Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S275261AbTHSAdF (ORCPT ); Mon, 18 Aug 2003 20:33:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S275262AbTHSAdF (ORCPT ); Mon, 18 Aug 2003 20:33:05 -0400 Received: from mail.kroah.org ([65.200.24.183]:22722 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S275261AbTHSAc5 (ORCPT ); Mon, 18 Aug 2003 20:32:57 -0400 Date: Mon, 18 Aug 2003 17:33:05 -0700 From: Greg KH To: linux-kernel@vger.kernel.org Cc: rml@tech9.net Subject: [RFC] /sys/class/mem support Message-ID: <20030819003305.GA1546@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3023 Lines: 126 Hi, Here's a patch against the latest 2.6.0-test3-bk tree that adds /sys/class/mem support for the "memory" char devices. I know that Robert Love was thinking of moving some of the /proc/sys/kernel/random/ files into sysfs, so this patch is needed for him to do this (Robert, you will need to export some variables for this to work, this patch is just a start...) This patch is needed for a complete persistant device naming scheme (such as udev.) Anyway, with this patch, /sys/class/mem looks like the following: $ tree /sys/class/mem/ /sys/class/mem/ |-- full | `-- dev |-- kmem | `-- dev |-- kmsg | `-- dev |-- mem | `-- dev |-- null | `-- dev |-- port | `-- dev |-- random | `-- dev |-- urandom | `-- dev `-- zero `-- dev $ cat /sys/class/mem/*/dev 1:7 1:2 1:11 1:1 1:3 1:4 1:8 1:9 1:5 Memory devices are never unregistered from the kernel, so that is why this patch does not have any support for this. Comments? thanks, greg k-h --- a/drivers/char/mem.c Mon Aug 18 16:51:45 2003 +++ b/drivers/char/mem.c Mon Aug 18 16:51:45 2003 @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -649,7 +650,7 @@ .open = memory_open, /* just a selector for the real open */ }; -static const struct { +static const struct mem_dev { unsigned int minor; char *name; umode_t mode; @@ -668,6 +669,23 @@ {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops}, }; +static void release_mem_dev(struct class_device *class_dev) +{ + kfree(class_dev); +} + +static struct class mem_class = { + .name = "mem", + .release = &release_mem_dev, +}; + +static ssize_t show_dev(struct class_device *class_dev, char *buf) +{ + struct mem_dev *mem_dev = class_get_devdata(class_dev); + return print_dev_t(buf, MKDEV(MEM_MAJOR, mem_dev->minor)); +} +static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL); + static int __init chr_dev_init(void) { int i; @@ -675,7 +693,20 @@ if (register_chrdev(MEM_MAJOR,"mem",&memory_fops)) printk("unable to get major %d for memory devs\n", MEM_MAJOR); + class_register(&mem_class); for (i = 0; i < ARRAY_SIZE(devlist); i++) { + struct class_device *class_dev; + + class_dev = kmalloc(sizeof(*class_dev), GFP_KERNEL); + if (class_dev) { + memset(class_dev, 0x00, sizeof(*class_dev)); + class_dev->class = &mem_class; + strncpy(class_dev->class_id, devlist[i].name, BUS_ID_SIZE); + class_set_devdata(class_dev, (void *)&devlist[i]); + if (!class_device_register(class_dev)); + class_device_create_file(class_dev, &class_device_attr_dev); + } + devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor), S_IFCHR | devlist[i].mode, devlist[i].name); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/