From patchwork Tue May 19 15:27:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: stuart hayes X-Patchwork-Id: 11558055 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F11F690 for ; Tue, 19 May 2020 15:27:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D699020809 for ; Tue, 19 May 2020 15:27:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rWVW9SWw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728994AbgESP1s (ORCPT ); Tue, 19 May 2020 11:27:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728778AbgESP1s (ORCPT ); Tue, 19 May 2020 11:27:48 -0400 Received: from mail-oi1-x243.google.com (mail-oi1-x243.google.com [IPv6:2607:f8b0:4864:20::243]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 027F9C08C5C0; Tue, 19 May 2020 08:27:47 -0700 (PDT) Received: by mail-oi1-x243.google.com with SMTP id o24so86749oic.0; Tue, 19 May 2020 08:27:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=RYbtw7YF74B1TP3f62w+MMm9AmH3T7TyQIzVADm4joc=; b=rWVW9SWwfu2ivOfML4vV88PpbtolLbU1Bt6z/GmKJYKvEr/IJAxC6A+Jan25TLv+67 f6IE5DHTZLO9gGFEuM+g3oHnVyHSJ/1mLnjUrYYjZXAPz9BWUue+vLouwKC8JwFv8lE+ xL0/DA4BFZAhctA7RjlV5tZSuNUaLhrxtuRqhK1yUPOYp6ErfW5gQDsQhUO0CmAWPi2Z lRHLTdU/LN8H/XKQdofqT8kMbuaGuRe9RWzMqzwGXf8vsOpikWH1l25S/9gJ0m6Du4nz fhUu0iIpQbgyQDF1hVuLP7njtWygXPhhp3G0cbKdGYkrIyXJBvOft96+Te4iOvLsZYuX hYSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=RYbtw7YF74B1TP3f62w+MMm9AmH3T7TyQIzVADm4joc=; b=sXL0PrAJxCM7+BbxgNi4MefqlLC08qc+twxmLDIf0B661TywSYp4L+7XrBhh6QMgkg LQkR+lI1PrtOGt2Fty0O+n2aeOt4UZlUWWj5InimJdbBEeD2qumJ3I3eVqme4IOSdBFa an4yDKu5a13Tu1+3+DfUZr0UwSnKeVclHWh1imgSQaBMv3VBWkZVbh8a8HFA18Mvt27s EPX9gQ1lVndue+LHdaSzs9GKga+EDy67AeiDPq6PF/SUHUPB51vka9rJ1ExkedLmtPfI CS7RM2cgQviWLfnB5xDrKFWOpu0iLxaXt0mTCCZNNAeWneDyYeNg3W5EYItJh0ex+5LH MC3w== X-Gm-Message-State: AOAM532EvI7uyqtq8aNo4gZl2fR8LQB1WU/iLw4mE1BV/WvvShvUhXvl zX0fHUKQiIY8f8w9SKEdY2Y= X-Google-Smtp-Source: ABdhPJztuxWSwe1B/C48Pk77y+JPvKe2hhPzs11LdWiec1uOOAS4b8PdoDnud6zWas21oN/OFnRQeg== X-Received: by 2002:aca:fc0c:: with SMTP id a12mr3784oii.50.1589902066973; Tue, 19 May 2020 08:27:46 -0700 (PDT) Received: from localhost.localdomain ([143.166.81.254]) by smtp.gmail.com with ESMTPSA id m63sm3858556otm.21.2020.05.19.08.27.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 May 2020 08:27:46 -0700 (PDT) From: Stuart Hayes To: Darren Hart , Andy Shevchenko , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Stuart Hayes Subject: [PATCH] dcdbas: Check SMBIOS for protected buffer address Date: Tue, 19 May 2020 11:27:33 -0400 Message-Id: <20200519152733.48689-1-stuart.w.hayes@gmail.com> X-Mailer: git-send-email 2.18.1 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org Add support for a new method for BIOS to provide the address and length of the protected SMI communication buffer, via SMBIOS OEM strings. Signed-off-by: Stuart Hayes --- drivers/platform/x86/dcdbas.c | 43 ++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/drivers/platform/x86/dcdbas.c b/drivers/platform/x86/dcdbas.c index 84f4cc839cc3..d513a59a5d47 100644 --- a/drivers/platform/x86/dcdbas.c +++ b/drivers/platform/x86/dcdbas.