From owner-freebsd-current@freebsd.org Sun Apr 30 01:02:32 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 2C4C5D4B3EE for ; Sun, 30 Apr 2017 01:02:32 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: from mail-ua0-x22e.google.com (mail-ua0-x22e.google.com [IPv6:2607:f8b0:400c:c08::22e]) (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 DA8501FC4; Sun, 30 Apr 2017 01:02:31 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: by mail-ua0-x22e.google.com with SMTP id 110so54262846uas.3; Sat, 29 Apr 2017 18:02:31 -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=/3jkVzrLazdhkGm5vHo7jaXdi7euqbZbtpIEW/F7Q64=; b=qC4Q416S8Z9szRpw6k5wHR68te5W8aRF8ie96Hmf29D9vnPiqIRv43RC6xrtongEA6 /0SIyVZiyUDm6IXB7G7tCvVTX6v58z4dFDRpVUDg8C4nSWmtmvzbKIfUzsyCK5JhxrjT M9QWTrk/eT2SYZWIZb+c0FgjvB5zNgvllFexHwZoVveVWVdBtjlju9Dzln3+jYTOLWWA Gcb70PME1ndlBr6bs+k2uh9+8Ov2zxfShtvdpq2Fgag8gUEccUeubx4Y6I/6bVtdrA+I lbJeZWAoAslf7BfZOI8xsIb7+c+4UhPwNS6PrmLqaczAPMIRGtIzppeL7sqbQulk3uOJ Pqzw== 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=/3jkVzrLazdhkGm5vHo7jaXdi7euqbZbtpIEW/F7Q64=; b=oWhKGklmqxxtczKBX+9eMheeigjZqAvTqb3rWoywyDYFR+gYE4qnGSnmWHfuHN/Klv H88wb3Mkb2aA2WrCbwFwaBB9At8ZYUQLCHbZDSICDIL4Eb7852H6zHaBExrHh/nWJqjo mPyAbFLRvnSWE/TdFAvScjHajYacBz9HaqWKLSqPZSMm3pTL78+OmeKQDea+n8v8SdAk R8Joeethcc3QUYPPAXbrpeaxlzpKDyeLruh8o6y9Sn9UESwuex1hybM2+uB1mErNpcwA kDSjboCwFScgHkOlHiP8ojQxIfMbuHwFN6DVfEEjTD+dVKsjEIIOLAU2BeDlnoOMpj7J CNLg== X-Gm-Message-State: AN3rC/50hFWGT2MQU5jdC5Zsq7+vYMS/c9blfjMlKFtria/Mzylmy2wx 09X8LC9mTo1u+J49ZFAiNr1QhckzKw== X-Received: by 10.176.16.85 with SMTP id g21mr10180461uab.77.1493514150927; Sat, 29 Apr 2017 18:02:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.176.80.97 with HTTP; Sat, 29 Apr 2017 18:02:30 -0700 (PDT) In-Reply-To: <1737882.TJdaAP1hO8@ralph.baldwin.cx> References: <3727893.2519smPuKm@ralph.baldwin.cx> <1737882.TJdaAP1hO8@ralph.baldwin.cx> From: Sepherosa Ziehau Date: Sun, 30 Apr 2017 09:02:30 +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: Sun, 30 Apr 2017 01:02:32 -0000 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. Thanks, sephe -- Tomorrow Will Never Die