From c0cfbe6941085f2ebd58e645c10f8836b6d28fe9 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 30 Mar 2017 12:06:09 -0700 Subject: irqchip: mips-cpu: Replace magic 0x100 with IE_SW0 Replace use of the magic number 0x100 (ie. bit 8) with the more explanatory IE_SW0 (ie. interrupt enable for software interrupt 0) or C_SW0 (ie. cause bit for software interrupt 0) as appropriate. Signed-off-by: Paul Burton Acked-by: Thomas Gleixner Cc: Jason Cooper Cc: Marc Zyngier Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15834/ Signed-off-by: Ralf Baechle --- drivers/irqchip/irq-mips-cpu.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c index 8c504f562e9d..e6b413669e57 100644 --- a/drivers/irqchip/irq-mips-cpu.c +++ b/drivers/irqchip/irq-mips-cpu.c @@ -41,13 +41,13 @@ static inline void unmask_mips_irq(struct irq_data *d) { - set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + set_c0_status(IE_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); irq_enable_hazard(); } static inline void mask_mips_irq(struct irq_data *d) { - clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_status(IE_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); irq_disable_hazard(); } @@ -70,7 +70,7 @@ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) { unsigned int vpflags = dvpe(); - clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_cause(C_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); evpe(vpflags); unmask_mips_irq(d); return 0; @@ -83,7 +83,7 @@ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) static void mips_mt_cpu_irq_ack(struct irq_data *d) { unsigned int vpflags = dvpe(); - clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_cause(C_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); evpe(vpflags); mask_mips_irq(d); } -- cgit v1.2.1 From 131735afc1838997da2c151b614b13f0352cf448 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 30 Mar 2017 12:06:10 -0700 Subject: irqchip: mips-cpu: Prepare for non-legacy IRQ domains The various struct irq_chip callbacks in the MIPS CPU interrupt controller driver have been calculating the hardware interrupt number by subtracting MIPS_CPU_IRQ_BASE from the virq number. This presumes a linear mapping beginning from MIPS_CPU_IRQ_BASE, and this will not hold once an IPI IRQ domain is introduced. Switch to using the hwirq field of struct irq_data which already contains the hardware interrupt number instead of attempting to calculate it. Similarly, plat_irq_dispatch calculated the virq number by adding MIPS_CPU_IRQ_BASE to the hardware interrupt number. Ready this for the introduction of an IPI IRQ domain by instead using irq_linear_revmap. Signed-off-by: Paul Burton Acked-by: Thomas Gleixner Cc: Jason Cooper Cc: Marc Zyngier Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15835/ Signed-off-by: Ralf Baechle --- drivers/irqchip/irq-mips-cpu.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c index e6b413669e57..338de924b269 100644 --- a/drivers/irqchip/irq-mips-cpu.c +++ b/drivers/irqchip/irq-mips-cpu.c @@ -39,15 +39,17 @@ #include #include +static struct irq_domain *irq_domain; + static inline void unmask_mips_irq(struct irq_data *d) { - set_c0_status(IE_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); + set_c0_status(IE_SW0 << d->hwirq); irq_enable_hazard(); } static inline void mask_mips_irq(struct irq_data *d) { - clear_c0_status(IE_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_status(IE_SW0 << d->hwirq); irq_disable_hazard(); } @@ -70,7 +72,7 @@ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) { unsigned int vpflags = dvpe(); - clear_c0_cause(C_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_cause(C_SW0 << d->hwirq); evpe(vpflags); unmask_mips_irq(d); return 0; @@ -83,7 +85,7 @@ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) static void mips_mt_cpu_irq_ack(struct irq_data *d) { unsigned int vpflags = dvpe(); - clear_c0_cause(C_SW0 << (d->irq - MIPS_CPU_IRQ_BASE)); + clear_c0_cause(C_SW0 << d->hwirq); evpe(vpflags); mask_mips_irq(d); } @@ -103,6 +105,7 @@ static struct irq_chip mips_mt_cpu_irq_controller = { asmlinkage void __weak plat_irq_dispatch(void) { unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM; + unsigned int virq; int irq; if (!pending) { @@ -113,7 +116,8 @@ asmlinkage void __weak plat_irq_dispatch(void) pending >>= CAUSEB_IP; while (pending) { irq = fls(pending) - 1; - do_IRQ(MIPS_CPU_IRQ_BASE + irq); + virq = irq_linear_revmap(irq_domain, irq); + do_IRQ(virq); pending &= ~BIT(irq); } } @@ -145,15 +149,14 @@ static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = { static void __init __mips_cpu_irq_init(struct device_node *of_node) { - struct irq_domain *domain; - /* Mask interrupts. */ clear_c0_status(ST0_IM); clear_c0_cause(CAUSEF_IP); - domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0, - &mips_cpu_intc_irq_domain_ops, NULL); - if (!domain) + irq_domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0, + &mips_cpu_intc_irq_domain_ops, + NULL); + if (!irq_domain) panic("Failed to add irqdomain for MIPS CPU"); } -- cgit v1.2.1 From 3838a547fda22a37faab5770d01acd72aaeabbf6 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 30 Mar 2017 12:06:11 -0700 Subject: irqchip: mips-cpu: Introduce IPI IRQ domain support Introduce support for registering an IPI IRQ domain suitable for use by systems using the MIPS MT (multithreading) ASE within a single core. This will allow for such systems to be supported generically, without the current kludge of IPI code split between the MIPS arch & the malta board support code. Signed-off-by: Paul Burton Acked-by: Thomas Gleixner Cc: Jason Cooper Cc: Marc Zyngier Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15836/ Signed-off-by: Ralf Baechle --- drivers/irqchip/Kconfig | 2 + drivers/irqchip/irq-mips-cpu.c | 125 ++++++++++++++++++++++++++++++++++++++--- 2 files changed, 119 insertions(+), 8 deletions(-) (limited to 'drivers/irqchip') diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 8162121bb1bc..f03ef434503b 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -128,7 +128,9 @@ config IMGPDC_IRQ config IRQ_MIPS_CPU bool select GENERIC_IRQ_CHIP + select GENERIC_IRQ_IPI if SYS_SUPPORTS_MULTITHREADING select IRQ_DOMAIN + select IRQ_DOMAIN_HIERARCHY if GENERIC_IRQ_IPI config CLPS711X_IRQCHIP bool diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c index 338de924b269..b247f3c743ac 100644 --- a/drivers/irqchip/irq-mips-cpu.c +++ b/drivers/irqchip/irq-mips-cpu.c @@ -17,15 +17,14 @@ /* * Almost all MIPS CPUs define 8 interrupt sources. They are typically * level triggered (i.e., cannot be cleared from CPU; must be cleared from - * device). The first two are software interrupts which we don't really - * use or support. The last one is usually the CPU timer interrupt if - * counter register is present or, for CPUs with an external FPU, by - * convention it's the FPU exception interrupt. + * device). * - * Don't even think about using this on SMP. You have been warned. + * The first two are software interrupts (i.e. not exposed as pins) which + * may be used for IPIs in multi-threaded single-core systems. * - * This file exports one global function: - * void mips_cpu_irq_init(void); + * The last one is usually the CPU timer interrupt if the counter register + * is present, or for old CPUs with an external FPU by convention it's the + * FPU exception interrupt. */ #include #include @@ -40,6 +39,7 @@ #include static struct irq_domain *irq_domain; +static struct irq_domain *ipi_domain; static inline void unmask_mips_irq(struct irq_data *d) { @@ -90,6 +90,29 @@ static void mips_mt_cpu_irq_ack(struct irq_data *d) mask_mips_irq(d); } +#ifdef CONFIG_GENERIC_IRQ_IPI + +static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu) +{ + irq_hw_number_t hwirq = irqd_to_hwirq(d); + unsigned long flags; + int vpflags; + + local_irq_save(flags); + + /* We can only send IPIs to VPEs within the local core */ + WARN_ON(cpu_data[cpu].core != current_cpu_data.core); + + vpflags = dvpe(); + settc(cpu_vpe_id(&cpu_data[cpu])); + write_vpe_c0_cause(read_vpe_c0_cause() | (C_SW0 << hwirq)); + evpe(vpflags); + + local_irq_restore(flags); +} + +#endif /* CONFIG_GENERIC_IRQ_IPI */ + static struct irq_chip mips_mt_cpu_irq_controller = { .name = "MIPS", .irq_startup = mips_mt_cpu_irq_startup, @@ -100,6 +123,9 @@ static struct irq_chip mips_mt_cpu_irq_controller = { .irq_eoi = unmask_mips_irq, .irq_disable = mask_mips_irq, .irq_enable = unmask_mips_irq, +#ifdef CONFIG_GENERIC_IRQ_IPI + .ipi_send_single = mips_mt_send_ipi, +#endif }; asmlinkage void __weak plat_irq_dispatch(void) @@ -116,7 +142,10 @@ asmlinkage void __weak plat_irq_dispatch(void) pending >>= CAUSEB_IP; while (pending) { irq = fls(pending) - 1; - virq = irq_linear_revmap(irq_domain, irq); + if (IS_ENABLED(CONFIG_GENERIC_IRQ_IPI) && irq < 2) + virq = irq_linear_revmap(ipi_domain, irq); + else + virq = irq_linear_revmap(irq_domain, irq); do_IRQ(virq); pending &= ~BIT(irq); } @@ -147,6 +176,79 @@ static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = { .xlate = irq_domain_xlate_onecell, }; +#ifdef CONFIG_GENERIC_IRQ_IPI + +struct cpu_ipi_domain_state { + DECLARE_BITMAP(allocated, 2); +}; + +static int mips_cpu_ipi_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + struct cpu_ipi_domain_state *state = domain->host_data; + unsigned int i, hwirq; + int ret; + + for (i = 0; i < nr_irqs; i++) { + hwirq = find_first_zero_bit(state->allocated, 2); + if (hwirq == 2) + return -EBUSY; + bitmap_set(state->allocated, hwirq, 1); + + ret = irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq, + &mips_mt_cpu_irq_controller, + NULL); + if (ret) + return ret; + + ret = irq_set_irq_type(virq + i, IRQ_TYPE_LEVEL_HIGH); + if (ret) + return ret; + } + + return 0; +} + +static int mips_cpu_ipi_match(struct irq_domain *d, struct device_node *node, + enum irq_domain_bus_token bus_token) +{ + bool is_ipi; + + switch (bus_token) { + case DOMAIN_BUS_IPI: + is_ipi = d->bus_token == bus_token; + return (!node || (to_of_node(d->fwnode) == node)) && is_ipi; + default: + return 0; + } +} + +static const struct irq_domain_ops mips_cpu_ipi_chip_ops = { + .alloc = mips_cpu_ipi_alloc, + .match = mips_cpu_ipi_match, +}; + +static void mips_cpu_register_ipi_domain(struct device_node *of_node) +{ + struct cpu_ipi_domain_state *ipi_domain_state; + + ipi_domain_state = kzalloc(sizeof(*ipi_domain_state), GFP_KERNEL); + ipi_domain = irq_domain_add_hierarchy(irq_domain, + IRQ_DOMAIN_FLAG_IPI_SINGLE, + 2, of_node, + &mips_cpu_ipi_chip_ops, + ipi_domain_state); + if (!ipi_domain) + panic("Failed to add MIPS CPU IPI domain"); + ipi_domain->bus_token = DOMAIN_BUS_IPI; +} + +#else /* !CONFIG_GENERIC_IRQ_IPI */ + +static inline void mips_cpu_register_ipi_domain(struct device_node *of_node) {} + +#endif /* !CONFIG_GENERIC_IRQ_IPI */ + static void __init __mips_cpu_irq_init(struct device_node *of_node) { /* Mask interrupts. */ @@ -158,6 +260,13 @@ static void __init __mips_cpu_irq_init(struct device_node *of_node) NULL); if (!irq_domain) panic("Failed to add irqdomain for MIPS CPU"); + + /* + * Only proceed to register the software interrupt IPI implementation + * for CPUs which implement the MIPS MT (multi-threading) ASE. + */ + if (cpu_has_mipsmt) + mips_cpu_register_ipi_domain(of_node); } void __init mips_cpu_irq_init(void) -- cgit v1.2.1