2 * Firmware replacement code.
4 * Work around broken BIOSes that don't set an aperture, only set the
5 * aperture in the AGP bridge, or set too small aperture.
7 * If all fails map the aperture over some low memory. This is cheaper than
8 * doing bounce buffering. The memory is lost. This is done at early boot
9 * because only the bootmem allocator can allocate 32+MB.
11 * Copyright 2002 Andi Kleen, SuSE Labs.
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/init.h>
16 #include <linux/bootmem.h>
17 #include <linux/mmzone.h>
18 #include <linux/pci_ids.h>
19 #include <linux/pci.h>
20 #include <linux/bitops.h>
21 #include <linux/ioport.h>
22 #include <linux/suspend.h>
23 #include <linux/kmemleak.h>
26 #include <asm/iommu.h>
28 #include <asm/pci-direct.h>
32 int gart_iommu_aperture
;
33 int gart_iommu_aperture_disabled __initdata
;
34 int gart_iommu_aperture_allowed __initdata
;
36 int fallback_aper_order __initdata
= 1; /* 64MB */
37 int fallback_aper_force __initdata
;
39 int fix_aperture __initdata
= 1;
41 struct bus_dev_range
{
47 static struct bus_dev_range bus_dev_ranges
[] __initdata
= {
53 static struct resource gart_resource
= {
55 .flags
= IORESOURCE_MEM
,
58 static void __init
insert_aperture_resource(u32 aper_base
, u32 aper_size
)
60 gart_resource
.start
= aper_base
;
61 gart_resource
.end
= aper_base
+ aper_size
- 1;
62 insert_resource(&iomem_resource
, &gart_resource
);
65 /* This code runs before the PCI subsystem is initialized, so just
66 access the northbridge directly. */
68 static u32 __init
allocate_aperture(void)
73 /* aper_size should <= 1G */
74 if (fallback_aper_order
> 5)
75 fallback_aper_order
= 5;
76 aper_size
= (32 * 1024 * 1024) << fallback_aper_order
;
79 * Aperture has to be naturally aligned. This means a 2GB aperture
80 * won't have much chance of finding a place in the lower 4GB of
81 * memory. Unfortunately we cannot move it up because that would
82 * make the IOMMU useless.
85 * using 512M as goal, in case kexec will load kernel_big
86 * that will do the on position decompress, and could overlap with
87 * that positon with gart that is used.
90 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
91 * ==> kernel_small(gart area become e820_reserved)
92 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
93 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
94 * so don't use 512M below as gart iommu, leave the space for kernel
97 p
= __alloc_bootmem_nopanic(aper_size
, aper_size
, 512ULL<<20);
99 * Kmemleak should not scan this block as it may not be mapped via the
100 * kernel direct mapping.
103 if (!p
|| __pa(p
)+aper_size
> 0xffffffff) {
105 "Cannot allocate aperture memory hole (%p,%uK)\n",
108 free_bootmem(__pa(p
), aper_size
);
111 printk(KERN_INFO
"Mapping aperture over %d KB of RAM @ %lx\n",
112 aper_size
>> 10, __pa(p
));
113 insert_aperture_resource((u32
)__pa(p
), aper_size
);
114 register_nosave_region((u32
)__pa(p
) >> PAGE_SHIFT
,
115 (u32
)__pa(p
+aper_size
) >> PAGE_SHIFT
);
121 /* Find a PCI capability */
122 static u32 __init
find_cap(int bus
, int slot
, int func
, int cap
)
127 if (!(read_pci_config_16(bus
, slot
, func
, PCI_STATUS
) &
128 PCI_STATUS_CAP_LIST
))
131 pos
= read_pci_config_byte(bus
, slot
, func
, PCI_CAPABILITY_LIST
);
132 for (bytes
= 0; bytes
< 48 && pos
>= 0x40; bytes
++) {
136 id
