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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/powerpc/sysdev/xics/xics-common.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/powerpc/sysdev/xics/xics-common.c')
-rw-r--r--arch/powerpc/sysdev/xics/xics-common.c544
1 files changed, 544 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
new file mode 100644
index 000000000..d3a4156e8
--- /dev/null
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -0,0 +1,544 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2011 IBM Corporation.
+ */
+#include <linux/types.h>
+#include <linux/threads.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/debugfs.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/rtas.h>
+#include <asm/xics.h>
+#include <asm/firmware.h>
+
+/* Globals common to all ICP/ICS implementations */
+const struct icp_ops *icp_ops;
+
+unsigned int xics_default_server = 0xff;
+unsigned int xics_default_distrib_server = 0;
+unsigned int xics_interrupt_server_size = 8;
+
+DEFINE_PER_CPU(struct xics_cppr, xics_cppr);
+
+struct irq_domain *xics_host;
+
+static struct ics *xics_ics;
+
+void xics_update_irq_servers(void)
+{
+ int i, j;
+ struct device_node *np;
+ u32 ilen;
+ const __be32 *ireg;
+ u32 hcpuid;
+
+ /* Find the server numbers for the boot cpu. */
+ np = of_get_cpu_node(boot_cpuid, NULL);
+ BUG_ON(!np);
+
+ hcpuid = get_hard_smp_processor_id(boot_cpuid);
+ xics_default_server = xics_default_distrib_server = hcpuid;
+
+ pr_devel("xics: xics_default_server = 0x%x\n", xics_default_server);
+
+ ireg = of_get_property(np, "ibm,ppc-interrupt-gserver#s", &ilen);
+ if (!ireg) {
+ of_node_put(np);
+ return;
+ }
+
+ i = ilen / sizeof(int);
+
+ /* Global interrupt distribution server is specified in the last
+ * entry of "ibm,ppc-interrupt-gserver#s" property. Get the last
+ * entry fom this property for current boot cpu id and use it as
+ * default distribution server
+ */
+ for (j = 0; j < i; j += 2) {
+ if (be32_to_cpu(ireg[j]) == hcpuid) {
+ xics_default_distrib_server = be32_to_cpu(ireg[j+1]);
+ break;
+ }
+ }
+ pr_devel("xics: xics_default_distrib_server = 0x%x\n",
+ xics_default_distrib_server);
+ of_node_put(np);
+}
+
+/* GIQ stuff, currently only supported on RTAS setups, will have
+ * to be sorted properly for bare metal
+ */
+void xics_set_cpu_giq(unsigned int gserver, unsigned int join)
+{
+#ifdef CONFIG_PPC_RTAS
+ int index;
+ int status;
+
+ if (!rtas_indicator_present(GLOBAL_INTERRUPT_QUEUE, NULL))
+ return;
+
+ index = (1UL << xics_interrupt_server_size) - 1 - gserver;
+
+ status = rtas_set_indicator_fast(GLOBAL_INTERRUPT_QUEUE, index, join);
+
+ WARN(status < 0, "set-indicator(%d, %d, %u) returned %d\n",
+ GLOBAL_INTERRUPT_QUEUE, index, join, status);
+#endif
+}
+
+void xics_setup_cpu(void)
+{
+ icp_ops->set_priority(LOWEST_PRIORITY);
+
+ xics_set_cpu_giq(xics_default_distrib_server, 1);
+}
+
+void xics_mask_unknown_vec(unsigned int vec)
+{
+ pr_err("Interrupt 0x%x (real) is invalid, disabling it.\n", vec);
+
+ if (WARN_ON(!xics_ics))
+ return;
+ xics_ics->mask_unknown(xics_ics, vec);
+}
+
+
+#ifdef CONFIG_SMP
+
+static void __init xics_request_ipi(void)
+{
+ unsigned int ipi;
+
+ ipi = irq_create_mapping(xics_host, XICS_IPI);
+ BUG_ON(!ipi);
+
+ /*
+ * IPIs are marked IRQF_PERCPU. The handler was set in map.
