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Diffstat (limited to 'drivers/hv/hv_common.c')
-rw-r--r--drivers/hv/hv_common.c48
1 files changed, 24 insertions, 24 deletions
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 64f9ceca887b..542a1d53b303 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -364,13 +364,20 @@ int hv_common_cpu_init(unsigned int cpu)
flags = irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL;
inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
- *inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
- if (!(*inputarg))
- return -ENOMEM;
- if (hv_root_partition) {
- outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
- *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+ /*
+ * hyperv_pcpu_input_arg and hyperv_pcpu_output_arg memory is already
+ * allocated if this CPU was previously online and then taken offline
+ */
+ if (!*inputarg) {
+ *inputarg = kmalloc(pgcount * HV_HYP_PAGE_SIZE, flags);
+ if (!(*inputarg))
+ return -ENOMEM;
+
+ if (hv_root_partition) {
+ outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
+ *outputarg = (char *)(*inputarg) + HV_HYP_PAGE_SIZE;
+ }
}
msr_vp_index = hv_get_register(HV_REGISTER_VP_INDEX);
@@ -385,24 +392,17 @@ int hv_common_cpu_init(unsigned int cpu)
int hv_common_cpu_die(unsigned int cpu)
{
- unsigned long flags;
- void **inputarg, **outputarg;
- void *mem;
-
- local_irq_save(flags);
-
- inputarg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
- mem = *inputarg;
- *inputarg = NULL;
-
- if (hv_root_partition) {
- outputarg = (void **)this_cpu_ptr(hyperv_pcpu_output_arg);
- *outputarg = NULL;
- }
-
- local_irq_restore(flags);
-
- kfree(mem);
+ /*
+ * The hyperv_pcpu_input_arg and hyperv_pcpu_output_arg memory
+ * is not freed when the CPU goes offline as the hyperv_pcpu_input_arg
+ * may be used by the Hyper-V vPCI driver in reassigning interrupts
+ * as part of the offlining process. The interrupt reassignment
+ * happens *after* the CPUHP_AP_HYPERV_ONLINE state has run and
+ * called this function.
+ *
+ * If a previously offlined CPU is brought back online again, the
+ * originally allocated memory is reused in hv_common_cpu_init().
+ */
return 0;
}