1 // SPDX-License-Identifier: GPL-2.0-only
3 * omap iommu: tlb and pagetable primitives
5 * Copyright (C) 2008-2010 Nokia Corporation
6 * Copyright (C) 2013-2017 Texas Instruments Incorporated - https://www.ti.com/
9 * Paul Mundt and Toshihiro Kobayashi
12 #include <linux/dma-mapping.h>
13 #include <linux/err.h>
14 #include <linux/slab.h>
15 #include <linux/interrupt.h>
16 #include <linux/ioport.h>
17 #include <linux/platform_device.h>
18 #include <linux/iommu.h>
19 #include <linux/omap-iommu.h>
20 #include <linux/mutex.h>
21 #include <linux/spinlock.h>
23 #include <linux/pm_runtime.h>
25 #include <linux/of_iommu.h>
26 #include <linux/of_irq.h>
27 #include <linux/of_platform.h>
28 #include <linux/regmap.h>
29 #include <linux/mfd/syscon.h>
31 #include <linux/platform_data/iommu-omap.h>
33 #include "omap-iopgtable.h"
34 #include "omap-iommu.h"
36 static const struct iommu_ops omap_iommu_ops;
38 #define to_iommu(dev) ((struct omap_iommu *)dev_get_drvdata(dev))
40 /* bitmap of the page sizes currently supported */
41 #define OMAP_IOMMU_PGSIZES (SZ_4K | SZ_64K | SZ_1M | SZ_16M)
43 #define MMU_LOCK_BASE_SHIFT 10
44 #define MMU_LOCK_BASE_MASK (0x1f << MMU_LOCK_BASE_SHIFT)
45 #define MMU_LOCK_BASE(x) \
46 ((x & MMU_LOCK_BASE_MASK) >> MMU_LOCK_BASE_SHIFT)
48 #define MMU_LOCK_VICT_SHIFT 4
49 #define MMU_LOCK_VICT_MASK (0x1f << MMU_LOCK_VICT_SHIFT)
50 #define MMU_LOCK_VICT(x) \
51 ((x & MMU_LOCK_VICT_MASK) >> MMU_LOCK_VICT_SHIFT)
53 static struct platform_driver omap_iommu_driver;
54 static struct kmem_cache *iopte_cachep;
57 * to_omap_domain - Get struct omap_iommu_domain from generic iommu_domain
58 * @dom: generic iommu domain handle
60 static struct omap_iommu_domain *to_omap_domain(struct iommu_domain *dom)
62 return container_of(dom, struct omap_iommu_domain, domain);
66 * omap_iommu_save_ctx - Save registers for pm off-mode support
69 * This should be treated as an deprecated API. It is preserved only
70 * to maintain existing functionality for OMAP3 ISP driver.
72 void omap_iommu_save_ctx(struct device *dev)
74 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
75 struct omap_iommu *obj;
82 while (arch_data->iommu_dev) {
83 obj = arch_data->iommu_dev;
85 for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
86 p[i] = iommu_read_reg(obj, i * sizeof(u32));
87 dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
93 EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
96 * omap_iommu_restore_ctx - Restore registers for pm off-mode support
99 * This should be treated as an deprecated API. It is preserved only
100 * to maintain existing functionality for OMAP3 ISP driver.