+ */
+ BUG_ON(request_irq(ipi, icp_ops->ipi_action,
+ IRQF_NO_DEBUG | IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
+}
+
+void __init xics_smp_probe(void)
+{
+ /* Register all the IPIs */
+ xics_request_ipi();
+
+ /* Setup cause_ipi callback based on which ICP is used */
+ smp_ops->cause_ipi = icp_ops->cause_ipi;
+}
+
+#endif /* CONFIG_SMP */
+
+noinstr void xics_teardown_cpu(void)
+{
+ struct xics_cppr *os_cppr = this_cpu_ptr(&xics_cppr);
+
+ /*
+ * we have to reset the cppr index to 0 because we're
+ * not going to return from the IPI
+ */
+ os_cppr->index = 0;
+ icp_ops->set_priority(0);
+ icp_ops->teardown_cpu();
+}
+
+noinstr void xics_kexec_teardown_cpu(int secondary)
+{
+ xics_teardown_cpu();
+
+ icp_ops->flush_ipi();
+
+ /*
+ * Some machines need to have at least one cpu in the GIQ,
+ * so leave the master cpu in the group.
+ */
+ if (secondary)
+ xics_set_cpu_giq(xics_default_distrib_server, 0);
+}
+
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/* Interrupts are disabled. */
+void xics_migrate_irqs_away(void)
+{
+ int cpu = smp_processor_id(), hw_cpu = hard_smp_processor_id();
+ unsigned int irq, virq;
+ struct irq_desc *desc;
+
+ pr_debug("%s: CPU %u\n", __func__, cpu);
+
+ /* If we used to be the default server, move to the new "boot_cpuid" */
+ if (hw_cpu == xics_default_server)
+ xics_update_irq_servers();
+
+ /* Reject any interrupt that was queued to us... */
+ icp_ops->set_priority(0);
+
+ /* Remove ourselves from the global interrupt queue */
+ xics_set_cpu_giq(xics_default_distrib_server, 0);
+
+ for_each_irq_desc(virq, desc) {
+ struct irq_chip *chip;
+ long server;
+ unsigned long flags;
+ struct irq_data *irqd;
+
+ /* We can't set affinity on ISA interrupts */
+ if (virq < NR_IRQS_LEGACY)
+ continue;
+ /* We only need to migrate enabled IRQS */
+ if (!desc->action)
+ continue;
+ /* We need a mapping in the XICS IRQ domain */
+ irqd = irq_domain_get_irq_data(xics_host, virq);
+ if (!irqd)
+ continue;
+ irq = irqd_to_hwirq(irqd);
+ /* We need to get IPIs still. */
+ if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
+ continue;
+ chip = irq_desc_get_chip(desc);
+ if (!chip || !chip->irq_set_affinity)
+ continue;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ /* Locate interrupt server */
+ server = xics_ics->get_server(xics_ics, irq);
+ if (server < 0) {
+ pr_err("%s: Can't find server for irq %d/%x\n",
+ __func__, virq, irq);
+ goto unlock;
+ }
+
+ /* We only support delivery to all cpus or to one cpu.
+ * The irq has to be migrated only in the single cpu
+ * case.
+ */
+ if (server != hw_cpu)
+ goto unlock;
+
+ /* This is expected during cpu offline. */
+ if (cpu_online(cpu))
+ pr_warn("IRQ %u affinity broken off cpu %u\n",
+ virq, cpu);
+
+ /* Reset affinity to all cpus */
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ irq_set_affinity(virq, cpu_all_mask);
+ continue;
+unlock:
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+
+ /* Allow "sufficient" time to drop any inflight IRQ's */
+ mdelay(5);
+
+ /*
+ * Allow IPIs again. This is done at the very end, after migrating all
+ * interrupts, the expectation is that we'll only get woken up by an IPI
+ * interrupt beyond this point, but leave externals masked just to be
+ * safe. If we're using icp-opal this may actually allow all
+ * interrupts anyway, but that should be OK.
+ */
+ icp_ops->set_priority(DEFAULT_PRIORITY);
+
+}
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#ifdef CONFIG_SMP
+/*
+ * For the moment we only implement delivery to all cpus or one cpu.
+ *
+ * If the requested affinity is cpu_all_mask, we set global affinity.
+ * If not we set it to the first cpu in the mask, even if multiple cpus
+ * are set. This is so things like irqbalance (which set core and package
+ * wide affinities) do the right thing.
