Re: [PATCH 09/13] ARM: imx: Remove unused IO_ADDRESS() macros

From: Arnd Bergmann <arnd@arndb.de>
To: Fabio Estevam <festevam@gmail.com>
Cc: Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Shawn Guo <shawnguo@kernel.org>,
	NXP Linux Team <linux-imx@nxp.com>,
	Sascha Hauer <kernel@pengutronix.de>
Subject: Re: [PATCH 09/13] ARM: imx: Remove unused IO_ADDRESS() macros
Date: Thu, 17 Sep 2020 09:16:22 +0200	[thread overview]
Message-ID: <CAK8P3a29hRu8vXubdroNfv3USC9FAKaKTzw=ORTsNFmRJZYAtg@mail.gmail.com> (raw)
In-Reply-To: <CAOMZO5AFK=D1137ofEqw=NTpZ549NszN-jNdgvB-XWsVR=UtOw@mail.gmail.com>

On Wed, Sep 16, 2020 at 11:56 PM Fabio Estevam <festevam@gmail.com> wrote:
> On Wed, Sep 16, 2020 at 6:35 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> > As far as I can tell, the MX27_IO_P2V() macro should be removed here as
> > well if MX27_IO_ADDRESS() gets removed.
>
> The MX27_IO_P2V() macro is still used. Here is the error when I try to
> remove it:
>
> In file included from arch/arm/mach-imx/mach-imx27.c:17:0:
> arch/arm/mach-imx/mach-imx27.c:30:16: error: implicit declaration of
> function ‘MX27_IO_P2V’; did you mean ‘MX35_IO_P2V’?
> [-Werror=implicit-function-declaration]
>   imx_map_entry(MX27, AIPI, MT_DEVICE),
>                 ^
> arch/arm/mach-imx/hardware.h:103:13: note: in definition of macro
> ‘imx_map_entry’
>   .virtual = soc ## _IO_P2V(soc ## _ ## name ## _BASE_ADDR), \

Ah, right. My grep did not catch the static mappings:

arch/arm/mach-imx/mm-imx21.c-/* MX21 memory map definition */
arch/arm/mach-imx/mm-imx21.c-static struct map_desc imx21_io_desc[]
__initdata = {
arch/arm/mach-imx/mm-imx21.c:   imx_map_entry(MX21, AIPI, MT_DEVICE),
arch/arm/mach-imx/mm-imx21.c:   imx_map_entry(MX21, SAHB1, MT_DEVICE),
arch/arm/mach-imx/mm-imx21.c:   imx_map_entry(MX21, X_MEMC, MT_DEVICE),
arch/arm/mach-imx/mm-imx21.c-};
--
arch/arm/mach-imx/mm-imx27.c-/* MX27 memory map definition */
arch/arm/mach-imx/mm-imx27.c-static struct map_desc imx27_io_desc[]
__initdata = {
arch/arm/mach-imx/mm-imx27.c:   imx_map_entry(MX27, AIPI, MT_DEVICE),
arch/arm/mach-imx/mm-imx27.c:   imx_map_entry(MX27, SAHB1, MT_DEVICE),
arch/arm/mach-imx/mm-imx27.c:   imx_map_entry(MX27, X_MEMC, MT_DEVICE),
arch/arm/mach-imx/mm-imx27.c-};
--
arch/arm/mach-imx/mm-imx3.c-static struct map_desc mx31_io_desc[] __initdata = {
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX31, X_MEMC, MT_DEVICE),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX31, AVIC, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX31, AIPS1, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX31, AIPS2, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX31, SPBA0, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c-};
--
arch/arm/mach-imx/mm-imx3.c-#ifdef CONFIG_SOC_IMX35
arch/arm/mach-imx/mm-imx3.c-static struct map_desc mx35_io_desc[] __initdata = {
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX35, X_MEMC, MT_DEVICE),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX35, AVIC, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX35, AIPS1, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX35, AIPS2, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c:    imx_map_entry(MX35, SPBA0, MT_DEVICE_NONSHARED),
arch/arm/mach-imx/mm-imx3.c-};

If all of the devices in here are now also mapped using of_iomap() or
ioremap(), then the iotables are not strictly needed any more, but most
of them are 1MB section sized, which helps slightly reduce TLB usage
compared to non-section ioremap() mappings, so we might want to
keep them anyway, possibly with the constants moved from the header
into the mm-imx??.c files.

Adding Linus to Cc for further thoughts, as he was looking at the early
io mappings recently.

      Arnd

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