Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753685Ab2KTBSW (ORCPT ); Mon, 19 Nov 2012 20:18:22 -0500 Received: from mail-ia0-f174.google.com ([209.85.210.174]:57569 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751889Ab2KTBSU (ORCPT ); Mon, 19 Nov 2012 20:18:20 -0500 Message-ID: <50AADA51.7020101@ozlabs.ru> Date: Tue, 20 Nov 2012 12:18:09 +1100 From: Alexey Kardashevskiy User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121028 Thunderbird/16.0.2 MIME-Version: 1.0 To: Alexey Kardashevskiy CC: Benjamin Herrenschmidt , Paul Mackerras , Anton Blanchard , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc: added DSCR support to ptrace References: <1350281910-5238-1-git-send-email-aik@ozlabs.ru> In-Reply-To: <1350281910-5238-1-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2954 Lines: 87 Ping? On 15/10/12 17:18, Alexey Kardashevskiy wrote: > 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); > > Signed-off-by: Alexey Kardashevskiy > --- > arch/powerpc/include/asm/ptrace.h | 3 ++- > arch/powerpc/kernel/ptrace.c | 16 ++++++++++++++++ > 2 files changed, 18 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h > index 84cc784..946c556 100644 > --- a/arch/powerpc/include/asm/ptrace.h > +++ b/arch/powerpc/include/asm/ptrace.h > @@ -276,7 +276,8 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, > #define PT_DAR 41 > #define PT_DSISR 42 > #define PT_RESULT 43 > -#define PT_REGS_COUNT 44 > +#define PT_DSCR 44 > +#define PT_REGS_COUNT 45 > > #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 8d8e028..4798acf 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -179,6 +179,17 @@ static int set_user_msr(struct task_struct *task, unsigned long msr) > return 0; > } > > +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; > + return 0; > +} > + > /* > * We prevent mucking around with the reserved area of trap > * which are used internally by the kernel. > @@ -200,6 +211,9 @@ 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 +232,8 @@ 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; > -- Alexey -- 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/