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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/x86/kernel/apic/msi.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/x86/kernel/apic/msi.c')
-rw-r--r--arch/x86/kernel/apic/msi.c348
1 files changed, 348 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
new file mode 100644
index 000000000..ab348aec8
--- /dev/null
+++ b/arch/x86/kernel/apic/msi.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support of MSI, HPET and DMAR interrupts.
+ *
+ * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
+ * Moved from arch/x86/kernel/apic/io_apic.c.
+ * Jiang Liu <jiang.liu@linux.intel.com>
+ * Convert to hierarchical irqdomain
+ */
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/pci.h>
+#include <linux/dmar.h>
+#include <linux/hpet.h>
+#include <linux/msi.h>
+#include <asm/irqdomain.h>
+#include <asm/hpet.h>
+#include <asm/hw_irq.h>
+#include <asm/apic.h>
+#include <asm/irq_remapping.h>
+#include <asm/xen/hypervisor.h>
+
+struct irq_domain *x86_pci_msi_default_domain __ro_after_init;
+
+static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
+{
+ struct msi_msg msg[2] = { [1] = { }, };
+
+ __irq_msi_compose_msg(cfg, msg, false);
+ irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
+}
+
+static int
+msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
+{
+ struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
+ struct irq_data *parent = irqd->parent_data;
+ unsigned int cpu;
+ int ret;
+
+ /* Save the current configuration */
+ cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
+ old_cfg = *cfg;
+
+ /* Allocate a new target vector */
+ ret = parent->chip->irq_set_affinity(parent, mask, force);
+ if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
+ return ret;
+
+ /*
+ * For non-maskable and non-remapped MSI interrupts the migration
+ * to a different destination CPU and a different vector has to be
+ * done careful to handle the possible stray interrupt which can be
+ * caused by the non-atomic update of the address/data pair.
+ *
+ * Direct update is possible when:
+ * - The MSI is maskable (remapped MSI does not use this code path).
+ * The reservation mode bit is set in this case.
+ * - The new vector is the same as the old vector
+ * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
+ * - The interrupt is not yet started up
+ * - The new destination CPU is the same as the old destination CPU
+ */
+ if (!irqd_can_reserve(irqd) ||
+ cfg->vector == old_cfg.vector ||
+ old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
+ !irqd_is_started(irqd) ||
+ cfg->dest_apicid == old_cfg.dest_apicid) {
+ irq_msi_update_msg(irqd, cfg);
+ return ret;
+ }
+
+ /*
+ * Paranoia: Validate that the interrupt target is the local
+ * CPU.
+ */
+ if (WARN_ON_ONCE(cpu != smp_processor_id())) {
+ irq_msi_update_msg(irqd, cfg);
+ return ret;
+ }
+
+ /*
+ * Redirect the interrupt to the new vector on the current CPU
+ * first. This might cause a spurious interrupt on this vector if
+ * the device raises an interrupt right between this update and the
+ * update to the final destination CPU.
+ *
+ * If the vector is in use then the installed device handler will
+ * denote it as spurious which is no harm as this is a rare event
+ * and interrupt handlers have to cope with spurious interrupts
+ * anyway. If the vector is unused, then it is marked so it won't
+ * trigger the 'No irq handler for vector' warning in
+ * common_interrupt().
+ *
+ * This requires to hold vector lock to prevent concurrent updates to
+ * the affected vector.
+ */
+ lock_vector_lock();
+
+ /*
+ * Mark the new target vector on the local CPU if it is currently
+ * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
+ * the CPU hotplug path for a similar purpose. This cannot be
+ * undone here as the current CPU has interrupts disabled and
+ * cannot handle the interrupt before the whole set_affinity()
+ * section is done. In the CPU unplug case, the current CPU is
+ * about to vanish and will not handle any interrupts anymore. The
+ * vector is cleaned up when the CPU comes online again.
+ */
+ if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
+ this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
+
+ /* Redirect it to the new vector on the local CPU temporarily */
+ old_cfg.vector = cfg->vector;
+ irq_msi_update_msg(irqd, &old_cfg);
+
+ /* Now transition it to the target CPU */
+ irq_msi_update_msg(irqd, cfg);
+
+ /*
+ * All interrupts after this point are now targeted at the new
+ * vector/CPU.
+ *
+ * Drop vector lock before testing whether the temporary assignment
+ * to the local CPU was hit by an interrupt raised in the device,
+ * because the retrigger function acquires vector lock again.
+ */
+ unlock_vector_lock();
+
+ /*
+ * Check whether the transition raced with a device interrupt and
+ * is pending in the local APICs IRR. It is safe to do this outside
+ * of vector lock as the irq_desc::lock of this interrupt is still
+ * held and interrupts are disabled: The check is not accessing the
+ * underlying vector store. It's just checking the local APIC's
+ * IRR.
+ */
+ if (lapic_vector_set_in_irr(cfg->vector))
+ irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
+
+ return ret;
+}
+
+/*
+ * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
+ * which implement the MSI or MSI-X Capability Structure.
