[PATCH v24 02/11] clocksource: arm_arch_timer: refactor arch_timer_needs_probing

fu.wei
2017-04-14T18:41:19Z

When booting with DT, it's possible for timer nodes to be probed in any
order. Some common initialisation needs to occur after all nodes have
been probed, and arch_timer_common_init() has code to detect when this
has happened.

This logic is DT-specific, and it would be best to factor it out of the
common code that will be shared with ACPI.

This patch folds this into the existing arch_timer_needs_probing(),
which is renamed to arch_timer_needs_of_probing(), and no longer takes
any arguments. This is only called when using DT, and not when using
ACPI, which will have a deterministic probe order.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
[Mark: reword commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
drivers/clocksource/arm_arch_timer.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 0138b0c..03d71d6 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1076,15 +1076,28 @@ static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
{},
};

-static bool __init
-arch_timer_needs_probing(int type, const struct of_device_id *matches)
+static bool __init arch_timer_needs_of_probing(void)
{
struct device_node *dn;
bool needs_probing = false;
+ unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;

- dn = of_find_matching_node(NULL, matches);
- if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
+ /* We have two timers, and both device-tree nodes are probed. */
+ if ((arch_timers_present & mask) == mask)
+ return false;
+
+ /*
+ * Only one type of timer is probed,
+ * check if we have another type of timer node in device-tree.
+ */
+ if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
+ dn = of_find_matching_node(NULL, arch_timer_mem_of_match);
+ else
+ dn = of_find_matching_node(NULL, arch_timer_of_match);
+
+ if (dn && of_device_is_available(dn))
needs_probing = true;
+
of_node_put(dn);

return needs_probing;
@@ -1092,17 +1105,8 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)

static int __init arch_timer_common_init(void)
{
- unsigned mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
-
- /* Wait until both nodes are probed if we have two timers */
- if ((arch_timers_present & mask) != mask) {
- if (arch_timer_needs_probing(ARCH_TIMER_TYPE_MEM,
- arch_timer_mem_of_match))
- return 0;
- if (arch_timer_needs_probing(ARCH_TIMER_TYPE_CP15,
- arch_timer_of_match))
- return 0;
- }
+ if (acpi_disabled && arch_timer_needs_of_probing())
+ return 0;

arch_timer_banner(arch_timers_present);
arch_counter_register(arch_timers_present);
--
2.9.3