[PATCH v3 3/6] ARM: arch_timer: configure and enable event stream

From: Sudeep KarkadaNagesha
Date: Tue Aug 13 2013 - 13:31:55 EST


From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>

This patch configures the event stream frequency and enables it.
It also adds the hwcaps definitions to the user to detect this event
stream feature.

Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
[sudeep: moving ARM/ARM64 changes into separate patches]
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@xxxxxxx>
---
arch/arm/include/asm/arch_timer.h | 11 +++++++++--
arch/arm/include/uapi/asm/hwcap.h | 1 +
arch/arm/kernel/setup.c | 1 +
3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 12f3fac..25abeb5 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -96,15 +96,22 @@ static inline void arch_counter_set_user_access(int divider)
asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));

/* Disable user access to both physical/virtual counters/timers. */
- /* 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_EVT_TRIGGER_MASK
| ARCH_TIMER_USR_VCT_ACCESS_EN
| ARCH_TIMER_USR_PCT_ACCESS_EN);
+ /* Set the divider and enable virtual event stream */
+ cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
+ | ARCH_TIMER_VIRT_EVT_EN;

asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
}
+
+static inline void arch_timer_set_hwcap_evtstrm(void)
+{
+ elf_hwcap |= HWCAP_EVTSTRM;
+}
#endif

#endif
diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h
index 6d34d08..7dcc10d 100644
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -26,5 +26,6 @@
#define HWCAP_VFPD32 (1 << 19) /* set if VFP has 32 regs (not 16) */
#define HWCAP_IDIV (HWCAP_IDIVA | HWCAP_IDIVT)
#define HWCAP_LPAE (1 << 20)
+#define HWCAP_EVTSTRM (1 << 21)

#endif /* _UAPI__ASMARM_HWCAP_H */
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index afc2489..305ffc9 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -975,6 +975,7 @@ static const char *hwcap_str[] = {
"idivt",
"vfpd32",
"lpae",
+ "evtstrm",
NULL
};

--
1.8.1.2


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/