From owner-freebsd-current@freebsd.org Fri Apr 28 09:38:33 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 EDAF3D53ECA for ; Fri, 28 Apr 2017 09:38:33 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: from mail-vk0-x235.google.com (mail-vk0-x235.google.com [IPv6:2607:f8b0:400c:c05::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 A6FEBD33; Fri, 28 Apr 2017 09:38:33 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: by mail-vk0-x235.google.com with SMTP id o76so5336154vkc.2; Fri, 28 Apr 2017 02:38:33 -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=yMw7+yRe9p3FUWjSyRHytEmSK9Hl0JYDvCUSxfJrBTw=; b=FebpL6gVPsfw/Hx3kcc/yRV6brLA8bmecUr2Q/aRJoWbaW7gAGl2mqolh/ju/Yde8I 95G4nMv1/f8na2YNgm4siZBUZvvc6LzRw3b2wnyA3MGNAW/283GpvbV6TaMU5QwCA0ls FUYF7bupLluOSyNcDkjTzNuIQQJ6JAvJ/gElRNEGIfozWhaHdZr2eLu1UoMmam1oEGEi jsFQe/wwU7h7dOeCEeNnC6SE7NZ3MqAES/6pQLQ+0BJammCl1SClchwOD/+2sCYo5LXU wUTBPM/EfgR2vJ80CJ2s41olXo54z+22N885W6iJxKfjMDFkGSA8EfB2HilZAGf41QNp d61Q== 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=yMw7+yRe9p3FUWjSyRHytEmSK9Hl0JYDvCUSxfJrBTw=; b=WJCrbzUM4QScfBFoeQFpogzCifYNp7pSagy4Z8MdWaIYLgYLPfRWINdJhdd+MCt94G 3mpxd0XieMJXzcY49X2oizWN8Ovj6r1kIxK5OP4Y8kQ82Rbj1QBEdBAXHiUgZPQXjT3s rUffaRwr1b46mcEZLyK0jPaEJZbmIe2XuoBYOYC+EswmTdxfQx2TKme9ngwmwLVaou4N XluabdCGnYp1Zp+qhMOCOemhCpVOjhsAezp2EjggbNZ+6xr2Pb/LzhHcZoPvqXRfMAGP ENeSH/ald05jCloTludRYkogvIf7PloKQNiEhykLNlWBK7oVmdDL1nkD5I3xZb6BT1He 2/Gg== X-Gm-Message-State: AN3rC/5m7NnblPXSwM5MnKV+5l3DQVLkogO45//iyDqM5gH/vUi4O3tx Sdwllm0fvw73GQP1gkRzxVC7Shb2IA== X-Received: by 10.31.79.131 with SMTP id d125mr5096298vkb.89.1493372312632; Fri, 28 Apr 2017 02:38:32 -0700 (PDT) MIME-Version: 1.0 Received: by 10.176.80.97 with HTTP; Fri, 28 Apr 2017 02:38:32 -0700 (PDT) In-Reply-To: <3727893.2519smPuKm@ralph.baldwin.cx> References: <5144516.9adee9646c@ralph.baldwin.cx> <3727893.2519smPuKm@ralph.baldwin.cx> From: Sepherosa Ziehau Date: Fri, 28 Apr 2017 17:38:32 +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: Fri, 28 Apr 2017 09:38:34 -0000 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. Thanks, sephe -- Tomorrow Will Never Die