From patchwork Wed Sep 26 21:50:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: stuart hayes X-Patchwork-Id: 10616921 X-Patchwork-Delegate: andy.shevchenko@gmail.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C159D913 for ; Wed, 26 Sep 2018 21:51:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B17912B89B for ; Wed, 26 Sep 2018 21:51:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A4A292B8A6; Wed, 26 Sep 2018 21:51:05 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04AF52B88F for ; Wed, 26 Sep 2018 21:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726650AbeI0EFj (ORCPT ); Thu, 27 Sep 2018 00:05:39 -0400 Received: from mail-ot1-f67.google.com ([209.85.210.67]:36502 "EHLO mail-ot1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726598AbeI0EFj (ORCPT ); Thu, 27 Sep 2018 00:05:39 -0400 Received: by mail-ot1-f67.google.com with SMTP id c18-v6so540827otm.3; Wed, 26 Sep 2018 14:50:39 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=s01L8+2N42mmy3/Sl6zdwx55us58oM8Y2Fl8Ftqtldc=; b=G2cAuQDLp1vF5bQ79kXgDtXPmk9dzw5IG9o74ueyH6zjDCGlw4Zjvi479i5G0cJC9C swNwFGx+hFBH/fzlayKJg8t2piZPjr2DyAQYAgpk8nsosH3UJQZiFw2SyGJGLH1jDYTC eAUcVpRp87WqDYRAAoTO+3OpvOCufSUtD8BmVZUHvx3g/XNqIpGEeRYvO/dRYNsFEunl fmYxnzGp76vqbcWhx4lZ6jtd3wGw2bnkm4MTAGyPdltE8HSD2P50ICSoz7DVt07lelrN fRtqUYAxkp0UyPRHy7AWK7SnncpKDkOznYnDzYEF6MAys1rsag9SfDZbQSo/h7OVdgAD h1CQ== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=s01L8+2N42mmy3/Sl6zdwx55us58oM8Y2Fl8Ftqtldc=; b=byuYjawOxQxN0aCsEnSz4/xx/fQbDVsPRk/9LDzY6SuZBLWP3XmcVraL5TRlYoxRvw Sdh83sVEJ1FP2lKT27fex1agCiNmJRJcJENSPaXRMHzp00e4RgilTu9NtrzkFg1Ko5MF XqF9aTFGu1qtUEX5uHiYNH7979RHqCWZGEn5p9SBXlrq9lQwtUOsvm7crlnyIPhtfe1X waMUCzHUccX6x8j30t+rXpwo+xwHD60DsuWU2XO7va/2syuZ76FK62Bvadc1xGGFUVth 1gO5QFC7HtauoZ5NHx5VrWnV6IWZWCj1u0zZhGzTpu/Jx+rMzhjExNOxgGxmCBsVeG2y sAPw== X-Gm-Message-State: ABuFfohG8y1HZef36naVtrGJwHVfqwMM7cUsL7juhqErViA4vR0GYd4F tKZDLETNZJfTyPSpQQBYHM4= X-Google-Smtp-Source: ACcGV625g6VvYypF+aXMRqWxX0hYIwzsu0iyb+I8Cq2QCquTsHLj1483FGHUIZkmsHbWZOirtbd0Xg== X-Received: by 2002:a9d:4384:: with SMTP id t4-v6mr3047028ote.336.1537998638614; Wed, 26 Sep 2018 14:50:38 -0700 (PDT) Received: from localhost.localdomain ([143.166.81.254]) by smtp.gmail.com with ESMTPSA id b124-v6sm95121oii.14.2018.09.26.14.50.37 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 26 Sep 2018 14:50:37 -0700 (PDT) From: Stuart Hayes To: dvhart@infradead.org, Andy Shevchenko Cc: Mario Limonciello , LKML , platform-driver-x86@vger.kernel.org, Doug Warzecha , Stuart Hayes Subject: [PATCH v2 2/5] firmware: dcdbas: Add support for WSMT ACPI table Date: Wed, 26 Sep 2018 16:50:18 -0500 Message-Id: <20180926215021.30471-3-stuart.w.hayes@gmail.com> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180926215021.30471-1-stuart.w.hayes@gmail.com> References: <20180926215021.30471-1-stuart.w.hayes@gmail.com> MIME-Version: 1.0 Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If the WSMT ACPI table is present and indicates that a fixed communication buffer should be used, use the firmware-specified buffer instead of allocating a buffer in memory for communications between the dcdbas driver and firmare. Signed-off-by: Stuart Hayes --- This patch has been discussed previously, see history at https://lore.kernel.org/patchwork/patch/958893/ drivers/firmware/dcdbas.c | 123 ++++++++++++++++++++++++++++++++++++-- drivers/firmware/dcdbas.h | 10 ++++ 2 files changed, 127 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c index 0bdea60c65dd..ae28e48ff7dc 100644 --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -21,6 +21,7 @@ */ #include +#include #include #include #include @@ -41,7 +42,7 @@ #include "dcdbas.h" #define DRIVER_NAME "dcdbas" -#define DRIVER_VERSION "5.6.0-3.2" +#define DRIVER_VERSION "5.6.0-3.3" #define DRIVER_DESCRIPTION "Dell Systems Management Base Driver" static struct platform_device *dcdbas_pdev; @@ -49,19 +50,23 @@ static struct platform_device *dcdbas_pdev; static u8 *smi_data_buf; static dma_addr_t smi_data_buf_handle; 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 unsigned int host_control_action; static unsigned int host_control_smi_type; static unsigned int host_control_on_shutdown; +static bool wsmt_enabled; + /** * smi_data_buf_free: free SMI data buffer */ static void smi_data_buf_free(void) { - if (!smi_data_buf) + if (!smi_data_buf || wsmt_enabled) return; dev_dbg(&dcdbas_pdev->dev, "%s: phys: %x size: %lu\n", @@ -86,7 +91,7 @@ static int smi_data_buf_realloc(unsigned long size) if (smi_data_buf_size >= size) return 0; - if (size > MAX_SMI_DATA_BUF_SIZE) + if (size > max_smi_data_buf_size) return -EINVAL; /* new buffer is needed */ @@ -169,7 +174,7 @@ static ssize_t smi_data_write(struct file *filp, struct kobject *kobj, { ssize_t ret; - if ((pos + count) > MAX_SMI_DATA_BUF_SIZE) + if ((pos + count) > max_smi_data_buf_size) return -EINVAL; mutex_lock(&smi_data_lock); @@ -322,8 +327,20 @@ static ssize_t smi_request_store(struct device *dev, ret = count; break; case 1: - /* Calling Interface SMI */ - smi_cmd->ebx = (u32) virt_to_phys(smi_cmd->command_buffer); + /* + * Calling Interface SMI + * + * Provide physical address of command buffer field within + * the struct smi_cmd to BIOS. + * + * Because the address that smi_cmd (smi_data_buf) points to + * will be from memremap() of a non-memory address if WSMT + * is present, we can't use virt_to_phys() on smi_cmd, so + * we have to use the physical address that was saved when + * the virtual address for smi_cmd was received. + */ + smi_cmd->ebx = smi_data_buf_phys_addr + + offsetof(struct smi_cmd, command_buffer); ret = dcdbas_smi_request(smi_cmd); if (!ret) ret = count; @@ -482,6 +499,93 @@ static void dcdbas_host_control(void) } } +/* WSMT */ + +static u8 checksum(u8 *buffer, u8 length) +{ + u8 sum = 0; + u8 *end = buffer + length; + + while (buffer < end) + sum += *buffer++; + return sum; +} + +static inline struct smm_eps_table *check_eps_table(u8 *addr) +{ + struct smm_eps_table *eps = (struct smm_eps_table *)addr; + + if (strncmp(eps->smm_comm_buff_anchor, SMM_EPS_SIG, 4) != 0) + return NULL; + + if (checksum(addr, eps->length) != 0) + return NULL; + + return eps; +} + +static int dcdbas_check_wsmt(void) +{ + struct acpi_table_wsmt *wsmt = NULL; + struct smm_eps_table *eps = NULL; + u64 remap_size; + u8 *addr; + + acpi_get_table(ACPI_SIG_WSMT, 0, (struct acpi_table_header **)&wsmt); + if (!wsmt) + return 0; + + /* Check if WSMT ACPI table shows that protection is enabled */ + if (!(wsmt->protection_flags & ACPI_WSMT_FIXED_COMM_BUFFERS) || + !(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION)) + return 0; + + /* Scan for EPS (entry point structure) */ + for (addr = (u8 *)__va(0xf0000); + addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table)); + addr += 16) { + eps = check_eps_table(addr); + if (eps) + break; + } + + if (!eps) { + dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no EPS found\n"); + return -ENODEV; + } + + /* + * 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"); + 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"); + 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_size = remap_size - 8; + max_smi_data_buf_size = smi_data_buf_size; + wsmt_enabled = true; + dev_info(&dcdbas_pdev->dev, + "WSMT found, using firmware-provided SMI buffer.\n"); + return 1; +} + /** * dcdbas_reboot_notify: handle reboot notification for host control */ @@ -548,6 +652,11 @@ static int dcdbas_probe(struct platform_device *dev) dcdbas_pdev = dev; + /* Check if ACPI WSMT table specifies protected SMI buffer address */ + error = dcdbas_check_wsmt(); + if (error < 0) + return error; + /* * BIOS SMI calls require buffer addresses be in 32-bit address space. * This is done by setting the DMA mask below. @@ -635,6 +744,8 @@ static void __exit dcdbas_exit(void) */ if (dcdbas_pdev) smi_data_buf_free(); + if (eps_buffer) + memunmap(eps_buffer); platform_device_unregister(dcdbas_pdev_reg); platform_driver_unregister(&dcdbas_driver); } diff --git a/drivers/firmware/dcdbas.h b/drivers/firmware/dcdbas.h index ca3cb0a54ab6..52729a494b00 100644 --- a/drivers/firmware/dcdbas.h +++ b/drivers/firmware/dcdbas.h @@ -53,6 +53,7 @@ #define EXPIRED_TIMER (0) #define SMI_CMD_MAGIC (0x534D4931) +#define SMM_EPS_SIG "$SCB" #define DCDBAS_DEV_ATTR_RW(_name) \ DEVICE_ATTR(_name,0600,_name##_show,_name##_store); @@ -103,5 +104,14 @@ struct apm_cmd { int dcdbas_smi_request(struct smi_cmd *smi_cmd); +struct smm_eps_table { + char smm_comm_buff_anchor[4]; + u8 length; + u8 checksum; + u8 version; + u64 smm_comm_buff_addr; + u64 num_of_4k_pages; +} __packed; + #endif /* _DCDBAS_H_ */