291 lines
7.1 KiB
C
291 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/dma-direct.h>
|
|
#include <linux/dma-debug.h>
|
|
#include <linux/dmar.h>
|
|
#include <linux/export.h>
|
|
#include <linux/bootmem.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/kmemleak.h>
|
|
|
|
#include <asm/proto.h>
|
|
#include <asm/dma.h>
|
|
#include <asm/iommu.h>
|
|
#include <asm/gart.h>
|
|
#include <asm/calgary.h>
|
|
#include <asm/x86_init.h>
|
|
#include <asm/iommu_table.h>
|
|
|
|
static int forbid_dac __read_mostly;
|
|
|
|
const struct dma_map_ops *dma_ops = &nommu_dma_ops;
|
|
EXPORT_SYMBOL(dma_ops);
|
|
|
|
static int iommu_sac_force __read_mostly;
|
|
|
|
#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;
|
|
|
|
/*
|
|
* This variable becomes 1 if iommu=pt is passed on the kernel command line.
|
|
* If this variable is 1, IOMMU implementations do no DMA translation for
|
|
* devices and allow every device to access to whole physical memory. This is
|
|
* useful if a user wants to use an IOMMU only for KVM device assignment to
|
|
* guests and not for driver dma translation.
|
|
*/
|
|
int iommu_pass_through __read_mostly;
|
|
|
|
extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
|
|
|
|
/* Dummy device used for NULL arguments (normally ISA). */
|
|
struct device x86_dma_fallback_dev = {
|
|
.init_name = "fallback device",
|
|
.coherent_dma_mask = ISA_DMA_BIT_MASK,
|
|
.dma_mask = &x86_dma_fallback_dev.coherent_dma_mask,
|
|
};
|
|
EXPORT_SYMBOL(x86_dma_fallback_dev);
|
|
|
|
/* Number of entries preallocated for DMA-API debugging */
|
|
#define PREALLOC_DMA_DEBUG_ENTRIES 65536
|
|
|
|
void __init pci_iommu_alloc(void)
|
|
{
|
|
struct iommu_table_entry *p;
|
|
|
|
sort_iommu_table(__iommu_table, __iommu_table_end);
|
|
check_iommu_entries(__iommu_table, __iommu_table_end);
|
|
|
|
for (p = __iommu_table; p < __iommu_table_end; p++) {
|
|
if (p && p->detect && p->detect() > 0) {
|
|
p->flags |= IOMMU_DETECTED;
|
|
if (p->early_init)
|
|
p->early_init();
|
|
if (p->flags & IOMMU_FINISH_IF_DETECTED)
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
void *dma_generic_alloc_coherent(struct device *dev, size_t size,
|
|
dma_addr_t *dma_addr, gfp_t flag,
|
|
unsigned long attrs)
|
|
{
|
|
unsigned long dma_mask;
|
|
struct page *page;
|
|
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
|
|
dma_addr_t addr;
|
|
|
|
dma_mask = dma_alloc_coherent_mask(dev, flag);
|
|
|
|
again:
|
|
page = NULL;
|
|
/* CMA can be used only in the context which permits sleeping */
|
|
if (gfpflags_allow_blocking(flag)) {
|
|
page = dma_alloc_from_contiguous(dev, count, get_order(size),
|
|
flag);
|
|
if (page) {
|
|
addr = phys_to_dma(dev, page_to_phys(page));
|
|
if (addr + size > dma_mask) {
|
|
dma_release_from_contiguous(dev, page, count);
|
|
page = NULL;
|
|
}
|
|
}
|
|
}
|
|
/* fallback */
|
|
if (!page)
|
|
page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
|
|
if (!page)
|
|
return NULL;
|
|
|
|
addr = phys_to_dma(dev, page_to_phys(page));
|
|
if (addr + size > dma_mask) {
|
|
__free_pages(page, get_order(size));
|
|
|
|
if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
|
|
flag = (flag & ~GFP_DMA32) | GFP_DMA;
|
|
goto again;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
memset(page_address(page), 0, size);
|
|
*dma_addr = addr;
|
|
return page_address(page);
|
|
}
|
|
|
|
void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
