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// SPDX-License-Identifier: GPL-2.0
/* Glue code to lib/swiotlb-xen.c */
#include <linux/dma-map-ops.h>
#include <linux/pci.h>
#include <xen/swiotlb-xen.h>
#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
#include <asm/iommu_table.h>
#include <asm/xen/swiotlb-xen.h>
#ifdef CONFIG_X86_64
#include <asm/iommu.h>
#include <asm/dma.h>
#endif
#include <linux/export.h>
static int xen_swiotlb __read_mostly;
/*
* 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 (!xen_pv_domain())
return 0;
/* If running as PV guest, either iommu=soft, or swiotlb=force will
* activate this IOMMU. If running as PV privileged, activate it
* irregardless.
*/
if (xen_initial_domain() || swiotlb || swiotlb_force == 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. */
swiotlb = 0;
#ifdef CONFIG_X86_64
/* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
* (so no iommu=X command line over-writes).
* Considering that PV guests do not want the *native SWIOTLB* but
* only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
*/
if (max_pfn > MAX_DMA32_PFN)
no_iommu = 1;
#endif
return xen_swiotlb;
}
static void __init pci_xen_swiotlb_init(void)
{
if (xen_swiotlb) {
xen_swiotlb_init_early();
dma_ops = &xen_swiotlb_dma_ops;
#ifdef CONFIG_PCI
/* Make sure ACS will be enabled */
pci_request_acs();
#endif
}
}
int pci_xen_swiotlb_init_late(void)
{
int rc;
if (xen_swiotlb)
return 0;
rc = xen_swiotlb_init();
if (rc)
return rc;
dma_ops = &xen_swiotlb_dma_ops;
#ifdef CONFIG_PCI
/* Make sure ACS will be enabled */
pci_request_acs();
#endif
return 0;
}
EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
NULL,
pci_xen_swiotlb_init,
NULL);
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