Merge tag 'for_v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
[linux-2.6-microblaze.git] / drivers / hv / hv.c
index f202ac7..e83507f 100644 (file)
 #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"
@@ -36,6 +37,42 @@ int hv_init(void)
        return 0;
 }
 
+/*
+ * Functions for allocating and freeing memory with size and
+ * alignment HV_HYP_PAGE_SIZE. These functions are needed because
+ * the guest page size may not be the same as the Hyper-V page
+ * size. We depend upon kmalloc() aligning power-of-two size
+ * allocations to the allocation size boundary, so that the
+ * allocated memory appears to Hyper-V as a page of the size
+ * it expects.
+ */
+
+void *hv_alloc_hyperv_page(void)
+{
+       BUILD_BUG_ON(PAGE_SIZE <  HV_HYP_PAGE_SIZE);
+
+       if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+               return (void *)__get_free_page(GFP_KERNEL);
+       else
+               return kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+}
+
+void *hv_alloc_hyperv_zeroed_page(void)
+{
+       if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+               return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+       else
+               return kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
+}
+
+void hv_free_hyperv_page(unsigned long addr)
+{
+       if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
+               free_page(addr);
+       else
+               kfree((void *)addr);
+}
+
 /*
  * hv_post_message - Post a message using the hypervisor message IPC.
  *
@@ -68,7 +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)
@@ -162,34 +199,48 @@ void hv_synic_enable_regs(unsigned int cpu)
        union hv_synic_scontrol sctrl;
 
        /* Setup the Synic's message page */
-       hv_get_simp(simp.as_uint64);
+       simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
        simp.simp_enabled = 1;
        simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
                >> HV_HYP_PAGE_SHIFT;
 
-       hv_set_simp(simp.as_uint64);
+       hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
 
        /* Setup the Synic's event page */
-       hv_get_siefp(siefp.as_uint64);
+       siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
        siefp.siefp_enabled = 1;
        siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
                >> HV_HYP_PAGE_SHIFT;
 
-       hv_set_siefp(siefp.as_uint64);
+       hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
        /* Setup the shared SINT. */
-       hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+       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();
-       hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+
+       /*
+        * 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);
 
        /* Enable the global synic bit */
-       hv_get_synic_state(sctrl.as_uint64);
+       sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
        sctrl.enable = 1;
 
-       hv_set_synic_state(sctrl.as_uint64);
+       hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
 }
 
 int hv_synic_init(unsigned int cpu)
@@ -211,30 +262,71 @@ void hv_synic_disable_regs(unsigned int cpu)
        union hv_synic_siefp siefp;
        union hv_synic_scontrol sctrl;
 
-       hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+       shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
+                                       VMBUS_MESSAGE_SINT);
 
        shared_sint.masked = 1;
 
        /* Need to correctly cleanup in the case of SMP!!! */
        /* Disable the interrupt */
-       hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+       hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
+                               shared_sint.as_uint64);
 
-       hv_get_simp(simp.as_uint64);
+       simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
        simp.simp_enabled = 0;
        simp.base_simp_gpa = 0;
 
-       hv_set_simp(simp.as_uint64);
+       hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
 
-       hv_get_siefp(siefp.as_uint64);
+       siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
        siefp.siefp_enabled = 0;
        siefp.base_siefp_gpa = 0;
 
-       hv_set_siefp(siefp.as_uint64);
+       hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
 
        /* Disable the global synic bit */
-       hv_get_synic_state(sctrl.as_uint64);
+       sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
        sctrl.enable = 0;
-       hv_set_synic_state(sctrl.as_uint64);
+       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)
@@ -242,6 +334,9 @@ 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
@@ -249,8 +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;
 
        /*
@@ -277,9 +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);