1 // SPDX-License-Identifier: GPL-2.0
3 * Support routines for initializing a PCI subsystem
5 * Extruded from code written by
6 * Dave Rusling (david.rusling@reo.mts.dec.com)
7 * David Mosberger (davidm@cs.arizona.edu)
8 * David Miller (davem@redhat.com)
10 * Fixed for multiple PCI buses, 1999 Andrea Arcangeli <andrea@suse.de>
12 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
16 #include <linux/kernel.h>
17 #include <linux/export.h>
18 #include <linux/pci.h>
19 #include <linux/errno.h>
20 #include <linux/ioport.h>
21 #include <linux/cache.h>
22 #include <linux/slab.h>
25 static void pci_std_update_resource(struct pci_dev
*dev
, int resno
)
27 struct pci_bus_region region
;
32 struct resource
*res
= dev
->resource
+ resno
;
34 /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */
39 * Ignore resources for unimplemented BARs and unused resource slots
45 if (res
->flags
& IORESOURCE_UNSET
)
49 * Ignore non-moveable resources. This might be legacy resources for
50 * which no functional BAR register exists or another important
51 * system resource we shouldn't move around.
53 if (res
->flags
& IORESOURCE_PCI_FIXED
)
56 pcibios_resource_to_bus(dev
->bus
, ®ion
, res
);
59 if (res
->flags
& IORESOURCE_IO
) {
60 mask
= (u32
)PCI_BASE_ADDRESS_IO_MASK
;
61 new |= res
->flags
& ~PCI_BASE_ADDRESS_IO_MASK
;
62 } else if (resno
== PCI_ROM_RESOURCE
) {
63 mask
= PCI_ROM_ADDRESS_MASK
;
65 mask
= (u32
)PCI_BASE_ADDRESS_MEM_MASK
;
66 new |= res
->flags
& ~PCI_BASE_ADDRESS_MEM_MASK
;
69 if (resno
< PCI_ROM_RESOURCE
) {
70 reg
= PCI_BASE_ADDRESS_0
+ 4 * resno
;
71 } else if (resno
== PCI_ROM_RESOURCE
) {
74 * Apparently some Matrox devices have ROM BARs that read
75 * as zero when disabled, so don't update ROM BARs unless
76 * they're enabled. See https://lkml.org/lkml/2005/8/30/138.
78 if (!(res
->flags
& IORESOURCE_ROM_ENABLE
))
81 reg
= dev
->rom_base_reg
;
82 new |= PCI_ROM_ADDRESS_ENABLE
;
87 * We can't update a 64-bit BAR atomically, so when possible,
88 * disable decoding so that a half-updated BAR won't conflict
89 * with another device.
91 disable
= (res
->flags
& IORESOURCE_MEM_64
) && !dev
->mmio_always_on
;
93 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
94 pci_write_config_word(dev
, PCI_COMMAND
,
95 cmd
& ~PCI_COMMAND_MEMORY
);
98 pci_write_config_dword(dev
, reg
, new);
99 pci_read_config_dword(dev
, reg
, &check
);
101 if ((new ^ check
) & mask
) {
102 pci_err(dev
, "BAR %d: error updating (%#08x != %#08x)\n",
106 if (res
->flags
& IORESOURCE_MEM_64
) {
107 new = region
.start
>> 16 >> 16;
108 pci_write_config_dword(dev
, reg
+ 4, new);
109 pci_read_config_dword(dev
, reg
+ 4, &check
);
111 pci_err(dev
, "BAR %d: error updating (high %#08x != %#08x)\n",
117 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);
120 void pci_update_resource(struct pci_dev
*dev
, int resno
)
122 if (resno
<= PCI_ROM_RESOURCE
)
123 pci_std_update_resource(dev
, resno
);
124 #ifdef CONFIG_PCI_IOV
125 else if (resno
>= PCI_IOV_RESOURCES
&& resno
<= PCI_IOV_RESOURCE_END
)
126 pci_iov_update_resource(dev
, resno
);
130 int pci_claim_resource(struct pci_dev
*dev
, int resource
)
132 struct resource
*res
= &dev
->resource
[resource
];
133 struct resource
*root
, *conflict
;
135 if (res
->flags
& IORESOURCE_UNSET
) {
136 pci_info(dev
, "can't claim BAR %d %pR: no address assigned\n",
142 * If we have a shadow copy in RAM, the PCI device doesn't respond
143 * to the shadow range, so we don't need to claim it, and upstream
144 * bridges don't need to route the range to the device.
