Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757719Ab3J2BWA (ORCPT ); Mon, 28 Oct 2013 21:22:00 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:44035 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756341Ab3J2BV6 (ORCPT ); Mon, 28 Oct 2013 21:21:58 -0400 Message-ID: <526F0DB5.8050800@codeaurora.org> Date: Mon, 28 Oct 2013 18:21:57 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Mark Rutland CC: "linux-edac@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , Russell King , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 3/6] ARM: Add Krait L2 accessor functions References: <1383006690-6754-1-git-send-email-sboyd@codeaurora.org> <1383006690-6754-4-git-send-email-sboyd@codeaurora.org> <20131029011942.GG4763@kartoffel> In-Reply-To: <20131029011942.GG4763@kartoffel> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2187 Lines: 55 On 10/28/13 18:19, Mark Rutland wrote: > On Tue, Oct 29, 2013 at 12:31:27AM +0000, Stephen Boyd wrote: >> Qualcomm's Krait CPUs have a handful of L2 cache controller >> registers that live behind a cp15 based indirection register. >> First you program the indirection register (l2cpselr) to point >> the L2 'window' register (l2cpdr) at what you want to read/write. >> Then you read/write the 'window' register to do what you want. >> The l2cpselr register is not banked per-cpu so we must lock >> around accesses to it to prevent other CPUs from re-pointing >> l2cpdr underneath us. >> >> Cc: Russell King >> Signed-off-by: Stephen Boyd >> --- >> arch/arm/common/Kconfig | 3 ++ >> arch/arm/common/Makefile | 1 + >> arch/arm/common/krait-l2-accessors.c | 52 +++++++++++++++++++++++++++++++ >> arch/arm/include/asm/krait-l2-accessors.h | 20 ++++++++++++ >> 4 files changed, 76 insertions(+) >> create mode 100644 arch/arm/common/krait-l2-accessors.c >> create mode 100644 arch/arm/include/asm/krait-l2-accessors.h > [...] > >> +void set_l2_indirect_reg(u32 addr, u32 val) >> +{ >> + unsigned long flags; >> + >> + raw_spin_lock_irqsave(&krait_l2_lock, flags); >> + >> + asm volatile ("mcr p15, 3, %0, c15, c0, 6" : : "r" (addr)); >> + isb(); >> + asm volatile ("mcr p15, 3, %0, c15, c0, 7" : : "r" (val)); >> + isb(); >> + >> + raw_spin_unlock_irqrestore(&krait_l2_lock, flags); >> +} >> +EXPORT_SYMBOL(set_l2_indirect_reg); > It might be worth commmenting inline as to what register each of these is > accessing. Inevitably the commit message will become harder to find and > associate with the code over time. > > Similarly for get_l2_indirect_reg. Do you mean with the "@" syntax in the assembly? The 80-character limit is out to get me. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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/