Commit bbbe5738 authored by Konrad Rzeszutek Wilk's avatar Konrad Rzeszutek Wilk
Browse files

pci-swiotlb-xen: Add glue code to setup dma_ops utilizing xen_swiotlb_* 


functions.

We add the glue code that sets up a dma_ops structure with the
xen_swiotlb_* functions. The code turns on xen_swiotlb flag
when it detects it is running under Xen and it is either
in privileged mode or the iommu=soft flag was passed in.

It also disables the bare-metal SWIOTLB if the Xen-SWIOTLB has
been enabled.

Note: The Xen-SWIOTLB is only built when CONFIG_XEN is enabled.

Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Albert Herranz <albert_herranz@yahoo.es>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
parent b097186f

arch/x86/include/asm/xen/swiotlb-xen.h

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#ifndef _ASM_X86_SWIOTLB_XEN_H

#define _ASM_X86_SWIOTLB_XEN_H



#ifdef CONFIG_SWIOTLB_XEN

extern int xen_swiotlb;

extern int __init pci_xen_swiotlb_detect(void);

extern void __init pci_xen_swiotlb_init(void);

#else

#define xen_swiotlb (0)

static inline int __init pci_xen_swiotlb_detect(void) { return 0; }

static inline void __init pci_xen_swiotlb_init(void) { }

#endif



#endif /* _ASM_X86_SWIOTLB_XEN_H */

arch/x86/xen/Makefile

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Original line number Diff line number Diff line
@@ -18,3 +18,4 @@ obj-$(CONFIG_SMP) += smp.o 
obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o

obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o



obj-$(CONFIG_SWIOTLB_XEN)	+= pci-swiotlb-xen.o

arch/x86/xen/pci-swiotlb-xen.c

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/* Glue code to lib/swiotlb-xen.c */



#include <linux/dma-mapping.h>

#include <xen/swiotlb-xen.h>



#include <asm/xen/hypervisor.h>

#include <xen/xen.h>



int xen_swiotlb __read_mostly;



static struct dma_map_ops xen_swiotlb_dma_ops = {

	.mapping_error = xen_swiotlb_dma_mapping_error,

	.alloc_coherent = xen_swiotlb_alloc_coherent,

	.free_coherent = xen_swiotlb_free_coherent,

	.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,

	.sync_single_for_device = xen_swiotlb_sync_single_for_device,

	.sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,

	.sync_sg_for_device = xen_swiotlb_sync_sg_for_device,

	.map_sg = xen_swiotlb_map_sg_attrs,

	.unmap_sg = xen_swiotlb_unmap_sg_attrs,

	.map_page = xen_swiotlb_map_page,

	.unmap_page = xen_swiotlb_unmap_page,

	.dma_supported = xen_swiotlb_dma_supported,

};



/*

 * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary

 *

 * This returns non-zero if we are forced to use xen_swiotlb (by the boot

 * option).

 */

int __init pci_xen_swiotlb_detect(void)

{



	/* If running as PV guest, either iommu=soft, or swiotlb=force will

	 * activate this IOMMU. If running as PV privileged, activate it

	 * irregardlesss.

	 */

	if ((xen_initial_domain() || swiotlb || swiotlb_force) &&

	    (xen_pv_domain()))

		xen_swiotlb = 1;



	/* If we are running under Xen, we MUST disable the native SWIOTLB.

	 * Don't worry about swiotlb_force flag activating the native, as

	 * the 'swiotlb' flag is the only one turning it on. */

	if (xen_pv_domain())

		swiotlb = 0;



	return xen_swiotlb;

}



void __init pci_xen_swiotlb_init(void)

{

	if (xen_swiotlb) {

		xen_swiotlb_init(1);

		dma_ops = &xen_swiotlb_dma_ops;

	}

}

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