[PATCH v7 08/10] Drivers: hv: vmbus: Add hooks for per-CPU IRQ

From: Michael Kelley <mikelley@microsoft.com>
To: will@kernel.org, ardb@kernel.org, arnd@arndb.de,
	catalin.marinas@arm.com, mark.rutland@arm.com, maz@kernel.org,
	linux-arm-kernel@lists.infradead.org, gregkh@linuxfoundation.org,
	linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-arch@vger.kernel.org,
	wei.liu@kernel.org, vkuznets@redhat.com, kys@microsoft.com
Cc: mikelley@microsoft.com, sunilmut@microsoft.com, boqun.feng@gmail.com
Subject: [PATCH v7 08/10] Drivers: hv: vmbus: Add hooks for per-CPU IRQ
Date: Mon, 24 Aug 2020 09:46:21 -0700	[thread overview]
Message-ID: <1598287583-71762-9-git-send-email-mikelley@microsoft.com> (raw)
In-Reply-To: <1598287583-71762-1-git-send-email-mikelley@microsoft.com>

Add hooks to enable/disable a per-CPU IRQ for VMbus. These hooks
are in the architecture independent setup and shutdown paths for
Hyper-V, and are needed by Linux guests on Hyper-V on ARM64.  The
x86/x64 implementation is null because VMbus interrupts on x86/x64
don't use an IRQ.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 arch/x86/include/asm/mshyperv.h | 4 ++++
 drivers/hv/hv.c                 | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index ffc2899..dd1365c 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -56,6 +56,10 @@ typedef int (*hyperv_fill_flush_list_func)(
 #define hv_get_raw_timer() rdtsc_ordered()
 #define hv_get_vector() HYPERVISOR_CALLBACK_VECTOR
 
+/* On x86/x64, there isn't a real IRQ to be enabled/disable */
+static inline void hv_enable_vmbus_irq(void) {}
+static inline void hv_disable_vmbus_irq(void) {}
+
 /*
  * Reference to pv_ops must be inline so objtool
  * detection of noinstr violations can work correctly.
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 2bd44fd..7499079 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -178,6 +178,7 @@ void hv_synic_enable_regs(unsigned int cpu)
 	hv_set_siefp(siefp.as_uint64);
 
 	/* Setup the shared SINT. */
+	hv_enable_vmbus_irq();
 	hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 
 	shared_sint.vector = hv_get_vector();
@@ -235,6 +236,8 @@ void hv_synic_disable_regs(unsigned int cpu)
 	hv_get_synic_state(sctrl.as_uint64);
 	sctrl.enable = 0;
 	hv_set_synic_state(sctrl.as_uint64);
+
+	hv_disable_vmbus_irq();
 }
 
 int hv_synic_cleanup(unsigned int cpu)
-- 
1.8.3.1

