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Commit 46efe547 authored by Sudeep Holla's avatar Sudeep Holla
Browse files

ARM64: arch_timer: add support to configure and enable event stream 



This patch adds support for configuring the event stream frequency
and enabling it.

It also adds the hwcaps as well as compat-specific definitions to
the user to detect this event stream feature.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
parent e9faebc6

arch/arm64/include/asm/arch_timer.h

+29 −3
Original line number Diff line number Diff line
@@ -92,21 +92,47 @@ static inline u32 arch_timer_get_cntfrq(void) 
	return val;

}



static inline void arch_counter_set_user_access(void)

static inline u32 arch_timer_get_cntkctl(void)

{

	u32 cntkctl;



	asm volatile("mrs	%0, cntkctl_el1" : "=r" (cntkctl));

	return cntkctl;

}



static inline void arch_timer_set_cntkctl(u32 cntkctl)

{

	asm volatile("msr	cntkctl_el1, %0" : : "r" (cntkctl));

}



static inline void arch_counter_set_user_access(void)

{

	u32 cntkctl = arch_timer_get_cntkctl();



	/* Disable user access to the timers and the physical counter */

	/* Also disable virtual event stream */

	cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN

			| ARCH_TIMER_USR_VT_ACCESS_EN

			| ARCH_TIMER_VIRT_EVT_EN

			| ARCH_TIMER_USR_PCT_ACCESS_EN);



	/* Enable user access to the virtual counter */

	cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;



	asm volatile("msr	cntkctl_el1, %0" : : "r" (cntkctl));

	arch_timer_set_cntkctl(cntkctl);

}



static inline void arch_timer_evtstrm_enable(int divider)

{

	u32 cntkctl = arch_timer_get_cntkctl();

	cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;

	/* Set the divider and enable virtual event stream */

	cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)

			| ARCH_TIMER_VIRT_EVT_EN;

	arch_timer_set_cntkctl(cntkctl);

	elf_hwcap |= HWCAP_EVTSTRM;

#ifdef CONFIG_COMPAT

	compat_elf_hwcap |= COMPAT_HWCAP_EVTSTRM;

#endif

}



static inline u64 arch_counter_get_cntvct(void)

arch/arm64/include/asm/hwcap.h

+6 −5
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#define COMPAT_HWCAP_IDIVA	(1 << 17)

#define COMPAT_HWCAP_IDIVT	(1 << 18)

#define COMPAT_HWCAP_IDIV	(COMPAT_HWCAP_IDIVA|COMPAT_HWCAP_IDIVT)

#define COMPAT_HWCAP_EVTSTRM	(1 << 21)



#ifndef __ASSEMBLY__

/*
@@ -37,11 +38,11 @@ 
 * instruction set this cpu supports.

 */

#define ELF_HWCAP		(elf_hwcap)

#define COMPAT_ELF_HWCAP	(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\

				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\

				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\

				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\

				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV)



#ifdef CONFIG_COMPAT

#define COMPAT_ELF_HWCAP	(compat_elf_hwcap)

extern unsigned int compat_elf_hwcap;

#endif



extern unsigned long elf_hwcap;

#endif

arch/arm64/include/uapi/asm/hwcap.h

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
 */

#define HWCAP_FP		(1 << 0)

#define HWCAP_ASIMD		(1 << 1)

#define HWCAP_EVTSTRM		(1 << 2)





#endif /* _UAPI__ASM_HWCAP_H */

arch/arm64/kernel/setup.c

+11 −0
Original line number Diff line number Diff line
@@ -60,6 +60,16 @@ EXPORT_SYMBOL(processor_id); 
unsigned long elf_hwcap __read_mostly;

EXPORT_SYMBOL_GPL(elf_hwcap);



#ifdef CONFIG_COMPAT

#define COMPAT_ELF_HWCAP_DEFAULT	\

				(COMPAT_HWCAP_HALF|COMPAT_HWCAP_THUMB|\

				 COMPAT_HWCAP_FAST_MULT|COMPAT_HWCAP_EDSP|\

				 COMPAT_HWCAP_TLS|COMPAT_HWCAP_VFP|\

				 COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\

				 COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV)

unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;

#endif



static const char *cpu_name;

static const char *machine_name;

phys_addr_t __fdt_pointer __initdata;
@@ -304,6 +314,7 @@ subsys_initcall(topology_init); 
static const char *hwcap_str[] = {

	"fp",

	"asimd",

	"evtstrm",

	NULL

};