+ *
+ * We need to fix this to implement support for the links
+ */
+int xics_get_irq_server(unsigned int virq, const struct cpumask *cpumask,
+ unsigned int strict_check)
+{
+
+ if (!distribute_irqs)
+ return xics_default_server;
+
+ if (!cpumask_subset(cpu_possible_mask, cpumask)) {
+ int server = cpumask_first_and(cpu_online_mask, cpumask);
+
+ if (server < nr_cpu_ids)
+ return get_hard_smp_processor_id(server);
+
+ if (strict_check)
+ return -1;
+ }
+
+ /*
+ * Workaround issue with some versions of JS20 firmware that
+ * deliver interrupts to cpus which haven't been started. This
+ * happens when using the maxcpus= boot option.
+ */
+ if (cpumask_equal(cpu_online_mask, cpu_present_mask))
+ return xics_default_distrib_server;
+
+ return xics_default_server;
+}
+#endif /* CONFIG_SMP */
+
+static int xics_host_match(struct irq_domain *h, struct device_node *node,
+ enum irq_domain_bus_token bus_token)
+{
+ if (WARN_ON(!xics_ics))
+ return 0;
+ return xics_ics->host_match(xics_ics, node) ? 1 : 0;
+}
+
+/* Dummies */
+static void xics_ipi_unmask(struct irq_data *d) { }
+static void xics_ipi_mask(struct irq_data *d) { }
+
+static struct irq_chip xics_ipi_chip = {
+ .name = "XICS",
+ .irq_eoi = NULL, /* Patched at init time */
+ .irq_mask = xics_ipi_mask,
+ .irq_unmask = xics_ipi_unmask,
+};
+
+static int xics_host_map(struct irq_domain *domain, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ pr_devel("xics: map virq %d, hwirq 0x%lx\n", virq, hwirq);
+
+ /*
+ * Mark interrupts as edge sensitive by default so that resend
+ * actually works. The device-tree parsing will turn the LSIs
+ * back to level.
+ */
+ irq_clear_status_flags(virq, IRQ_LEVEL);
+
+ /* Don't call into ICS for IPIs */
+ if (hwirq == XICS_IPI) {
+ irq_set_chip_and_handler(virq, &xics_ipi_chip,
+ handle_percpu_irq);
+ return 0;
+ }
+
+ if (WARN_ON(!xics_ics))
+ return -EINVAL;
+
+ if (xics_ics->check(xics_ics, hwirq))
+ return -EINVAL;
+
+ /* Let the ICS be the chip data for the XICS domain. For ICS native */
+ irq_domain_set_info(domain, virq, hwirq, xics_ics->chip,
+ xics_ics, handle_fasteoi_irq, NULL, NULL);
+
+ return 0;
+}
+
+static int xics_host_xlate(struct irq_domain *h, struct device_node *ct,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
+{
+ *out_hwirq = intspec[0];
+
+ /*
+ * If intsize is at least 2, we look for the type in the second cell,
+ * we assume the LSB indicates a level interrupt.
+ */
+ if (intsize > 1) {
+ if (intspec[1] & 1)
+ *out_flags = IRQ_TYPE_LEVEL_LOW;
+ else
+ *out_flags = IRQ_TYPE_EDGE_RISING;
+ } else
+ *out_flags = IRQ_TYPE_LEVEL_LOW;
+
+ return 0;
+}
+
+int xics_set_irq_type(struct irq_data *d, unsigned int flow_type)
+{
+ /*
+ * We only support these. This has really no effect other than setting
+ * the corresponding descriptor bits mind you but those will in turn
+ * affect the resend function when re-enabling an edge interrupt.
+ *
+ * Set set the default to edge as explained in map().
+ */
+ if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
+ flow_type = IRQ_TYPE_EDGE_RISING;
+
+ if (flow_type != IRQ_TYPE_EDGE_RISING &&
+ flow_type != IRQ_TYPE_LEVEL_LOW)
+ return -EINVAL;
+
+ irqd_set_trigger_type(d, flow_type);
+
+ return IRQ_SET_MASK_OK_NOCOPY;
+}
+
+int xics_retrigger(struct irq_data *data)
+{
+ /*
+ * We need to push a dummy CPPR when retriggering, since the subsequent
+ * EOI will try to pop it. Passing 0 works, as the function hard codes
+ * the priority value anyway.
