From d74361881f0dfe5f9dcac37d1b753a15a2345d8c Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 8 Jul 2016 16:37:08 +1000 Subject: [PATCH] powerpc/xics: Add ICP OPAL backend This adds a new XICS backend that uses OPAL calls, which can be used when we don't have native support for the platform interrupt controller. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/xics.h | 6 ++ arch/powerpc/sysdev/xics/Makefile | 2 +- arch/powerpc/sysdev/xics/icp-opal.c | 144 +++++++++++++++++++++++++++++++++ arch/powerpc/sysdev/xics/xics-common.c | 5 +- 4 files changed, 155 insertions(+), 2 deletions(-) create mode 100644 arch/powerpc/sysdev/xics/icp-opal.c diff --git a/arch/powerpc/include/asm/xics.h b/arch/powerpc/include/asm/xics.h index 04ef3ae..f5f729c 100644 --- a/arch/powerpc/include/asm/xics.h +++ b/arch/powerpc/include/asm/xics.h @@ -42,6 +42,12 @@ extern int icp_hv_init(void); static inline int icp_hv_init(void) { return -ENODEV; } #endif +#ifdef CONFIG_PPC_POWERNV +extern int icp_opal_init(void); +#else +static inline int icp_opal_init(void) { return -ENODEV; } +#endif + /* ICP ops */ struct icp_ops { unsigned int (*get_irq)(void); diff --git a/arch/powerpc/sysdev/xics/Makefile b/arch/powerpc/sysdev/xics/Makefile index c606aa8..5d7f5a6 100644 --- a/arch/powerpc/sysdev/xics/Makefile +++ b/arch/powerpc/sysdev/xics/Makefile @@ -4,4 +4,4 @@ obj-y += xics-common.o obj-$(CONFIG_PPC_ICP_NATIVE) += icp-native.o obj-$(CONFIG_PPC_ICP_HV) += icp-hv.o obj-$(CONFIG_PPC_ICS_RTAS) += ics-rtas.o -obj-$(CONFIG_PPC_POWERNV) += ics-opal.o +obj-$(CONFIG_PPC_POWERNV) += ics-opal.o icp-opal.o diff --git a/arch/powerpc/sysdev/xics/icp-opal.c b/arch/powerpc/sysdev/xics/icp-opal.c new file mode 100644 index 0000000..57d72f1 --- /dev/null +++ b/arch/powerpc/sysdev/xics/icp-opal.c @@ -0,0 +1,144 @@ +/* + * Copyright 2016 IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +static void icp_opal_teardown_cpu(void) +{ + int cpu = smp_processor_id(); + + /* Clear any pending IPI */ + opal_int_set_mfrr(cpu, 0xff); +} + +static void icp_opal_flush_ipi(void) +{ + /* + * We take the ipi irq but and never return so we need to EOI the IPI, + * but want to leave our priority 0. + * + * Should we check all the other interrupts too? + * Should we be flagging idle loop instead? + * Or creating some task to be scheduled? + */ + opal_int_eoi((0x00 << 24) | XICS_IPI); +} + +static unsigned int icp_opal_get_irq(void) +{ + unsigned int xirr; + unsigned int vec; + unsigned int irq; + int64_t rc; + + rc = opal_int_get_xirr(&xirr, false); + if (rc < 0) + return NO_IRQ; + xirr = be32_to_cpu(xirr); + vec = xirr & 0x00ffffff; + if (vec == XICS_IRQ_SPURIOUS) + return NO_IRQ; + + irq = irq_find_mapping(xics_host, vec); + if (likely(irq != NO_IRQ)) { + xics_push_cppr(vec); + return irq; + } + + /* We don't have a linux mapping, so have rtas mask it. */ + xics_mask_unknown_vec(vec); + + /* We might learn about it later, so EOI it */ + opal_int_eoi(xirr); + + return NO_IRQ; +} + +static void icp_opal_set_cpu_priority(unsigned char cppr) +{ + xics_set_base_cppr(cppr); + opal_int_set_cppr(cppr); + iosync(); +} + +static void icp_opal_eoi(struct irq_data *d) +{ + unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); + int64_t rc; + + iosync(); + rc = opal_int_eoi((xics_pop_cppr() << 24) | hw_irq); + + /* + * EOI tells us whether there are more interrupts to fetch. + * + * Some HW implementations might not be able to send us another + * external interrupt in that case, so we force a replay. + */ + if (rc > 0) + force_external_irq_replay(); +} + +#ifdef CONFIG_SMP + +static void icp_opal_cause_ipi(int cpu, unsigned long data) +{ + opal_int_set_mfrr(cpu, IPI_PRIORITY); +} + +static irqreturn_t icp_opal_ipi_action(int irq, void *dev_id) +{ + int cpu = smp_processor_id(); + + opal_int_set_mfrr(cpu, 0xff); + + return smp_ipi_demux(); +} + +#endif /* CONFIG_SMP */ + +static const struct icp_ops icp_opal_ops = { + .get_irq = icp_opal_get_irq, + .eoi = icp_opal_eoi, + .set_priority = icp_opal_set_cpu_priority, + .teardown_cpu = icp_opal_teardown_cpu, + .flush_ipi = icp_opal_flush_ipi, +#ifdef CONFIG_SMP + .ipi_action = icp_opal_ipi_action, + .cause_ipi = icp_opal_cause_ipi, +#endif +}; + +int icp_opal_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "ibm,opal-intc"); + if (!np) + return -ENODEV; + + icp_ops = &icp_opal_ops; + + printk("XICS: Using OPAL ICP fallbacks\n"); + + return 0; +} + diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c index 47e43b7..a795a5f 100644 --- a/arch/powerpc/sysdev/xics/xics-common.c +++ b/arch/powerpc/sysdev/xics/xics-common.c @@ -404,8 +404,11 @@ void __init xics_init(void) /* Fist locate ICP */ if (firmware_has_feature(FW_FEATURE_LPAR)) rc = icp_hv_init(); - if (rc < 0) + if (rc < 0) { rc = icp_native_init(); + if (rc == -ENODEV) + rc = icp_opal_init(); + } if (rc < 0) { pr_warning("XICS: Cannot find a Presentation Controller !\n"); return; -- 2.7.4