[patch RFC 18/38] x86/irq: Initialize PCI/MSI domain at PCI init time

Thomas Gleixner
2020-08-21T02:19:31Z

[-- Attachment #1: x86-irq--Initialize-PCI-MSI-domain-at-PCI-init-time.patch --]
[-- Type: text/plain, Size: 4855 bytes --]

No point in initializing the default PCI/MSI interrupt domain early and no
point to create it when XEN PV/HVM/DOM0 are active.

Move the initialization to pci_arch_init() and convert it to init ops so
that XEN can override it as XEN has it's own PCI/MSI management. The XEN
override comes in a later step.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-pci@vger.kernel.org
---
arch/x86/include/asm/irqdomain.h | 6 ++++--
arch/x86/include/asm/x86_init.h | 3 +++
arch/x86/kernel/apic/msi.c | 26 ++++++++++++++++----------
arch/x86/kernel/apic/vector.c | 2 --
arch/x86/kernel/x86_init.c | 3 ++-
arch/x86/pci/init.c | 3 +++
6 files changed, 28 insertions(+), 15 deletions(-)

--- a/arch/x86/include/asm/irqdomain.h
+++ b/arch/x86/include/asm/irqdomain.h
@@ -51,9 +51,11 @@ extern int mp_irqdomain_ioapic_idx(struc
#endif /* CONFIG_X86_IO_APIC */

#ifdef CONFIG_PCI_MSI
-extern void arch_init_msi_domain(struct irq_domain *domain);
+void x86_create_pci_msi_domain(void);
+struct irq_domain *native_create_pci_msi_domain(void);
#else
-static inline void arch_init_msi_domain(struct irq_domain *domain) { }
+static inline void x86_create_pci_msi_domain(void) { }
+#define native_create_pci_msi_domain NULL
#endif

#endif
--- a/arch/x86/include/asm/x86_init.h
+++ b/arch/x86/include/asm/x86_init.h
@@ -8,6 +8,7 @@ struct mpc_bus;
struct mpc_cpu;
struct mpc_table;
struct cpuinfo_x86;
+struct irq_domain;

/**
* struct x86_init_mpparse - platform specific mpparse ops
@@ -42,12 +43,14 @@ struct x86_init_resources {
* @intr_init: interrupt init code
* @intr_mode_select: interrupt delivery mode selection
* @intr_mode_init: interrupt delivery mode setup
+ * @create_pci_msi_domain: Create the PCI/MSI interrupt domain
*/
struct x86_init_irqs {
void (*pre_vector_init)(void);
void (*intr_init)(void);
void (*intr_mode_select)(void);
void (*intr_mode_init)(void);
+ struct irq_domain *(*create_pci_msi_domain)(void);
};

/**
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -21,7 +21,7 @@
#include <asm/apic.h>
#include <asm/irq_remapping.h>

-static struct irq_domain *msi_default_domain;
+static struct irq_domain *x86_pci_msi_default_domain __ro_after_init;

static void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg)
{
@@ -192,7 +192,7 @@ int native_setup_msi_irqs(struct pci_dev

domain = irq_remapping_get_irq_domain(&info);
if (domain == NULL)
- domain = msi_default_domain;
+ domain = x86_pci_msi_default_domain;
if (domain == NULL)
return -ENOSYS;

@@ -243,25 +243,31 @@ static struct msi_domain_info pci_msi_do
.handler_name = "edge",
};

-void __init arch_init_msi_domain(struct irq_domain *parent)
+struct irq_domain * __init native_create_pci_msi_domain(void)
{
struct fwnode_handle *fn;
+ struct irq_domain *d;

if (disable_apic)
- return;
+ return NULL;

fn = irq_domain_alloc_named_fwnode("PCI-MSI");
if (fn) {
- msi_default_domain =
- pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
- parent);
+ d = pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
+ x86_vector_domain);
}
- if (!msi_default_domain) {
+ if (!d) {
irq_domain_free_fwnode(fn);
- pr_warn("failed to initialize irqdomain for MSI/MSI-x.\n");
+ pr_warn("Failed to initialize PCI-MSI irqdomain.\n");
} else {
- msi_default_domain->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
+ d->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
}
+ 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
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -713,8 +713,6 @@ int __init arch_early_irq_init(void)
BUG_ON(x86_vector_domain == NULL);
irq_set_default_host(x86_vector_domain);

- arch_init_msi_domain(x86_vector_domain);
-
BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));

/*
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -76,7 +76,8 @@ struct x86_init_ops x86_init __initdata
.pre_vector_init = init_ISA_irqs,
.intr_init = native_init_IRQ,
.intr_mode_select = apic_intr_mode_select,
- .intr_mode_init = apic_intr_mode_init
+ .intr_mode_init = apic_intr_mode_init,
+ .create_pci_msi_domain = native_create_pci_msi_domain,
},

.oem = {
--- a/arch/x86/pci/init.c
+++ b/arch/x86/pci/init.c
@@ -3,6 +3,7 @@
#include <linux/init.h>
#include <asm/pci_x86.h>
#include <asm/x86_init.h>
+#include <asm/irqdomain.h>

/* arch_initcall has too random ordering, so call the initializers
in the right sequence from here. */
@@ -10,6 +11,8 @@ static __init int pci_arch_init(void)
{
int type;

+ x86_create_pci_msi_domain();
+
type = pci_direct_probe();

if (!(pci_probe & PCI_PROBE_NOEARLY))