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linux-next/include/clocksource/arm_arch_timer.h
Stephen Boyd e09f3cc018 clocksource: arch_timer: Make register accessors less error-prone
Using an enum for the register we wish to access allows newer
compilers to determine if we've forgotten a case in our switch
statement. This allows us to remove the BUILD_BUG() instances in
the arm64 port, avoiding problems where optimizations may not
happen.

To try and force better code generation we're currently marking
the accessor functions as inline, but newer compilers can ignore
the inline keyword unless it's marked __always_inline. Luckily on
arm and arm64 inline is __always_inline, but let's make
everything __always_inline to be explicit.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
2013-08-01 01:13:35 +02:00

60 lines
1.4 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __CLKSOURCE_ARM_ARCH_TIMER_H
#define __CLKSOURCE_ARM_ARCH_TIMER_H
#include <linux/clocksource.h>
#include <linux/types.h>
#define ARCH_TIMER_CTRL_ENABLE (1 << 0)
#define ARCH_TIMER_CTRL_IT_MASK (1 << 1)
#define ARCH_TIMER_CTRL_IT_STAT (1 << 2)
enum arch_timer_reg {
ARCH_TIMER_REG_CTRL,
ARCH_TIMER_REG_TVAL,
};
#define ARCH_TIMER_PHYS_ACCESS 0
#define ARCH_TIMER_VIRT_ACCESS 1
#ifdef CONFIG_ARM_ARCH_TIMER
extern u32 arch_timer_get_rate(void);
extern u64 arch_timer_read_counter(void);
extern struct timecounter *arch_timer_get_timecounter(void);
#else
static inline u32 arch_timer_get_rate(void)
{
return 0;
}
static inline u64 arch_timer_read_counter(void)
{
return 0;
}
static inline struct timecounter *arch_timer_get_timecounter(void)
{
return NULL;
}
#endif
#endif