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authorSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>2013-08-13 14:30:32 +0100
committerSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>2013-09-26 09:47:26 +0100
commite9faebc66ec74f1ab7f267d683b45e80faa69763 (patch)
tree5c80fc2ef2db81221734db3dfa263d587ed15b4a /arch/arm
parent28061758dc83df445a05af347b5ce55ccd968c03 (diff)
downloadblackbird-op-linux-e9faebc66ec74f1ab7f267d683b45e80faa69763.tar.gz
blackbird-op-linux-e9faebc66ec74f1ab7f267d683b45e80faa69763.zip
ARM: 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 definitions to the user to detect this event stream feature. Cc: Russell King <linux@arm.linux.org.uk> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/arch_timer.h27
-rw-r--r--arch/arm/include/uapi/asm/hwcap.h1
-rw-r--r--arch/arm/kernel/setup.c1
3 files changed, 26 insertions, 3 deletions
diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index d57e04de8e8c..0704e0cf5571 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -87,11 +87,21 @@ static inline u64 arch_counter_get_cntvct(void)
return cval;
}
-static inline void arch_counter_set_user_access(void)
+static inline u32 arch_timer_get_cntkctl(void)
{
u32 cntkctl;
-
asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
+ return cntkctl;
+}
+
+static inline void arch_timer_set_cntkctl(u32 cntkctl)
+{
+ asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
+}
+
+static inline void arch_counter_set_user_access(void)
+{
+ u32 cntkctl = arch_timer_get_cntkctl();
/* Disable user access to both physical/virtual counters/timers */
/* Also disable virtual event stream */
@@ -100,9 +110,20 @@ static inline void arch_counter_set_user_access(void)
| ARCH_TIMER_VIRT_EVT_EN
| ARCH_TIMER_USR_VCT_ACCESS_EN
| ARCH_TIMER_USR_PCT_ACCESS_EN);
+ arch_timer_set_cntkctl(cntkctl);
+}
- asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (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;
}
+
#endif
#endif
diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h
index 6d34d080372a..7dcc10d67253 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 0e1e2b3afa45..5d65438685d8 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
};
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