From: Christoph Hellwig <hch@lst.de>
To: Leon Romanovsky <leon@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
Robin Murphy <robin.murphy@arm.com>,
iommu@lists.linux.dev, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will@kernel.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Xi Ruoyao <xry111@xry111.site>
Subject: Re: [PATCH 2/2] iommu/dma: remove most stubs in iommu-dma.h
Date: Sun, 22 Sep 2024 16:32:06 +0200 [thread overview]
Message-ID: <20240922143206.GA16843@lst.de> (raw)
In-Reply-To: <20240922142819.GD11337@unreal>
On Sun, Sep 22, 2024 at 05:28:19PM +0300, Leon Romanovsky wrote:
> On Sun, Sep 22, 2024 at 04:07:35PM +0200, Christoph Hellwig wrote:
> > The direct calls from mapping.c all guarded by use_dma_iommu(), so don't
> > bother to provide stubs, but instead just expose the prototypes
> > unconditionally.
>
> I was afraid to do such a change because of fear that some compiler will
> call to the !CONFIG_IOMMU_DMA functions without checking the condition.
The kernel relies on this style of dead code elimination in many
places. The IS_ENABLED() macro could not exist without it.
next prev parent reply other threads:[~2024-09-22 14:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-22 14:07 iommu-dma direct call fixups Christoph Hellwig
2024-09-22 14:07 ` [PATCH 1/2] dma-mapping: fix vmap and mmap of noncontiougs allocations Christoph Hellwig
2024-09-22 15:02 ` Leon Romanovsky
2024-09-22 14:07 ` [PATCH 2/2] iommu/dma: remove most stubs in iommu-dma.h Christoph Hellwig
2024-09-22 14:28 ` Leon Romanovsky
2024-09-22 14:32 ` Christoph Hellwig [this message]
2024-09-22 15:02 ` Leon Romanovsky
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