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>
25 #include <asm/iommu.h>
27 #include <asm/pci-direct.h>
31 int gart_iommu_aperture
;
32 int gart_iommu_aperture_disabled __initdata
;
33 int gart_iommu_aperture_allowed __initdata
;
35 int fallback_aper_order __initdata
= 1; /* 64MB */
36 int fallback_aper_force __initdata
;
38 int fix_aperture __initdata
= 1;
40 struct bus_dev_range
{
46 static struct bus_dev_range bus_dev_ranges
[] __initdata
= {
52 static struct resource gart_resource
= {
54 .flags
= IORESOURCE_MEM
,
57 static void __init
insert_aperture_resource(u32 aper_base
, u32 aper_size
)
59 gart_resource
.start
= aper_base
;
60 gart_resource
.end
= aper_base
+ aper_size
- 1;
61 insert_resource(&iomem_resource
, &gart_resource
);
64 /* This code runs before the PCI subsystem is initialized, so just
65 access the northbridge directly. */
67 static u32 __init
allocate_aperture(void)
72 /* aper_size should <= 1G */
73 if (fallback_aper_order
> 5)
74 fallback_aper_order
= 5;
75 aper_size
= (32 * 1024 * 1024) << fallback_aper_order
;
78 * Aperture has to be naturally aligned. This means a 2GB aperture
79 * won't have much chance of finding a place in the lower 4GB of
80 * memory. Unfortunately we cannot move it up because that would
81 * make the IOMMU useless.
84 * using 512M as goal, in case kexec will load kernel_big
85 * that will do the on position decompress, and could overlap with
86 * that positon with gart that is used.
89 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
90 * ==> kernel_small(gart area become e820_reserved)
91 * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
92 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
93 * so don't use 512M below as gart iommu, leave the space for kernel
96 p
= __alloc_bootmem_nopanic(aper_size
, aper_size
, 512ULL<<20);
97 if (!p
|| __pa(p
)+aper_size
> 0xffffffff) {
99 "Cannot allocate aperture memory hole (%p,%uK)\n",
102 free_bootmem(__pa(p
), aper_size
);
105 printk(KERN_INFO
"Mapping aperture over %d KB of RAM @ %lx\n",
106 aper_size
>> 10, __pa(p
));
107 insert_aperture_resource((u32
)__pa(p
), aper_size
);
108 register_nosave_region((u32
)__pa(p
) >> PAGE_SHIFT
,
109 (u32
)__pa(p
+aper_size
) >> PAGE_SHIFT
);
115 /* Find a PCI capability */
116 static u32 __init
find_cap(int bus
, int slot
, int func
, int cap
)
121 if (!(read_pci_config_16(bus
, slot
, func
, PCI_STATUS
) &
122 PCI_STATUS_CAP_LIST
))
125 pos
= read_pci_config_byte(bus
, slot
, func
, PCI_CAPABILITY_LIST
);
126 for (bytes
= 0; bytes
< 48 && pos
>= 0x40; bytes
++) {
130 id
= read_pci_config_byte(bus
, slot
, func
, pos
+PCI_CAP_LIST_ID
);
135 pos
= read_pci_config_byte(bus
, slot
, func
,
136 pos
+PCI_CAP_LIST_NEXT
);
141 /* Read a standard AGPv3 bridge header */
142 static u32 __init
read_agp(int bus
, int slot
, int func
, int cap
, u32
*order
)
147 u32 aper_low
, aper_hi
;
151 printk(KERN_INFO
"AGP bridge at %02x:%02x:%02x\n", bus
, slot
, func
);
152 apsizereg
= read_pci_config_16(bus
, slot
, func
, cap
+ 0x14);
153 if (apsizereg
== 0xffffffff) {
154 printk(KERN_ERR
"APSIZE in AGP bridge unreadable\n");
158 /* old_order could be the value from NB gart setting */
161 apsize
= apsizereg
& 0xfff;
162 /* Some BIOS use weird encodings not in the AGPv3 table. */
165 nbits
= hweight16(apsize
);
167 if ((int)*order
< 0) /* < 32MB */
170 aper_low
= read_pci_config(bus
, slot
, func
, 0x10);
171 aper_hi
= read_pci_config(bus
, slot
, func
, 0x14);
172 aper
= (aper_low
& ~((1<<22)-1)) | ((u64
)aper_hi
<< 32);
175 * On some sick chips, APSIZE is 0. It means it wants 4G
176 * so let double check that order, and lets trust AMD NB settings:
178 printk(KERN_INFO
"Aperture from AGP @ %Lx old size %u MB\n",
179 aper
, 32 << old_order
);
180 if (aper
+ (32ULL<<(20 + *order
)) > 0x100000000ULL
) {
181 printk(KERN_INFO
"Aperture size %u MB (APSIZE %x) is not right, using settings from NB\n",
182 32 << *order
, apsizereg
);
186 printk(KERN_INFO
"Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n",
187 aper
, 32 << *order
, apsizereg
);
189 if (!aperture_valid(aper
, (32*1024*1024) << *order
, 32<<20))
195 * Look for an AGP bridge. Windows only expects the aperture in the
196 * AGP bridge and some BIOS forget to initialize the Northbridge too.
