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>
(cherry picked from commit e9faebc66ec74f1ab7f267d683b45e80faa69763)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
	arch/arm/include/asm/arch_timer.h
	arch/arm/include/uapi/asm/hwcap.h
	arch/arm/kernel/setup.c

diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 481f66e935ee4cdd2a467d29f621543ed32cfdbe..a60052b24916b764a7b37fe7d55c29744925d947 100644 (file)
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -89,11 +89,21 @@ static inline u64 arch_counter_get_cntvct(void)
        return cval;
 }
 
-static inline void __cpuinit 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 __cpuinit 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 */
@@ -102,9 +112,20 @@ static inline void __cpuinit 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 3688fd15a32dd5a5e5f81aef148cf397022fc2d7..7dcc10d6725352b9b1d35f7c5583187cb3a744c1 100644 (file)
--- a/arch/arm/include/uapi/asm/hwcap.h
+++ b/arch/arm/include/uapi/asm/hwcap.h
@@ -25,6 +25,7 @@
 #define HWCAP_IDIVT    (1 << 18)
 #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 1e839e0ed5b727174ea2e912695561de76bca9fa..29beb8c76560ff3e706f0770877257501efb690c 100644 (file)
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -914,6 +914,9 @@ static const char *hwcap_str[] = {
        "vfpv4",
        "idiva",
        "idivt",
+       "vfpd32",
+       "lpae",
+       "evtstrm",
        NULL
 };