2 * Copyright IBM Corp. 2012
5 * Jan Glauber <jang@linux.vnet.ibm.com>
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/export.h>
11 #include <linux/iommu-helper.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/vmalloc.h>
14 #include <linux/pci.h>
15 #include <asm/pci_dma.h>
17 static struct kmem_cache *dma_region_table_cache;
18 static struct kmem_cache *dma_page_table_cache;
19 static int s390_iommu_strict;
21 static int zpci_refresh_global(struct zpci_dev *zdev)
23 return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
24 zdev->iommu_pages * PAGE_SIZE);
27 unsigned long *dma_alloc_cpu_table(void)
29 unsigned long *table, *entry;
31 table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
35 for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
36 *entry = ZPCI_TABLE_INVALID;
40 static void dma_free_cpu_table(void *table)
42 kmem_cache_free(dma_region_table_cache, table);
45 static unsigned long *dma_alloc_page_table(void)
47 unsigned long *table, *entry;
49 table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
53 for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
54 *entry = ZPCI_PTE_INVALID;
58 static void dma_free_page_table(void *table)
60 kmem_cache_free(dma_page_table_cache, table);
63 static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
67 if (reg_entry_isvalid(*entry))
68 sto = get_rt_sto(*entry);
70 sto = dma_alloc_cpu_table();
74 set_rt_sto(entry, sto);
75 validate_rt_entry(entry);
76 entry_clr_protected(entry);
81 static unsigned long *dma_get_page_table_origin(unsigned long *entry)
85 if (reg_entry_isvalid(*entry))
86 pto = get_st_pto(*entry);
88 pto = dma_alloc_page_table();
91 set_st_pto(entry, pto);
92 validate_st_entry(entry);
93 entry_clr_protected(entry);
98 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
100 unsigned long *sto, *pto;
101 unsigned int rtx, sx, px;
103 rtx = calc_rtx(dma_addr);
104 sto = dma_get_seg_table_origin(&rto[rtx]);
108 sx = calc_sx(dma_addr);
109 pto = dma_get_page_table_origin(&sto[sx]);
113 px = calc_px(dma_addr);
117 void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
119 if (flags & ZPCI_PTE_INVALID) {
120 invalidate_pt_entry(entry);
122 set_pt_pfaa(entry, page_addr);
123 validate_pt_entry(entry);
126 if (flags & ZPCI_TABLE_PROTECTED)
127 entry_set_protected(entry);
129 entry_clr_protected(entry);
132 static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
133 dma_addr_t dma_addr, size_t size, int flags)
135 unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
136 u8 *page_addr = (u8 *) (pa & PAGE_MASK);
137 dma_addr_t start_dma_addr = dma_addr;
138 unsigned long irq_flags;
139 unsigned long *entry;
145 spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
146 if (!zdev->dma_table) {
151 for (i = 0; i < nr_pages; i++) {
152 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
157 dma_update_cpu_trans(entry, page_addr, flags);
158 page_addr += PAGE_SIZE;
159 dma_addr += PAGE_SIZE;
163 * With zdev->tlb_refresh == 0, rpcit is not required to establish new
164 * translations when previously invalid translation-table entries are
165 * validated. With lazy unmap, it also is skipped for previously valid
166 * entries, but a global rpcit is then required before any address can
167 * be re-used, i.e. after each iommu bitmap wrap-around.