197 * Work around this here.
199 * Do an PCI bus scan by hand because we're running before the PCI
202 * All K8 AGP bridges are AGPv3 compliant, so we can do this scan
203 * generically. It's probably overkill to always scan all slots because
204 * the AGP bridges should be always an own bus on the HT hierarchy,
205 * but do it here for future safety.
207 static u32 __init
search_agp_bridge(u32
*order
, int *valid_agp
)
211 /* Poor man's PCI discovery */
212 for (bus
= 0; bus
< 256; bus
++) {
213 for (slot
= 0; slot
< 32; slot
++) {
214 for (func
= 0; func
< 8; func
++) {
217 class = read_pci_config(bus
, slot
, func
,
219 if (class == 0xffffffff)
222 switch (class >> 16) {
223 case PCI_CLASS_BRIDGE_HOST
:
224 case PCI_CLASS_BRIDGE_OTHER
: /* needed? */
226 cap
= find_cap(bus
, slot
, func
,
231 return read_agp(bus
, slot
, func
, cap
,
235 /* No multi-function device? */
236 type
= read_pci_config_byte(bus
, slot
, func
,
243 printk(KERN_INFO
"No AGP bridge found\n");
248 static int gart_fix_e820 __initdata
= 1;
250 static int __init
parse_gart_mem(char *p
)
255 if (!strncmp(p
, "off", 3))
257 else if (!strncmp(p
, "on", 2))
262 early_param("gart_fix_e820", parse_gart_mem
);
264 void __init
early_gart_iommu_check(void)
267 * in case it is enabled before, esp for kexec/kdump,
268 * previous kernel already enable that. memset called
269 * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
270 * or second kernel have different position for GART hole. and new
271 * kernel could use hole as RAM that is still used by GART set by
273 * or BIOS forget to put that in reserved.
274 * try to update e820 to make that region as reserved.
278 u32 aper_size
= 0, aper_order
= 0, last_aper_order
= 0;
279 u64 aper_base
= 0, last_aper_base
= 0;
280 int aper_enabled
= 0, last_aper_enabled
= 0, last_valid
= 0;
282 if (!early_pci_allowed())
285 /* This is mostly duplicate of iommu_hole_init */
287 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
289 int dev_base
, dev_limit
;
291 bus
= bus_dev_ranges
[i
].bus
;
292 dev_base
= bus_dev_ranges
[i
].dev_base
;
293 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
295 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
296 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
299 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
300 aper_enabled
= ctl
& AMD64_GARTEN
;
301 aper_order
= (ctl
>> 1) & 7;
302 aper_size
= (32 * 1024 * 1024) << aper_order
;
303 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
307 if ((aper_order
!= last_aper_order
) ||
308 (aper_base
!= last_aper_base
) ||
309 (aper_enabled
!= last_aper_enabled
)) {
315 last_aper_order
= aper_order
;
316 last_aper_base
= aper_base
;
317 last_aper_enabled
= aper_enabled
;
322 if (!fix
&& !aper_enabled
)
325 if (!aper_base
|| !aper_size
|| aper_base
+ aper_size
> 0x100000000UL
)
328 if (gart_fix_e820
&& !fix
&& aper_enabled
) {
329 if (e820_any_mapped(aper_base
, aper_base
+ aper_size
,
331 /* reserve it, so we can reuse it in second kernel */
332 printk(KERN_INFO
"update e820 for GART\n");
333 e820_add_region(aper_base
, aper_size
, E820_RESERVED
);
341 /* different nodes have different setting, disable them all at first*/
342 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
344 int dev_base
, dev_limit
;
346 bus
= bus_dev_ranges
[i
].bus
;
347 dev_base
= bus_dev_ranges
[i
].dev_base
;
348 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
350 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
351 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
354 ctl
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
);
355 ctl
&= ~AMD64_GARTEN
;
356 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, ctl
);