102 void omap_iommu_restore_ctx(struct device *dev)
104 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
105 struct omap_iommu *obj;
112 while (arch_data->iommu_dev) {
113 obj = arch_data->iommu_dev;
115 for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
116 iommu_write_reg(obj, p[i], i * sizeof(u32));
117 dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i,
123 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
125 static void dra7_cfg_dspsys_mmu(struct omap_iommu *obj, bool enable)
132 mask = (1 << (obj->id * DSP_SYS_MMU_CONFIG_EN_SHIFT));
133 val = enable ? mask : 0;
134 regmap_update_bits(obj->syscfg, DSP_SYS_MMU_CONFIG, mask, val);
137 static void __iommu_set_twl(struct omap_iommu *obj, bool on)
139 u32 l = iommu_read_reg(obj, MMU_CNTL);
142 iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
144 iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
148 l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
150 l |= (MMU_CNTL_MMU_EN);
152 iommu_write_reg(obj, l, MMU_CNTL);
155 static int omap2_iommu_enable(struct omap_iommu *obj)
159 if (!obj->iopgd || !IS_ALIGNED((unsigned long)obj->iopgd, SZ_16K))
162 pa = virt_to_phys(obj->iopgd);
163 if (!IS_ALIGNED(pa, SZ_16K))
166 l = iommu_read_reg(obj, MMU_REVISION);
167 dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
168 (l >> 4) & 0xf, l & 0xf);
170 iommu_write_reg(obj, pa, MMU_TTB);
172 dra7_cfg_dspsys_mmu(obj, true);
174 if (obj->has_bus_err_back)
175 iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
177 __iommu_set_twl(obj, true);
182 static void omap2_iommu_disable(struct omap_iommu *obj)
184 u32 l = iommu_read_reg(obj, MMU_CNTL);
187 iommu_write_reg(obj, l, MMU_CNTL);
188 dra7_cfg_dspsys_mmu(obj, false);
190 dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
193 static int iommu_enable(struct omap_iommu *obj)
197 ret = pm_runtime_get_sync(obj->dev);
199 pm_runtime_put_noidle(obj->dev);
201 return ret < 0 ? ret : 0;
204 static void iommu_disable(struct omap_iommu *obj)
206 pm_runtime_put_sync(obj->dev);
212 static u32 iotlb_cr_to_virt(struct cr_regs *cr)
214 u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
215 u32 mask = get_cam_va_mask(cr->cam & page_size);
217 return cr->cam & mask;
220 static u32 get_iopte_attr(struct iotlb_entry *e)
224 attr = e->mixed << 5;
226 attr |= e->elsz >> 3;
227 attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
228 (e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
232 static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
234 u32 status, fault_addr;
236 status = iommu_read_reg(obj, MMU_IRQSTATUS);
237 status &= MMU_IRQ_MASK;
243 fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
246 iommu_write_reg(obj, status, MMU_IRQSTATUS);
251 void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
255 val = iommu_read_reg(obj, MMU_LOCK);
257 l->base = MMU_LOCK_BASE(val);
258 l->vict = MMU_LOCK_VICT(val);
261 void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
265 val = (l->base << MMU_LOCK_BASE_SHIFT);
266 val |= (l->vict << MMU_LOCK_VICT_SHIFT);
268 iommu_write_reg(obj, val, MMU_LOCK);
271 static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
273 cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
274 cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
277 static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
279 iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
280 iommu_write_reg(obj, cr->ram, MMU_RAM);
282 iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
283 iommu_write_reg(obj, 1, MMU_LD_TLB);
286 /* only used in iotlb iteration for-loop */
287 struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
292 iotlb_lock_get(obj, &l);
294 iotlb_lock_set(obj, &l);
295 iotlb_read_cr(obj, &cr);
300 #ifdef PREFETCH_IOTLB
301 static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
302 struct iotlb_entry *e)
309 if (e->da & ~(get_cam_va_mask(e->pgsz))) {
310 dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
312 return ERR_PTR(-EINVAL);
315 cr = kmalloc(sizeof(*cr), GFP_KERNEL);
317 return ERR_PTR(-ENOMEM);
319 cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
320 cr->ram = e->pa | e->endian | e->elsz | e->mixed;
326 * load_iotlb_entry - Set an iommu tlb entry
328 * @e: an iommu tlb entry info
330 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
336 if (!obj || !obj->nr_tlb_entries || !e)
339 pm_runtime_get_sync(obj->dev);
341 iotlb_lock_get(obj, &l);
342 if (l.base == obj->nr_tlb_entries) {
343 dev_warn(obj->dev, "%s: preserve entries full\n", __func__);
351 for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, tmp)
352 if (!iotlb_cr_valid(&tmp))
355 if (i == obj->nr_tlb_entries) {
356 dev_dbg(obj->dev, "%s: full: no entry\n", __func__);
361 iotlb_lock_get(obj, &l);
364 iotlb_lock_set(obj, &l);
367 cr = iotlb_alloc_cr(obj, e);
369 pm_runtime_put_sync(obj->dev);
373 iotlb_load_cr(obj, cr);
378 /* increment victim for next tlb load */
379 if (++l.vict == obj->nr_tlb_entries)
381 iotlb_lock_set(obj, &l);
383 pm_runtime_put_sync(obj->dev);
387 #else /* !PREFETCH_IOTLB */
389 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
394 #endif /* !PREFETCH_IOTLB */
396 static int prefetch_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
398 return load_iotlb_entry(obj, e);
402 * flush_iotlb_page - Clear an iommu tlb entry
404 * @da: iommu device virtual address
406 * Clear an iommu tlb entry which includes 'da' address.
