[PATCH v16 06/15] clocksource/drivers/arm_arch_timer: separate out arch_timer_uses_ppi init code to prepare for GTDT.

From: fu . wei
Date: Wed Nov 16 2016 - 08:50:49 EST


From: Fu Wei <fu.wei@xxxxxxxxxx>

The patch refactor original arch_timer_uses_ppi init code:
(1) Extract a subfunction: arch_timer_uses_ppi_init
(2) Use the new subfunction in arch_timer_of_init and
arch_timer_acpi_init

Signed-off-by: Fu Wei <fu.wei@xxxxxxxxxx>
---
drivers/clocksource/arm_arch_timer.c | 73 +++++++++++++++++++++---------------
1 file changed, 42 insertions(+), 31 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 6de164f..af22953 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -821,40 +821,42 @@ static int __init arch_timer_common_init(void)
return arch_timer_arch_init();
}

-static int __init arch_timer_init(void)
+/*
+ * If HYP mode is available, we know that the physical timer
+ * has been configured to be accessible from PL1. Use it, so
+ * that a guest can use the virtual timer instead.
+ *
+ * If no interrupt provided for virtual timer, we'll have to
+ * stick to the physical timer. It'd better be accessible...
+ * On ARM64, we we only use ARCH_TIMER_PHYS_NONSECURE_PPI in Linux.
+ *
+ * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
+ * accesses to CNTP_*_EL1 registers are silently redirected to
+ * their CNTHP_*_EL2 counterparts, and use a different PPI
+ * number.
+ */
+static int __init arch_timer_uses_ppi_init(void)
{
- int ret;
- /*
- * If HYP mode is available, we know that the physical timer
- * has been configured to be accessible from PL1. Use it, so
- * that a guest can use the virtual timer instead.
- *
- * If no interrupt provided for virtual timer, we'll have to
- * stick to the physical timer. It'd better be accessible...
- *
- * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
- * accesses to CNTP_*_EL1 registers are silently redirected to
- * their CNTHP_*_EL2 counterparts, and use a different PPI
- * number.
- */
- if (is_hyp_mode_available() || !arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) {
- bool has_ppi;
-
- if (is_kernel_in_hyp_mode()) {
- arch_timer_uses_ppi = ARCH_TIMER_HYP_PPI;
- has_ppi = !!arch_timer_ppi[ARCH_TIMER_HYP_PPI];
- } else {
+ if (is_hyp_mode_available() && is_kernel_in_hyp_mode()) {
+ arch_timer_uses_ppi = ARCH_TIMER_HYP_PPI;
+ } else if (!arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) {
+ if (IS_ENABLED(CONFIG_ARM64))
+ arch_timer_uses_ppi = ARCH_TIMER_PHYS_NONSECURE_PPI;
+ else
arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
- has_ppi = (!!arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI] ||
- !!arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
- }
-
- if (!has_ppi) {
- pr_warn("No interrupt available, giving up\n");
- return -EINVAL;
- }
}

+ if (arch_timer_ppi[arch_timer_uses_ppi])
+ return 0;
+
+ pr_warn("No interrupt available, giving up\n");
+ return -EINVAL;
+}
+
+static int __init arch_timer_init(void)
+{
+ int ret;
+
ret = arch_timer_register();
if (ret)
return ret;
@@ -870,7 +872,7 @@ static int __init arch_timer_init(void)

static int __init arch_timer_of_init(struct device_node *np)
{
- int i;
+ int i, ret;

if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
pr_warn("multiple nodes in dt, skipping\n");
@@ -902,6 +904,10 @@ static int __init arch_timer_of_init(struct device_node *np)
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;

+ ret = arch_timer_uses_ppi_init();
+ if (ret)
+ return ret;
+
return arch_timer_init();
}
CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
@@ -1011,6 +1017,7 @@ static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
/* Initialize per-processor generic timer */
static int __init arch_timer_acpi_init(struct acpi_table_header *table)
{
+ int ret;
struct acpi_table_gtdt *gtdt;

if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
@@ -1041,6 +1048,10 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table)
/* Get the frequency from CNTFRQ */
arch_timer_detect_rate(NULL, NULL);

+ ret = arch_timer_uses_ppi_init();
+ if (ret)
+ return ret;
+
/* Always-on capability */
arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);

--
2.7.4