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1#include <linux/dma-mapping.h>
2#include <linux/dma-debug.h>
3#include <linux/dmar.h>
4#include <linux/export.h>
5#include <linux/bootmem.h>
6#include <linux/gfp.h>
7#include <linux/pci.h>
8#include <linux/kmemleak.h>
9
10#include <asm/proto.h>
11#include <asm/dma.h>
12#include <asm/iommu.h>
13#include <asm/gart.h>
14#include <asm/calgary.h>
15#include <asm/x86_init.h>
16#include <asm/iommu_table.h>
17
18static int forbid_dac __read_mostly;
19
20struct dma_map_ops *dma_ops = &nommu_dma_ops;
21EXPORT_SYMBOL(dma_ops);
22
23static int iommu_sac_force __read_mostly;
24
25#ifdef CONFIG_IOMMU_DEBUG
26int panic_on_overflow __read_mostly = 1;
27int force_iommu __read_mostly = 1;
28#else
29int panic_on_overflow __read_mostly = 0;
30int force_iommu __read_mostly = 0;
31#endif
32
33int iommu_merge __read_mostly = 0;
34
35int no_iommu __read_mostly;
36/* Set this to 1 if there is a HW IOMMU in the system */
37int iommu_detected __read_mostly = 0;
38
39/*
40 * This variable becomes 1 if iommu=pt is passed on the kernel command line.
41 * If this variable is 1, IOMMU implementations do no DMA translation for
42 * devices and allow every device to access to whole physical memory. This is
43 * useful if a user wants to use an IOMMU only for KVM device assignment to
44 * guests and not for driver dma translation.
45 */
46int iommu_pass_through __read_mostly;
47
48/*
49 * Group multi-function PCI devices into a single device-group for the
50 * iommu_device_group interface. This tells the iommu driver to pretend
51 * it cannot distinguish between functions of a device, exposing only one
52 * group for the device. Useful for disallowing use of individual PCI
53 * functions from userspace drivers.
54 */
55int iommu_group_mf __read_mostly;
56
57extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
58
59/* Dummy device used for NULL arguments (normally ISA). */
60struct device x86_dma_fallback_dev = {
61 .init_name = "fallback device",
62 .coherent_dma_mask = ISA_DMA_BIT_MASK,
63 .dma_mask = &x86_dma_fallback_dev.coherent_dma_mask,
64};
65EXPORT_SYMBOL(x86_dma_fallback_dev);
66
67/* Number of entries preallocated for DMA-API debugging */
68#define PREALLOC_DMA_DEBUG_ENTRIES 32768
69
70int dma_set_mask(struct device *dev, u64 mask)
71{
72 if (!dev->dma_mask || !dma_supported(dev, mask))
73 return -EIO;
74
75 *dev->dma_mask = mask;
76
77 return 0;
78}
79EXPORT_SYMBOL(dma_set_mask);
80
81void __init pci_iommu_alloc(void)
82{
83 struct iommu_table_entry *p;
84
85 sort_iommu_table(__iommu_table, __iommu_table_end);
86 check_iommu_entries(__iommu_table, __iommu_table_end);
87
88 for (p = __iommu_table; p < __iommu_table_end; p++) {
89 if (p && p->detect && p->detect() > 0) {
90 p->flags |= IOMMU_DETECTED;
91 if (p->early_init)
92 p->early_init();
93 if (p->flags & IOMMU_FINISH_IF_DETECTED)
94 break;
95 }
96 }
97}
98void *dma_generic_alloc_coherent(struct device *dev, size_t size,
99 dma_addr_t *dma_addr, gfp_t flag,
100 struct dma_attrs *attrs)
101{
102 unsigned long dma_mask;
103 struct page *page;
104 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
105 dma_addr_t addr;
106
107 dma_mask = dma_alloc_coherent_mask(dev, flag);
108
109 flag |= __GFP_ZERO;
110again:
111 page = NULL;
112 if (!(flag & GFP_ATOMIC))
113 page = dma_alloc_from_contiguous(dev, count, get_order(size));
114 if (!page)
115 page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
116 if (!page)
117 return NULL;
118
119 addr = page_to_phys(page);
120 if (addr + size > dma_mask) {
121 __free_pages(page, get_order(size));
122
123 if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) {
124 flag = (flag & ~GFP_DMA32) | GFP_DMA;
125 goto again;
126 }
127
128 return NULL;
129 }
130
131 *dma_addr = addr;
132 return page_address(page);
133}
134
135void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr,
136 dma_addr_t dma_addr, struct dma_attrs *attrs)
137{
138 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
139 struct page *page = virt_to_page(vaddr);
140
141 if (!dma_release_from_contiguous(dev, page, count))
142 free_pages((unsigned long)vaddr, get_order(size));
143}
144
145/*
146 * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel
147 * parameter documentation.