+ */
+ xics_push_cppr(0);
+
+ /* Tell the core to do a soft retrigger */
+ return 0;
+}
+
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+static int xics_host_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
+ unsigned long *hwirq, unsigned int *type)
+{
+ return xics_host_xlate(d, to_of_node(fwspec->fwnode), fwspec->param,
+ fwspec->param_count, hwirq, type);
+}
+
+static int xics_host_domain_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq;
+ unsigned int type = IRQ_TYPE_NONE;
+ int i, rc;
+
+ rc = xics_host_domain_translate(domain, fwspec, &hwirq, &type);
+ if (rc)
+ return rc;
+
+ pr_debug("%s %d/%lx #%d\n", __func__, virq, hwirq, nr_irqs);
+
+ for (i = 0; i < nr_irqs; i++)
+ irq_domain_set_info(domain, virq + i, hwirq + i, xics_ics->chip,
+ xics_ics, handle_fasteoi_irq, NULL, NULL);
+
+ return 0;
+}
+
+static void xics_host_domain_free(struct irq_domain *domain,
+ unsigned int virq, unsigned int nr_irqs)
+{
+ pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
+}
+#endif
+
+static const struct irq_domain_ops xics_host_ops = {
+#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
+ .alloc = xics_host_domain_alloc,
+ .free = xics_host_domain_free,
+ .translate = xics_host_domain_translate,
+#endif
+ .match = xics_host_match,
+ .map = xics_host_map,
+ .xlate = xics_host_xlate,
+};
+
+static int __init xics_allocate_domain(void)
+{
+ struct fwnode_handle *fn;
+
+ fn = irq_domain_alloc_named_fwnode("XICS");
+ if (!fn)
+ return -ENOMEM;
+
+ xics_host = irq_domain_create_tree(fn, &xics_host_ops, NULL);
+ if (!xics_host) {
+ irq_domain_free_fwnode(fn);
+ return -ENOMEM;
+ }
+
+ irq_set_default_host(xics_host);
+ return 0;
+}
+
+void __init xics_register_ics(struct ics *ics)
+{
+ if (WARN_ONCE(xics_ics, "XICS: Source Controller is already defined !"))
+ return;
+ xics_ics = ics;
+}
+
+static void __init xics_get_server_size(void)
+{
+ struct device_node *np;
+ const __be32 *isize;
+
+ /* We fetch the interrupt server size from the first ICS node
+ * we find if any
+ */
+ np = of_find_compatible_node(NULL, NULL, "ibm,ppc-xics");
+ if (!np)
+ return;
+
+ isize = of_get_property(np, "ibm,interrupt-server#-size", NULL);
+ if (isize)
+ xics_interrupt_server_size = be32_to_cpu(*isize);
+
+ of_node_put(np);
+}
+
+void __init xics_init(void)
+{
+ int rc = -1;
+
+ /* Fist locate ICP */
+ if (firmware_has_feature(FW_FEATURE_LPAR))
+ rc = icp_hv_init();
+ if (rc < 0) {
+ rc = icp_native_init();
+ if (rc == -ENODEV)
+ rc = icp_opal_init();
+ }
+ if (rc < 0) {
+ pr_warn("XICS: Cannot find a Presentation Controller !\n");
+ return;
+ }
+
+ /* Copy get_irq callback over to ppc_md */
+ ppc_md.get_irq = icp_ops->get_irq;
+
+ /* Patch up IPI chip EOI */
+ xics_ipi_chip.irq_eoi = icp_ops->eoi;
+
+ /* Now locate ICS */
+ rc = ics_rtas_init();
+ if (rc < 0)
+ rc = ics_opal_init();
+ if (rc < 0)
+ rc = ics_native_init();
+ if (rc < 0)
+ pr_warn("XICS: Cannot find a Source Controller !\n");
+
+ /* Initialize common bits */
+ xics_get_server_size();
+ xics_update_irq_servers();
+ rc = xics_allocate_domain();
+ if (rc < 0)
+ pr_err("XICS: Failed to create IRQ domain");
+ xics_setup_cpu();
+}