169 if (!zdev->tlb_refresh &&
170 (!s390_iommu_strict ||
171 ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)))
174 rc = zpci_refresh_trans((u64) zdev->fh << 32, start_dma_addr,
175 nr_pages * PAGE_SIZE);
177 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
178 flags = ZPCI_PTE_INVALID;
180 page_addr -= PAGE_SIZE;
181 dma_addr -= PAGE_SIZE;
182 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
185 dma_update_cpu_trans(entry, page_addr, flags);
190 spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
194 void dma_free_seg_table(unsigned long entry)
196 unsigned long *sto = get_rt_sto(entry);
199 for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
200 if (reg_entry_isvalid(sto[sx]))
201 dma_free_page_table(get_st_pto(sto[sx]));
203 dma_free_cpu_table(sto);
206 void dma_cleanup_tables(unsigned long *table)
213 for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
214 if (reg_entry_isvalid(table[rtx]))
215 dma_free_seg_table(table[rtx]);
217 dma_free_cpu_table(table);
220 static unsigned long __dma_alloc_iommu(struct device *dev,
221 unsigned long start, int size)
223 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
224 unsigned long boundary_size;
226 boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
227 PAGE_SIZE) >> PAGE_SHIFT;
228 return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
229 start, size, 0, boundary_size, 0);
232 static unsigned long dma_alloc_iommu(struct device *dev, int size)
234 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
235 unsigned long offset, flags;
238 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
239 offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
242 offset = __dma_alloc_iommu(dev, 0, size);
247 zdev->next_bit = offset + size;
248 if (!zdev->tlb_refresh && !s390_iommu_strict && wrap)
249 /* global flush after wrap-around with lazy unmap */
250 zpci_refresh_global(zdev);
252 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
256 static void dma_free_iommu(struct device *dev, unsigned long offset, int size)
258 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
261 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
262 if (!zdev->iommu_bitmap)
264 bitmap_clear(zdev->iommu_bitmap, offset, size);
266 * Lazy flush for unmap: need to move next_bit to avoid address re-use
269 if (!s390_iommu_strict && offset >= zdev->next_bit)
270 zdev->next_bit = offset + size;
272 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
275 static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
280 } __packed data = {rc, addr};
282 zpci_err_hex(&data, sizeof(data));
285 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
286 unsigned long offset, size_t size,
287 enum dma_data_direction direction,
288 struct dma_attrs *attrs)
290 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
291 unsigned long nr_pages, iommu_page_index;
292 unsigned long pa = page_to_phys(page) + offset;
293 int flags = ZPCI_PTE_VALID;
297 /* This rounds up number of pages based on size and offset */
298 nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
299 iommu_page_index = dma_alloc_iommu(dev, nr_pages);
300 if (iommu_page_index == -1) {
305 /* Use rounded up size */
306 size = nr_pages * PAGE_SIZE;
308 dma_addr = zdev->start_dma + iommu_page_index * PAGE_SIZE;
309 if (dma_addr + size > zdev->end_dma) {
314 if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
315 flags |= ZPCI_TABLE_PROTECTED;
317 ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
321 atomic64_add(nr_pages, &zdev->mapped_pages);
322 return dma_addr + (offset & ~PAGE_MASK);
325 dma_free_iommu(dev, iommu_page_index, nr_pages);
327 zpci_err("map error:\n");
328 zpci_err_dma(ret, pa);
329 return DMA_ERROR_CODE;
332 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
333 size_t size, enum dma_data_direction direction,
334 struct dma_attrs *attrs)
336 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
337 unsigned long iommu_page_index;
340 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
341 dma_addr = dma_addr & PAGE_MASK;
342 ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
345 zpci_err("unmap error:\n");
346 zpci_err_dma(ret, dma_addr);
350 atomic64_add(npages, &zdev->unmapped_pages);
351 iommu_page_index = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
352 dma_free_iommu(dev, iommu_page_index, npages);
355 static void *s390_dma_alloc(struct device *dev, size_t size,
356 dma_addr_t *dma_handle, gfp_t flag,
357 struct dma_attrs *attrs)
359 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
364 size = PAGE_ALIGN(size);
365 page = alloc_pages(flag, get_order(size));
