powerpc/pseries/mobility: signal suspend cancellation to platform

If we're returning an error to user space, use H_VASI_SIGNAL to send a
cancellation request to the platform. This isn't strictly required but
it communicates that Linux will not attempt to complete the suspend,
which allows the various entities involved to promptly end the
operation in progress.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201207215200.1785968-14-nathanl@linux.ibm.com

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 5a3951626a9639f0b31efd3df50bcd76229d35b5..f234a7ed87aac8f1e88b1d06bd5487ad21acb569 100644 (file)
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -513,6 +513,35 @@ static int do_join(void *arg)
        return ret;
 }
 
+/*
+ * Abort reason code byte 0. We use only the 'Migrating partition' value.
+ */
+enum vasi_aborting_entity {
+       ORCHESTRATOR        = 1,
+       VSP_SOURCE          = 2,
+       PARTITION_FIRMWARE  = 3,
+       PLATFORM_FIRMWARE   = 4,
+       VSP_TARGET          = 5,
+       MIGRATING_PARTITION = 6,
+};
+
+static void pseries_cancel_migration(u64 handle, int err)
+{
+       u32 reason_code;
+       u32 detail;
+       u8 entity;
+       long hvrc;
+
+       entity = MIGRATING_PARTITION;
+       detail = abs(err) & 0xffffff;
+       reason_code = (entity << 24) | detail;
+
+       hvrc = plpar_hcall_norets(H_VASI_SIGNAL, handle,
+                                 H_VASI_SIGNAL_CANCEL, reason_code);
+       if (hvrc)
+               pr_err("H_VASI_SIGNAL error: %ld\n", hvrc);
+}
+
 static int pseries_migrate_partition(u64 handle)
 {
        atomic_t counter = ATOMIC_INIT(0);
@@ -525,6 +554,8 @@ static int pseries_migrate_partition(u64 handle)
        ret = stop_machine(do_join, &counter, cpu_online_mask);
        if (ret == 0)
                post_mobility_fixup();
+       else
+               pseries_cancel_migration(handle, ret);
 
        return ret;
 }