Drivers: hv: vmbus: Move handling of VMbus interrupts

VMbus interrupts are most naturally modelled as per-cpu IRQs.  But
because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used.  Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception.  Do this
by incorporating standard Linux per-cpu IRQ allocation into the main VMbus
driver, and bypassing it in the x86/x64 exception case. For x86/x64,
special case code is retained under arch/x86, but no VMbus interrupt
handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

1 files changed, 4 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index e88bc296afca..41fd84a88783 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -60,23 +60,18 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
 	set_irq_regs(old_regs);
 }
 
-int hv_setup_vmbus_irq(int irq, void (*handler)(void))
+void hv_setup_vmbus_handler(void (*handler)(void))
 {
-	/*
-	 * The 'irq' argument is ignored on x86/x64 because a hard-coded
-	 * interrupt vector is used for Hyper-V interrupts.
-	 */
 	vmbus_handler = handler;
-	return 0;
 }
+EXPORT_SYMBOL_GPL(hv_setup_vmbus_handler);
 
-void hv_remove_vmbus_irq(void)
+void hv_remove_vmbus_handler(void)
 {
 	/* We have no way to deallocate the interrupt gate */
 	vmbus_handler = NULL;
 }
-EXPORT_SYMBOL_GPL(hv_setup_vmbus_irq);
-EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
+EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
 
 /*
  * Routines to do per-architecture handling of stimer0