From patchwork Tue Jan 20 09:29:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanjun Guo X-Patchwork-Id: 5666611 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id CEEFCC058D for ; Tue, 20 Jan 2015 09:32:15 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4C7A7203AF for ; Tue, 20 Jan 2015 09:32:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A9F32203AE for ; Tue, 20 Jan 2015 09:32:12 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YDV8S-0001LQ-Cr; Tue, 20 Jan 2015 09:30:08 +0000 Received: from mail-pa0-f49.google.com ([209.85.220.49]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YDV8N-0000Or-7q for linux-arm-kernel@lists.infradead.org; Tue, 20 Jan 2015 09:30:04 +0000 Received: by mail-pa0-f49.google.com with SMTP id hz1so13910067pad.8 for ; Tue, 20 Jan 2015 01:29:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=qpQpqWwpYlvkNzP0mSv4dm2nkxY5XOyeqEkKr0wK35Y=; b=ZlvTWUTY8NunRWQoyqmlpRlhiLYJxzxFg/AOV37O1GfXaMdCdCIA2x4tGE9caRCI7W ydQv8+VawEx0efjFQw255P2I37zZ2KbTEH69R1NecDp2X4XVk5U0PzkurOsiN2+oBTdp JkCiKLlIcrkyYcWGWj3OXBXVBvpvPWZhRbOZNvmo4M3MDpR0CjDCh5NAIeCVBsnUIQNW AVbIJGt/9cq26RmgBOR36/pwkVyyEL0v2HvKP2MXgWILKNpCXHAtk5i2BkGkRko/ODo2 DQ4skbSC1xOyfeOPY4cst8duQvgAGnL1Y/iYzUsiyWpWww95GAGetKrJWw/F/CAVtp/t OtZg== X-Gm-Message-State: ALoCoQkVerFPJIWABVoCnveqGNT9lnJ99bPr13otlPullQjffiHQ0kRWz/2V4tUr/MNQg87307uj X-Received: by 10.68.134.134 with SMTP id pk6mr52705079pbb.146.1421746181491; Tue, 20 Jan 2015 01:29:41 -0800 (PST) Received: from [10.10.3.142] ([167.160.116.82]) by mx.google.com with ESMTPSA id c17sm14012227pdl.6.2015.01.20.01.29.23 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Jan 2015 01:29:40 -0800 (PST) Message-ID: <54BE1FEA.5040109@linaro.org> Date: Tue, 20 Jan 2015 17:29:14 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Mark Rutland , Catalin Marinas Subject: Re: [PATCH v7 04/17] ARM64 / ACPI: Introduce early_param for "acpi" and pass acpi=force to enable ACPI References: <1421247905-3749-1-git-send-email-hanjun.guo@linaro.org> <1421247905-3749-5-git-send-email-hanjun.guo@linaro.org> <20150119114255.GF11835@e104818-lin.cambridge.arm.com> <20150119135144.GI11835@e104818-lin.cambridge.arm.com> <20150119151350.21B65C40948@trevor.secretlab.ca> <54BD3803.6020307@redhat.com> <20150119175233.GK11835@e104818-lin.cambridge.arm.com> <20150119180122.GJ21553@leverpostej> In-Reply-To: <20150119180122.GJ21553@leverpostej> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150120_013003_359469_1AB3178F X-CRM114-Status: GOOD ( 28.32 ) X-Spam-Score: -0.7 (/) Cc: "linaro-acpi@lists.linaro.org" , Will Deacon , "wangyijing@huawei.com" , Rob Herring , Lorenzo Pieralisi , Al Stone , Timur Tabi , "linux-acpi@vger.kernel.org" , "grant.likely@linaro.org" , Charles Garcia-Tobin , "phoenix.liyi@huawei.com" , Robert Richter , Jason Cooper , Arnd Bergmann , Marc Zyngier , "jcm@redhat.com" , Mark Brown , Bjorn Helgaas , "linux-arm-kernel@lists.infradead.org" , "graeme.gregory@linaro.org" , Ard Biesheuvel , Randy Dunlap , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , "suravee.suthikulpanit@amd.com" , Sudeep Holla , Olof Johansson X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 2015?01?20? 02:01, Mark Rutland wrote: > On Mon, Jan 19, 2015 at 05:52:33PM +0000, Catalin Marinas wrote: >> On Mon, Jan 19, 2015 at 04:59:47PM +0000, Jon Masters wrote: >>> On 01/19/2015 10:13 AM, Grant Likely wrote: >>>> On Mon, 19 Jan 2015 13:51:45 +0000 >>>> , Catalin Marinas >>>> wrote: >>>>> On Mon, Jan 19, 2015 at 11:55:32AM +0000, Ard Biesheuvel wrote: >>>>>> On 19 January 2015 at 11:42, Catalin Marinas wrote: >>>>>>> On Wed, Jan 14, 2015 at 03:04:52PM +0000, Hanjun Guo wrote: >>>>>>>> From: Al Stone >>>>>>>> >>>>>>>> Introduce one early parameters "off" and "force" for "acpi", acpi=off >>>>>>>> will be the default behavior for ARM64, so introduce acpi=force to >>>>>>>> enable ACPI on ARM64. >>>>>>>> >>>>>>>> Disable ACPI before early parameters parsed, and enable it to pass >>>>>>>> "acpi=force" if people want use ACPI on ARM64. This ensures DT be >>>>>>>> the prefer one if ACPI table and DT both are provided at this moment. >>>>>>> [...] >>>>>>>> --- a/arch/arm64/kernel/setup.c >>>>>>>> +++ b/arch/arm64/kernel/setup.c >>>>>>>> @@ -62,6 +62,7 @@ >>>>>>>> #include >>>>>>>> #include >>>>>>>> #include >>>>>>>> +#include >>>>>>>> >>>>>>>> unsigned int processor_id; >>>>>>>> EXPORT_SYMBOL(processor_id); >>>>>>>> @@ -388,6 +389,8 @@ void __init setup_arch(char **cmdline_p) >>>>>>>> early_fixmap_init(); >>>>>>>> early_ioremap_init(); >>>>>>>> >>>>>>>> + disable_acpi(); >>>>>>>> + >>>>>>>> parse_early_param(); >>>>>>>> >>>>>>>> /* >>>>>>> >>>>>>> Did we get to any conclusion here? DT being the preferred one is fine >>>>>>> when both DT and ACPI are present but do we still want the kernel to >>>>>>> ignore ACPI altogether if DT is not present? It's a bit harder to detect >>>>>>> the presence of DT at this point since the EFI_STUB added one already. I >>>>>>> guess we could move the "acpi=force" argument passing to EFI_STUB if no >>>>>>> DT is present at boot. >>>>>> >>>>>> Since the EFI stub populates the /chosen node in DT, I would prefer >>>>>> for it to add a property there to indicate whether it created the DT >>>>>> from scratch rather than adding ACPI specific stuff in there (even if >>>>>> it is just a string to concatenate) >>>>> >>>>> This works for me. So we could pass "acpi=force" in EFI stub if it >>>>> created the DT from scratch *and* ACPI tables are present (can it detect >>>>> the latter? And maybe it could print something if none are available). >>>>> If that works, the actual kernel can assume that ACPI needs to be >>>>> explicitly enabled via acpi=force, irrespective of how much information >>>>> it has in DT. >>>> >>>> Ditto for me. I think this is a fine solution. And, yes, the stub can >>>> easily detect the presence of ACPI by looking in the UEFI config table. >>> >>> I get the point behind doing this, but could we not have it pass in a >>> different parameter than =force? Perhaps something new? I'd like to >>> separate out the case that it was enabled automatically vs explicitly >>> forced on by a user wanting to use ACPI on a system with both tables. >> >> Ard had a point, so we should probably not pass acpi=force from EFI stub >> (especially since a user may explicitly pass acpi=off irrespective of DT >> presence). Some other property in the chosen node? It's not even an ABI >> since that's a contract between EFI stub and the rest of the kernel, so >> an in-kernel only interface. > > Not strictly true once kexec is in place. Then it becomes a stub -> > kernel -> kernel -> kernel -> ... interface, alnog with the rest of the > properties the stub puts in the DTB. > > Having something like /chosen/linux,uefi-stub-generated-dtb sounds sane > regardless. How about the patch (just RFC, maybe it is horrible :) ) below: When system supporting both DT and ACPI but firmware providing no dtb, we can use this linux,uefi-stub-generated-dtb property to let kernel know that we can try ACPI configuration data. Signed-off-by: Hanjun Guo --- Documentation/devicetree/bindings/chosen.txt | 19 ++++++++++++++++ arch/arm64/kernel/setup.c | 34 +++++++++++++++++++++++++++- drivers/firmware/efi/libstub/fdt.c | 6 +++++ 3 files changed, 58 insertions(+), 1 deletion(-) fdt_set_fail: diff --git a/Documentation/devicetree/bindings/chosen.txt b/Documentation/devicetree/bindings/chosen.txt index ed838f4..18776b9 100644 --- a/Documentation/devicetree/bindings/chosen.txt +++ b/Documentation/devicetree/bindings/chosen.txt @@ -44,3 +44,22 @@ Implementation note: Linux will look for the property "linux,stdout-path" or on PowerPC "stdout" if "stdout-path" is not found. However, the "linux,stdout-path" and "stdout" properties are deprecated. New platforms should only use the "stdout-path" property. + + +linux,uefi-stub-generated-dtb property +-------------------------------------- + +UEFI stub will generate this property in the chosen node to let linux kernel +know that there is no DTB provided by firmware. + +There is a use case for system supporting both DT and ACPI, when firmware +doesn't provide DT, we can try ACPI configration data to boot the system. + +Usage: + +linux,uefi-stub-generated-dtb = "true" means that it is true that the dtb +is generated by uefi stub + +or + +linux,uefi-stub-generated-dtb = "false" is the reverse. diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 54e39e3..8268c7b 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -371,6 +371,31 @@ static void __init request_standard_resources(void) } } +int __init dt_scan_chosen(unsigned long node, const char *uname, + int depth, void *data) +{ + const char *p; + + if (depth != 1 || !data || + (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) + return 0; + + p = of_get_flat_dt_prop(node, "linux,uefi-stub-generated-dtb", NULL); + if (!p && !strcmp(p, "true")) + *data = true; + + return 1; +} + +static bool __init is_uefi_stub_generated_dtb(void) +{ + bool flag = false; + + of_scan_flat_dt(dt_scan_chosen, &flag); + + return flag; +} + u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; void __init setup_arch(char **cmdline_p) @@ -389,7 +414,14 @@ void __init setup_arch(char **cmdline_p) early_fixmap_init(); early_ioremap_init(); - disable_acpi(); + /* + * If no dtb provided by firmware, enable ACPI + * and try to boot with ACPI configuration data + */ + if (is_uefi_stub_generated_dtb()) + enable_acpi(); + else + disable_acpi(); parse_early_param(); diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index c846a96..9e2084b 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -154,6 +154,12 @@ efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, if (status) goto fdt_set_fail; + /* Add a property to show the dtb is generated by uefi stub or not */ + status = fdt_setprop_string(fdt, node, "linux,uefi-stub-generated-dtb", + orig_fdt ? "false" : "true"); + if (status) + goto fdt_set_fail; + return EFI_SUCCESS;