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>
31 #include <asm/x86_init.h>
33 int gart_iommu_aperture
;
34 int gart_iommu_aperture_disabled __initdata
;
35 int gart_iommu_aperture_allowed __initdata
;
37 int fallback_aper_order __initdata
= 1; /* 64MB */
38 int fallback_aper_force __initdata
;
40 int fix_aperture __initdata
= 1;
42 struct bus_dev_range
{
48 static struct bus_dev_range bus_dev_ranges
[] __initdata
= {
54 static struct resource gart_resource
= {
56 .flags
= IORESOURCE_MEM
,
59 static void __init
insert_aperture_resource(u32 aper_base
, u32 aper_size
)
61 gart_resource
.start
= aper_base
;
62 gart_resource
.end
= aper_base
+ aper_size
- 1;
63 insert_resource(&iomem_resource
, &gart_resource
);
66 /* This code runs before the PCI subsystem is initialized, so just
67 access the northbridge directly. */
69 static u32 __init
allocate_aperture(void)
74 /* aper_size should <= 1G */
75 if (fallback_aper_order
> 5)
76 fallback_aper_order
= 5;
77 aper_size
= (32 * 1024 * 1024) << fallback_aper_order
;
80 * Aperture has to be naturally aligned. This means a 2GB aperture
81 * won't have much chance of finding a place in the lower 4GB of
82 * memory. Unfortunately we cannot move it up because that would
83 * make the IOMMU useless.
86 * using 512M as goal, in case kexec will load kernel_big
87 * that will do the on position decompress, and could overlap with
88 * that positon with gart that is used.
91 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
92 * ==> kernel_small(gart area become e820_reserved)
93 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
94 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
95 * so don't use 512M below as gart iommu, leave the space for kernel
98 p
= __alloc_bootmem_nopanic(aper_size
, aper_size
, 512ULL<<20);
100 * Kmemleak should not scan this block as it may not be mapped via the
101 * kernel direct mapping.
104 if (!p
|| __pa(p
)+aper_size
> 0xffffffff) {
106 "Cannot allocate aperture memory hole (%p,%uK)\n",
109 free_bootmem(__pa(p
), aper_size
);
112 printk(KERN_INFO
"Mapping aperture over %d KB of RAM @ %lx\n",
113 aper_size
>> 10, __pa(p
));
114 insert_aperture_resource((u32
)__pa(p
), aper_size
);
115 register_nosave_region((u32
)__pa(p
) >> PAGE_SHIFT
,
116 (u32
)__pa(p
+aper_size
) >> PAGE_SHIFT
);
122 /* Find a PCI capability */
123 static u32 __init
find_cap(int bus
, int slot
, int func
, int cap
)
128 if (!(read_pci_config_16(bus
, slot
, func
, PCI_STATUS
) &
129 PCI_STATUS_CAP_LIST
))
132 pos
= read_pci_config_byte(bus
, slot
, func
, PCI_CAPABILITY_LIST
);
133 for (bytes
= 0; bytes
< 48 && pos
>= 0x40; bytes
++) {
137 id
= read_pci_config_byte(bus
, slot
, func
, pos
+PCI_CAP_LIST_ID
);
142 pos
= read_pci_config_byte(bus
, slot
, func
,
143 pos
+PCI_CAP_LIST_NEXT
);
148 /* Read a standard AGPv3 bridge header */
149 static u32 __init
read_agp(int bus
, int slot
, int func
, int cap
, u32
*order
)
154 u32 aper_low
, aper_hi
;
158 printk(KERN_INFO
"AGP bridge at %02x:%02x:%02x\n", bus
, slot
, func
);
159 apsizereg
= read_pci_config_16(bus
, slot
, func
, cap
+ 0x14);
160 if (apsizereg
== 0xffffffff) {
161 printk(KERN_ERR
"APSIZE in AGP bridge unreadable\n");
165 /* old_order could be the value from NB gart setting */
168 apsize
= apsizereg
& 0xfff;
169 /* Some BIOS use weird encodings not in the AGPv3 table. */
172 nbits
= hweight16(apsize
);
174 if ((int)*order
< 0) /* < 32MB */
177 aper_low
= read_pci_config(bus
, slot
, func
, 0x10);
178 aper_hi
= read_pci_config(bus
, slot
, func
, 0x14);
179 aper
= (aper_low
& ~((1<<22)-1)) | ((u64
)aper_hi
<< 32);
182 * On some sick chips, APSIZE is 0. It means it wants 4G
183 * so let double check that order, and lets trust AMD NB settings:
185 printk(KERN_INFO
"Aperture from AGP @ %Lx old size %u MB\n",
186 aper
, 32 << old_order
);
187 if (aper
+ (32ULL<<(20 + *order
)) > 0x100000000ULL
) {
188 printk(KERN_INFO
"Aperture size %u MB (APSIZE %x) is not right, using settings from NB\n",
189 32 << *order
, apsizereg
);
193 printk(KERN_INFO
"Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n",
194 aper
, 32 << *order
, apsizereg
);
196 if (!aperture_valid(aper
, (32*1024*1024) << *order
, 32<<20))
202 * Look for an AGP bridge. Windows only expects the aperture in the
203 * AGP bridge and some BIOS forget to initialize the Northbridge too.