= read_pci_config_byte(bus
, slot
, func
, pos
+PCI_CAP_LIST_ID
);
141 pos
= read_pci_config_byte(bus
, slot
, func
,
142 pos
+PCI_CAP_LIST_NEXT
);
147 /* Read a standard AGPv3 bridge header */
148 static u32 __init
read_agp(int bus
, int slot
, int func
, int cap
, u32
*order
)
153 u32 aper_low
, aper_hi
;
157 printk(KERN_INFO
"AGP bridge at %02x:%02x:%02x\n", bus
, slot
, func
);
158 apsizereg
= read_pci_config_16(bus
, slot
, func
, cap
+ 0x14);
159 if (apsizereg
== 0xffffffff) {
160 printk(KERN_ERR
"APSIZE in AGP bridge unreadable\n");
164 /* old_order could be the value from NB gart setting */
167 apsize
= apsizereg
& 0xfff;
168 /* Some BIOS use weird encodings not in the AGPv3 table. */
171 nbits
= hweight16(apsize
);
173 if ((int)*order
< 0) /* < 32MB */
176 aper_low
= read_pci_config(bus
, slot
, func
, 0x10);
177 aper_hi
= read_pci_config(bus
, slot
, func
, 0x14);
178 aper
= (aper_low
& ~((1<<22)-1)) | ((u64
)aper_hi
<< 32);
181 * On some sick chips, APSIZE is 0. It means it wants 4G
182 * so let double check that order, and lets trust AMD NB settings:
184 printk(KERN_INFO
"Aperture from AGP @ %Lx old size %u MB\n",
185 aper
, 32 << old_order
);
186 if (aper
+ (32ULL<<(20 + *order
)) > 0x100000000ULL
) {
187 printk(KERN_INFO
"Aperture size %u MB (APSIZE %x) is not right, using settings from NB\n",
188 32 << *order
, apsizereg
);
192 printk(KERN_INFO
"Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n",
193 aper
, 32 << *order
, apsizereg
);
195 if (!aperture_valid(aper
, (32*1024*1024) << *order
, 32<<20))
201 * Look for an AGP bridge. Windows only expects the aperture in the
202 * AGP bridge and some BIOS forget to initialize the Northbridge too.
203 * Work around this here.
205 * Do an PCI bus scan by hand because we're running before the PCI
208 * All K8 AGP bridges are AGPv3 compliant, so we can do this scan
209 * generically. It's probably overkill to always scan all slots because
210 * the AGP bridges should be always an own bus on the HT hierarchy,
211 * but do it here for future safety.
213 static u32 __init
search_agp_bridge(u32
*order
, int *valid_agp
)
217 /* Poor man's PCI discovery */
218 for (bus
= 0; bus
< 256; bus
++) {
219 for (slot
= 0; slot
< 32; slot
++) {
220 for (func
= 0; func
< 8; func
++) {
223 class = read_pci_config(bus
, slot
, func
,
225 if (class == 0xffffffff)
228 switch (class >> 16) {
229 case PCI_CLASS_BRIDGE_HOST
:
230 case PCI_CLASS_BRIDGE_OTHER
: /* needed? */
232 cap
= find_cap(bus
, slot
, func
,
237 return read_agp(bus
, slot
, func
, cap
,
241 /* No multi-function device? */
242 type
= read_pci_config_byte(bus
, slot
, func
,
249 printk(KERN_INFO
"No AGP bridge found\n");
254 static int gart_fix_e820 __initdata
= 1;
256 static int __init
parse_gart_mem(char *p
)
261 if (!strncmp(p
, "off", 3))
263 else if (!strncmp(p
, "on", 2))
268 early_param("gart_fix_e820", parse_gart_mem
);
270 void __init
early_gart_iommu_check(void)
273 * in case it is enabled before, esp for kexec/kdump,
274 * previous kernel already enable that. memset called
275 * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
276 * or second kernel have different position for GART hole. and new
277 * kernel could use hole as RAM that is still used by GART set by
279 * or BIOS forget to put that in reserved.
280 * try to update e820 to make that region as reserved.
