val);
 }
 
-uint32_t gic_irq_translate(uint32_t type, uint32_t hw_irq)
+int32_t gic_irq_translate(uint32_t type, uint32_t hw_irq)
 {
        uint32_t irq;
 
diff --git a/plat/drivers/include/gic/gic-v2.h 
b/plat/drivers/include/gic/gic-v2.h
index 24da1eb..c28b7a7 100644
--- a/plat/drivers/include/gic/gic-v2.h
+++ b/plat/drivers/include/gic/gic-v2.h
@@ -365,7 +365,7 @@ int gic_is_irq_active(uint32_t irq);
 void gic_set_irq_type(uint32_t irq, int trigger);
 
 /* Translate to hwirq according to type e.g. PPI SPI SGI */
-uint32_t gic_irq_translate(uint32_t type, uint32_t hw_irq);
+int gic_irq_translate(uint32_t type, uint32_t hw_irq);
 
 /* Handle IRQ entry */
 void gic_handle_irq(void);
diff --git a/plat/drivers/include/ofw/gic_fdt.h 
b/plat/drivers/include/ofw/gic_fdt.h
index e81bc28..e555892 100644
--- a/plat/drivers/include/ofw/gic_fdt.h
+++ b/plat/drivers/include/ofw/gic_fdt.h
@@ -47,5 +47,5 @@
  */
 int gic_get_irq_from_dtb(const void *fdt, int nodeoffset, int index,
                        uint32_t *irq_type, uint32_t *hwirq,
-                       uint32_t *trigger_type)
+                       uint32_t *trigger_type);
 #endif /* __PLAT_DRV_GIC_FDT_H__ */
-- 
2.17.1


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