204 * Work around this here.
206 * Do an PCI bus scan by hand because we're running before the PCI
209 * All K8 AGP bridges are AGPv3 compliant, so we can do this scan
210 * generically. It's probably overkill to always scan all slots because
211 * the AGP bridges should be always an own bus on the HT hierarchy,
212 * but do it here for future safety.
214 static u32 __init
search_agp_bridge(u32
*order
, int *valid_agp
)
218 /* Poor man's PCI discovery */
219 for (bus
= 0; bus
< 256; bus
++) {
220 for (slot
= 0; slot
< 32; slot
++) {
221 for (func
= 0; func
< 8; func
++) {
224 class = read_pci_config(bus
, slot
, func
,
226 if (class == 0xffffffff)
229 switch (class >> 16) {
230 case PCI_CLASS_BRIDGE_HOST
:
231 case PCI_CLASS_BRIDGE_OTHER
: /* needed? */
233 cap
= find_cap(bus
, slot
, func
,
238 return read_agp(bus
, slot
, func
, cap
,
242 /* No multi-function device? */
243 type
= read_pci_config_byte(bus
, slot
, func
,
250 printk(KERN_INFO
"No AGP bridge found\n");
255 static int gart_fix_e820 __initdata
= 1;
257 static int __init
parse_gart_mem(char *p
)
262 if (!strncmp(p
, "off", 3))
264 else if (!strncmp(p
, "on", 2))
269 early_param("gart_fix_e820", parse_gart_mem
);
271 void __init
early_gart_iommu_check(void)
274 * in case it is enabled before, esp for kexec/kdump,
275 * previous kernel already enable that. memset called
276 * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
277 * or second kernel have different position for GART hole. and new
278 * kernel could use hole as RAM that is still used by GART set by
280 * or BIOS forget to put that in reserved.
281 * try to update e820 to make that region as reserved.
283 u32 agp_aper_base
= 0, agp_aper_order
= 0;
284 int i
, fix
, slot
, valid_agp
= 0;
286 u32 aper_size
= 0, aper_order
= 0, last_aper_order
= 0;
287 u64 aper_base
= 0, last_aper_base
= 0;
288 int aper_enabled
= 0, last_aper_enabled
= 0, last_valid
= 0;
290 if (!early_pci_allowed())
293 /* This is mostly duplicate of iommu_hole_init */
294 agp_aper_base
= search_agp_bridge(&agp_aper_order
, &valid_agp
);
297 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
299 int dev_base
, dev_limit
;
301 bus
= bus_dev_ranges
[i
].bus
;
302 dev_base
= bus_dev_ranges
[i
].dev_base
;
303 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
305 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
306 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
309 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
310 aper_enabled
= ctl
& AMD64_GARTEN
;
311 aper_order
= (ctl
>> 1) & 7;
312 aper_size
= (32 * 1024 * 1024) << aper_order
;
313 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
317 if ((aper_order
!= last_aper_order
) ||
318 (aper_base
!= last_aper_base
) ||
319 (aper_enabled
!= last_aper_enabled
)) {
325 last_aper_order
= aper_order
;
326 last_aper_base
= aper_base
;
327 last_aper_enabled
= aper_enabled
;
332 if (!fix
&& !aper_enabled
)
335 if (!aper_base
|| !aper_size
|| aper_base
+ aper_size
> 0x100000000UL
)
338 if (gart_fix_e820
&& !fix
&& aper_enabled
) {
339 if (e820_any_mapped(aper_base
, aper_base
+ aper_size
,
341 /* reserve it, so we can reuse it in second kernel */
342 printk(KERN_INFO
"update e820 for GART\n");
343 e820_add_region(aper_base
, aper_size
, E820_RESERVED
);
351 /* disable them all at first */
352 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
354 int dev_base
, dev_limit
;
356 bus
= bus_dev_ranges
[i
].bus
;
357 dev_base
= bus_dev_ranges
[i
].dev_base
;
358 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
360 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
361 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
364 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
365 ctl
&= ~AMD64_GARTEN
;
366 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, ctl
);
372 static int __initdata printed_gart_size_msg
;
374 void __init
gart_iommu_hole_init(void)
