From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-15?Q?Stephan_M=FCller?= Subject: [PATCH] Change userspace MKDEV, MAJOR, MINOR-macros from 8+8 bit, to 12+20 bit layout Date: Sun, 14 Sep 2014 19:35:28 +0200 Message-ID: <5415D1E0.3020905@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Linux Kernel Mailing List Cc: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org Delete old userspace-only versions (8+8 bit). Instead expose the kernel-space definitions (12+20 bit). Signed-off-by: Stephan Mueller --- Browsing some code I found that user-space and kernel-space macros for (un-)packing major/minor device numbers differ. The user-space ones using still the old 16 bit scheme. There was no explaining comment around and most libraries have their own macros anyway so it should not be a problematic UAPI change. So IMHO we could win some coherence in abandon this discrepancy. Please correct me if I am wrong. include/linux/kdev_t.h | 7 ------- include/uapi/linux/kdev_t.h | 16 +++++++--------- 2 files changed, 7 insertions(+), 16 deletions(-) diff --git a/include/linux/kdev_t.h b/include/linux/kdev_t.h index c838abe..0b09c12 100644 --- a/include/linux/kdev_t.h +++ b/include/linux/kdev_t.h @@ -3,13 +3,6 @@ #include -#define MINORBITS 20 -#define MINORMASK ((1U << MINORBITS) - 1) - -#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) -#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) -#define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi)) - #define print_dev_t(buffer, dev) \ sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev)) diff --git a/include/uapi/linux/kdev_t.h b/include/uapi/linux/kdev_t.h index 0d881fa..6a8356b 100644 --- a/include/uapi/linux/kdev_t.h +++ b/include/uapi/linux/kdev_t.h @@ -1,13 +1,11 @@ #ifndef _UAPI_LINUX_KDEV_T_H #define _UAPI_LINUX_KDEV_T_H -#ifndef __KERNEL__ -/* -Some programs want their definitions of MAJOR and MINOR and MKDEV -from the kernel sources. These must be the externally visible ones. -*/ -#define MAJOR(dev) ((dev)>>8) -#define MINOR(dev) ((dev) & 0xff) -#define MKDEV(ma,mi) ((ma)<<8 | (mi)) -#endif /* __KERNEL__ */ +#define MINORBITS 20 +#define MINORMASK ((1U << MINORBITS) - 1) + +#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) +#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) +#define MKDEV(ma, mi) (((ma) << MINORBITS) | (mi)) + #endif /* _UAPI_LINUX_KDEV_T_H */ -- 1.9.3