From patchwork Thu Feb 18 17:45:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Auger Eric X-Patchwork-Id: 62222 Delivered-To: patches@linaro.org Received: by 10.112.43.199 with SMTP id y7csp721242lbl; Thu, 18 Feb 2016 09:45:59 -0800 (PST) X-Received: by 10.28.97.135 with SMTP id v129mr4810419wmb.90.1455817559460; Thu, 18 Feb 2016 09:45:59 -0800 (PST) Return-Path: Received: from mail-wm0-x230.google.com (mail-wm0-x230.google.com. [2a00:1450:400c:c09::230]) by mx.google.com with ESMTPS id wm7si11855242wjc.125.2016.02.18.09.45.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 Feb 2016 09:45:59 -0800 (PST) Received-SPF: pass (google.com: domain of eric.auger@linaro.org designates 2a00:1450:400c:c09::230 as permitted sender) client-ip=2a00:1450:400c:c09::230; Authentication-Results: mx.google.com; spf=pass (google.com: domain of eric.auger@linaro.org designates 2a00:1450:400c:c09::230 as permitted sender) smtp.mailfrom=eric.auger@linaro.org; dkim=pass header.i=@linaro.org Received: by mail-wm0-x230.google.com with SMTP id g62so36762041wme.0 for ; Thu, 18 Feb 2016 09:45:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=9JcvusmsSYmq2iVVrVRlwyEMNqlP92VK7fOHUPeayJM=; b=SjLM9sPEcb4MGhyudKeA8i1ljhbCt75D2lGkMm7gMOjvpo3Uycu36AyeaQ55GhxeCW gWA3YpwXPGugQ0IHWHYTgpafB99a+aHMWt/wWIUAEtApGhEQ7a3DaXoMr7Z6wZsVtref HNVbHSinX91FOjjA536fyx5qhY6m8BXoisrrQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=9JcvusmsSYmq2iVVrVRlwyEMNqlP92VK7fOHUPeayJM=; b=PY5wd0aRLBcsqdUxHch8U+29Jic6CJqjfmSchEgQwbzgt3ZWgilbr0i8smxFIv6qda Al0sbLkXsmoHLZU3tO6DVJWEio7ltkRfwBJ7OC6GMYvcmLWfac51lVCZPhwuB7ERDT9e lSeQaCw/OitNba5LxtKl4/muzAEDhLtNcEyeRvecncZ+GdtQtdCBIcWDyl5ia48FPGae 0xAho7+VlG7nA3l7lnd1nFnHZETk71mmPXEhyueF4GYtmV/PVFMoGQUNuHFzMfGMOCOY cEU52zTrhG15PcwQCiZbCedGfJtFaKiTfFQigM1oER3fVcfg5jlv2V3rYmnxzR2tAllQ d3lg== X-Gm-Message-State: AG10YORMnyX06gONaV89xkNhNS7bVfkzmmioYkiuG18seU/ewDwajtY2HcsK8MZ57xiOehBL5vU= X-Received: by 10.195.13.98 with SMTP id ex2mr8617418wjd.45.1455817559195; Thu, 18 Feb 2016 09:45:59 -0800 (PST) Return-Path: Received: from midway01-04-00.lavalab ([81.128.185.50]) by smtp.gmail.com with ESMTPSA id ct2sm7592997wjb.46.2016.02.18.09.45.56 (version=TLS1_1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 18 Feb 2016 09:45:57 -0800 (PST) From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, peter.maydell@linaro.org, alex.williamson@redhat.com, david@gibson.dropbear.id.au Cc: christoffer.dall@linaro.org, suravee.suthikulpanit@amd.com, alex.bennee@linaro.org, thuth@redhat.com, crosthwaitepeter@gmail.com, patches@linaro.org, pbonzini@redhat.com, b.reynal@virtualopensystems.com, thomas.lendacky@amd.com Subject: [PATCH v7 2/8] device_tree: introduce load_device_tree_from_sysfs Date: Thu, 18 Feb 2016 17:45:40 +0000 Message-Id: <1455817546-6564-3-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1455817546-6564-1-git-send-email-eric.auger@linaro.org> References: <1455817546-6564-1-git-send-email-eric.auger@linaro.org> This function returns the host device tree blob from sysfs (/proc/device-tree). It uses a recursive function inspired from dtc read_fstree. Signed-off-by: Eric Auger Reviewed-by: Peter Maydell --- v6 -> v7: - rebase on d38ea87ac54af64ef611de434d07c12dc0399216: "all: Clean up includes" - add Peter's R-b v5 -> v6: - fix some spelling mistakes - error_report + exit replaced by error_setg - const char *parent_node; - use g_strdup_printf instead of g_strjoin - add a doc comment for load_device_tree_from_sysfs v1 -> v2: - do not implement/expose read_fstree and load_device_tree_from_sysfs if CONFIG_LINUX is not defined (lstat is not implemeted in mingw) - correct indentation in read_fstree - use /proc/device-tree symlink instead of /sys/firmware/devicetree/base path (kernel.org/doc/Documentation/ABI/testing/sysfs-firmware-ofw) - use g_file_get_contents in read_fstree - introduce SYSFS_DT_BASEDIR macro and use strlen - exit on error in load_device_tree_from_sysfs - user error_setg RFC -> v1: - remove runtime dependency on dtc binary and introduce read_fstree --- device_tree.c | 100 +++++++++++++++++++++++++++++++++++++++++++ include/sysemu/device_tree.h | 8 ++++ 2 files changed, 108 insertions(+) -- 1.8.3.2 diff --git a/device_tree.c b/device_tree.c index b1ad836..9e77c69 100644 --- a/device_tree.c +++ b/device_tree.c @@ -13,6 +13,10 @@ #include "qemu/osdep.h" +#ifdef CONFIG_LINUX +#include +#endif + #include "qemu-common.h" #include "qemu/error-report.h" #include "sysemu/device_tree.h" @@ -112,6 +116,102 @@ fail: return NULL; } +#ifdef CONFIG_LINUX + +#define SYSFS_DT_BASEDIR "/proc/device-tree" + +/** + * read_fstree: this function is inspired from dtc read_fstree + * @fdt: preallocated fdt blob buffer, to be populated + * @dirname: directory to scan under SYSFS_DT_BASEDIR + * the search is recursive and the tree is searched down to the + * leaves (property files). + * + * the function asserts in case of error + */ +static void read_fstree(void *fdt, const char *dirname) +{ + DIR *d; + struct dirent *de; + struct stat st; + const char *root_dir = SYSFS_DT_BASEDIR; + const char *parent_node; + + if (strstr(dirname, root_dir) != dirname) { + error_setg(&error_fatal, "%s: %s must be searched within %s", + __func__, dirname, root_dir); + } + parent_node = &dirname[strlen(SYSFS_DT_BASEDIR)]; + + d = opendir(dirname); + if (!d) { + error_setg(&error_fatal, "%s cannot open %s", __func__, dirname); + } + + while ((de = readdir(d)) != NULL) { + char *tmpnam; + + if (!g_strcmp0(de->d_name, ".") + || !g_strcmp0(de->d_name, "..")) { + continue; + } + + tmpnam = g_strdup_printf("%s/%s", dirname, de->d_name); + + if (lstat(tmpnam, &st) < 0) { + error_setg(&error_fatal, "%s cannot lstat %s", __func__, tmpnam); + } + + if (S_ISREG(st.st_mode)) { + gchar *val; + gsize len; + + if (!g_file_get_contents(tmpnam, &val, &len, NULL)) { + error_setg(&error_fatal, "%s not able to extract info from %s", + __func__, tmpnam); + } + + if (strlen(parent_node) > 0) { + qemu_fdt_setprop(fdt, parent_node, + de->d_name, val, len); + } else { + qemu_fdt_setprop(fdt, "/", de->d_name, val, len); + } + g_free(val); + } else if (S_ISDIR(st.st_mode)) { + char *node_name; + + node_name = g_strdup_printf("%s/%s", + parent_node, de->d_name); + qemu_fdt_add_subnode(fdt, node_name); + g_free(node_name); + read_fstree(fdt, tmpnam); + } + + g_free(tmpnam); + } + + closedir(d); +} + +/* load_device_tree_from_sysfs: extract the dt blob from host sysfs */ +void *load_device_tree_from_sysfs(void) +{ + void *host_fdt; + int host_fdt_size; + + host_fdt = create_device_tree(&host_fdt_size); + read_fstree(host_fdt, SYSFS_DT_BASEDIR); + if (fdt_check_header(host_fdt)) { + error_setg(&error_fatal, + "%s host device tree extracted into memory is invalid", + __func__); + } + return host_fdt; +} + +#endif /* CONFIG_LINUX */ + static int findnode_nofail(void *fdt, const char *node_path) { int offset; diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h index 359e143..62093ba 100644 --- a/include/sysemu/device_tree.h +++ b/include/sysemu/device_tree.h @@ -16,6 +16,14 @@ void *create_device_tree(int *sizep); void *load_device_tree(const char *filename_path, int *sizep); +#ifdef CONFIG_LINUX +/** + * load_device_tree_from_sysfs: reads the device tree information in the + * /proc/device-tree directory and return the corresponding binary blob + * buffer pointer. Asserts in case of error. + */ +void *load_device_tree_from_sysfs(void); +#endif int qemu_fdt_setprop(void *fdt, const char *node_path, const char *property, const void *val, int size);