148 */
149static __init int iommu_setup(char *p)
150{
151 iommu_merge = 1;
152
153 if (!p)
154 return -EINVAL;
155
156 while (*p) {
157 if (!strncmp(p, "off", 3))
158 no_iommu = 1;
159 /* gart_parse_options has more force support */
160 if (!strncmp(p, "force", 5))
161 force_iommu = 1;
162 if (!strncmp(p, "noforce", 7)) {
163 iommu_merge = 0;
164 force_iommu = 0;
165 }
166
167 if (!strncmp(p, "biomerge", 8)) {
168 iommu_merge = 1;
169 force_iommu = 1;
170 }
171 if (!strncmp(p, "panic", 5))
172 panic_on_overflow = 1;
173 if (!strncmp(p, "nopanic", 7))
174 panic_on_overflow = 0;
175 if (!strncmp(p, "merge", 5)) {
176 iommu_merge = 1;
177 force_iommu = 1;
178 }
179 if (!strncmp(p, "nomerge", 7))
180 iommu_merge = 0;
181 if (!strncmp(p, "forcesac", 8))
182 iommu_sac_force = 1;
183 if (!strncmp(p, "allowdac", 8))
184 forbid_dac = 0;
185 if (!strncmp(p, "nodac", 5))
186 forbid_dac = 1;
187 if (!strncmp(p, "usedac", 6)) {
188 forbid_dac = -1;
189 return 1;
190 }
191#ifdef CONFIG_SWIOTLB
192 if (!strncmp(p, "soft", 4))
193 swiotlb = 1;
194#endif
195 if (!strncmp(p, "pt", 2))
196 iommu_pass_through = 1;
197 if (!strncmp(p, "group_mf", 8))
198 iommu_group_mf = 1;
199
200 gart_parse_options(p);
201
202#ifdef CONFIG_CALGARY_IOMMU
203 if (!strncmp(p, "calgary", 7))
204 use_calgary = 1;
205#endif /* CONFIG_CALGARY_IOMMU */
206
207 p += strcspn(p, ",");
208 if (*p == ',')
209 ++p;
210 }
211 return 0;
212}
213early_param("iommu", iommu_setup);
214
215int dma_supported(struct device *dev, u64 mask)
216{
217 struct dma_map_ops *ops = get_dma_ops(dev);
218
219#ifdef CONFIG_PCI
220 if (mask > 0xffffffff && forbid_dac > 0) {
221 dev_info(dev, "PCI: Disallowing DAC for device\n");
222 return 0;
223 }
224#endif
225
226 if (ops->dma_supported)
227 return ops->dma_supported(dev, mask);
228
229 /* Copied from i386. Doesn't make much sense, because it will
230 only work for pci_alloc_coherent.
231 The caller just has to use GFP_DMA in this case. */
232 if (mask < DMA_BIT_MASK(24))
233 return 0;
234
235 /* Tell the device to use SAC when IOMMU force is on. This
236 allows the driver to use cheaper accesses in some cases.
237
238 Problem with this is that if we overflow the IOMMU area and
239 return DAC as fallback address the device may not handle it
240 correctly.
