Reviewed-by: Jinank Jain <jinankjain@xxxxxxxxxxxxxxxxxxx>
On 4/9/2023 3:04 AM, Dexuan Cui wrote:
The post_msg_page was introduced in 2014 in
commit b29ef3546aec ("Drivers: hv: vmbus: Cleanup hv_post_message()")
Commit 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments") introduced
the hyperv_pcpu_input_arg in 2018, which can be used in hv_post_message().
Remove post_msg_page to simplify the code a little bit.
Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---
drivers/hv/hv.c | 20 +++++---------------
drivers/hv/hyperv_vmbus.h | 4 ----
2 files changed, 5 insertions(+), 19 deletions(-)
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 8b0dd8e5244d7..30bf122a502ae 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -84,14 +84,15 @@ int hv_post_message(union hv_connection_id connection_id,
void *payload, size_t payload_size)
{
struct hv_input_post_message *aligned_msg;
- struct hv_per_cpu_context *hv_cpu;
+ unsigned long flags;
u64 status;
if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
return -EMSGSIZE;
- hv_cpu = get_cpu_ptr(hv_context.cpu_context);
- aligned_msg = hv_cpu->post_msg_page;
+ local_irq_save(flags);
+
+ aligned_msg = *this_cpu_ptr(hyperv_pcpu_input_arg);
aligned_msg->connectionid = connection_id;
aligned_msg->reserved = 0;
aligned_msg->message_type = message_type;
@@ -106,11 +107,7 @@ int hv_post_message(union hv_connection_id connection_id,
status = hv_do_hypercall(HVCALL_POST_MESSAGE,
aligned_msg, NULL);
- /* Preemption must remain disabled until after the hypercall
- * so some other thread can't get scheduled onto this cpu and
- * corrupt the per-cpu post_msg_page
- */
- put_cpu_ptr(hv_cpu);
+ local_irq_restore(flags);
return hv_result(status);
}
@@ -162,12 +159,6 @@ int hv_synic_alloc(void)
goto err;
}
}
-
- hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
- if (hv_cpu->post_msg_page == NULL) {
- pr_err("Unable to allocate post msg page\n");
- goto err;
- }
}
return 0;
@@ -190,7 +181,6 @@ void hv_synic_free(void)
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
- free_page((unsigned long)hv_cpu->post_msg_page);
}
kfree(hv_context.hv_numa_map);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index dc673edf053c3..d8322049ecd08 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -122,10 +122,6 @@ enum {
struct hv_per_cpu_context {
void *synic_message_page;
void *synic_event_page;
- /*
- * buffer to post messages to the host.
- */
- void *post_msg_page;
/*
* Starting with win8, we can take channel interrupts on any CPU;
