lkml.org 
[lkml]   [2023]   [Apr]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] Drivers: hv: vmbus: Remove the per-CPU post_msg_page
From
Reviewed-by: Jinank Jain <jinankjain@linux.microsoft.com>

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@microsoft.com>
> ---
> 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;

\
 
 \ /
  Last update: 2023-04-10 06:29    [W:0.068 / U:0.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site