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From:   Firoz Khan <firoz.khan@linaro.org>
To:     linuxppc-dev@lists.ozlabs.org,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Ram Pai <linuxram@us.ibm.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Breno Leitao <leitao@debian.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Philippe Ombredanne <pombredanne@nexb.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Kate Stewart <kstewart@linuxfoundation.org>
Cc:     y2038@lists.linaro.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org, arnd@arndb.de, deepa.kernel@gmail.com,
        marcin.juszkiewicz@linaro.org, firoz.khan@linaro.org
Subject: [PATCH v4 1/5] powerpc: add __NR_syscalls along with NR_syscalls
Date:   Fri,  7 Dec 2018 11:41:36 +0530
Message-Id: <1544163100-15510-2-git-send-email-firoz.khan@linaro.org>
In-Reply-To: <1544163100-15510-1-git-send-email-firoz.khan@linaro.org>
References: <1544163100-15510-1-git-send-email-firoz.khan@linaro.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

NR_syscalls macro holds the number of system call exist
in powerpc architecture. We have to change the value of
NR_syscalls, if we add or delete a system call.

One of the patch in this patch series has a script which
will generate a uapi header based on syscall.tbl file.
The syscall.tbl file contains the number of system call
information. So we have two option to update NR_syscalls
value.

1. Update NR_syscalls in asm/unistd.h manually by count-
   ing the no.of system calls. No need to update NR_sys-
   calls until we either add a new system call or delete
   existing system call.

2. We can keep this feature in above mentioned script,
   that will count the number of syscalls and keep it in
   a generated file. In this case we don't need to expli-
   citly update NR_syscalls in asm/unistd.h file.

The 2nd option will be the recommended one. For that, I
added the __NR_syscalls macro in uapi/asm/unistd.h along
with NR_syscalls asm/unistd.h. The macro __NR_syscalls
also added for making the name convention same across all
architecture. While __NR_syscalls isn't strictly part of
the uapi, having it as part of the generated header to
simplifies the implementation. We also need to enclose
this macro with #ifdef __KERNEL__ to avoid side effects.

Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
---
 arch/powerpc/include/asm/unistd.h      | 3 +--
 arch/powerpc/include/uapi/asm/unistd.h | 5 ++++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index b0de85b..a3c35e6 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -11,8 +11,7 @@
 
 #include <uapi/asm/unistd.h>
 
-
-#define NR_syscalls		389
+#define NR_syscalls	__NR_syscalls
 
 #define __NR__exit __NR_exit
 
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h
index 985534d..7195868 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -10,7 +10,6 @@
 #ifndef _UAPI_ASM_POWERPC_UNISTD_H_
 #define _UAPI_ASM_POWERPC_UNISTD_H_
 
-
 #define __NR_restart_syscall	  0
 #define __NR_exit		  1
 #define __NR_fork		  2
@@ -401,4 +400,8 @@
 #define __NR_rseq		387
 #define __NR_io_pgetevents	388
 
+#ifdef __KERNEL__
+#define __NR_syscalls		389
+#endif
+
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
-- 
1.9.1