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Commit 1aee5d7a authored by Mark Rutland's avatar Mark Rutland
Browse files

arm64: move from arm_generic to arm_arch_timer 



The arch_timer driver supports a superset of the functionality of the
arm_generic driver, and is not tied to a particular arch.

This patch moves arm64 to use the arch_timer driver, gaining additional
functionality in doing so, and removes the (now unused) arm_generic
driver. Timer-related hooks specific to arm64 are moved into
arch/arm64/kernel/time.c.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
parent 1dac0dd7

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ config ARM64 
	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE

	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION

	select ARM_AMBA

	select ARM_ARCH_TIMER

	select CLONE_BACKWARDS

	select COMMON_CLK

	select GENERIC_CLOCKEVENTS

arch/arm64/include/asm/arm_generic.h→arch/arm64/include/asm/arch_timer.h

+133 −0
Original line number Diff line number Diff line 
/*

 * arch/arm64/include/asm/arm_generic.h

 * arch/arm64/include/asm/arch_timer.h

 *

 * Copyright (C) 2012 ARM Ltd.

 * Author: Marc Zyngier <marc.zyngier@arm.com>
@@ -16,21 +16,19 @@ 
 * 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 __ASM_ARM_GENERIC_H

#define __ASM_ARM_GENERIC_H

#ifndef __ASM_ARCH_TIMER_H

#define __ASM_ARCH_TIMER_H



#include <linux/clocksource.h>

#include <asm/barrier.h>



#define ARCH_TIMER_CTRL_ENABLE		(1 << 0)

#define ARCH_TIMER_CTRL_IMASK		(1 << 1)

#define ARCH_TIMER_CTRL_ISTATUS		(1 << 2)

#include <linux/init.h>

#include <linux/types.h>



#define ARCH_TIMER_REG_CTRL		0

#define ARCH_TIMER_REG_FREQ		1

#define ARCH_TIMER_REG_TVAL		2

#include <clocksource/arm_arch_timer.h>



static inline void arch_timer_reg_write(int reg, u32 val)

static inline void arch_timer_reg_write(int access, int reg, u32 val)

{

	if (access == ARCH_TIMER_PHYS_ACCESS) {

		switch (reg) {

		case ARCH_TIMER_REG_CTRL:

			asm volatile("msr cntp_ctl_el0,  %0" : : "r" (val));
@@ -41,32 +39,65 @@ static inline void arch_timer_reg_write(int reg, u32 val) 
		default:

			BUILD_BUG();

		}

	} else if (access == ARCH_TIMER_VIRT_ACCESS) {

		switch (reg) {

		case ARCH_TIMER_REG_CTRL:

			asm volatile("msr cntv_ctl_el0,  %0" : : "r" (val));

			break;

		case ARCH_TIMER_REG_TVAL:

			asm volatile("msr cntv_tval_el0, %0" : : "r" (val));

			break;

		default:

			BUILD_BUG();

		}

	} else {

		BUILD_BUG();

	}



	isb();

}



static inline u32 arch_timer_reg_read(int reg)

static inline u32 arch_timer_reg_read(int access, int reg)

{

	u32 val;



	if (access == ARCH_TIMER_PHYS_ACCESS) {

		switch (reg) {

		case ARCH_TIMER_REG_CTRL:

			asm volatile("mrs %0,  cntp_ctl_el0" : "=r" (val));

			break;

	case ARCH_TIMER_REG_FREQ:

		asm volatile("mrs %0,   cntfrq_el0" : "=r" (val));

		break;

		case ARCH_TIMER_REG_TVAL:

			asm volatile("mrs %0, cntp_tval_el0" : "=r" (val));

			break;

		default:

			BUILD_BUG();

		}

	} else if (access == ARCH_TIMER_VIRT_ACCESS) {

		switch (reg) {

		case ARCH_TIMER_REG_CTRL:

			asm volatile("mrs %0,  cntv_ctl_el0" : "=r" (val));

			break;

		case ARCH_TIMER_REG_TVAL:

			asm volatile("mrs %0, cntv_tval_el0" : "=r" (val));

			break;

		default:

			BUILD_BUG();

		}

	} else {

		BUILD_BUG();

	}



	return val;

}



static inline u32 arch_timer_get_cntfrq(void)

{

	u32 val;

	asm volatile("mrs %0,   cntfrq_el0" : "=r" (val));

	return val;

}



static inline void __cpuinit arch_counter_enable_user_access(void)

static inline void __cpuinit arch_counter_set_user_access(void)

{

	u32 cntkctl;
@@ -79,9 +110,9 @@ static inline void __cpuinit arch_counter_enable_user_access(void) 
	asm volatile("msr	cntkctl_el1, %0" : : "r" (cntkctl));

}



static inline cycle_t arch_counter_get_cntpct(void)

static inline u64 arch_counter_get_cntpct(void)

{

	cycle_t cval;

	u64 cval;



	isb();

	asm volatile("mrs %0, cntpct_el0" : "=r" (cval));
@@ -89,9 +120,9 @@ static inline cycle_t arch_counter_get_cntpct(void) 
	return cval;

}



static inline cycle_t arch_counter_get_cntvct(void)

static inline u64 arch_counter_get_cntvct(void)

{

	cycle_t cval;

	u64 cval;



	isb();

	asm volatile("mrs %0, cntvct_el0" : "=r" (cval));

arch/arm64/kernel/time.c

+27 −2
Original line number Diff line number Diff line
@@ -31,8 +31,9 @@ 
#include <linux/syscore_ops.h>

#include <linux/timer.h>

#include <linux/irq.h>

#include <linux/delay.h>



#include <clocksource/arm_generic.h>

#include <clocksource/arm_arch_timer.h>



#include <asm/thread_info.h>

#include <asm/stacktrace.h>
@@ -59,7 +60,31 @@ unsigned long profile_pc(struct pt_regs *regs) 
EXPORT_SYMBOL(profile_pc);

#endif



static u64 sched_clock_mult __read_mostly;



unsigned long long notrace sched_clock(void)

{

	return arch_timer_read_counter() * sched_clock_mult;

}



int read_current_timer(unsigned long *timer_value)

{

	*timer_value = arch_timer_read_counter();

	return 0;

}



void __init time_init(void)

{

	arm_generic_timer_init();

	u32 arch_timer_rate;



	if (arch_timer_init())

		panic("Unable to initialise architected timer.\n");



	arch_timer_rate = arch_timer_get_rate();



	/* Cache the sched_clock multiplier to save a divide in the hot path. */

	sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;



	/* Calibrate the delay loop directly */

	lpj_fine = arch_timer_rate / HZ;

}

drivers/clocksource/Kconfig

+0 −5
Original line number Diff line number Diff line
@@ -54,10 +54,5 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK 
	help

	  Use the always on PRCMU Timer as sched_clock



config CLKSRC_ARM_GENERIC

	def_bool y if ARM64

	help

	  This option enables support for the ARM generic timer.



config ARM_ARCH_TIMER

	bool

drivers/clocksource/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -17,5 +17,4 @@ obj-$(CONFIG_ARMADA_370_XP_TIMER) += time-armada-370-xp.o 
obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835_timer.o

obj-$(CONFIG_SUNXI_TIMER)	+= sunxi_timer.o



obj-$(CONFIG_CLKSRC_ARM_GENERIC)	+= arm_generic.o

obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o