376 u32 agp_aper_base
= 0, agp_aper_order
= 0;
377 u32 aper_size
, aper_alloc
= 0, aper_order
= 0, last_aper_order
= 0;
378 u64 aper_base
, last_aper_base
= 0;
379 int fix
, slot
, valid_agp
= 0;
382 if (gart_iommu_aperture_disabled
|| !fix_aperture
||
383 !early_pci_allowed())
386 printk(KERN_INFO
"Checking aperture...\n");
388 if (!fallback_aper_force
)
389 agp_aper_base
= search_agp_bridge(&agp_aper_order
, &valid_agp
);
393 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
395 int dev_base
, dev_limit
;
398 bus
= bus_dev_ranges
[i
].bus
;
399 dev_base
= bus_dev_ranges
[i
].dev_base
;
400 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
402 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
403 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
407 gart_iommu_aperture
= 1;
408 x86_init
.iommu
.iommu_init
= gart_iommu_init
;
410 ctl
= read_pci_config(bus
, slot
, 3,
411 AMD64_GARTAPERTURECTL
);
414 * Before we do anything else disable the GART. It may
415 * still be enabled if we boot into a crash-kernel here.
416 * Reconfiguring the GART while it is enabled could have
417 * unknown side-effects.
420 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, ctl
);
422 aper_order
= (ctl
>> 1) & 7;
423 aper_size
= (32 * 1024 * 1024) << aper_order
;
424 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
427 printk(KERN_INFO
"Node %d: aperture @ %Lx size %u MB\n",
428 node
, aper_base
, aper_size
>> 20);
431 if (!aperture_valid(aper_base
, aper_size
, 64<<20)) {
432 if (valid_agp
&& agp_aper_base
&&
433 agp_aper_base
== aper_base
&&
434 agp_aper_order
== aper_order
) {
435 /* the same between two setting from NB and agp */
437 max_pfn
> MAX_DMA32_PFN
&&
438 !printed_gart_size_msg
) {
439 printk(KERN_ERR
"you are using iommu with agp, but GART size is less than 64M\n");
440 printk(KERN_ERR
"please increase GART size in your BIOS setup\n");
441 printk(KERN_ERR
"if BIOS doesn't have that option, contact your HW vendor!\n");
442 printed_gart_size_msg
= 1;
450 if ((last_aper_order
&& aper_order
!= last_aper_order
) ||
451 (last_aper_base
&& aper_base
!= last_aper_base
)) {
455 last_aper_order
= aper_order
;
456 last_aper_base
= aper_base
;
461 if (!fix
&& !fallback_aper_force
) {
462 if (last_aper_base
) {
463 unsigned long n
= (32 * 1024 * 1024) << last_aper_order
;
465 insert_aperture_resource((u32
)last_aper_base
, n
);
470 if (!fallback_aper_force
) {
471 aper_alloc
= agp_aper_base
;
472 aper_order
= agp_aper_order
;
476 /* Got the aperture from the AGP bridge */
477 } else if ((!no_iommu
&& max_pfn
> MAX_DMA32_PFN
) ||
480 fallback_aper_force
) {
482 "Your BIOS doesn't leave a aperture memory hole\n");
484 "Please enable the IOMMU option in the BIOS setup\n");
486 "This costs you %d MB of RAM\n",
487 32 << fallback_aper_order
);
489 aper_order
= fallback_aper_order
;
490 aper_alloc
= allocate_aperture();
493 * Could disable AGP and IOMMU here, but it's
494 * probably not worth it. But the later users
495 * cannot deal with bad apertures and turning
496 * on the aperture over memory causes very
497 * strange problems, so it's better to panic
500 panic("Not enough memory for aperture");
506 /* Fix up the north bridges */
507 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
509 int dev_base
, dev_limit
;
511 bus
= bus_dev_ranges
[i
].bus
;
512 dev_base
= bus_dev_ranges
[i
].dev_base
;
513 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
514 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
515 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
518 /* Don't enable translation yet. That is done later.
519 Assume this BIOS didn't initialise the GART so
520 just overwrite all previous bits */
521 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, aper_order
<< 1);
522 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
, aper_alloc
>> 25);
526 set_up_gart_resume(aper_order
, aper_alloc
);