From patchwork Fri Jan 11 06:29:09 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 211211 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 6A3F92C03F1 for ; Fri, 11 Jan 2013 17:29:59 +1100 (EST) Received: from mail-ie0-f175.google.com (mail-ie0-f175.google.com [209.85.223.175]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A238A2C01FA for ; Fri, 11 Jan 2013 17:29:29 +1100 (EST) Received: by mail-ie0-f175.google.com with SMTP id qd14so1874720ieb.6 for ; Thu, 10 Jan 2013 22:29:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer :x-gm-message-state; bh=daU/ILtkfEXEQsfTVf7RXGobG93vW6Il+65LdG1tR5M=; b=TaMzZKYR4x22/ymQpih92/pW9tjRfSQrWl4AtrbenZpP6Q5Nt4fcfnCpPBstRGlBjH Ywv+lnaVTdFgH2fGhR7yRYyQ+oQV8qXz9+TgKqneYW44zSvAgdAzdM1V4Cc9tLRCF3sV Y5X06IZf7b71BSCntmKaCJSeocfgfhskZapamzXSb4qRsU1CJkg5X/Z7iveiBKMP6kit +IMTbXSH7ZdYT2HCF/sLjBRHfngeHkrmjlF3Qb5mET6RzV4Ol632rkcsvm3rTzjTJnTP ERyT6M6pRGKsep/CaiboDgOO7bHEm1ou+coyMa57hRoeJhYzWAqB52ewqeovCKoGrsNG w08g== X-Received: by 10.50.53.226 with SMTP id e2mr8264459igp.92.1357885766249; Thu, 10 Jan 2013 22:29:26 -0800 (PST) Received: from ka1.ozlabs.ibm.com (ibmaus65.lnk.telstra.net. [165.228.126.9]) by mx.google.com with ESMTPS id ez8sm3963959igb.17.2013.01.10.22.29.21 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Jan 2013 22:29:24 -0800 (PST) From: Alexey Kardashevskiy To: Benjamin Herrenschmidt Subject: [PATCH] powerpc: added DSCR support to ptrace Date: Fri, 11 Jan 2013 17:29:09 +1100 Message-Id: <1357885749-14042-1-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 1.7.10.4 X-Gm-Message-State: ALoCoQkPRE/EicBqwzA0QiP9UjF5PVM2j6CaoQEB1+hC0X/8JSTJnYe/ivoNakJWK0Wx3YDVFAfm Cc: Alexey Kardashevskiy , Michael Neuling , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The DSCR (aka Data Stream Control Register) is supported on some server PowerPC chips and allow some control over the prefetch of data streams. The kernel already supports DSCR value per thread but there is also a need in a ability to change it from an external process for the specific pid. The patch adds new register index PT_DSCR (index=44) which can be set/get by: ptrace(PTRACE_POKEUSER, traced_process, PT_DSCR << 3, dscr); dscr = ptrace(PTRACE_PEEKUSER, traced_process, PT_DSCR << 3, NULL); The patch does not increase PT_REGS_COUNT as the pt_regs struct has not been changed. Signed-off-by: Alexey Kardashevskiy --- arch/powerpc/include/uapi/asm/ptrace.h | 1 + arch/powerpc/kernel/ptrace.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h index ee67a2b..5a4863c 100644 --- a/arch/powerpc/include/uapi/asm/ptrace.h +++ b/arch/powerpc/include/uapi/asm/ptrace.h @@ -108,6 +108,7 @@ struct pt_regs { #define PT_DAR 41 #define PT_DSISR 42 #define PT_RESULT 43 +#define PT_DSCR 44 #define PT_REGS_COUNT 44 #define PT_FPR0 48 /* each FP reg occupies 2 slots in this space */ diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index d4afccc..245c1b6 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -179,6 +179,30 @@ static int set_user_msr(struct task_struct *task, unsigned long msr) return 0; } +#ifdef CONFIG_PPC64 +static unsigned long get_user_dscr(struct task_struct *task) +{ + return task->thread.dscr; +} + +static int set_user_dscr(struct task_struct *task, unsigned long dscr) +{ + task->thread.dscr = dscr; + task->thread.dscr_inherit = 1; + return 0; +} +#else +static unsigned long get_user_dscr(struct task_struct *task) +{ + return -EIO; +} + +static int set_user_dscr(struct task_struct *task, unsigned long dscr) +{ + return -EIO; +} +#endif + /* * We prevent mucking around with the reserved area of trap * which are used internally by the kernel. @@ -200,6 +224,9 @@ unsigned long ptrace_get_reg(struct task_struct *task, int regno) if (regno == PT_MSR) return get_user_msr(task); + if (regno == PT_DSCR) + return get_user_dscr(task); + if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) return ((unsigned long *)task->thread.regs)[regno]; @@ -218,6 +245,8 @@ int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data) return set_user_msr(task, data); if (regno == PT_TRAP) return set_user_trap(task, data); + if (regno == PT_DSCR) + return set_user_dscr(task, data); if (regno <= PT_MAX_PUT_REG) { ((unsigned long *)task->thread.regs)[regno] = data;