Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping fixes from Christoph Hellwig:
- swiotlb area sizing fixes (Petr Tesarik)
* tag 'dma-mapping-6.5-2023-07-09' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: reduce the number of areas to match actual memory pool size
swiotlb: always set the number of areas before allocating the pool
+35
-11
+35
-11
kernel/dma/swiotlb.c
+35
-11
kernel/dma/swiotlb.c
···
115
115
return true;
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116
}
117
117
118
+
/**
119
+
* swiotlb_adjust_nareas() - adjust the number of areas and slots
120
+
* @nareas: Desired number of areas. Zero is treated as 1.
121
+
*
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+
* Adjust the default number of areas in a memory pool.
123
+
* The default size of the memory pool may also change to meet minimum area
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+
* size requirements.
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+
*/
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static void swiotlb_adjust_nareas(unsigned int nareas)
119
127
{
120
-
/* use a single area when non is specified */
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128
if (!nareas)
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nareas = 1;
123
130
else if (!is_power_of_2(nareas))
···
136
129
if (round_up_default_nslabs())
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130
pr_info("SWIOTLB bounce buffer size roundup to %luMB",
138
131
(default_nslabs << IO_TLB_SHIFT) >> 20);
132
+
}
133
+
134
+
/**
135
+
* limit_nareas() - get the maximum number of areas for a given memory pool size
136
+
* @nareas: Desired number of areas.
137
+
* @nslots: Total number of slots in the memory pool.
138
+
*
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+
* Limit the number of areas to the maximum possible number of areas in
140
+
* a memory pool of the given size.
141
+
*
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+
* Return: Maximum possible number of areas.
143
+
*/
144
+
static unsigned int limit_nareas(unsigned int nareas, unsigned long nslots)
145
+
{
146
+
if (nslots < nareas * IO_TLB_SEGSIZE)
147
+
return nslots / IO_TLB_SEGSIZE;
148
+
return nareas;
139
149
}
140
150
141
151
static int __init
···
314
290
{
315
291
struct io_tlb_mem *mem = &io_tlb_default_mem;
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292
unsigned long nslabs;
293
+
unsigned int nareas;
317
294
size_t alloc_size;
318
295
void *tlb;
319
296
···
323
298
if (swiotlb_force_disable)
324
299
return;
325
300
326
-
/*
327
-
* default_nslabs maybe changed when adjust area number.
328
-
* So allocate bounce buffer after adjusting area number.
329
-
*/
330
301
if (!default_nareas)
331
302
swiotlb_adjust_nareas(num_possible_cpus());
332
303
333
304
nslabs = default_nslabs;
305
+
nareas = limit_nareas(default_nareas, nslabs);
334
306
while ((tlb = swiotlb_memblock_alloc(nslabs, flags, remap)) == NULL) {
335
307
if (nslabs <= IO_TLB_MIN_SLABS)
336
308
return;
337
309
nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE);
310
+
nareas = limit_nareas(nareas, nslabs);
338
311
}
339
312
340
313
if (default_nslabs != nslabs) {
···
378
355
{
379
356
struct io_tlb_mem *mem = &io_tlb_default_mem;
380
357
unsigned long nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);
358
+
unsigned int nareas;
381
359
unsigned char *vstart = NULL;
382
360
unsigned int order, area_order;
383
361
bool retried = false;
···
386
362
387
363
if (swiotlb_force_disable)
388
364
return 0;
365
+
366
+
if (!default_nareas)
367
+
swiotlb_adjust_nareas(num_possible_cpus());
389
368
390
369
retry:
391
370
order = get_order(nslabs << IO_TLB_SHIFT);
···
424
397
(PAGE_SIZE << order) >> 20);
425
398
}
426
399
427
-
if (!default_nareas)
428
-
swiotlb_adjust_nareas(num_possible_cpus());
429
-
430
-
area_order = get_order(array_size(sizeof(*mem->areas),
431
-
default_nareas));
400
+
nareas = limit_nareas(default_nareas, nslabs);
401
+
area_order = get_order(array_size(sizeof(*mem->areas), nareas));
432
402
mem->areas = (struct io_tlb_area *)
433
403
__get_free_pages(GFP_KERNEL | __GFP_ZERO, area_order);
434
404
if (!mem->areas)
···
439
415
set_memory_decrypted((unsigned long)vstart,
440
416
(nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT);
441
417
swiotlb_init_io_tlb_mem(mem, virt_to_phys(vstart), nslabs, 0, true,
442
-
default_nareas);
418
+
nareas);
443
419
444
420
swiotlb_print_info();
445
421
return 0;