From patchwork Fri Jun 24 17:44:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 9197971 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1DB6E60754 for ; Fri, 24 Jun 2016 17:45:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F9182094F for ; Fri, 24 Jun 2016 17:45:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 00671284BB; Fri, 24 Jun 2016 17:45:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3BA342094F for ; Fri, 24 Jun 2016 17:45:10 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 89B581A1DF5; Fri, 24 Jun 2016 10:45:42 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by ml01.01.org (Postfix) with ESMTP id EFD501A1DF5 for ; Fri, 24 Jun 2016 10:45:40 -0700 (PDT) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 24 Jun 2016 10:45:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,522,1459839600"; d="scan'208";a="724570634" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.14]) by FMSMGA003.fm.intel.com with ESMTP; 24 Jun 2016 10:45:08 -0700 Subject: [PATCH] acpi, nfit: fix acpi_check_dsm() vs zero functions implemented From: Dan Williams To: linux-nvdimm@lists.01.org Date: Fri, 24 Jun 2016 10:44:25 -0700 Message-ID: <146679026571.24395.11569929364936343871.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.17.1-9-g687f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Xiao Guangrong , linux-acpi@vger.kernel.org, "Rafael J. Wysocki" , Len Brown Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP QEMU 2.6 implements nascent support for nvdimm DSMs. Depending on configuration it may only implement the function0 dsm to indicate that no other DSMs are available. Commit 31eca76ba2fc "nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism" breaks QEMU, but QEMU is spec compliant. Per the spec the way to indicate that no functions are supported is: If Function Index is zero, the return is a buffer containing one bit for each function index, starting with zero. Bit 0 indicates whether there is support for any functions other than function 0 for the specified UUID and Revision ID. If set to zero, no functions are supported (other than function zero) for the specified UUID and Revision ID. Update the nfit driver to determine the family (interface UUID) without requiring the implementation to define any other functions, i.e. short-circuit acpi_check_dsm() to succeed per the spec. The nfit driver appears to be the only user passing funcs==0 to acpi_check_dsm(), so this behavior change of the common routine should be limited to the probing done by the nfit driver. Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Jerry Hoemann Fixes: 31eca76ba2fc ("nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism") Reported-by: Xiao Guangrong Tested-by: Xiao Guangrong Signed-off-by: Dan Williams --- drivers/acpi/nfit.c | 6 +++--- drivers/acpi/utils.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c index 2215fc847fa9..32579a7b71d5 100644 --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -1131,11 +1131,11 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc, /* * Until standardization materializes we need to consider up to 3 - * different command sets. Note, that checking for function0 (bit0) - * tells us if any commands are reachable through this uuid. + * different command sets. Note, that checking for zero functions + * tells us if any commands might be reachable through this uuid. */ for (i = NVDIMM_FAMILY_INTEL; i <= NVDIMM_FAMILY_HPE2; i++) - if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 1)) + if (acpi_check_dsm(adev_dimm->handle, to_nfit_uuid(i), 1, 0)) break; /* limit the supported commands to those that are publicly documented */ diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c index 22c09952e177..b4de130f2d57 100644 --- a/drivers/acpi/utils.c +++ b/drivers/acpi/utils.c @@ -680,9 +680,6 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs) u64 mask = 0; union acpi_object *obj; - if (funcs == 0) - return false; - obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL); if (!obj) return false; @@ -695,6 +692,9 @@ bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, u64 rev, u64 funcs) mask |= (((u64)obj->buffer.pointer[i]) << (i * 8)); ACPI_FREE(obj); + if (funcs == 0) + return true; + /* * Bit 0 indicates whether there's support for any functions other than * function 0 for the specified UUID and revision.