From 4502b6bb720d7a519c4cea76cf68a2425b481a45 Mon Sep 17 00:00:00 2001 From: Fu Wei Date: Wed, 18 Jan 2017 21:25:30 +0800 Subject: clocksource: arm_arch_timer: rework PPI selection Currently, the arch timer driver uses ARCH_TIMER_PHYS_SECURE_PPI to mean the driver will use the secure PPI *and* potentially also use the non-secure PPI. This is somewhat confusing. For arm64 it never makes sense to use the secure PPI, but we do anyway, inheriting this behaviour from 32-bit arm. For ACPI, we may not even have a valid secure PPI, so we need to be able to only request the non-secure PPI. To that end, this patch reworks the timer driver so that we can request the non-secure PPI alone. The PPI selection is split out into a new function, arch_timer_select_ppi(), and verification of the selected PPI is shifted out to callers (as DT may select the PPI by other means and must handle this anyway). We now consistently use arch_timer_has_nonsecure_ppi() to determine whether we must manage a non-secure PPI *in addition* to a secure PPI. When we only have a non-secure PPI, this returns false. Signed-off-by: Fu Wei Tested-by: Xiongfeng Wang [Mark: reword commit message] Signed-off-by: Mark Rutland --- drivers/clocksource/arm_arch_timer.c | 77 +++++++++++++++++++++--------------- 1 file changed, 46 insertions(+), 31 deletions(-) (limited to 'drivers/clocksource/arm_arch_timer.c') diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 15059c958be7..94de018c65d0 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -992,7 +992,7 @@ static int __init arch_timer_register(void) case ARCH_TIMER_PHYS_NONSECURE_PPI: err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt); - if (!err && arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]) { + if (!err && arch_timer_has_nonsecure_ppi()) { ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]; err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt); @@ -1114,39 +1114,41 @@ static int __init arch_timer_common_init(void) return arch_timer_arch_init(); } -static int __init arch_timer_init(void) +/** + * arch_timer_select_ppi() - Select suitable PPI for the current system. + * + * If HYP mode is available, we know that the physical timer + * has been configured to be accessible from PL1. Use it, so + * that a guest can use the virtual timer instead. + * + * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE + * accesses to CNTP_*_EL1 registers are silently redirected to + * their CNTHP_*_EL2 counterparts, and use a different PPI + * number. + * + * If no interrupt provided for virtual timer, we'll have to + * stick to the physical timer. It'd better be accessible... + * For arm64 we never use the secure interrupt. + * + * Return: a suitable PPI type for the current system. + */ +static enum arch_timer_ppi_nr __init arch_timer_select_ppi(void) { - int ret; - /* - * If HYP mode is available, we know that the physical timer - * has been configured to be accessible from PL1. Use it, so - * that a guest can use the virtual timer instead. - * - * If no interrupt provided for virtual timer, we'll have to - * stick to the physical timer. It'd better be accessible... - * - * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE - * accesses to CNTP_*_EL1 registers are silently redirected to - * their CNTHP_*_EL2 counterparts, and use a different PPI - * number. - */ - if (is_hyp_mode_available() || !arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) { - bool has_ppi; + if (is_kernel_in_hyp_mode()) + return ARCH_TIMER_HYP_PPI; - if (is_kernel_in_hyp_mode()) { - arch_timer_uses_ppi = ARCH_TIMER_HYP_PPI; - has_ppi = !!arch_timer_ppi[ARCH_TIMER_HYP_PPI]; - } else { - arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI; - has_ppi = (!!arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI] || - !!arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]); - } + if (!is_hyp_mode_available() && arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) + return ARCH_TIMER_VIRT_PPI; - if (!has_ppi) { - pr_warn("No interrupt available, giving up\n"); - return -EINVAL; - } - } + if (IS_ENABLED(CONFIG_ARM64)) + return ARCH_TIMER_PHYS_NONSECURE_PPI; + + return ARCH_TIMER_PHYS_SECURE_PPI; +} + +static int __init arch_timer_init(void) +{ + int ret; ret = arch_timer_register(); if (ret) @@ -1188,6 +1190,13 @@ static int __init arch_timer_of_init(struct device_node *np) if (IS_ENABLED(CONFIG_ARM) && of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI; + else + arch_timer_uses_ppi = arch_timer_select_ppi(); + + if (!arch_timer_ppi[arch_timer_uses_ppi]) { + pr_err("No interrupt available, giving up\n"); + return -EINVAL; + } /* On some systems, the counter stops ticking when in suspend. */ arch_counter_suspend_stop = of_property_read_bool(np, @@ -1333,6 +1342,12 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) /* Get the frequency from CNTFRQ */ arch_timer_detect_rate(NULL, NULL); + arch_timer_uses_ppi = arch_timer_select_ppi(); + if (!arch_timer_ppi[arch_timer_uses_ppi]) { + pr_err("No interrupt available, giving up\n"); + return -EINVAL; + } + /* Always-on capability */ arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); -- cgit v1.2.3