From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v3 3/6] iommu: add ARM short descriptor page table allocator.
Date: Fri, 31 Jul 2015 12:32:17 +0100 [thread overview]
Message-ID: <20150731113217.GE29497@arm.com> (raw)
In-Reply-To: <1438329337.25925.147.camel@mhfsdcap03>
On Fri, Jul 31, 2015 at 08:55:37AM +0100, Yong Wu wrote:
> About the AP bits, I may have to add a new quirk for it...
>
> Current I add AP in pte like this:
> #define ARM_SHORT_PTE_RD_WR (3 << 4)
> #define ARM_SHORT_PTE_RDONLY BIT(9)
>
> pteprot |= ARM_SHORT_PTE_RD_WR;
>
>
> If(!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
>
>
> pteprot |= ARM_SHORT_PTE_RDONLY;
>
> The problem is that the BIT(9) in the level1 and level2 pagetable of our
> HW has been used for PA[32] that is for the dram size over 4G.
Aha, now *thats* a case of page-table abuse!
> so I had to add a quirk to disable bit9 while RDONLY case.
> (If BIT9 isn't disabled, the HW treat it as the PA[32] case then it will
> translation fault..)
>
> like: IO_PGTABLE_QUIRK_SHORT_MTK ?
Given that you don't have XN either, maybe IO_PGTABLE_QUIRK_NO_PERMS?
When set, IOMMU_READ/WRITE/EXEC are ignored and the mapping will never
generate a permission fault.
Will
next prev parent reply other threads:[~2015-07-31 11:32 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-16 9:04 [PATCH v3 0/6] MT8173 IOMMU SUPPORT Yong Wu
2015-07-16 9:04 ` [PATCH v3 1/6] dt-bindings: iommu: Add binding for mediatek IOMMU Yong Wu
2015-07-16 9:04 ` [PATCH v3 2/6] dt-bindings: mediatek: Add smi dts binding Yong Wu
2015-07-16 9:04 ` [PATCH v3 3/6] iommu: add ARM short descriptor page table allocator Yong Wu
2015-07-21 17:11 ` Will Deacon
2015-07-24 5:24 ` Yong Wu
2015-07-24 16:53 ` Will Deacon
2015-07-27 4:21 ` Yong Wu
2015-07-27 14:05 ` Robin Murphy
2015-07-27 14:11 ` Will Deacon
2015-07-28 5:08 ` Yong Wu
2015-07-28 11:00 ` Will Deacon
2015-07-28 13:37 ` Yong Wu
2015-07-28 13:47 ` Will Deacon
[not found] ` <1438329337.25925.147.camel@mhfsdcap03>
2015-07-31 11:32 ` Will Deacon [this message]
2015-09-14 12:25 ` Yong Wu
2015-09-16 12:55 ` Will Deacon
2015-09-17 2:38 ` Yong Wu
2015-07-16 9:04 ` [PATCH v3 4/6] memory: mediatek: Add SMI driver Yong Wu
2015-07-16 9:04 ` [PATCH v3 5/6] iommu/mediatek: Add mt8173 IOMMU driver Yong Wu
2015-07-21 14:59 ` Will Deacon
2015-07-24 5:43 ` Yong Wu
2015-07-24 16:55 ` Will Deacon
2015-07-27 4:24 ` Yong Wu
2015-07-27 15:48 ` Will Deacon
2015-07-27 13:23 ` Robin Murphy
2015-07-27 15:31 ` Russell King - ARM Linux
2015-07-27 15:49 ` Robin Murphy
2015-07-29 5:41 ` Yong Wu
2015-07-29 10:31 ` Will Deacon
2015-07-29 6:32 ` Yong Wu
2015-07-16 9:04 ` [PATCH v3 6/6] dts: mt8173: Add iommu/smi nodes for mt8173 Yong Wu
2015-07-23 14:40 ` Daniel Kurtz
2015-07-29 7:29 ` Yong Wu
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