Commit f5079a9a authored by Stefano Stabellini's avatar Stefano Stabellini Committed by Juergen Gross
Browse files

xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped 



Newer Xen versions expose two Xen feature flags to tell us if the domain
is directly mapped or not. Only when a domain is directly mapped it
makes sense to enable swiotlb-xen on ARM.

Introduce a function on ARM to check the new Xen feature flags and also
to deal with the legacy case. Call the function xen_swiotlb_detect.

Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent a929e124

arch/arm/include/asm/xen/swiotlb-xen.h

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#include <xen/arm/swiotlb-xen.h>

arch/arm/xen/mm.c

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@@ -135,10 +135,22 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) 
	return;

}



int xen_swiotlb_detect(void)

{

	if (!xen_domain())

		return 0;

	if (xen_feature(XENFEAT_direct_mapped))

		return 1;

	/* legacy case */

	if (!xen_feature(XENFEAT_not_direct_mapped) && xen_initial_domain())

		return 1;

	return 0;

}



static int __init xen_mm_init(void)

{

	struct gnttab_cache_flush cflush;

	if (!xen_initial_domain())

	if (!xen_swiotlb_detect())

		return 0;

	xen_swiotlb_init(1, false);

arch/arm64/include/asm/xen/swiotlb-xen.h

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#include <xen/arm/swiotlb-xen.h>

arch/arm64/mm/dma-mapping.c

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@@ -53,7 +53,7 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, 
		iommu_setup_dma_ops(dev, dma_base, size);



#ifdef CONFIG_XEN

	if (xen_initial_domain())

	if (xen_swiotlb_detect())

		dev->dma_ops = &xen_swiotlb_dma_ops;

#endif

}

include/xen/arm/swiotlb-xen.h

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/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_ARM_SWIOTLB_XEN_H

#define _ASM_ARM_SWIOTLB_XEN_H



extern int xen_swiotlb_detect(void);



#endif /* _ASM_ARM_SWIOTLB_XEN_H */