84 lines
1.8 KiB
C
84 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Glue code to lib/swiotlb.c */
|
|
|
|
#include <linux/pci.h>
|
|
#include <linux/cache.h>
|
|
#include <linux/init.h>
|
|
#include <linux/swiotlb.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/dma-direct.h>
|
|
#include <linux/mem_encrypt.h>
|
|
|
|
#include <asm/iommu.h>
|
|
#include <asm/swiotlb.h>
|
|
#include <asm/dma.h>
|
|
#include <asm/xen/swiotlb-xen.h>
|
|
#include <asm/iommu_table.h>
|
|
|
|
int swiotlb __read_mostly;
|
|
|
|
/*
|
|
* pci_swiotlb_detect_override - set swiotlb to 1 if necessary
|
|
*
|
|
* This returns non-zero if we are forced to use swiotlb (by the boot
|
|
* option).
|
|
*/
|
|
int __init pci_swiotlb_detect_override(void)
|
|
{
|
|
if (swiotlb_force == SWIOTLB_FORCE)
|
|
swiotlb = 1;
|
|
|
|
return swiotlb;
|
|
}
|
|
IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
|
|
pci_xen_swiotlb_detect,
|
|
pci_swiotlb_init,
|
|
pci_swiotlb_late_init);
|
|
|
|
/*
|
|
* If 4GB or more detected (and iommu=off not set) or if SME is active
|
|
* then set swiotlb to 1 and return 1.
|
|
*/
|
|
int __init pci_swiotlb_detect_4gb(void)
|
|
{
|
|
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
|
|
#ifdef CONFIG_X86_64
|
|
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
|
|
swiotlb = 1;
|
|
#endif
|
|
|
|
/*
|
|
* If SME is active then swiotlb will be set to 1 so that bounce
|
|
* buffers are allocated and used for devices that do not support
|
|
* the addressing range required for the encryption mask.
|
|
*/
|
|
if (sme_active())
|
|
swiotlb = 1;
|
|
|
|
return swiotlb;
|
|
}
|
|
IOMMU_INIT(pci_swiotlb_detect_4gb,
|
|
pci_swiotlb_detect_override,
|
|
pci_swiotlb_init,
|
|
pci_swiotlb_late_init);
|
|
|
|
void __init pci_swiotlb_init(void)
|
|
{
|
|
if (swiotlb) {
|
|
swiotlb_init(0);
|
|
dma_ops = &swiotlb_dma_ops;
|
|
}
|
|
}
|
|
|
|
void __init pci_swiotlb_late_init(void)
|
|
{
|
|
/* An IOMMU turned us off. */
|
|
if (!swiotlb)
|
|
swiotlb_exit();
|
|
else {
|
|
printk(KERN_INFO "PCI-DMA: "
|
|
"Using software bounce buffering for IO (SWIOTLB)\n");
|
|
swiotlb_print_info();
|
|
}
|
|
}
|