284 u32 aper_size
= 0, aper_order
= 0, last_aper_order
= 0;
285 u64 aper_base
= 0, last_aper_base
= 0;
286 int aper_enabled
= 0, last_aper_enabled
= 0, last_valid
= 0;
288 if (!early_pci_allowed())
291 /* This is mostly duplicate of iommu_hole_init */
293 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
295 int dev_base
, dev_limit
;
297 bus
= bus_dev_ranges
[i
].bus
;
298 dev_base
= bus_dev_ranges
[i
].dev_base
;
299 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
301 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
302 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
305 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
306 aper_enabled
= ctl
& AMD64_GARTEN
;
307 aper_order
= (ctl
>> 1) & 7;
308 aper_size
= (32 * 1024 * 1024) << aper_order
;
309 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
313 if ((aper_order
!= last_aper_order
) ||
314 (aper_base
!= last_aper_base
) ||
315 (aper_enabled
!= last_aper_enabled
)) {
321 last_aper_order
= aper_order
;
322 last_aper_base
= aper_base
;
323 last_aper_enabled
= aper_enabled
;
328 if (!fix
&& !aper_enabled
)
331 if (!aper_base
|| !aper_size
|| aper_base
+ aper_size
> 0x100000000UL
)
334 if (gart_fix_e820
&& !fix
&& aper_enabled
) {
335 if (e820_any_mapped(aper_base
, aper_base
+ aper_size
,
337 /* reserve it, so we can reuse it in second kernel */
338 printk(KERN_INFO
"update e820 for GART\n");
339 e820_add_region(aper_base
, aper_size
, E820_RESERVED
);
347 /* different nodes have different setting, disable them all at first*/
348 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
350 int dev_base
, dev_limit
;
352 bus
= bus_dev_ranges
[i
].bus
;
353 dev_base
= bus_dev_ranges
[i
].dev_base
;
354 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
356 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
357 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
360 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
361 ctl
&= ~AMD64_GARTEN
;
362 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, ctl
);
368 static int __initdata printed_gart_size_msg
;
370 void __init
gart_iommu_hole_init(void)
372 u32 agp_aper_base
= 0, agp_aper_order
= 0;
373 u32 aper_size
, aper_alloc
= 0, aper_order
= 0, last_aper_order
= 0;
374 u64 aper_base
, last_aper_base
= 0;
375 int fix
, slot
, valid_agp
= 0;
378 if (gart_iommu_aperture_disabled
|| !fix_aperture
||
379 !early_pci_allowed())
382 printk(KERN_INFO
"Checking aperture...\n");
384 if (!fallback_aper_force
)
385 agp_aper_base
= search_agp_bridge(&agp_aper_order
, &valid_agp
);
389 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
391 int dev_base
, dev_limit
;
393 bus
= bus_dev_ranges
[i
].bus
;
394 dev_base
= bus_dev_ranges
[i
].dev_base
;
395 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
397 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
398 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
402 gart_iommu_aperture
= 1;
404 aper_order
= (read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
) >> 1) & 7;
405 aper_size
= (32 * 1024 * 1024) << aper_order
;
406 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
409 printk(KERN_INFO
"Node %d: aperture @ %Lx size %u MB\n",
410 node
, aper_base
, aper_size
>> 20);
413 if (!aperture_valid(aper_base
, aper_size
, 64<<20)) {
414 if (valid_agp
&& agp_aper_base
&&
415 agp_aper_base
== aper_base
&&
416 agp_aper_order
== aper_order
) {
417 /* the same between two setting from NB and agp */
419 max_pfn
> MAX_DMA32_PFN
&&
420 !printed_gart_size_msg
) {
421 printk(KERN_ERR
"you are using iommu with agp, but GART size is less than 64M\n");
422 printk(KERN_ERR
"please increase GART size in your BIOS setup\n");
423 printk(KERN_ERR
"if BIOS doesn't have that option, contact your HW vendor!\n");
424 printed_gart_size_msg
= 1;
432 if ((last_aper_order
&& aper_order
!= last_aper_order
) ||
433 (last_aper_base
&& aper_base
!= last_aper_base
)) {
437 last_aper_order
= aper_order
;
438 last_aper_base
= aper_base
;
443 if (!fix
&& !fallback_aper_force
) {
444 if (last_aper_base
) {
445 unsigned long n
= (32 * 1024 * 1024) << last_aper_order
;
447 insert_aperture_resource((u32
)last_aper_base
, n
);
452 if (!fallback_aper_force
) {
453 aper_alloc
= agp_aper_base
;
454 aper_order
= agp_aper_order
;
458 /* Got the aperture from the AGP bridge */
459 } else if (swiotlb
&& !valid_agp
) {
461 } else if ((!no_iommu
&& max_pfn
> MAX_DMA32_PFN
) ||
464 fallback_aper_force
) {
466 "Your BIOS doesn't leave a aperture memory hole\n");
468 "Please enable the IOMMU option in the BIOS setup\n");
470 "This costs you %d MB of RAM\n",
471 32 << fallback_aper_order
);
473 aper_order
= fallback_aper_order
;
474 aper_alloc
= allocate_aperture();
477 * Could disable AGP and IOMMU here, but it's
478 * probably not worth it. But the later users
479 * cannot deal with bad apertures and turning
480 * on the aperture over memory causes very
481 * strange problems, so it's better to panic
484 panic("Not enough memory for aperture");
490 /* Fix up the north bridges */
491 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
493 int dev_base
, dev_limit
;
495 bus
= bus_dev_ranges
[i
].bus
;
496 dev_base
= bus_dev_ranges
[i
].dev_base
;
497 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
498 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
499 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
502 /* Don't enable translation yet. That is done later.
503 Assume this BIOS didn't initialise the GART so
504 just overwrite all previous bits */
505 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, aper_order
<< 1);
506 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
, aper_alloc
>> 25);
510 set_up_gart_resume(aper_order
, aper_alloc
);