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Date:   Wed, 21 Aug 2019 00:28:28 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, npiggin@gmail.com,
        hch@lst.de, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 05/12] powerpc/mm: rework io-workaround invocation.
Message-ID: <20190820222828.GC18433@lst.de>
References: <cover.1566309262.git.christophe.leroy@c-s.fr> <5fa3ef069fbd0f152512afaae19e7a60161454cf.1566309262.git.christophe.leroy@c-s.fr>
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On Tue, Aug 20, 2019 at 02:07:13PM +0000, Christophe Leroy wrote:
> ppc_md.ioremap() is only used for I/O workaround on CELL platform,
> so indirect function call can be avoided.
> 
> This patch reworks the io-workaround and ioremap() functions to
> use the global 'io_workaround_inited' flag for the activation
> of io-workaround.
> 
> When CONFIG_PPC_IO_WORKAROUNDS or CONFIG_PPC_INDIRECT_MMIO are not
> selected, the I/O workaround ioremap() voids and the global flag is
> not used.

Note that CONFIG_PPC_IO_WORKAROUNDS is only selected by a specific cell
config,  and CONFIG_PPC_INDIRECT_MMIO is always selected by cell, so
I think we can make CONFIG_PPC_IO_WORKAROUNDS depend on
CONFIG_PPC_INDIRECT_MMIO

>  #define _IO_WORKAROUNDS_H
>  
> +#ifdef CONFIG_PPC_IO_WORKAROUNDS
>  #include <linux/io.h>
>  #include <asm/pci-bridge.h>
>  
> @@ -32,4 +33,23 @@ extern int spiderpci_iowa_init(struct iowa_bus *, void *);
>  #define SPIDER_PCI_DUMMY_READ		0x0810
>  #define SPIDER_PCI_DUMMY_READ_BASE	0x0814
>  
> +#endif
> +
> +#if defined(CONFIG_PPC_IO_WORKAROUNDS) && defined(CONFIG_PPC_INDIRECT_MMIO)

and simplify the ifdefs here a bit.

Otherwise this looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>