| Message ID | 20181008125009.3721-3-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/7] clocksource: exynos_mct: Remove dead code | expand |
On Mon, 8 Oct 2018 at 14:50, Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > To get ARM Architected Timers working on Samsung Exynos SoCs, one has to > first configure and enable Exynos Multi-Core Timer, because they both > share some common hardware blocks. This patch adds a mode of cooperation > with arch_timer driver, so kernel can use CP15 based timer interface via > arch_timer driver, which is mandatory on ARM64. In such mode driver only > configures MCT registers and starts the timer but don't register any > clocksource or events in the system. Those are left to be handled by > arch_timer driver. > > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/clocksource/exynos_mct.c | 28 ++++++++++++++++++++++------ > 1 file changed, 22 insertions(+), 6 deletions(-) > > diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c > index 43b335ff4a96..05b201ed8ef5 100644 > --- a/drivers/clocksource/exynos_mct.c > +++ b/drivers/clocksource/exynos_mct.c > @@ -57,6 +57,7 @@ > #define TICK_BASE_CNT 1 > > enum { > + MCT_INT_NONE = 0, > MCT_INT_SPI, > MCT_INT_PPI > }; > @@ -238,6 +239,9 @@ static int __init exynos4_clocksource_init(void) > { > exynos4_mct_frc_start(); > > + if (!mct_int_type) > + return 0; > + > #if defined(CONFIG_ARM) > exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; > exynos4_delay_timer.freq = clk_rate; > @@ -343,6 +347,9 @@ static struct irqaction mct_comp_event_irq = { > > static int exynos4_clockevent_init(void) > { > + if (!mct_int_type) > + return 0; > + > mct_comp_device.cpumask = cpumask_of(0); > clockevents_config_and_register(&mct_comp_device, clk_rate, > 0xf, 0xffffffff); > @@ -476,12 +483,12 @@ static int exynos4_mct_starting_cpu(unsigned int cpu) > > irq_force_affinity(evt->irq, cpumask_of(cpu)); > enable_irq(evt->irq); > - } else { > + } else if (mct_int_type == MCT_INT_PPI) { > enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0); > } > - clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1), > - 0xf, 0x7fffffff); > - > + if (mct_int_type) > + clockevents_config_and_register(evt, > + clk_rate / (TICK_BASE_CNT + 1), 0xf, 0x7fffffff); > return 0; > } > > @@ -496,7 +503,7 @@ static int exynos4_mct_dying_cpu(unsigned int cpu) > if (evt->irq != -1) > disable_irq_nosync(evt->irq); > exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); > - } else { > + } else if (mct_int_type == MCT_INT_PPI) { > disable_percpu_irq(mct_irqs[MCT_L0_IRQ]); > } > return 0; > @@ -529,7 +536,7 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem * > &percpu_mct_tick); > WARN(err, "MCT: can't request IRQ %d (%d)\n", > mct_irqs[MCT_L0_IRQ], err); > - } else { > + } else if (mct_int_type == MCT_INT_SPI) { > for_each_possible_cpu(cpu) { > int mct_irq = mct_irqs[MCT_L0_IRQ + cpu]; > struct mct_clock_event_device *pcpu_mevt = The error path of cpuhp_setup_state() does not look correct because request_percpu_irq() was not called. The error path looks suspicious also for MCT_INT_SPI path - the IRQs were allocated with regular request_irq but are freed with percpu version. > @@ -573,6 +580,15 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type) > > mct_int_type = int_type; > > + if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) { > + struct device_node *np = of_find_compatible_node(NULL, NULL, > + "arm,armv8-timer"); > + if (np) { > + mct_int_type = MCT_INT_NONE; > + of_node_put(np); In this case, later the mct_irqs are being assigned but totally not used. Are they needed? Best regards, Krzysztof > + } > + } > + > /* This driver uses only one global timer interrupt */ > mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ); > > -- > 2.17.1 >
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index 43b335ff4a96..05b201ed8ef5 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -57,6 +57,7 @@ #define TICK_BASE_CNT 1 enum { + MCT_INT_NONE = 0, MCT_INT_SPI, MCT_INT_PPI }; @@ -238,6 +239,9 @@ static int __init exynos4_clocksource_init(void) { exynos4_mct_frc_start(); + if (!mct_int_type) + return 0; + #if defined(CONFIG_ARM) exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer; exynos4_delay_timer.freq = clk_rate; @@ -343,6 +347,9 @@ static struct irqaction mct_comp_event_irq = { static int exynos4_clockevent_init(void) { + if (!mct_int_type) + return 0; + mct_comp_device.cpumask = cpumask_of(0); clockevents_config_and_register(&mct_comp_device, clk_rate, 0xf, 0xffffffff); @@ -476,12 +483,12 @@ static int exynos4_mct_starting_cpu(unsigned int cpu) irq_force_affinity(evt->irq, cpumask_of(cpu)); enable_irq(evt->irq); - } else { + } else if (mct_int_type == MCT_INT_PPI) { enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0); } - clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1), - 0xf, 0x7fffffff); - + if (mct_int_type) + clockevents_config_and_register(evt, + clk_rate / (TICK_BASE_CNT + 1), 0xf, 0x7fffffff); return 0; } @@ -496,7 +503,7 @@ static int exynos4_mct_dying_cpu(unsigned int cpu) if (evt->irq != -1) disable_irq_nosync(evt->irq); exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET); - } else { + } else if (mct_int_type == MCT_INT_PPI) { disable_percpu_irq(mct_irqs[MCT_L0_IRQ]); } return 0; @@ -529,7 +536,7 @@ static int __init exynos4_timer_resources(struct device_node *np, void __iomem * &percpu_mct_tick); WARN(err, "MCT: can't request IRQ %d (%d)\n", mct_irqs[MCT_L0_IRQ], err); - } else { + } else if (mct_int_type == MCT_INT_SPI) { for_each_possible_cpu(cpu) { int mct_irq = mct_irqs[MCT_L0_IRQ + cpu]; struct mct_clock_event_device *pcpu_mevt = @@ -573,6 +580,15 @@ static int __init mct_init_dt(struct device_node *np, unsigned int int_type) mct_int_type = int_type; + if (IS_ENABLED(CONFIG_ARM64) && IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) { + struct device_node *np = of_find_compatible_node(NULL, NULL, + "arm,armv8-timer"); + if (np) { + mct_int_type = MCT_INT_NONE; + of_node_put(np); + } + } + /* This driver uses only one global timer interrupt */ mct_irqs[MCT_G0_IRQ] = irq_of_parse_and_map(np, MCT_G0_IRQ);
To get ARM Architected Timers working on Samsung Exynos SoCs, one has to first configure and enable Exynos Multi-Core Timer, because they both share some common hardware blocks. This patch adds a mode of cooperation with arch_timer driver, so kernel can use CP15 based timer interface via arch_timer driver, which is mandatory on ARM64. In such mode driver only configures MCT registers and starts the timer but don't register any clocksource or events in the system. Those are left to be handled by arch_timer driver. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- drivers/clocksource/exynos_mct.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-)