|
|
dma_addr_t dma_addr, unsigned long attrs)
|
|
{
|
|
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
|
|
struct page *page = virt_to_page(vaddr);
|
|
|
|
if (!dma_release_from_contiguous(dev, page, count))
|
|
free_pages((unsigned long)vaddr, get_order(size));
|
|
}
|
|
|
|
bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
|
|
{
|
|
if (!*dev)
|
|
*dev = &x86_dma_fallback_dev;
|
|
|
|
*gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);
|
|
|
|
if (!is_device_dma_capable(*dev))
|
|
return false;
|
|
return true;
|
|
|
|
}
|
|
EXPORT_SYMBOL(arch_dma_alloc_attrs);
|
|
|
|
/*
|
|
* See <Documentation/x86/x86_64/boot-options.txt> 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))
|
|
iommu_sac_force = 1;
|
|
if (!strncmp(p, "allowdac", 8))
|
|
forbid_dac = 0;
|
|
if (!strncmp(p, "nodac", 5))
|
|
forbid_dac = 1;
|
|
if (!strncmp(p, "usedac", 6)) {
|
|
forbid_dac = -1;
|
|
return 1;
|
|
}
|
|
#ifdef CONFIG_SWIOTLB
|
|
if (!strncmp(p, "soft", 4))
|
|
swiotlb = 1;
|
|
#endif
|
|
if (!strncmp(p, "pt", 2))
|
|
iommu_pass_through = 1;
|
|
|
|
gart_parse_options(p);
|
|
|
|
#ifdef CONFIG_CALGARY_IOMMU
|
|
if (!strncmp(p, "calgary", 7))
|
|
use_calgary = 1;
|
|
#endif /* CONFIG_CALGARY_IOMMU */
|
|
|
|
p += strcspn(p, ",");
|
|
if (*p == ',')
|
|
++p;
|
|
}
|
|
return 0;
|
|
}
|
|
early_param("iommu", iommu_setup);
|
|
|
|
int arch_dma_supported(struct device *dev, u64 mask)
|
|
{
|
|
#ifdef CONFIG_PCI
|
|
if (mask > 0xffffffff && forbid_dac > 0) {
|
|
dev_info(dev, "PCI: Disallowing DAC for device\n");
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/* Tell the device to use SAC when IOMMU force is on. This
|
|
allows the driver to use cheaper accesses in some cases.
|
|
|
|
Problem with this is that if we overflow the IOMMU area and
|
|
return DAC as fallback address the device may not handle it
|
|
correctly.
|
|
|
|
As a special case some controllers have a 39bit address
|
|
mode that is as efficient as 32bit (aic79xx). Don't force
|
|
SAC for these. Assume all masks <= 40 bits are of this
|
|
type. Normally this doesn't make any difference, but gives
|
|
more gentle handling of IOMMU overflow. */
|
|
if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
|
|
dev_info(dev, "Force SAC with mask %Lx\n", mask);
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL(arch_dma_supported);
|
|
|
|
int x86_dma_supported(struct device *dev, u64 mask)
|
|
{
|
|
/* Copied from i386. Doesn't make much sense, because it will
|
|
only work for pci_alloc_coherent.
|
|
The caller just has to use GFP_DMA in this case. */
|
|
if (mask < DMA_BIT_MASK(24))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static int __init pci_iommu_init(void)
|
|
{
|
|
struct iommu_table_entry *p;
|
|
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
|
|
|
|
#ifdef CONFIG_PCI
|
|
dma_debug_add_bus(&pci_bus_type);
|
|
#endif
|
|
x86_init.iommu.iommu_init();
|
|
|
|
for (p = __iommu_table; p < __iommu_table_end; p++) {
|
|
if (p && (p->flags & IOMMU_DETECTED) && p->late_init)
|
|
p->late_init();
|
|
}
|
|
|
|
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 void via_no_dac(struct pci_dev *dev)
|
|
{
|
|
if (forbid_dac == 0) {
|
|
dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
|
|
forbid_dac = 1;
|
|
}
|
|
}
|
|
DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,
|
|
PCI_CLASS_BRIDGE_PCI, 8, via_no_dac);
|
|
#endif
|