From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FBA3C76196 for ; Mon, 10 Apr 2023 04:29:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229526AbjDJE3C (ORCPT ); Mon, 10 Apr 2023 00:29:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbjDJE3A (ORCPT ); Mon, 10 Apr 2023 00:29:00 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 34E8F3C28; Sun, 9 Apr 2023 21:28:59 -0700 (PDT) Received: from [10.156.156.87] (unknown [167.220.238.23]) by linux.microsoft.com (Postfix) with ESMTPSA id 8E266213C158; Sun, 9 Apr 2023 21:28:56 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8E266213C158 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1681100938; bh=9Moh8CG8b4PgnpEyV4D2wg4ZRKVsMVbyR2eo8f0Fhhk=; h=Date:Subject:To:References:From:In-Reply-To:From; b=eXSFBfAd+xLmbZ9Hl1xU3Ls9cyUnxYiovoxiv6a/yz7eXVm8pNgyOENRUCLKYfW17 QxUoasX99h1U5uGfnlCqlGANpUD7wk2KKsk/HBXEmFFP/5X6Rzf+jHbuvT3xY3LMGE fk1v1pL8Tf5xszYEbrcIShqlHyj/072QIkceLdIs= Message-ID: Date: Mon, 10 Apr 2023 09:58:54 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH] Drivers: hv: vmbus: Remove the per-CPU post_msg_page Content-Language: en-US To: Dexuan Cui , kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com References: <20230408213441.15472-1-decui@microsoft.com> From: Jinank Jain In-Reply-To: <20230408213441.15472-1-decui@microsoft.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reviewed-by: Jinank Jain 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 > --- > 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;