Commit 9a6b1a17 authored by Dexuan Cui's avatar Dexuan Cui Committed by Wei Liu
Browse files

Drivers: hv: vmbus: Remove the per-CPU post_msg_page 



The post_msg_page was introduced in 2014 in
commit b29ef354 ("Drivers: hv: vmbus: Cleanup hv_post_message()")

Commit 68bb7bfb ("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: default avatarDexuan Cui <decui@microsoft.com>
Reviewed-by: default avatarJinank Jain <jinankjain@linux.microsoft.com>
Link: https://lore.kernel.org/r/20230408213441.15472-1-decui@microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent c0e96acf

drivers/hv/hv.c

+5 −15
Original line number Diff line number Diff line
@@ -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);

drivers/hv/hyperv_vmbus.h

+0 −4
Original line number Diff line number Diff line
@@ -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;