408 static void flush_iotlb_page(struct omap_iommu *obj, u32 da)
413 pm_runtime_get_sync(obj->dev);
415 for_each_iotlb_cr(obj, obj->nr_tlb_entries, i, cr) {
419 if (!iotlb_cr_valid(&cr))
422 start = iotlb_cr_to_virt(&cr);
423 bytes = iopgsz_to_bytes(cr.cam & 3);
425 if ((start <= da) && (da < start + bytes)) {
426 dev_dbg(obj->dev, "%s: %08x<=%08x(%zx)\n",
427 __func__, start, da, bytes);
428 iotlb_load_cr(obj, &cr);
429 iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
433 pm_runtime_put_sync(obj->dev);
435 if (i == obj->nr_tlb_entries)
436 dev_dbg(obj->dev, "%s: no page for %08x\n", __func__, da);
440 * flush_iotlb_all - Clear all iommu tlb entries
443 static void flush_iotlb_all(struct omap_iommu *obj)
447 pm_runtime_get_sync(obj->dev);
451 iotlb_lock_set(obj, &l);
453 iommu_write_reg(obj, 1, MMU_GFLUSH);
455 pm_runtime_put_sync(obj->dev);
459 * H/W pagetable operations
461 static void flush_iopte_range(struct device *dev, dma_addr_t dma,
462 unsigned long offset, int num_entries)
464 size_t size = num_entries * sizeof(u32);
466 dma_sync_single_range_for_device(dev, dma, offset, size, DMA_TO_DEVICE);
469 static void iopte_free(struct omap_iommu *obj, u32 *iopte, bool dma_valid)
473 /* Note: freed iopte's must be clean ready for re-use */
476 pt_dma = virt_to_phys(iopte);
477 dma_unmap_single(obj->dev, pt_dma, IOPTE_TABLE_SIZE,
481 kmem_cache_free(iopte_cachep, iopte);
485 static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd,
486 dma_addr_t *pt_dma, u32 da)
489 unsigned long offset = iopgd_index(da) * sizeof(da);
491 /* a table has already existed */
496 * do the allocation outside the page table lock
498 spin_unlock(&obj->page_table_lock);
499 iopte = kmem_cache_zalloc(iopte_cachep, GFP_KERNEL);
500 spin_lock(&obj->page_table_lock);
504 return ERR_PTR(-ENOMEM);
506 *pt_dma = dma_map_single(obj->dev, iopte, IOPTE_TABLE_SIZE,
508 if (dma_mapping_error(obj->dev, *pt_dma)) {
509 dev_err(obj->dev, "DMA map error for L2 table\n");
510 iopte_free(obj, iopte, false);
511 return ERR_PTR(-ENOMEM);
515 * we rely on dma address and the physical address to be
516 * the same for mapping the L2 table
518 if (WARN_ON(*pt_dma != virt_to_phys(iopte))) {
519 dev_err(obj->dev, "DMA translation error for L2 table\n");
520 dma_unmap_single(obj->dev, *pt_dma, IOPTE_TABLE_SIZE,
522 iopte_free(obj, iopte, false);
523 return ERR_PTR(-ENOMEM);
526 *iopgd = virt_to_phys(iopte) | IOPGD_TABLE;
528 flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
529 dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
531 /* We raced, free the reduniovant table */
532 iopte_free(obj, iopte, false);
536 iopte = iopte_offset(iopgd, da);
537 *pt_dma = iopgd_page_paddr(iopgd);
539 "%s: da:%08x pgd:%p *pgd:%08x pte:%p *pte:%08x\n",