369 pa = page_to_phys(page);
370 memset((void *) pa, 0, size);
372 map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, NULL);
373 if (dma_mapping_error(dev, map)) {
374 free_pages(pa, get_order(size));
378 atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
384 static void s390_dma_free(struct device *dev, size_t size,
385 void *pa, dma_addr_t dma_handle,
386 struct dma_attrs *attrs)
388 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
390 size = PAGE_ALIGN(size);
391 atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
392 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, NULL);
393 free_pages((unsigned long) pa, get_order(size));
396 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
397 int nr_elements, enum dma_data_direction dir,
398 struct dma_attrs *attrs)
400 int mapped_elements = 0;
401 struct scatterlist *s;
404 for_each_sg(sg, s, nr_elements, i) {
405 struct page *page = sg_page(s);
406 s->dma_address = s390_dma_map_pages(dev, page, s->offset,
407 s->length, dir, NULL);
408 if (!dma_mapping_error(dev, s->dma_address)) {
409 s->dma_length = s->length;
415 return mapped_elements;
418 for_each_sg(sg, s, mapped_elements, i) {
420 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
429 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
430 int nr_elements, enum dma_data_direction dir,
431 struct dma_attrs *attrs)
433 struct scatterlist *s;
436 for_each_sg(sg, s, nr_elements, i) {
437 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir, NULL);
443 int zpci_dma_init_device(struct zpci_dev *zdev)
448 * At this point, if the device is part of an IOMMU domain, this would
449 * be a strong hint towards a bug in the IOMMU API (common) code and/or
450 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
452 WARN_ON(zdev->s390_domain);
454 spin_lock_init(&zdev->iommu_bitmap_lock);
455 spin_lock_init(&zdev->dma_table_lock);
457 zdev->dma_table = dma_alloc_cpu_table();
458 if (!zdev->dma_table) {
464 * Restrict the iommu bitmap size to the minimum of the following:
466 * - 3-level pagetable address limit minus start_dma offset
467 * - DMA address range allowed by the hardware (clp query pci fn)
469 * Also set zdev->end_dma to the actual end address of the usable
470 * range, instead of the theoretical maximum as reported by hardware.
472 zdev->iommu_size = min3((u64) high_memory,
473 ZPCI_TABLE_SIZE_RT - zdev->start_dma,
474 zdev->end_dma - zdev->start_dma + 1);
475 zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
476 zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
477 zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
478 if (!zdev->iommu_bitmap) {
483 rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
484 (u64) zdev->dma_table);
490 dma_free_cpu_table(zdev->dma_table);
495 void zpci_dma_exit_device(struct zpci_dev *zdev)
498 * At this point, if the device is part of an IOMMU domain, this would
499 * be a strong hint towards a bug in the IOMMU API (common) code and/or
500 * simultaneous access via IOMMU and DMA API. So let's issue a warning.
502 WARN_ON(zdev->s390_domain);
504 zpci_unregister_ioat(zdev, 0);
505 dma_cleanup_tables(zdev->dma_table);
506 zdev->dma_table = NULL;
507 vfree(zdev->iommu_bitmap);
508 zdev->iommu_bitmap = NULL;
512 static int __init dma_alloc_cpu_table_caches(void)
514 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
515 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
517 if (!dma_region_table_cache)
520 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
521 ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
523 if (!dma_page_table_cache) {
524 kmem_cache_destroy(dma_region_table_cache);
530 int __init zpci_dma_init(void)
532 return dma_alloc_cpu_table_caches();
535 void zpci_dma_exit(void)
537 kmem_cache_destroy(dma_page_table_cache);
538 kmem_cache_destroy(dma_region_table_cache);
541 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
543 static int __init dma_debug_do_init(void)
545 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
548 fs_initcall(dma_debug_do_init);
550 struct dma_map_ops s390_pci_dma_ops = {
551 .alloc = s390_dma_alloc,
552 .free = s390_dma_free,
553 .map_sg = s390_dma_map_sg,
554 .unmap_sg = s390_dma_unmap_sg,
555 .map_page = s390_dma_map_pages,
556 .unmap_page = s390_dma_unmap_pages,
557 /* if we support direct DMA this must be conditional */
559 /* dma_supported is unconditionally true without a callback */
561 EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
563 static int __init s390_iommu_setup(char *str)
565 if (!strncmp(str, "strict", 6))
566 s390_iommu_strict = 1;
570 __setup("s390_iommu=", s390_iommu_setup);