From: David Miller <davem@davemloft.net>
To: torvalds@linux-foundation.org
Cc: linux@armlinux.org.uk, hch@lst.de, linux-arch@vger.kernel.org,
linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org,
robin.murphy@arm.com, x86@kernel.org,
linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-alpha@vger.kernel.org, xen-devel@lists.xenproject.org,
dwmw2@infradead.org, linux-arm-kernel@lists.infradead.org
Subject: Re: remove the ->mapping_error method from dma_map_ops V2
Date: Wed, 28 Nov 2018 11:27:17 -0800 (PST) [thread overview]
Message-ID: <20181128.112717.149234960284639699.davem@davemloft.net> (raw)
In-Reply-To: <CAHk-=whnz4Kty6cas11bc2Gh=9zTzeeRS2k=dV9Hfc4B=xnHkQ@mail.gmail.com>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 28 Nov 2018 10:00:06 -0800
> Not all memory is accessible even to the kernel. If you have memory
> that shows up in the last page of phys_addr_t, you just mark it
> reserved at boot-time.
It's not the physical memory at the end that needs to be reserved.
It's the IOMMU mapping arena.
That basically requires changes to every IOMMU implementation in
the tree. Not saying it's hard or impossible, but it is real
meticulous work that needs to be done in order to realize this.
next prev parent reply other threads:[~2018-11-28 19:27 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 14:02 remove the ->mapping_error method from dma_map_ops V2 Christoph Hellwig
2018-11-22 14:02 ` [PATCH 01/24] dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB Christoph Hellwig
2018-11-22 14:02 ` [PATCH 02/24] swiotlb: Skip cache maintenance on map error Christoph Hellwig
2018-11-22 14:02 ` [PATCH 03/24] dma-mapping: provide a generic DMA_MAPPING_ERROR Christoph Hellwig
2018-11-22 14:03 ` [PATCH 04/24] dma-direct: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 05/24] arm: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 06/24] powerpc/iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 07/24] mips/jazz: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 08/24] s390: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 09/24] sparc: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 10/24] parisc/ccio: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 11/24] parisc/sba_iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 12/24] arm64: remove the dummy_dma_ops mapping_error method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 13/24] alpha: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 14/24] ia64/sba_iommu: improve internal map_page users Christoph Hellwig
2018-11-22 14:03 ` [PATCH 15/24] ia64/sba_iommu: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 16/24] ia64/sn: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 17/24] x86/amd_gart: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 18/24] x86/calgary: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 19/24] iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 20/24] iommu/intel: small map_page cleanup Christoph Hellwig
2018-11-22 14:03 ` [PATCH 21/24] iommu/vt-d: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 22/24] iommu/dma-iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 23/24] xen-swiotlb: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 24/24] dma-mapping: " Christoph Hellwig
2018-11-22 16:50 ` remove the ->mapping_error method from dma_map_ops V2 Linus Torvalds
2018-11-22 17:07 ` Russell King - ARM Linux
2018-11-22 17:09 ` Linus Torvalds
2018-11-22 17:14 ` Russell King - ARM Linux
2018-11-22 17:52 ` Robin Murphy
2018-11-22 17:55 ` Linus Torvalds
2018-11-22 18:05 ` Russell King - ARM Linux
2018-11-23 6:57 ` Christoph Hellwig
2018-11-23 6:55 ` Christoph Hellwig
2018-11-28 7:41 ` Christoph Hellwig
2018-11-28 16:47 ` Linus Torvalds
2018-11-28 17:45 ` Russell King - ARM Linux
2018-11-28 18:00 ` Linus Torvalds
2018-11-28 18:08 ` Russell King - ARM Linux
2018-11-28 19:23 ` Russell King - ARM Linux
[not found] ` <CAHk-=whcbiSxSUprsKjVPEdN5-+o8WnTGiKxEV-+HbKNDs=iNA@mail.gmail.com>
2018-11-28 19:31 ` Russell King - ARM Linux
2018-11-29 16:23 ` Christoph Hellwig
2018-11-29 17:44 ` Linus Torvalds
2018-11-29 18:31 ` Christoph Hellwig
2018-11-29 18:53 ` Linus Torvalds
2018-11-29 18:55 ` Christoph Hellwig
2018-11-28 19:27 ` David Miller [this message]
2018-11-28 19:47 ` Russell King - ARM Linux
2018-11-28 23:01 ` Shuah Khan
2018-11-23 10:49 ` Joerg Roedel
2018-11-23 11:01 ` Russell King - ARM Linux
2018-11-23 13:03 ` Joerg Roedel
2018-11-23 13:20 ` Russell King - ARM Linux
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