362 static int __initdata printed_gart_size_msg
;
364 void __init
gart_iommu_hole_init(void)
366 u32 agp_aper_base
= 0, agp_aper_order
= 0;
367 u32 aper_size
, aper_alloc
= 0, aper_order
= 0, last_aper_order
= 0;
368 u64 aper_base
, last_aper_base
= 0;
369 int fix
, slot
, valid_agp
= 0;
372 if (gart_iommu_aperture_disabled
|| !fix_aperture
||
373 !early_pci_allowed())
376 printk(KERN_INFO
"Checking aperture...\n");
378 if (!fallback_aper_force
)
379 agp_aper_base
= search_agp_bridge(&agp_aper_order
, &valid_agp
);
383 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
385 int dev_base
, dev_limit
;
387 bus
= bus_dev_ranges
[i
].bus
;
388 dev_base
= bus_dev_ranges
[i
].dev_base
;
389 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
391 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
392 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
396 gart_iommu_aperture
= 1;
398 aper_order
= (read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
) >> 1) & 7;
399 aper_size
= (32 * 1024 * 1024) << aper_order
;
400 aper_base
= read_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
) & 0x7fff;
403 printk(KERN_INFO
"Node %d: aperture @ %Lx size %u MB\n",
404 node
, aper_base
, aper_size
>> 20);
407 if (!aperture_valid(aper_base
, aper_size
, 64<<20)) {
408 if (valid_agp
&& agp_aper_base
&&
409 agp_aper_base
== aper_base
&&
410 agp_aper_order
== aper_order
) {
411 /* the same between two setting from NB and agp */
413 max_pfn
> MAX_DMA32_PFN
&&
414 !printed_gart_size_msg
) {
415 printk(KERN_ERR
"you are using iommu with agp, but GART size is less than 64M\n");
416 printk(KERN_ERR
"please increase GART size in your BIOS setup\n");
417 printk(KERN_ERR
"if BIOS doesn't have that option, contact your HW vendor!\n");
418 printed_gart_size_msg
= 1;
426 if ((last_aper_order
&& aper_order
!= last_aper_order
) ||
427 (last_aper_base
&& aper_base
!= last_aper_base
)) {
431 last_aper_order
= aper_order
;
432 last_aper_base
= aper_base
;
437 if (!fix
&& !fallback_aper_force
) {
438 if (last_aper_base
) {
439 unsigned long n
= (32 * 1024 * 1024) << last_aper_order
;
441 insert_aperture_resource((u32
)last_aper_base
, n
);
446 if (!fallback_aper_force
) {
447 aper_alloc
= agp_aper_base
;
448 aper_order
= agp_aper_order
;
452 /* Got the aperture from the AGP bridge */
453 } else if (swiotlb
&& !valid_agp
) {
455 } else if ((!no_iommu
&& max_pfn
> MAX_DMA32_PFN
) ||
458 fallback_aper_force
) {
460 "Your BIOS doesn't leave a aperture memory hole\n");
462 "Please enable the IOMMU option in the BIOS setup\n");
464 "This costs you %d MB of RAM\n",
465 32 << fallback_aper_order
);
467 aper_order
= fallback_aper_order
;
468 aper_alloc
= allocate_aperture();
471 * Could disable AGP and IOMMU here, but it's
472 * probably not worth it. But the later users
473 * cannot deal with bad apertures and turning
474 * on the aperture over memory causes very
475 * strange problems, so it's better to panic
478 panic("Not enough memory for aperture");
484 /* Fix up the north bridges */
485 for (i
= 0; i
< ARRAY_SIZE(bus_dev_ranges
); i
++) {
487 int dev_base
, dev_limit
;
489 bus
= bus_dev_ranges
[i
].bus
;
490 dev_base
= bus_dev_ranges
[i
].dev_base
;
491 dev_limit
= bus_dev_ranges
[i
].dev_limit
;
492 for (slot
= dev_base
; slot
< dev_limit
; slot
++) {
493 if (!early_is_k8_nb(read_pci_config(bus
, slot
, 3, 0x00)))
496 /* Don't enable translation yet. That is done later.
497 Assume this BIOS didn't initialise the GART so
498 just overwrite all previous bits */
499 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTURECTL
, aper_order
<< 1);
500 write_pci_config(bus
, slot
, 3, AMD64_GARTAPERTUREBASE
, aper_alloc
>> 25);
504 set_up_gart_resume(aper_order
, aper_alloc
);