linux-kernel - [PATCH] clocksource/arm_arch_timer: add __ro_after_init and _

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Message-ID: <20210330140444.4fb2a7cb@xhacker.debian>
Date:   Tue, 30 Mar 2021 14:04:44 +0800
From:   Jisheng Zhang <Jisheng.Zhang@...aptics.com>
To:     Mark Rutland <mark.rutland@....com>, Marc Zyngier <maz@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH] clocksource/arm_arch_timer: add __ro_after_init and __init

Some functions are not needed after booting, so mark them as __init
to move them to the .init section.

Some global variables are never modified after init, so can be
__ro_after_init.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@...aptics.com>
---
 drivers/clocksource/arm_arch_timer.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index d0177824c518..1b885964fb34 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -51,7 +51,7 @@
 
 static unsigned arch_timers_present __initdata;
 
-static void __iomem *arch_counter_base;
+static void __iomem *arch_counter_base __ro_after_init;
 
 struct arch_timer {
 	void __iomem *base;
@@ -60,15 +60,16 @@ struct arch_timer {
 
 #define to_arch_timer(e) container_of(e, struct arch_timer, evt)
 
-static u32 arch_timer_rate;
-static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI];
+static u32 arch_timer_rate __ro_after_init;
+u32 arch_timer_rate1 __ro_after_init;
+static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI] __ro_after_init;
 
 static struct clock_event_device __percpu *arch_timer_evt;
 
-static enum arch_timer_ppi_nr arch_timer_uses_ppi = ARCH_TIMER_VIRT_PPI;
-static bool arch_timer_c3stop;
-static bool arch_timer_mem_use_virtual;
-static bool arch_counter_suspend_stop;
+static enum arch_timer_ppi_nr arch_timer_uses_ppi __ro_after_init = ARCH_TIMER_VIRT_PPI;
+static bool arch_timer_c3stop __ro_after_init;
+static bool arch_timer_mem_use_virtual __ro_after_init;
+static bool arch_counter_suspend_stop __ro_after_init;
 #ifdef CONFIG_GENERIC_GETTIMEOFDAY
 static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
 #else
@@ -76,7 +77,7 @@ static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
 #endif /* CONFIG_GENERIC_GETTIMEOFDAY */
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
-static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
+static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
 
 static int __init early_evtstrm_cfg(char *buf)
 {
@@ -176,7 +177,7 @@ static notrace u64 arch_counter_get_cntvct(void)
  * to exist on arm64. arm doesn't use this before DT is probed so even
  * if we don't have the cp15 accessors we won't have a problem.
  */
-u64 (*arch_timer_read_counter)(void) = arch_counter_get_cntvct;
+u64 (*arch_timer_read_counter)(void) __ro_after_init = arch_counter_get_cntvct;
 EXPORT_SYMBOL_GPL(arch_timer_read_counter);
 
 static u64 arch_counter_read(struct clocksource *cs)
@@ -925,7 +926,7 @@ static int validate_timer_rate(void)
  * rate was probed first, and don't verify that others match. If the first node
  * probed has a clock-frequency property, this overrides the HW register.
  */
-static void arch_timer_of_configure_rate(u32 rate, struct device_node *np)
+static void __init arch_timer_of_configure_rate(u32 rate, struct device_node *np)
 {
 	/* Who has more than one independent system counter? */
 	if (arch_timer_rate)
@@ -939,7 +940,7 @@ static void arch_timer_of_configure_rate(u32 rate, struct device_node *np)
 		pr_warn("frequency not available\n");
 }
 
-static void arch_timer_banner(unsigned type)
+static void __init arch_timer_banner(unsigned type)
 {
 	pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
 		type & ARCH_TIMER_TYPE_CP15 ? "cp15" : "",
-- 
2.31.0