From: David Woodhouse <dwmw@xxxxxxxxxxxx>
It took me a while to realise that this "IRQ remapping" driver exists
not to actually remap interrupts, but to return -EINVAL if anyone ever
tries to set the affinity to a set of CPUs which can't be reached
*without* remapping. Having fixed the core IRQ domain code to handle
such limited, all this hackery can now die.
I haven't deleted it entirely because its existence still causes the
kernel to use X2APIC in cluster mode not physical. I'm not sure we
*want* that, but it wants further thought and testing before ripping
it out too.
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
---
drivers/iommu/hyperv-iommu.c | 149 +----------------------------------
1 file changed, 1 insertion(+), 148 deletions(-)
diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c
index e09e2d734c57..46a794d34f57 100644
--- a/drivers/iommu/hyperv-iommu.c
+++ b/drivers/iommu/hyperv-iommu.c
@@ -24,156 +24,12 @@
#include "irq_remapping.h"
#ifdef CONFIG_IRQ_REMAP
-
-/*
- * According 82093AA IO-APIC spec , IO APIC has a 24-entry Interrupt
- * Redirection Table. Hyper-V exposes one single IO-APIC and so define
- * 24 IO APIC remmapping entries.
- */
-#define IOAPIC_REMAPPING_ENTRY 24
-
-static cpumask_t ioapic_max_cpumask = { CPU_BITS_NONE };
-static struct irq_domain *ioapic_ir_domain;
-
-static int hyperv_ir_set_affinity(struct irq_data *data,
- const struct cpumask *mask, bool force)
-{
- struct irq_data *parent = data->parent_data;
- struct irq_cfg *cfg = irqd_cfg(data);
- struct IO_APIC_route_entry *entry;
- int ret;
-
- /* Return error If new irq affinity is out of ioapic_max_cpumask. */
- if (!cpumask_subset(mask, &ioapic_max_cpumask))
- return -EINVAL;
-
- ret = parent->chip->irq_set_affinity(parent, mask, force);
- if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
- return ret;
-
- entry = data->chip_data;
- entry->dest = cfg->dest_apicid;
- entry->vector = cfg->vector;
- send_cleanup_vector(cfg);
-
- return 0;
-}
-
-static struct irq_chip hyperv_ir_chip = {
- .name = "HYPERV-IR",
- .irq_ack = apic_ack_irq,
- .irq_set_affinity = hyperv_ir_set_affinity,
-};
-
-static int hyperv_irq_remapping_alloc(struct irq_domain *domain,
- unsigned int virq, unsigned int nr_irqs,
- void *arg)
-{
- struct irq_alloc_info *info = arg;
- struct irq_data *irq_data;
- struct irq_desc *desc;
- int ret = 0;
-
- if (!info || info->type != X86_IRQ_ALLOC_TYPE_IOAPIC || nr_irqs > 1)
- return -EINVAL;
-
- ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);
- if (ret < 0)
- return ret;
-
- irq_data = irq_domain_get_irq_data(domain, virq);
- if (!irq_data) {
- irq_domain_free_irqs_common(domain, virq, nr_irqs);
- return -EINVAL;
- }
-
- irq_data->chip = &hyperv_ir_chip;
-
- /*
- * If there is interrupt remapping function of IOMMU, setting irq
- * affinity only needs to change IRTE of IOMMU. But Hyper-V doesn't
- * support interrupt remapping function, setting irq affinity of IO-APIC
- * interrupts still needs to change IO-APIC registers. But ioapic_
- * configure_entry() will ignore value of cfg->vector and cfg->
- * dest_apicid when IO-APIC's parent irq domain is not the vector
- * domain.(See ioapic_configure_entry()) In order to setting vector
- * and dest_apicid to IO-APIC register, IO-APIC entry pointer is saved
- * in the chip_data and hyperv_irq_remapping_activate()/hyperv_ir_set_
- * affinity() set vector and dest_apicid directly into IO-APIC entry.
- */
- irq_data->chip_data = info->ioapic.entry;
-
- /*
- * Hypver-V IO APIC irq affinity should be in the scope of
- * ioapic_max_cpumask because no irq remapping support.
- */
- desc = irq_data_to_desc(irq_data);
- cpumask_copy(desc->irq_common_data.affinity, &ioapic_max_cpumask);
-
- return 0;
-}
-
-static void hyperv_irq_remapping_free(struct irq_domain *domain,
- unsigned int virq, unsigned int nr_irqs)
-{
- irq_domain_free_irqs_common(domain, virq, nr_irqs);
-}
-
-static int hyperv_irq_remapping_activate(struct irq_domain *domain,
- struct irq_data *irq_data, bool reserve)
-{
- struct irq_cfg *cfg = irqd_cfg(irq_data);
- struct IO_APIC_route_entry *entry = irq_data->chip_data;
-
- entry->dest = cfg->dest_apicid;
- entry->vector = cfg->vector;
-
- return 0;
-}
-
-static const struct irq_domain_ops hyperv_ir_domain_ops = {
- .alloc = hyperv_irq_remapping_alloc,
- .free = hyperv_irq_remapping_free,
- .activate = hyperv_irq_remapping_activate,
-};
-
static int __init hyperv_prepare_irq_remapping(void)
{
- struct fwnode_handle *fn;
- int i;
-
if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) ||
!x2apic_supported())
return -ENODEV;
- fn = irq_domain_alloc_named_id_fwnode("HYPERV-IR", 0);
- if (!fn)
- return -ENOMEM;
-
- ioapic_ir_domain =
- irq_domain_create_hierarchy(arch_get_ir_parent_domain(),
- 0, IOAPIC_REMAPPING_ENTRY, fn,
- &hyperv_ir_domain_ops, NULL);
-
- if (!ioapic_ir_domain) {
- irq_domain_free_fwnode(fn);
- return -ENOMEM;
- }
-
- /*
- * Hyper-V doesn't provide irq remapping function for
- * IO-APIC and so IO-APIC only accepts 8-bit APIC ID.
- * Cpu's APIC ID is read from ACPI MADT table and APIC IDs
- * in the MADT table on Hyper-v are sorted monotonic increasingly.
- * APIC ID reflects cpu topology. There maybe some APIC ID
- * gaps when cpu number in a socket is not power of two. Prepare
- * max cpu affinity for IOAPIC irqs. Scan cpu 0-255 and set cpu
- * into ioapic_max_cpumask if its APIC ID is less than 256.
- */
- for (i = min_t(unsigned int, num_possible_cpus() - 1, 255); i >= 0; i--)
- if (cpu_physical_id(i) < 256)
- cpumask_set_cpu(i, &ioapic_max_cpumask);
-
return 0;
}
@@ -184,10 +40,7 @@ static int __init hyperv_enable_irq_remapping(void)
static struct irq_domain *hyperv_get_irq_domain(struct irq_alloc_info *info)
{
- if (info->type == X86_IRQ_ALLOC_TYPE_IOAPIC_GET_PARENT)
- return ioapic_ir_domain;
- else
- return NULL;
+ return NULL;
}
struct irq_remap_ops hyperv_irq_remap_ops = {
--
2.26.2