241
242 As a special case some controllers have a 39bit address
243 mode that is as efficient as 32bit (aic79xx). Don't force
244 SAC for these. Assume all masks <= 40 bits are of this
245 type. Normally this doesn't make any difference, but gives
246 more gentle handling of IOMMU overflow. */
247 if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
248 dev_info(dev, "Force SAC with mask %Lx\n", mask);
249 return 0;
250 }
251
252 return 1;
253}
254EXPORT_SYMBOL(dma_supported);
255
256static int __init pci_iommu_init(void)
257{
258 struct iommu_table_entry *p;
259 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
260
261#ifdef CONFIG_PCI
262 dma_debug_add_bus(&pci_bus_type);
263#endif
264 x86_init.iommu.iommu_init();
265
266 for (p = __iommu_table; p < __iommu_table_end; p++) {
267 if (p && (p->flags & IOMMU_DETECTED) && p->late_init)
268 p->late_init();
269 }
270
271 return 0;
272}
273/* Must execute after PCI subsystem */
274rootfs_initcall(pci_iommu_init);
275
276#ifdef CONFIG_PCI
277/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
278
279static __devinit void via_no_dac(struct pci_dev *dev)
280{
281 if (forbid_dac == 0) {
282 dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
283 forbid_dac = 1;
284 }
285}
286DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,
287 PCI_CLASS_BRIDGE_PCI, 8, via_no_dac);
288#endif
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/dma-direct.h>
3#include <linux/dma-debug.h>
4#include <linux/dmar.h>
5#include <linux/export.h>
6#include <linux/bootmem.h>
7#include <linux/gfp.h>
8#include <linux/pci.h>
9
10#include <asm/proto.h>
11#include <asm/dma.h>
12#include <asm/iommu.h>
13#include <asm/gart.h>
14#include <asm/calgary.h>
15#include <asm/x86_init.h>
16#include <asm/iommu_table.h>
17
18static int forbid_dac __read_mostly;
19
20const struct dma_map_ops *dma_ops = &dma_direct_ops;
21EXPORT_SYMBOL(dma_ops);
22
23static int iommu_sac_force __read_mostly;
24
25#ifdef CONFIG_IOMMU_DEBUG
26int panic_on_overflow __read_mostly = 1;
27int force_iommu __read_mostly = 1;
28#else
29int panic_on_overflow __read_mostly = 0;
30int force_iommu __read_mostly = 0;
31#endif
32
33int iommu_merge __read_mostly = 0;
34
35int no_iommu __read_mostly;
36/* Set this to 1 if there is a HW IOMMU in the system */
37int iommu_detected __read_mostly = 0;
38
39/*
40 * This variable becomes 1 if iommu=pt is passed on the kernel command line.
41 * If this variable is 1, IOMMU implementations do no DMA translation for
42 * devices and allow every device to access to whole physical memory. This is
43 * useful if a user wants to use an IOMMU only for KVM device assignment to
44 * guests and not for driver dma translation.
45 */
46int iommu_pass_through __read_mostly;
47
48extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
49
50/* Dummy device used for NULL arguments (normally ISA). */
51struct device x86_dma_fallback_dev = {
52 .init_name = "fallback device",
53 .coherent_dma_mask = ISA_DMA_BIT_MASK,
54 .dma_mask = &x86_dma_fallback_dev.coherent_dma_mask,
55};
56EXPORT_SYMBOL(x86_dma_fallback_dev);
57
58/* Number of entries preallocated for DMA-API debugging */
59#define PREALLOC_DMA_DEBUG_ENTRIES 65536
60
61void __init pci_iommu_alloc(void)
62{
63 struct iommu_table_entry *p;
64
65 sort_iommu_table(__iommu_table, __iommu_table_end);
66 check_iommu_entries(__iommu_table, __iommu_table_end);
67
68 for (p = __iommu_table; p < __iommu_table_end; p++) {
69 if (p && p->detect && p->detect() > 0) {
70 p->flags |= IOMMU_DETECTED;
71 if (p->early_init)
72 p->early_init();
73 if (p->flags & IOMMU_FINISH_IF_DETECTED)
74 break;
75 }
76 }
77}
78
79bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
80{
81 if (!*dev)
82 *dev = &x86_dma_fallback_dev;
83
84 if (!is_device_dma_capable(*dev))
85 return false;
86 return true;
87
88}
89EXPORT_SYMBOL(arch_dma_alloc_attrs);
90
91/*
92 * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel
93 * parameter documentation.
