Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.
Hi Arnd,
On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
@@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device
*pdev)
goto clk_dis_ahb;
}
+#if defined(CONFIG_IOMMU_SUPPORT)
+ sdhci_arasan-domain = iommu_domain_alloc(amba_bustype);
+ if (!sdhci_arasan-domain) {
+ dev_err(pdev-dev, Unable to allocate iommu domain\n);
+ return PTR_ERR(sdhci_arasan-domain);
+ }
+
+ iommu_attach_device(sdhci_arasan-domain, pdev-dev);
+#endif
+
Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.
After refer to iommu binding , there is a service that allows Remap
address space to allow devices to access physical memory ranges that
they otherwise wouldn't be capable of accessing. eg : 32-bit to 64
bit DMA .
So do we have any existing driver that uses this service ? Just asking
for suggestions.
On Tue, Dec 16, 2014 at 2:57 AM, Arnd Bergmann a...@arndb.de wrote:
On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
@@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device
*pdev)
goto clk_dis_ahb;
}
+#if defined(CONFIG_IOMMU_SUPPORT)
+ sdhci_arasan-domain = iommu_domain_alloc(amba_bustype);
+ if (!sdhci_arasan-domain) {
+ dev_err(pdev-dev, Unable to allocate iommu domain\n);
+ return PTR_ERR(sdhci_arasan-domain);
+ }
+
+ iommu_attach_device(sdhci_arasan-domain, pdev-dev);
+#endif
+
Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.
Arnd
--
Thanks,
with regards,
Suman Tripathi
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Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.
On Tuesday 06 January 2015 17:10:29 Suman Tripathi wrote:
Hi Arnd,
On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
@@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct
platform_device *pdev)
goto clk_dis_ahb;
}
+#if defined(CONFIG_IOMMU_SUPPORT)
+ sdhci_arasan-domain = iommu_domain_alloc(amba_bustype);
+ if (!sdhci_arasan-domain) {
+ dev_err(pdev-dev, Unable to allocate iommu
domain\n);
+ return PTR_ERR(sdhci_arasan-domain);
+ }
+
+ iommu_attach_device(sdhci_arasan-domain, pdev-dev);
+#endif
+
Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.
After refer to iommu binding , there is a service that allows Remap
address space to allow devices to access physical memory ranges that
they otherwise wouldn't be capable of accessing. eg : 32-bit to 64
bit DMA .
So do we have any existing driver that uses this service ? Just asking
for suggestions.
The interface is completely transparent to device drivers, it is
implemented as a separate 'struct dma_map_ops' that is normally
architecture independent, and that handles all sorts of DMA remapping
issues for the driver, including
- address space limits
- offsets between CPU and device addresses for the same memory
- cache flushes
- bus-level synchronization
On arm32, we currently support six sets of dma_map_ops including
two for IOMMU (coherent and noncoherent). On arm64, we currently
always use swiotlb, which solves your problem by copying memory to
bounce buffers. This is rather inefficient, and a new implementation
is being worked on, based on the arm32 implementation to support
IOMMUs in a generic way.
Arnd
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Re: [PATCH 1/2] mmc: host: arasan: Add addition of-arasan quirks and add IOMMU support.
On Monday 15 December 2014 22:31:06 Suman Tripathi wrote:
@@ -162,6 +206,16 @@ static int sdhci_arasan_probe(struct platform_device
*pdev)
goto clk_dis_ahb;
}
+#if defined(CONFIG_IOMMU_SUPPORT)
+ sdhci_arasan-domain = iommu_domain_alloc(amba_bustype);
+ if (!sdhci_arasan-domain) {
+ dev_err(pdev-dev, Unable to allocate iommu domain\n);
+ return PTR_ERR(sdhci_arasan-domain);
+ }
+
+ iommu_attach_device(sdhci_arasan-domain, pdev-dev);
+#endif
+
Device drivers should never care about the implementation details
of the iommu. Please change the code to use the regular dma_map_*
interfaces that will work both with and without IOMMU.
Arnd
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