Merge tag 'regmap-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie...

[linux-2.6-microblaze.git] / drivers / hv / hv.c

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 0c1fa69..e83507f 100644 (file)
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -13,9 +13,10 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/hyperv.h>
-#include <linux/version.h>
 #include <linux/random.h>
 #include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
 #include <clocksource/hyperv_timer.h>
 #include <asm/mshyperv.h>
 #include "hyperv_vmbus.h"
@@ -104,7 +105,7 @@ int hv_post_message(union hv_connection_id connection_id,
         */
        put_cpu_ptr(hv_cpu);
 
-       return status & 0xFFFF;
+       return hv_result(status);
 }
 
 int hv_synic_alloc(void)
@@ -214,12 +215,24 @@ void hv_synic_enable_regs(unsigned int cpu)
        hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
        /* Setup the shared SINT. */
+       if (vmbus_irq != -1)
+               enable_percpu_irq(vmbus_irq, 0);
        shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
                                        VMBUS_MESSAGE_SINT);
 
-       shared_sint.vector = hv_get_vector();
+       shared_sint.vector = vmbus_interrupt;
        shared_sint.masked = false;
-       shared_sint.auto_eoi = hv_recommend_using_aeoi();
+
+       /*
+        * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
+        * it doesn't provide a recommendation flag and AEOI must be disabled.
+        */
+#ifdef HV_DEPRECATING_AEOI_RECOMMENDED
+       shared_sint.auto_eoi =
+                       !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
+#else
+       shared_sint.auto_eoi = 0;
+#endif
        hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
                                shared_sint.as_uint64);
 
@@ -275,14 +288,55 @@ void hv_synic_disable_regs(unsigned int cpu)
        sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
        sctrl.enable = 0;
        hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
+
+       if (vmbus_irq != -1)
+               disable_percpu_irq(vmbus_irq);
 }
 
+#define HV_MAX_TRIES 3
+/*
+ * Scan the event flags page of 'this' CPU looking for any bit that is set.  If we find one
+ * bit set, then wait for a few milliseconds.  Repeat these steps for a maximum of 3 times.
+ * Return 'true', if there is still any set bit after this operation; 'false', otherwise.
+ *
+ * If a bit is set, that means there is a pending channel interrupt.  The expectation is
+ * that the normal interrupt handling mechanism will find and process the channel interrupt
+ * "very soon", and in the process clear the bit.
+ */
+static bool hv_synic_event_pending(void)
+{
+       struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context);
+       union hv_synic_event_flags *event =
+               (union hv_synic_event_flags *)hv_cpu->synic_event_page + VMBUS_MESSAGE_SINT;
+       unsigned long *recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */
+       bool pending;
+       u32 relid;
+       int tries = 0;
+
+retry:
+       pending = false;
+       for_each_set_bit(relid, recv_int_page, HV_EVENT_FLAGS_COUNT) {
+               /* Special case - VMBus channel protocol messages */
+               if (relid == 0)
+                       continue;
+               pending = true;
+               break;
+       }
+       if (pending && tries++ < HV_MAX_TRIES) {
+               usleep_range(10000, 20000);
+               goto retry;
+       }
+       return pending;
+}
 
 int hv_synic_cleanup(unsigned int cpu)
 {
        struct vmbus_channel *channel, *sc;
        bool channel_found = false;
 
+       if (vmbus_connection.conn_state != CONNECTED)
+               goto always_cleanup;
+
        /*
         * Hyper-V does not provide a way to change the connect CPU once
         * it is set; we must prevent the connect CPU from going offline
@@ -290,8 +344,7 @@ int hv_synic_cleanup(unsigned int cpu)
         * path where the vmbus is already disconnected, the CPU must be
         * allowed to shut down.
         */
-       if (cpu == VMBUS_CONNECT_CPU &&
-           vmbus_connection.conn_state == CONNECTED)
+       if (cpu == VMBUS_CONNECT_CPU)
                return -EBUSY;
 
        /*
@@ -318,9 +371,21 @@ int hv_synic_cleanup(unsigned int cpu)
        }
        mutex_unlock(&vmbus_connection.channel_mutex);
 
-       if (channel_found && vmbus_connection.conn_state == CONNECTED)
+       if (channel_found)
+               return -EBUSY;
+
+       /*
+        * channel_found == false means that any channels that were previously
+        * assigned to the CPU have been reassigned elsewhere with a call of
+        * vmbus_send_modifychannel().  Scan the event flags page looking for
+        * bits that are set and waiting with a timeout for vmbus_chan_sched()
+        * to process such bits.  If bits are still set after this operation
+        * and VMBus is connected, fail the CPU offlining operation.
+        */
+       if (vmbus_proto_version >= VERSION_WIN10_V4_1 && hv_synic_event_pending())
                return -EBUSY;
 
+always_cleanup:
        hv_stimer_legacy_cleanup(cpu);
 
        hv_synic_disable_regs(cpu);