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_*


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 <>
Acked-by: default avatarJeremy Fitzhardinge <>
Cc: FUJITA Tomonori <>
Cc: Albert Herranz <>
Cc: Ian Campbell <>
parent b097186f
#ifndef _ASM_X86_SWIOTLB_XEN_H
#define _ASM_X86_SWIOTLB_XEN_H
extern int xen_swiotlb;
extern int __init pci_xen_swiotlb_detect(void);
extern void __init pci_xen_swiotlb_init(void);
#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 /* _ASM_X86_SWIOTLB_XEN_H */
......@@ -18,3 +18,4 @@ obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_XEN_DEBUG_FS) += debugfs.o
obj-$(CONFIG_SWIOTLB_XEN) += pci-swiotlb-xen.o
/* 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_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) {
dma_ops = &xen_swiotlb_dma_ops;
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