From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D1FE625484B; Tue, 11 Mar 2025 11:57:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741694224; cv=none; b=guDGY+qZ6OL4onX0NpDoFnGyTAYsqkuN1Hc39pQ8u/i+LeHBQ3n6a9RyvGW8hof85kzUki/758/i9pBRm7dXHmmNaI7WkQ7KJfoJNonCXv4kg1HunkS/mbq/73OtQPbOp0WibNqjg5N0jZM/UPM0fUxje7DW1E1AWwC57MR27Cc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741694224; c=relaxed/simple; bh=6tLKVC8o5+18lHdZOJWSNGcVwXUG7agr0bxrrZ3Ba5c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eRKE4dp41s1OI5sJ74ajO6da55mqTJRmEDD7ri8cZPg0kntd4Spgo1aWAHxfZ0YvZsni3/XZxiF1jrQBMnAN1GnW4fNCJwMNiLLJz9kNnVevC0Z12hofdZCtfudlunBvWZgT10G1YWXKZKqdGZ54QHnPHxSKEaF0u53IQRQQPSA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5455D152B; Tue, 11 Mar 2025 04:57:13 -0700 (PDT) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0FE553F673; Tue, 11 Mar 2025 04:57:00 -0700 (PDT) Date: Tue, 11 Mar 2025 11:56:58 +0000 From: Sudeep Holla To: "lihuisong (C)" Cc: , , Jassi Brar , Adam Young , Robbie King Subject: Re: [PATCH v2 07/13] mailbox: pcc: Always map the shared memory communication address Message-ID: References: <20250305-pcc_fixes_updates-v2-0-1b1822bc8746@arm.com> <20250305-pcc_fixes_updates-v2-7-1b1822bc8746@arm.com> <0552e10d-acde-33cd-7f9c-5d7b28fee735@huawei.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0552e10d-acde-33cd-7f9c-5d7b28fee735@huawei.com> On Tue, Mar 11, 2025 at 07:32:34PM +0800, lihuisong (C) wrote: > > 在 2025/3/6 0:38, Sudeep Holla 写道: > > Currently the shared memory communication address was mapped by the > > mailbox client drivers leading to all sorts of inconsistencies. > > > > It also has resulted in the inconsistent attributes used while mapping > > the shared memory regions. > > > > In order to remove/eliminate any issues, let us ensures the shared > > memory address is always mapped and unmapped when the PCC channels are > > requested and release. > > > > We need to map them as the ACPI PCCT associates these shared memory > > with each channel subspace and may need use the status or the flags in > > the headers of those shared memory communication address regions to > > manage the transport/channel. > > > > Since there are no users of pcc_chan_ioremap() and also it is mapped > > by default, we can stop exporting it and merge the functionality into > > pcc_mbox_request_channel(). > There are two ioremap for the existing mbox client driver after this patch. > The existing mbox client driver would not use this variable, and no one else > uses it. So it is safe, right? IIUC yes, it should be fine. > Do we need to make a statement that the two iommaps have no impact on the > existing mbox client drivers? We can add one, but again it will be become obsolete once we change driver to use this new mapping. That's why I didn't add it. We can merge all the changes together if that is the concern. I am fine either way. Thanks a lot for all the review and testing. -- Regards, Sudeep