From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F2F9C6778C for ; Tue, 3 Jul 2018 16:20:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4481123ECE for ; Tue, 3 Jul 2018 16:20:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oYJU76VG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4481123ECE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933878AbeGCQU3 (ORCPT ); Tue, 3 Jul 2018 12:20:29 -0400 Received: from mail-oi0-f65.google.com ([209.85.218.65]:35826 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933569AbeGCQUZ (ORCPT ); Tue, 3 Jul 2018 12:20:25 -0400 Received: by mail-oi0-f65.google.com with SMTP id i12-v6so4972174oik.2; Tue, 03 Jul 2018 09:20:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=zsgypG04OW6kcYuDEeplrtJIK66q56vyi8ZE06TomNM=; b=oYJU76VGOUofJ9/KvNrZeU9A8xHAwAkjneQ1rGDCRTfIIeKGZEnVkzkAGHDW89717O YsM/BJGXeTJ7dpOFPZpZCap2Gt2vYx5nhIrZqmG1ZRN3BMZJmqrdfg51W3XZxal3cLkQ Swn2EM5lhB/fQd/HIi0cYXtD9A2FHbMqJL4R3MDudublaZoXh3z45PGFcc1lL4aGlAWH CQbwJY539INz45DDJdrwiGRErJla1MYl/1IQa89OOxXZ+uBuC9M9MIbkcQeS6Eh3lgdD XFOeCVTTbZ7IJGNVueVXVjrtnO3T3QMWpwVOqH8qGoXSP5tUXOWwQoisDNORi003WxIO KgiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=zsgypG04OW6kcYuDEeplrtJIK66q56vyi8ZE06TomNM=; b=ghjPQEzwx02KOqhRyUGr1jD1POPySjQxb8e2EAhZRYYPl67SYu1MCFdR2GVvP20azS ZkLJdwqn1C+dW4KIaS9Nvat6GdUhQ+bwZjJ6ftDpf9CGz+D5PcS5BjZUQyUNna6uqyIV i414hQHpdI66HkSL2U1DU4cdsNCFFYmEVEA7kOiWrcnx+8rvJdpJhGNP9n8lCsdviMOC r/bJ+vL0iNLQmSV75zRWMwrcAXW/kfkGvzr8pH1cbxoYV9yraaaSmxcv7RRviURuNReg bbFo5wNCW9bCxQkhyUrEG8EfN46PCIKC9SKy650uTDdX2GF5ebwwytHkmLxLf7QWAcjH xzWg== X-Gm-Message-State: APt69E3hFXQDWtIldwwstaZsMARSdU5ijlHmpILVhWszScXElRTJtCcv IsGm/GyNo/5xzQ+KruijcpFAubtH X-Google-Smtp-Source: AAOMgpetCILNp77lzoFBTkRsPf04Okd0i1DaNKiDJTJm9xIB4xk/HC7q9ZKvV2iH0By5AmpZzSZwug== X-Received: by 2002:aca:3507:: with SMTP id c7-v6mr5996959oia.46.1530634824813; Tue, 03 Jul 2018 09:20:24 -0700 (PDT) Received: from [192.168.0.2] (cpe-70-124-142-160.austin.res.rr.com. [70.124.142.160]) by smtp.gmail.com with ESMTPSA id w62-v6sm641936otb.0.2018.07.03.09.20.23 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Jul 2018 09:20:23 -0700 (PDT) Subject: [PATCH v5] dcdbas: Add support for WSMT ACPI table To: Mario.Limonciello@dell.com, andy.shevchenko@gmail.com Cc: dvhart@infradead.org, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org References: <45b8bde6-aaa8-3f3f-0528-81e5e931751c@gmail.com> <20180609010420.GA112645@localhost.localdomain> <8307f1e0-c480-3f78-9327-e248208e5349@gmail.com> <367a12e9-7d10-98e4-4791-69cdc7d01129@gmail.com> <73c53c23c0824e4595292bfafc6054ee@ausx13mpc120.AMER.DELL.COM> From: Stuart Hayes Message-ID: <4e26f407-58c0-09b6-6735-f004d5e86969@gmail.com> Date: Tue, 3 Jul 2018 11:20:21 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <73c53c23c0824e4595292bfafc6054ee@ausx13mpc120.AMER.DELL.COM> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Antivirus: Avast (VPS 180703-2, 07/03/2018), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- v2 Bumped driver version to 5.6.0-3.3 v3 Removed dependency on ACPI in Kconfig Moved the added #include to be in alphabetical order Added comments in smi_request_store() Simplified checksum code Changed loop searching 0xf0000 to be more readable Reworked calculation of remap_size & smi_data_buf_size v4 Fixed comment that starts with "Calling Interface SMI" Fixed formatting of first "if" statement in dcdbas_check_wsmt() v5 Reworked comment that starts with "Calling Interface SMI" Changed EPS scanning loop to check every 16 bytes 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_ */ -- 2.14.2