[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v3] xen/arm: split the init_xen_time() in 2 parts



Hi Oleksandr,

Thank you for the quick change.

On 27/01/2015 18:59, Oleksandr Tyshchenko wrote:
Create preinit_xen_time() and move to it minimum required
subset of operations needed to properly initialized
cpu_khz and boot_count vars. This is allow us to use udelay()
immediately after the call.

Signed-off-by: Oleksandr Tyshchenko <oleksandr.tyshchenko@xxxxxxxxxxxxxxx>
CC: Julien Grall <julien.grall@xxxxxxxxxx>

Reviewed-by: Julien Grall <julien.grall@xxxxxxxxxx>

Regards,

---
Changes in v2:
1. Move timer_ids out of the find_timer_node() and frop this func.
2. Use void as a return value for preinit_xen_time().
3. Move platform_init() before calling preinit_xen_time().

Changes in v3:
1. Store the device node for timer outside the funcs.

---
  xen/arch/arm/setup.c   |  6 ++++--
  xen/arch/arm/time.c    | 57 ++++++++++++++++++++++++++++----------------------
  xen/include/xen/time.h |  1 +
  3 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index f49569d..a916ca6 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -743,6 +743,10 @@ void __init start_xen(unsigned long boot_phys_offset,

      init_IRQ();

+    platform_init();
+
+    preinit_xen_time();
+
      dt_uart_init();
      console_init_preirq();
      console_init_ring();
@@ -751,8 +755,6 @@ void __init start_xen(unsigned long boot_phys_offset,

      processor_id();

-    platform_init();
-
      smp_init_cpus();
      cpus = smp_get_max_cpus();

diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index 0add494..04291f9 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -61,56 +61,63 @@ unsigned int timer_get_irq(enum timer_ppi ppi)
      return muldiv64(ns, 1000 * cpu_khz, SECONDS(1));
  }

-/* Set up the timer on the boot CPU */
-int __init init_xen_time(void)
+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 const struct dt_device_match timer_ids[] __initconst =
      {
          DT_MATCH_TIMER,
          { /* sentinel */ },
      };
-    struct dt_device_node *dev;
      int res;
-    unsigned int i;
      u32 rate;

-    dev = dt_find_matching_node(NULL, timer_ids);
-    if ( !dev )
+    timer = dt_find_matching_node(NULL, timer_ids);
+    if ( !timer )
          panic("Unable to find a compatible timer in the device tree");

-    dt_device_set_used_by(dev, DOMID_XEN);
+    dt_device_set_used_by(timer, DOMID_XEN);
+
+    res = platform_init_time();
+    if ( res )
+        panic("Timer: Cannot initialize platform timer");
+
+    res = dt_property_read_u32(timer, "clock-frequency", &rate);
+    if ( res )
+        cpu_khz = rate / 1000;
+    else
+        cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
+
+    boot_count = READ_SYSREG64(CNTPCT_EL0);
+}
+
+/* Set up the timer on the boot CPU (late init function) */
+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++ )
      {
-        res = platform_get_irq(dev, 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;
      }

-    printk("Generic Timer IRQ: phys=%u hyp=%u virt=%u\n",
-           timer_irq[TIMER_PHYS_NONSECURE_PPI],
-           timer_irq[TIMER_HYP_PPI],
-           timer_irq[TIMER_VIRT_PPI]);
-
-    res = platform_init_time();
-    if ( res )
-        panic("Timer: Cannot initialize platform timer");
-
      /* Check that this CPU supports the Generic Timer interface */
      if ( !cpu_has_gentimer )
          panic("CPU does not support the Generic Timer v1 interface");

-    res = dt_property_read_u32(dev, "clock-frequency", &rate);
-    if ( res )
-        cpu_khz = rate / 1000;
-    else
-        cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
-
-    boot_count = READ_SYSREG64(CNTPCT_EL0);
-    printk("Using generic timer at %lu KHz\n", cpu_khz);
+    printk("Generic Timer IRQ: phys=%u hyp=%u virt=%u Freq: %lu KHz\n",
+           timer_irq[TIMER_PHYS_NONSECURE_PPI],
+           timer_irq[TIMER_HYP_PPI],
+           timer_irq[TIMER_VIRT_PPI],
+           cpu_khz);

      return 0;
  }
diff --git a/xen/include/xen/time.h b/xen/include/xen/time.h
index 709501f..bb6259d 100644
--- a/xen/include/xen/time.h
+++ b/xen/include/xen/time.h
@@ -12,6 +12,7 @@
  #include <public/xen.h>

  extern int init_xen_time(void);
+void preinit_xen_time(void);
  extern void cstate_restore_tsc(void);

  extern unsigned long cpu_khz;


--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.