+ */
+static struct irq_chip pci_msi_controller = {
+ .name = "PCI-MSI",
+ .irq_unmask = pci_msi_unmask_irq,
+ .irq_mask = pci_msi_mask_irq,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_set_affinity = msi_set_affinity,
+ .flags = IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
+ msi_alloc_info_t *arg)
+{
+ init_irq_alloc_info(arg, NULL);
+ if (to_pci_dev(dev)->msix_enabled) {
+ arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
+ } else {
+ arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
+ arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_msi_prepare);
+
+static struct msi_domain_ops pci_msi_domain_ops = {
+ .msi_prepare = pci_msi_prepare,
+};
+
+static struct msi_domain_info pci_msi_domain_info = {
+ .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX,
+ .ops = &pci_msi_domain_ops,
+ .chip = &pci_msi_controller,
+ .handler = handle_edge_irq,
+ .handler_name = "edge",
+};
+
+struct irq_domain * __init native_create_pci_msi_domain(void)
+{
+ struct fwnode_handle *fn;
+ struct irq_domain *d;
+
+ if (disable_apic)
+ return NULL;
+
+ fn = irq_domain_alloc_named_fwnode("PCI-MSI");
+ if (!fn)
+ return NULL;
+
+ d = pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
+ x86_vector_domain);
+ if (!d) {
+ irq_domain_free_fwnode(fn);
+ pr_warn("Failed to initialize PCI-MSI irqdomain.\n");
+ }
+ return d;
+}
+
+void __init x86_create_pci_msi_domain(void)
+{
+ x86_pci_msi_default_domain = x86_init.irqs.create_pci_msi_domain();
+}
+
+#ifdef CONFIG_IRQ_REMAP
+static struct irq_chip pci_msi_ir_controller = {
+ .name = "IR-PCI-MSI",
+ .irq_unmask = pci_msi_unmask_irq,
+ .irq_mask = pci_msi_mask_irq,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .flags = IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static struct msi_domain_info pci_msi_ir_domain_info = {
+ .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
+ .ops = &pci_msi_domain_ops,
+ .chip = &pci_msi_ir_controller,
+ .handler = handle_edge_irq,
+ .handler_name = "edge",
+};
+
+struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
+ const char *name, int id)
+{
+ struct fwnode_handle *fn;
+ struct irq_domain *d;
+
+ fn = irq_domain_alloc_named_id_fwnode(name, id);
+ if (!fn)
+ return NULL;
+ d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
+ if (!d)
+ irq_domain_free_fwnode(fn);
+ return d;
+}
+#endif
+
+#ifdef CONFIG_DMAR_TABLE
+/*
+ * The Intel IOMMU (ab)uses the high bits of the MSI address to contain the
+ * high bits of the destination APIC ID. This can't be done in the general
+ * case for MSIs as it would be targeting real memory above 4GiB not the
+ * APIC.
+ */
+static void dmar_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ __irq_msi_compose_msg(irqd_cfg(data), msg, true);
+}
+
+static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ dmar_msi_write(data->irq, msg);
+}
+
+static struct irq_chip dmar_msi_controller = {
+ .name = "DMAR-MSI",
+ .irq_unmask = dmar_msi_unmask,
+ .irq_mask = dmar_msi_mask,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_set_affinity = msi_domain_set_affinity,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_compose_msi_msg = dmar_msi_compose_msg,
+ .irq_write_msi_msg = dmar_msi_write_msg,
+ .flags = IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_AFFINITY_PRE_STARTUP,
+};
+
+static int dmar_msi_init(struct irq_domain *domain,
+ struct msi_domain_info *info, unsigned int virq,
+ irq_hw_number_t hwirq, msi_alloc_info_t *arg)
+{
+ irq_domain_set_info(domain, virq, arg->devid, info->chip, NULL,
+ handle_edge_irq, arg->data, "edge");
+
+ return 0;
+}
+
+static struct msi_domain_ops dmar_msi_domain_ops = {
+ .msi_init = dmar_msi_init,
+};
+
+static struct msi_domain_info dmar_msi_domain_info = {
+ .ops = &dmar_msi_domain_ops,
+ .chip = &dmar_msi_controller,
+ .flags = MSI_FLAG_USE_DEF_DOM_OPS,
+};
+
+static struct irq_domain *dmar_get_irq_domain(void)
+{
+ static struct irq_domain *dmar_domain;
+ static DEFINE_MUTEX(dmar_lock);
+ struct fwnode_handle *fn;
+
+ mutex_lock(&dmar_lock);
+ if (dmar_domain)
+ goto out;
+
+ fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
+ if (fn) {
+ dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
+ x86_vector_domain);
+ if (!dmar_domain)
+ irq_domain_free_fwnode(fn);
+ }
+out:
+ mutex_unlock(&dmar_lock);
+ return dmar_domain;
+}
+
+int dmar_alloc_hwirq(int id, int node, void *arg)
+{
+ struct irq_domain *domain = dmar_get_irq_domain();
+ struct irq_alloc_info info;
+
+ if (!domain)
+ return -1;
+
+ init_irq_alloc_info(&info, NULL);
+ info.type = X86_IRQ_ALLOC_TYPE_DMAR;
+ info.devid = id;
+ info.hwirq = id;
+ info.data = arg;
+
+ return irq_domain_alloc_irqs(domain, 1, node, &info);
+}
+
+void dmar_free_hwirq(int irq)
+{
+ irq_domain_free_irqs(irq, 1);
+}
+#endif
+
+bool arch_restore_msi_irqs(struct pci_dev *dev)
+{
+ return xen_initdom_restore_msi(dev);
+}