| Message ID | 1376414984-14182-5-git-send-email-Sudeep.KarkadaNagesha@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sudeep, Couple of comments inline... On Tue, Aug 13, 2013 at 06:29:42PM +0100, Sudeep KarkadaNagesha wrote: > From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > > This patch configures the event stream frequency and enables it. > It also adds the hwcaps as well as compat-specific definitions to > the user to detect this event stream feature. > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Signed-off-by: Will Deacon <will.deacon@arm.com> > [sudeep: moving ARM/ARM64 changes into separate patches] > Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> > --- > arch/arm64/include/asm/arch_timer.h | 12 ++++++++++-- > arch/arm64/include/asm/hwcap.h | 4 +++- > arch/arm64/include/uapi/asm/hwcap.h | 1 + > arch/arm64/kernel/setup.c | 1 + > 4 files changed, 15 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h > index 69f5c8e..43f322a 100644 > --- a/arch/arm64/include/asm/arch_timer.h > +++ b/arch/arm64/include/asm/arch_timer.h > @@ -106,14 +106,22 @@ static inline void arch_counter_set_user_access(int divider) > /* Disable user access to the timers and the physical counter. */ > cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN > | ARCH_TIMER_USR_VT_ACCESS_EN > + | ARCH_TIMER_EVT_TRIGGER_MASK > | ARCH_TIMER_USR_PCT_ACCESS_EN); > > - /* Enable user access to the virtual counter. */ > - cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; > + /* Enable event stream and user access to the virtual counter */ > + cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT) > + | ARCH_TIMER_VIRT_EVT_EN > + | ARCH_TIMER_USR_VCT_ACCESS_EN; > > asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl)); > } > > +static inline void arch_timer_set_hwcap_evtstrm(void) > +{ > + elf_hwcap |= HWCAP_EVTSTRM; > +} > + > static inline u64 arch_counter_get_cntvct(void) > { > u64 cval; > diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h > index 6d4482f..effd8f9 100644 > --- a/arch/arm64/include/asm/hwcap.h > +++ b/arch/arm64/include/asm/hwcap.h > @@ -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) Looking at the context, we should also add COMPAT_HWCAP_LPAE as a separate patch (not part of this series). > #ifndef __ASSEMBLY__ > /* > @@ -41,7 +42,8 @@ > 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) > + COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\ > + COMPAT_HWCAP_EVTSTRM) So here you're hardcoding COMPAT_HWCAP_EVTSTRM in the COMPAT_ELF_HWCAP, yet we only enable the native one from the arch-timer driver. The question then is "Can we rely on the event-stream working for AArch64?". If so, we don't need the native hwcap at all. If not, then we need to make the compat hwcap dynamic. Will
diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 69f5c8e..43f322a 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -106,14 +106,22 @@ static inline void arch_counter_set_user_access(int divider) /* Disable user access to the timers and the physical counter. */ cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN | ARCH_TIMER_USR_VT_ACCESS_EN + | ARCH_TIMER_EVT_TRIGGER_MASK | ARCH_TIMER_USR_PCT_ACCESS_EN); - /* Enable user access to the virtual counter. */ - cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN; + /* Enable event stream and user access to the virtual counter */ + cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT) + | ARCH_TIMER_VIRT_EVT_EN + | ARCH_TIMER_USR_VCT_ACCESS_EN; asm volatile("msr cntkctl_el1, %0" : : "r" (cntkctl)); } +static inline void arch_timer_set_hwcap_evtstrm(void) +{ + elf_hwcap |= HWCAP_EVTSTRM; +} + static inline u64 arch_counter_get_cntvct(void) { u64 cval; diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 6d4482f..effd8f9 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -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__ /* @@ -41,7 +42,8 @@ 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) + COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV|\ + COMPAT_HWCAP_EVTSTRM) extern unsigned int elf_hwcap; #endif diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index eea4975..9b12476 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -21,6 +21,7 @@ */ #define HWCAP_FP (1 << 0) #define HWCAP_ASIMD (1 << 1) +#define HWCAP_EVTSTRM (1 << 2) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index add6ea6..1111833 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -309,6 +309,7 @@ subsys_initcall(topology_init); static const char *hwcap_str[] = { "fp", "asimd", + "evtstrm", NULL };