[patch V2 43/44] x86/idt: Simplify alloc_intr_gate

Thomas Gleixner
2017-08-25T21:58:30Z

[-- Attachment #1: x86-idt--Simplify-alloc_intr_gate.patch --]
[-- Type: text/plain, Size: 2202 bytes --]

The only users of alloc_intr_gate() are hypervisors, which both check the
used_vectors bitmap whether they have allocated the gate already. Move that
check into alloc_intr_gate() and simplify the users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
---
arch/x86/kernel/cpu/mshyperv.c | 9 ++-------
arch/x86/kernel/idt.c | 6 +++---
drivers/xen/events/events_base.c | 6 ++----
3 files changed, 7 insertions(+), 14 deletions(-)

--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -59,13 +59,8 @@ void hyperv_vector_handler(struct pt_reg
void hv_setup_vmbus_irq(void (*handler)(void))
{
vmbus_handler = handler;
- /*
- * Setup the IDT for hypervisor callback. Prevent reallocation
- * at module reload.
- */
- if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
- alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
- hyperv_callback_vector);
+ /* Setup the IDT for hypervisor callback */
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, hyperv_callback_vector);
}

void hv_remove_vmbus_irq(void)
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -352,7 +352,7 @@ void set_intr_gate(unsigned int n, const

void alloc_intr_gate(unsigned int n, const void *addr)
{
- BUG_ON(test_bit(n, used_vectors) || n < FIRST_SYSTEM_VECTOR);
- set_bit(n, used_vectors);
- set_intr_gate(n, addr);
+ BUG_ON(n < FIRST_SYSTEM_VECTOR);
+ if (!test_and_set_bit(n, used_vectors))
+ set_intr_gate(n, addr);
}
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1653,10 +1653,8 @@ void xen_callback_vector(void)
return;
}
pr_info("Xen HVM callback vector for event delivery is enabled\n");
- /* in the restore case the vector has already been allocated */
- if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
- alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
- xen_hvm_callback_vector);
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
+ xen_hvm_callback_vector);
}
}
#else