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -34,7 +35,7 @@ #include "dcdbas.h" #define DRIVER_NAME "dcdbas" -#define DRIVER_VERSION "5.6.0-3.3" +#define DRIVER_VERSION "5.6.0-3.4" #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver" static struct platform_device *dcdbas_pdev; @@ -45,7 +46,7 @@ static unsigned long smi_data_buf_size; static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE; static u32 smi_data_buf_phys_addr; static DEFINE_MUTEX(smi_data_lock); -static u8 *eps_buffer; +static u8 *bios_buffer; static unsigned int host_control_action; static unsigned int host_control_smi_type; @@ -518,8 +519,10 @@ static inline struct smm_eps_table *check_eps_table(u8 *addr) static int dcdbas_check_wsmt(void) { + const struct dmi_device *dev = NULL; struct acpi_table_wsmt *wsmt = NULL; struct smm_eps_table *eps = NULL; + u64 bios_buf_paddr; u64 remap_size; u8 *addr; @@ -532,6 +535,17 @@ static int dcdbas_check_wsmt(void) !(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION)) return 0; + /* + * BIOS could provide the address/size of the protected buffer + * in an SMBIOS string or in an EPS structure in 0xFxxxx. + */ + + /* Check SMBIOS for buffer address */ + while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev))) + if (sscanf(dev->name, "30[%16llx;%8llx]", &bios_buf_paddr, + &remap_size) == 2) + goto remap; + /* Scan for EPS (entry point structure) */ for (addr = (u8 *)__va(0xf0000); addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table)); @@ -542,34 +556,37 @@ static int dcdbas_check_wsmt(void) } if (!eps) { - dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no EPS found\n"); + dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no firmware buffer found\n"); return -ENODEV; } + bios_buf_paddr = eps->smm_comm_buff_addr; + remap_size = eps->num_of_4k_pages * PAGE_SIZE; +remap: /* * Get physical address of buffer and map to virtual address. * Table gives size in 4K pages, regardless of actual system page size. */ - if (upper_32_bits(eps->smm_comm_buff_addr + 8)) { - dev_warn(&dcdbas_pdev->dev, "found WSMT, but EPS buffer address is above 4GB\n"); + if (upper_32_bits(bios_buf_paddr + 8)) { + dev_warn(&dcdbas_pdev->dev, "found WSMT, but buffer address is above 4GB\n"); return -EINVAL; } /* * Limit remap size to MAX_SMI_DATA_BUF_SIZE + 8 (since the first 8 * bytes are used for a semaphore, not the data buffer itself). */ - remap_size = eps->num_of_4k_pages * PAGE_SIZE; if (remap_size > MAX_SMI_DATA_BUF_SIZE + 8) remap_size = MAX_SMI_DATA_BUF_SIZE + 8; - eps_buffer = memremap(eps->smm_comm_buff_addr, remap_size, MEMREMAP_WB); - if (!eps_buffer) { - dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map EPS buffer\n"); + + bios_buffer = memremap(bios_buf_paddr, remap_size, MEMREMAP_WB); + if (!bios_buffer) { + dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map buffer\n"); return -ENOMEM; } /* First 8 bytes is for a semaphore, not part of the smi_data_buf */ - smi_data_buf_phys_addr = eps->smm_comm_buff_addr + 8; - smi_data_buf = eps_buffer + 8; + smi_data_buf_phys_addr = bios_buf_paddr + 8; + smi_data_buf = bios_buffer + 8; smi_data_buf_size = remap_size - 8; max_smi_data_buf_size = smi_data_buf_size; wsmt_enabled = true; @@ -736,8 +753,8 @@ static void __exit dcdbas_exit(void) */ if (dcdbas_pdev) smi_data_buf_free(); - if (eps_buffer) - memunmap(eps_buffer); + if (bios_buffer) + memunmap(bios_buffer); platform_device_unregister(dcdbas_pdev_reg); platform_driver_unregister(&dcdbas_driver); }