From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH 01/11] irqchip: Allow irq_reg_{readl,writel} to use __raw_{readl_writel} Date: Wed, 29 Oct 2014 20:10:07 +0100 (CET) Message-ID: References: <1414555138-6500-1-git-send-email-cernekee@gmail.com> <11255905.1JsQYcArO7@wuerfel> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Kevin Cernekee Cc: Arnd Bergmann , Florian Fainelli , Jason Cooper , Ralf Baechle , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , Maxime Bizon , Jonas Gorski , Linux MIPS Mailing List List-Id: devicetree@vger.kernel.org On Wed, 29 Oct 2014, Kevin Cernekee wrote: > Thomas: > > How does that work with multi arch kernels? > > I am assuming this question refers to e.g. CONFIG_ARCH_MULTIPLATFORM > > If GENERIC_IRQ_CHIP is being used, the current implementation of > generic-chip.c will have to pick one global definition of > irq_reg_{readl,writel} for all supported SoCs. > > One possibility is that individual irqchip drivers requiring special > accessors can pass in their own function pointers, similar to this: > > struct sdhci_ops { > #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS > u32 (*read_l)(struct sdhci_host *host, int reg); > u16 (*read_w)(struct sdhci_host *host, int reg); > u8 (*read_b)(struct sdhci_host *host, int reg); > void (*write_l)(struct sdhci_host *host, u32 val, int reg); > void (*write_w)(struct sdhci_host *host, u16 val, int reg); > void (*write_b)(struct sdhci_host *host, u8 val, int reg); > #endif > > and fall back to readl/writel if none are supplied. It would be nice > if this provided common definitions for the __raw_ and maybe the BE > variants too. > > Or, we could add IRQ_GC_NATIVE_IO and/or IRQ_GC_BE_IO to enum irq_gc_flags. I definitely prefer to have these options in the generic chip implementation so we avoid that driver writers duplicate code in creative and wrong ways. Thanks, tglx