[PATCH 2/4] clocksource: arm_arch_timer: enable counter access for 32-bit ARM
From: Nathan Lynch <hidden>
Date: 2014-08-22 21:43:15
Subsystem:
arm architected timer driver, clocksource, clockevent drivers, the rest · Maintainers:
Mark Rutland, Marc Zyngier, Daniel Lezcano, Thomas Gleixner, Linus Torvalds
The only difference between arm and arm64's implementations of arch_counter_set_user_access is that 32-bit ARM does not enable user access to the virtual counter. We want to enable this access for the 32-bit ARM VDSO, so copy the arm64 version to the driver itself, giving it a slightly different name (arch_counter_set_access) to avoid redefinition. The arch_timer_evtstrm_enable hooks are also substantially similar, the only difference being a CONFIG_COMPAT-conditional section which is relevant only for arm64. Copy the arm64 version to the driver, again slightly renaming (arch_timer_evtstrm_enable => arch_timer_enable_evtstrm). With this change, the arch_counter_set_user_access and arch_timer_evtstrm_enable hooks in both arm and arm64 become unused, to be removed in followup patches. Signed-off-by: Nathan Lynch <redacted> --- drivers/clocksource/arm_arch_timer.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index c99afdf12e98..0188332ad24b 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c@@ -23,6 +23,7 @@ #include <linux/sched_clock.h> #include <asm/arch_timer.h> +#include <asm/hwcap.h> #include <asm/virt.h> #include <clocksource/arm_arch_timer.h>
@@ -299,6 +300,20 @@ static void __arch_timer_setup(unsigned type, clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff); } +static void arch_timer_enable_evtstrm(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 void arch_timer_configure_evtstream(void) { int evt_stream_div, pos;
@@ -309,7 +324,24 @@ static void arch_timer_configure_evtstream(void) if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) pos--; /* enable event stream */ - arch_timer_evtstrm_enable(min(pos, 15)); + arch_timer_enable_evtstrm(min(pos, 15)); +} + +static void arch_counter_set_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; + + arch_timer_set_cntkctl(cntkctl); } static int arch_timer_setup(struct clock_event_device *clk)
@@ -324,7 +356,7 @@ static int arch_timer_setup(struct clock_event_device *clk) enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0); } - arch_counter_set_user_access(); + arch_counter_set_access(); if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM)) arch_timer_configure_evtstream();
--
1.9.3