94 */
95static __init int iommu_setup(char *p)
96{
97 iommu_merge = 1;
98
99 if (!p)
100 return -EINVAL;
101
102 while (*p) {
103 if (!strncmp(p, "off", 3))
104 no_iommu = 1;
105 /* gart_parse_options has more force support */
106 if (!strncmp(p, "force", 5))
107 force_iommu = 1;
108 if (!strncmp(p, "noforce", 7)) {
109 iommu_merge = 0;
110 force_iommu = 0;
111 }
112
113 if (!strncmp(p, "biomerge", 8)) {
114 iommu_merge = 1;
115 force_iommu = 1;
116 }
117 if (!strncmp(p, "panic", 5))
118 panic_on_overflow = 1;
119 if (!strncmp(p, "nopanic", 7))
120 panic_on_overflow = 0;
121 if (!strncmp(p, "merge", 5)) {
122 iommu_merge = 1;
123 force_iommu = 1;
124 }
125 if (!strncmp(p, "nomerge", 7))
126 iommu_merge = 0;
127 if (!strncmp(p, "forcesac", 8))
128 iommu_sac_force = 1;
129 if (!strncmp(p, "allowdac", 8))
130 forbid_dac = 0;
131 if (!strncmp(p, "nodac", 5))
132 forbid_dac = 1;
133 if (!strncmp(p, "usedac", 6)) {
134 forbid_dac = -1;
135 return 1;
136 }
137#ifdef CONFIG_SWIOTLB
138 if (!strncmp(p, "soft", 4))
139 swiotlb = 1;
140#endif
141 if (!strncmp(p, "pt", 2))
142 iommu_pass_through = 1;
143
144 gart_parse_options(p);
145
146#ifdef CONFIG_CALGARY_IOMMU
147 if (!strncmp(p, "calgary", 7))
148 use_calgary = 1;
149#endif /* CONFIG_CALGARY_IOMMU */
150
151 p += strcspn(p, ",");
152 if (*p == ',')
153 ++p;
154 }
155 return 0;
156}
157early_param("iommu", iommu_setup);
158
159int arch_dma_supported(struct device *dev, u64 mask)
160{
161#ifdef CONFIG_PCI
162 if (mask > 0xffffffff && forbid_dac > 0) {
163 dev_info(dev, "PCI: Disallowing DAC for device\n");
164 return 0;
165 }
166#endif
167
168 /* Tell the device to use SAC when IOMMU force is on. This
169 allows the driver to use cheaper accesses in some cases.
170
171 Problem with this is that if we overflow the IOMMU area and
172 return DAC as fallback address the device may not handle it
173 correctly.
174
175 As a special case some controllers have a 39bit address
176 mode that is as efficient as 32bit (aic79xx). Don't force
177 SAC for these. Assume all masks <= 40 bits are of this
178 type. Normally this doesn't make any difference, but gives
179 more gentle handling of IOMMU overflow. */
180 if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
181 dev_info(dev, "Force SAC with mask %Lx\n", mask);
182 return 0;
183 }
184
185 return 1;
186}
187EXPORT_SYMBOL(arch_dma_supported);
188
189static int __init pci_iommu_init(void)
190{
191 struct iommu_table_entry *p;
192 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
193
194#ifdef CONFIG_PCI
195 dma_debug_add_bus(&pci_bus_type);
196#endif
197 x86_init.iommu.iommu_init();
198
199 for (p = __iommu_table; p < __iommu_table_end; p++) {
200 if (p && (p->flags & IOMMU_DETECTED) && p->late_init)
201 p->late_init();
202 }
203
204 return 0;
205}
206/* Must execute after PCI subsystem */
207rootfs_initcall(pci_iommu_init);
208
209#ifdef CONFIG_PCI
210/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
211
212static void via_no_dac(struct pci_dev *dev)
213{
214 if (forbid_dac == 0) {
215 dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
216 forbid_dac = 1;
217 }
218}
219DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,
220 PCI_CLASS_BRIDGE_PCI, 8, via_no_dac);
221#endif