146 if (res
->flags
& IORESOURCE_ROM_SHADOW
)
149 root
= pci_find_parent_resource(dev
, res
);
151 pci_info(dev
, "can't claim BAR %d %pR: no compatible bridge window\n",
153 res
->flags
|= IORESOURCE_UNSET
;
157 conflict
= request_resource_conflict(root
, res
);
159 pci_info(dev
, "can't claim BAR %d %pR: address conflict with %s %pR\n",
160 resource
, res
, conflict
->name
, conflict
);
161 res
->flags
|= IORESOURCE_UNSET
;
167 EXPORT_SYMBOL(pci_claim_resource
);
169 void pci_disable_bridge_window(struct pci_dev
*dev
)
171 /* MMIO Base/Limit */
172 pci_write_config_dword(dev
, PCI_MEMORY_BASE
, 0x0000fff0);
174 /* Prefetchable MMIO Base/Limit */
175 pci_write_config_dword(dev
, PCI_PREF_LIMIT_UPPER32
, 0);
176 pci_write_config_dword(dev
, PCI_PREF_MEMORY_BASE
, 0x0000fff0);
177 pci_write_config_dword(dev
, PCI_PREF_BASE_UPPER32
, 0xffffffff);
181 * Generic function that returns a value indicating that the device's
182 * original BIOS BAR address was not saved and so is not available for
185 * Can be over-ridden by architecture specific code that implements
186 * reinstatement functionality rather than leaving it disabled when
187 * normal allocation attempts fail.
189 resource_size_t __weak
pcibios_retrieve_fw_addr(struct pci_dev
*dev
, int idx
)
194 static int pci_revert_fw_address(struct resource
*res
, struct pci_dev
*dev
,
195 int resno
, resource_size_t size
)
197 struct resource
*root
, *conflict
;
198 resource_size_t fw_addr
, start
, end
;
200 fw_addr
= pcibios_retrieve_fw_addr(dev
, resno
);
206 res
->start
= fw_addr
;
207 res
->end
= res
->start
+ size
- 1;
208 res
->flags
&= ~IORESOURCE_UNSET
;
210 root
= pci_find_parent_resource(dev
, res
);
212 if (res
->flags
& IORESOURCE_IO
)
213 root
= &ioport_resource
;
215 root
= &iomem_resource
;
218 pci_info(dev
, "BAR %d: trying firmware assignment %pR\n",
220 conflict
= request_resource_conflict(root
, res
);
222 pci_info(dev
, "BAR %d: %pR conflicts with %s %pR\n",
223 resno
, res
, conflict
->name
, conflict
);
226 res
->flags
|= IORESOURCE_UNSET
;
233 * We don't have to worry about legacy ISA devices, so nothing to do here.
234 * This is marked as __weak because multiple architectures define it; it should
235 * eventually go away.
237 resource_size_t __weak
pcibios_align_resource(void *data
,
238 const struct resource
*res
,
239 resource_size_t size
,
240 resource_size_t align
)
245 static int __pci_assign_resource(struct pci_bus
*bus
, struct pci_dev
*dev
,
246 int resno
, resource_size_t size
, resource_size_t align
)
248 struct resource
*res
= dev
->resource
+ resno
;
252 min
= (res
->flags
& IORESOURCE_IO
) ? PCIBIOS_MIN_IO
: PCIBIOS_MIN_MEM
;
255 * First, try exact prefetching match. Even if a 64-bit
256 * prefetchable bridge window is below 4GB, we can't put a 32-bit
257 * prefetchable resource in it because pbus_size_mem() assumes a
258 * 64-bit window will contain no 32-bit resources. If we assign
259 * things differently than they were sized, not everything will fit.
261 ret
= pci_bus_alloc_resource(bus
, res
, size
, align
, min
,
262 IORESOURCE_PREFETCH
| IORESOURCE_MEM_64
,
263 pcibios_align_resource
, dev
);
268 * If the prefetchable window is only 32 bits wide, we can put
269 * 64-bit prefetchable resources in it.
271 if ((res
->flags
& (IORESOURCE_PREFETCH
| IORESOURCE_MEM_64
)) ==
272 (IORESOURCE_PREFETCH
| IORESOURCE_MEM_64
)) {
273 ret
= pci_bus_alloc_resource(bus
, res
, size
, align
, min
,
275 pcibios_align_resource
, dev
);
281 * If we didn't find a better match, we can put any memory resource
282 * in a non-prefetchable window. If this resource is 32 bits and
283 * non-prefetchable, the first call already tried the only possibility
284 * so we don't need to try again.
286 if (res
->flags
& (IORESOURCE_PREFETCH
| IORESOURCE_MEM_64
))
287 ret
= pci_bus_alloc_resource(bus
, res
, size
, align
, min
, 0,
288 pcibios_align_resource
, dev
);
293 static int _pci_assign_resource(struct pci_dev
*dev
, int resno
,
294 resource_size_t size
, resource_size_t min_align
)
300 while ((ret
= __pci_assign_resource(bus
, dev
, resno
, size
, min_align
))) {
301 if (!bus
->parent
|| !bus
->self
->transparent
)
309 int pci_assign_resource(struct pci_dev
*dev
, int resno
)
311 struct resource
*res
= dev
->resource
+ resno
;
312 resource_size_t align
, size
;
315 if (res
->flags
& IORESOURCE_PCI_FIXED
)
318 res
->flags
|= IORESOURCE_UNSET
;
319 align
= pci_resource_alignment(dev
, res
);
321 pci_info(dev
, "BAR %d: can't assign %pR (bogus alignment)\n",
326 size
= resource_size(res
);
327 ret
= _pci_assign_resource(dev
, resno
, size
, align
);
330 * If we failed to assign anything, let's try the address
331 * where firmware left it. That at least has a chance of
332 * working, which is better than just leaving it disabled.
