From owner-freebsd-current@freebsd.org Tue May 2 03:28:38 2017 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 04904D58F93 for ; Tue, 2 May 2017 03:28:38 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: from mail-ua0-x235.google.com (mail-ua0-x235.google.com [IPv6:2607:f8b0:400c:c08::235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BC461252; Tue, 2 May 2017 03:28:37 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: by mail-ua0-x235.google.com with SMTP id e55so45637529uaa.2; Mon, 01 May 2017 20:28:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=4v2K/j6FeSMWC+plDczqTJm4QOnAe8GffsWZ/BvYeoo=; b=usio0RL4js+GyqO/nss88VoUssVL3yi0yBQaacvd7GQS3bYeSukVbL5P9cx7ff4q6w zD9HlfY8Iu0GyMoEF00Fj4WW7yjNMDk4GhiW3EV54m1EuZTejzHC6DnR1JiA/D9SBgwk iKiuwPbTZBeiKwQmyERvvYOL4GeMY1BFEowGnArnlPjngcCM73a7Qvd3q1MsTKk6loLK 8MWRfNIaWoJrdq09KS+wTQ7T/id8eiwYPMp8wqzYA+MZwL2AqmiubmTysPfzqjJ1OdWf pyC4nSQvNroX4ErdPaaZpICbHMoB096d0E4ywFiGObR1k2Yba6/ltuB7tpR2V4jpUl0f jg7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=4v2K/j6FeSMWC+plDczqTJm4QOnAe8GffsWZ/BvYeoo=; b=KsHAiSwfZn+H1UsEaX3ZQA0CQHGbTk+TygsySJSG63cFNQxmWbqN1HEfWbEEjRNksu 91fwbg2UUMnCSij+s57X9Xw8A2NBqI5NmQPHpvyG5YsbrAHkQcmups3tuS/2PLfSyWVM sNcnUwfdDrthdgTFQ0dA5DP43BToh2LskPXDn2UMzeUg3Wfr90NzNMawM7zTNvXfOt9m T50aiMvi4lVY88GN0Q3fODuM0vYWx6HL+dJxs8gxktZHVpoEgWNWnDssUnfSjv0K9uh5 1oFHHs4kxl0D0wKX5ilwdbI4ID1jwWs9TQYj2/oM+xOtyznumrQN22aLNfGQXiJWdqPE MAzQ== X-Gm-Message-State: AN3rC/79uT6GURXZlWQSg31J9plDlastQgCh37huzc+kFUZ/GdPfJ1vA PmKKYzbrNsXanqd8u4D1ETP/as1AIA== X-Received: by 10.159.48.144 with SMTP id j16mr2644160uab.131.1493695716229; Mon, 01 May 2017 20:28:36 -0700 (PDT) MIME-Version: 1.0 Received: by 10.176.76.43 with HTTP; Mon, 1 May 2017 20:28:35 -0700 (PDT) In-Reply-To: <6993108.fO6lomHkak@ralph.baldwin.cx> References: <1737882.TJdaAP1hO8@ralph.baldwin.cx> <6993108.fO6lomHkak@ralph.baldwin.cx> From: Sepherosa Ziehau Date: Tue, 2 May 2017 11:28:35 +0800 Message-ID: Subject: Re: Add support for ACPI Module Device ACPI0004? To: John Baldwin Cc: Dexuan Cui , "freebsd-current@freebsd.org" , Jung-uk Kim , Yanmin Qiao Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 May 2017 03:28:38 -0000 On Tue, May 2, 2017 at 12:25 AM, John Baldwin wrote: > On Sunday, April 30, 2017 09:02:30 AM Sepherosa Ziehau wrote: >> On Sat, Apr 29, 2017 at 12:01 AM, John Baldwin wrote: >> > On Friday, April 28, 2017 05:38:32 PM Sepherosa Ziehau wrote: >> >> On Thu, Apr 27, 2017 at 12:14 AM, John Baldwin wrote: >> >> > On Wednesday, April 26, 2017 09:18:48 AM Sepherosa Ziehau wrote: >> >> >> On Wed, Apr 26, 2017 at 4:36 AM, John Baldwin wrote: >> >> >> > On Thursday, April 20, 2017 02:29:30 AM Dexuan Cui wrote: >> >> >> >> > From: John Baldwin [mailto:jhb@freebsd.org] >> >> >> >> > Sent: Thursday, April 20, 2017 02:34 >> >> >> >> > > Can we add the support of "ACPI0004" with the below one-line change? >> >> >> >> > > >> >> >> >> > > acpi_sysres_probe(device_t dev) >> >> >> >> > > { >> >> >> >> > > - static char *sysres_ids[] = { "PNP0C01", "PNP0C02", NULL }; >> >> >> >> > > + static char *sysres_ids[] = { "PNP0C01", "PNP0C02", "ACPI0004", NULL }; >> >> >> >> > > >> >> >> >> > Hmm, so the role of C01 and C02 is to reserve system resources, though we >> >> >> >> > in turn allow any child of acpi0 to suballocate those ranges (since historically >> >> >> >> > c01 and c02 tend to allocate I/O ranges that are then used by things like the >> >> >> >> > EC, PS/2 keyboard controller, etc.). From my reading of ACPI0004 in the ACPI >> >> >> >> > 6.1 spec it's not quite clear that ACPI0004 is like that? In particular, it >> >> >> >> > seems that 004 should only allow direct children to suballocate? This >> >> >> >> > change might work, but it will allow more devices to allocate the ranges in >> >> >> >> > _CRS than otherwise. >> >> >> >> > >> >> >> >> > Do you have an acpidump from a guest system that contains an ACPI0004 >> >> >> >> > node that you can share? >> >> >> >> > >> >> >> >> > John Baldwin >> >> >> >> >> >> >> >> Hi John, >> >> >> >> Thanks for the help! >> >> >> >> >> >> >> >> Please see the attached file, which is got by >> >> >> >> "acpidump -dt | gzip -c9 > acpidump.dt.gz" >> >> >> >> >> >> >> >> In the dump, we can see the "ACPI0004" node (VMOD) is the parent of >> >> >> >> "VMBus" (VMBS). >> >> >> >> It looks the _CRS of ACPI0004 is dynamically generated. Though we can't >> >> >> >> see the length of the MMIO range in the dumped asl code, it does have >> >> >> >> a 512MB MMIO range [0xFE0000000, 0xFFFFFFFFF]. >> >> >> >> >> >> >> >> It looks FreeBSD can't detect ACPI0004 automatically. >> >> >> >> With the above one-line change, I can first find the child device >> >> >> >> acpi_sysresource0 of acpi0, then call AcpiWalkResources() to get >> >> >> >> the _CRS of acpi_sysresource0, i.e. the 512MB MMIO range. >> >> >> >> >> >> >> >> If you think we shouldn't touch acpi_sysresource0 here, I guess >> >> >> >> we can add a new small driver for ACPI0004, just like we added VMBus >> >> >> >> driver as a child device of acpi0? >> >> >> > >> >> >> > Hmmm, so looking at this, the "right" thing is probably to have a device >> >> >> > driver for the ACPI0004 device that parses its _CRS and then allows its >> >> >> > child devices to sub-allocate resources from the ranges in _CRS. However, >> >> >> > this would mean make VMBus be a child of the ACPI0004 device. Suppose >> >> >> > we called the ACPI0004 driver 'acpi_module' then the 'acpi_module0' device >> >> >> > would need to create a child device for all of its child devices. Right >> >> >> > now acpi0 also creates devices for them which is somewhat messy (acpi0 >> >> >> > creates child devices anywhere in its namespace that have a valid _HID). >> >> >> > You can find those duplicates and remove them during acpi_module0's attach >> >> >> > routine before creating its own child device_t devices. (We associate >> >> >> > a device_t with each Handle when creating device_t's for ACPI handles >> >> >> > which is how you can find the old device that is a direct child of acpi0 >> >> >> > so that it can be removed). >> >> >> >> >> >> The remove/reassociate vmbus part seems kinda "messy" to me. I'd just >> >> >> hook up a new acpi0004 driver, and let vmbus parse the _CRS like what >> >> >> we did to the hyper-v's pcib0. >> >> > >> >> > The acpi_pci driver used to do the remove/reassociate part. What acpi0 >> >> > should probably be doing is only creating device_t nodes for immediate >> >> > children. This would require an ACPI-aware isa0 for LPC devices below >> >> > the ISA bus in the ACPI namespace. We haven't done that in part because >> >> > BIOS vendors are not always consistent in placing LPC devices under an >> >> > ISA bus. However, you otherwise have no good way to find your parent >> >> > ACPI0004 device. You could perhaps find your ACPI handle, ask for its >> >> > parent handle, then ask for the device_t of that handle to find the >> >> > ACPI0004 device, but then you'd need to have all your bus_alloc_resource >> >> > calls go to that device, not your "real" parent of acpi0, which means >> >> > you can't use any of the standard bus_alloc_resource() methods like >> >> > bus_alloc_resource_any() but would have to manually use BUS_ALLOC_RESOURCE >> >> > with the ACPI0004 device as the explicit first argument. It is primarily >> >> > the ability to let ACPI0004's driver transparently intercept all the >> >> > resource allocation so it can manage that is the reason for "VMBus" >> >> > to be a child of ACPI0004 rather than its sibling. >> >> >> >> Well, there could be more then one ACPI0004 typed devices, which could >> >> not form a device tree for vmbus. >> > >> > Are you saing a vmbus would need resources from multiple ACPI0004 devices? >> >> ACPI0004 (and several other PNP ids, see dexuan's submission) is >> something just like the acpi_sysresource. Not directly related to the >> vmbus at all. > > In the acpidump, the "vmbus" device was a direct child of ACPI0004. This is > quite different from acpi_sysresource0 which can be in random places in the > namespace (sometimes it is off of isab0, sometimes it is a child of isab0 or > of _SB_), and thus devices that suballocate ranges it reserves (like ipmi0 > or acpi_ec0) are sometimes siblings, etc. That doesn't seem to be true for > ACPI004 as it is explicitly described as a container object. Thanks for the suggestion. We are reorganizing the tree. The original ACPI device (VMBUS) is left as a resource device, instead of moving it around. Thanks, sephe -- Tomorrow Will Never Die