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// SPDX-License-Identifier: GPL-2.0
#include <linux/dma-map-ops.h>
#include <linux/dma-direct.h>
#include <linux/iommu.h>
#include <linux/dmar.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/gfp.h>
#include <linux/pci.h>
#include <linux/amd-iommu.h>
#include <asm/proto.h>
#include <asm/dma.h>
#include <asm/iommu.h>
#include <asm/gart.h>
#include <asm/x86_init.h>
#include <xen/xen.h>
#include <xen/swiotlb-xen.h>
static bool disable_dac_quirk __read_mostly;
const struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);
#ifdef CONFIG_IOMMU_DEBUG
int panic_on_overflow __read_mostly = 1;
int force_iommu __read_mostly = 1;
#else
int panic_on_overflow __read_mostly = 0;
int force_iommu __read_mostly = 0;
#endif
int iommu_merge __read_mostly = 0;
int no_iommu __read_mostly;
/* Set this to 1 if there is a HW IOMMU in the system */
int iommu_detected __read_mostly = 0;
#ifdef CONFIG_SWIOTLB
bool x86_swiotlb_enable;
static unsigned int x86_swiotlb_flags;
static void __init pci_swiotlb_detect(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
x86_swiotlb_enable = true;
/*
* Set swiotlb to 1 so that bounce buffers are allocated and used for
* devices that can't support DMA to encrypted memory.
*/
if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT))
x86_swiotlb_enable = true;
/*
* Guest with guest memory encryption currently perform all DMA through
* bounce buffers as the hypervisor can't access arbitrary VM memory
* that is not explicitly shared with it.
*/
if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
x86_swiotlb_enable = true;
x86_swiotlb_flags |= SWIOTLB_FORCE;
}
}
#else
static inline void __init pci_swiotlb_detect(void)
{
}
#define x86_swiotlb_flags 0
#endif /* CONFIG_SWIOTLB */
#ifdef CONFIG_SWIOTLB_XEN
static void __init pci_xen_swiotlb_init(void)
{
if (!xen_initial_domain() && !x86_swiotlb_enable)
return;
x86_swiotlb_enable = true;
x86_swiotlb_flags |= SWIOTLB_ANY;
swiotlb_init_remap(true, x86_swiotlb_flags, xen_swiotlb_fixup);
dma_ops = &xen_swiotlb_dma_ops;
if (IS_ENABLED(CONFIG_PCI))
pci_request_acs();
}
int pci_xen_swiotlb_init_late(void)
{
if (dma_ops == &xen_swiotlb_dma_ops)
return 0;
/* we can work with the default swiotlb */
if (!io_tlb_default_mem.nslabs) {
int rc = swiotlb_init_late(swiotlb_size_or_default(),
GFP_KERNEL, xen_swiotlb_fixup);
if (rc < 0)
return rc;
}
/* XXX: this switches the dma ops under live devices! */
dma_ops = &xen_swiotlb_dma_ops;
if (IS_ENABLED(CONFIG_PCI))
pci_request_acs();
return 0;
}
EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
#else
static inline void __init pci_xen_swiotlb_init(void)
{
}
#endif /* CONFIG_SWIOTLB_XEN */
void __init pci_iommu_alloc(void)
{
if (xen_pv_domain()) {
pci_xen_swiotlb_init();
return;
}
pci_swiotlb_detect();
gart_iommu_hole_init();
amd_iommu_detect();
detect_intel_iommu();
swiotlb_init(x86_swiotlb_enable, x86_swiotlb_flags);
}
/*
* See <Documentation/arch/x86/x86_64/boot-options.rst> for the iommu kernel
* parameter documentation.
*/
static __init int iommu_setup(char *p)
{
iommu_merge = 1;
if (!p)
return -EINVAL;
while (*p) {
if (!strncmp(p, "off", 3))
no_iommu = 1;
/* gart_parse_options has more force support */
if (!strncmp(p, "force", 5))
force_iommu = 1;
if (!strncmp(p, "noforce", 7)) {
iommu_merge = 0;
force_iommu = 0;
}
if (!strncmp(p, "biomerge", 8)) {
iommu_merge = 1;
force_iommu = 1;
}
if (!strncmp(p, "panic", 5))
panic_on_overflow = 1;
if (!strncmp(p, "nopanic", 7))
panic_on_overflow = 0;
if (!strncmp(p, "merge", 5)) {
iommu_merge = 1;
force_iommu = 1;
}
if (!strncmp(p, "nomerge", 7))
iommu_merge = 0;
if (!strncmp(p, "forcesac", 8))
pr_warn("forcesac option ignored.\n");
if (!strncmp(p, "allowdac", 8))
pr_warn("allowdac option ignored.\n");
if (!strncmp(p, "nodac", 5))
pr_warn("nodac option ignored.\n");
if (!strncmp(p, "usedac", 6)) {
disable_dac_quirk = true;
return 1;
}
#ifdef CONFIG_SWIOTLB
if (!strncmp(p, "soft", 4))
x86_swiotlb_enable = true;
#endif
if (!strncmp(p, "pt", 2))
iommu_set_default_passthrough(true);
if (!strncmp(p, "nopt", 4))
iommu_set_default_translated(true);
gart_parse_options(p);
p += strcspn(p, ",");
if (*p == ',')
++p;
}
return 0;
}
early_param("iommu", iommu_setup);
static int __init pci_iommu_init(void)
{
x86_init.iommu.iommu_init();
#ifdef CONFIG_SWIOTLB
/* An IOMMU turned us off. */
if (x86_swiotlb_enable) {
pr_info("PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
swiotlb_print_info();
} else {
swiotlb_exit();
}
#endif
return 0;
}
/* Must execute after PCI subsystem */
rootfs_initcall(pci_iommu_init);
#ifdef CONFIG_PCI
/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
static int via_no_dac_cb(struct pci_dev *pdev, void *data)
{
pdev->dev.bus_dma_limit = DMA_BIT_MASK(32);
return 0;
}
static void via_no_dac(struct pci_dev *dev)
{
if (!disable_dac_quirk) {
dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
pci_walk_bus(dev->subordinate, via_no_dac_cb, NULL);
}
}
DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,
PCI_CLASS_BRIDGE_PCI, 8, via_no_dac);
#endif
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