335 pci_info(dev
, "BAR %d: no space for %pR\n", resno
, res
);
336 ret
= pci_revert_fw_address(res
, dev
, resno
, size
);
340 pci_info(dev
, "BAR %d: failed to assign %pR\n", resno
, res
);
344 res
->flags
&= ~IORESOURCE_UNSET
;
345 res
->flags
&= ~IORESOURCE_STARTALIGN
;
346 pci_info(dev
, "BAR %d: assigned %pR\n", resno
, res
);
347 if (resno
< PCI_BRIDGE_RESOURCES
)
348 pci_update_resource(dev
, resno
);
352 EXPORT_SYMBOL(pci_assign_resource
);
354 int pci_reassign_resource(struct pci_dev
*dev
, int resno
, resource_size_t addsize
,
355 resource_size_t min_align
)
357 struct resource
*res
= dev
->resource
+ resno
;
359 resource_size_t new_size
;
362 if (res
->flags
& IORESOURCE_PCI_FIXED
)
366 res
->flags
|= IORESOURCE_UNSET
;
368 pci_info(dev
, "BAR %d: can't reassign an unassigned resource %pR\n",
373 /* already aligned with min_align */
374 new_size
= resource_size(res
) + addsize
;
375 ret
= _pci_assign_resource(dev
, resno
, new_size
, min_align
);
378 pci_info(dev
, "BAR %d: %pR (failed to expand by %#llx)\n",
379 resno
, res
, (unsigned long long) addsize
);
383 res
->flags
&= ~IORESOURCE_UNSET
;
384 res
->flags
&= ~IORESOURCE_STARTALIGN
;
385 pci_info(dev
, "BAR %d: reassigned %pR (expanded by %#llx)\n",
386 resno
, res
, (unsigned long long) addsize
);
387 if (resno
< PCI_BRIDGE_RESOURCES
)
388 pci_update_resource(dev
, resno
);
393 void pci_release_resource(struct pci_dev
*dev
, int resno
)
395 struct resource
*res
= dev
->resource
+ resno
;
397 pci_info(dev
, "BAR %d: releasing %pR\n", resno
, res
);
402 release_resource(res
);
403 res
->end
= resource_size(res
) - 1;
405 res
->flags
|= IORESOURCE_UNSET
;
407 EXPORT_SYMBOL(pci_release_resource
);
409 int pci_resize_resource(struct pci_dev
*dev
, int resno
, int size
)
411 struct resource
*res
= dev
->resource
+ resno
;
416 /* Make sure the resource isn't assigned before resizing it. */
417 if (!(res
->flags
& IORESOURCE_UNSET
))
420 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
421 if (cmd
& PCI_COMMAND_MEMORY
)
424 sizes
= pci_rebar_get_possible_sizes(dev
, resno
);
428 if (!(sizes
& BIT(size
)))
431 old
= pci_rebar_get_current_size(dev
, resno
);
435 ret
= pci_rebar_set_size(dev
, resno
, size
);
439 res
->end
= res
->start
+ pci_rebar_size_to_bytes(size
) - 1;
441 /* Check if the new config works by trying to assign everything. */
442 ret
= pci_reassign_bridge_resources(dev
->bus
->self
, res
->flags
);
449 pci_rebar_set_size(dev
, resno
, old
);
450 res
->end
= res
->start
+ pci_rebar_size_to_bytes(old
) - 1;
453 EXPORT_SYMBOL(pci_resize_resource
);
455 int pci_enable_resources(struct pci_dev
*dev
, int mask
)
461 pci_read_config_word(dev
, PCI_COMMAND
, &cmd
);
464 for (i
= 0; i
< PCI_NUM_RESOURCES
; i
++) {
465 if (!(mask
& (1 << i
)))
468 r
= &dev
->resource
[i
];
470 if (!(r
->flags
& (IORESOURCE_IO
| IORESOURCE_MEM
)))
472 if ((i
== PCI_ROM_RESOURCE
) &&
473 (!(r
->flags
& IORESOURCE_ROM_ENABLE
)))
476 if (r
->flags
& IORESOURCE_UNSET
) {
477 pci_err(dev
, "can't enable device: BAR %d %pR not assigned\n",
483 pci_err(dev
, "can't enable device: BAR %d %pR not claimed\n",
488 if (r
->flags
& IORESOURCE_IO
)
489 cmd
|= PCI_COMMAND_IO
;
490 if (r
->flags
& IORESOURCE_MEM
)
491 cmd
|= PCI_COMMAND_MEMORY
;
494 if (cmd
!= old_cmd
) {
495 pci_info(dev
, "enabling device (%04x -> %04x)\n", old_cmd
, cmd
);
496 pci_write_config_word(dev
, PCI_COMMAND
, cmd
);