540 __func__, da, iopgd, *iopgd, iopte, *iopte);
545 static int iopgd_alloc_section(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
547 u32 *iopgd = iopgd_offset(obj, da);
548 unsigned long offset = iopgd_index(da) * sizeof(da);
550 if ((da | pa) & ~IOSECTION_MASK) {
551 dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
552 __func__, da, pa, IOSECTION_SIZE);
556 *iopgd = (pa & IOSECTION_MASK) | prot | IOPGD_SECTION;
557 flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
561 static int iopgd_alloc_super(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
563 u32 *iopgd = iopgd_offset(obj, da);
564 unsigned long offset = iopgd_index(da) * sizeof(da);
567 if ((da | pa) & ~IOSUPER_MASK) {
568 dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
569 __func__, da, pa, IOSUPER_SIZE);
573 for (i = 0; i < 16; i++)
574 *(iopgd + i) = (pa & IOSUPER_MASK) | prot | IOPGD_SUPER;
575 flush_iopte_range(obj->dev, obj->pd_dma, offset, 16);
579 static int iopte_alloc_page(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
581 u32 *iopgd = iopgd_offset(obj, da);
583 u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
584 unsigned long offset = iopte_index(da) * sizeof(da);
587 return PTR_ERR(iopte);
589 *iopte = (pa & IOPAGE_MASK) | prot | IOPTE_SMALL;
590 flush_iopte_range(obj->dev, pt_dma, offset, 1);
592 dev_vdbg(obj->dev, "%s: da:%08x pa:%08x pte:%p *pte:%08x\n",
593 __func__, da, pa, iopte, *iopte);
598 static int iopte_alloc_large(struct omap_iommu *obj, u32 da, u32 pa, u32 prot)
600 u32 *iopgd = iopgd_offset(obj, da);
602 u32 *iopte = iopte_alloc(obj, iopgd, &pt_dma, da);
603 unsigned long offset = iopte_index(da) * sizeof(da);
606 if ((da | pa) & ~IOLARGE_MASK) {
607 dev_err(obj->dev, "%s: %08x:%08x should aligned on %08lx\n",
608 __func__, da, pa, IOLARGE_SIZE);
613 return PTR_ERR(iopte);
615 for (i = 0; i < 16; i++)
616 *(iopte + i) = (pa & IOLARGE_MASK) | prot | IOPTE_LARGE;
617 flush_iopte_range(obj->dev, pt_dma, offset, 16);
622 iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
624 int (*fn)(struct omap_iommu *, u32, u32, u32);
632 case MMU_CAM_PGSZ_16M:
633 fn = iopgd_alloc_super;
635 case MMU_CAM_PGSZ_1M:
636 fn = iopgd_alloc_section;
638 case MMU_CAM_PGSZ_64K:
639 fn = iopte_alloc_large;
641 case MMU_CAM_PGSZ_4K:
642 fn = iopte_alloc_page;
652 prot = get_iopte_attr(e);
654 spin_lock(&obj->page_table_lock);
655 err = fn(obj, e->da, e->pa, prot);
656 spin_unlock(&obj->page_table_lock);
662 * omap_iopgtable_store_entry - Make an iommu pte entry
664 * @e: an iommu tlb entry info
667 omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
671 flush_iotlb_page(obj, e->da);
672 err = iopgtable_store_entry_core(obj, e);
674 prefetch_iotlb_entry(obj, e);
679 * iopgtable_lookup_entry - Lookup an iommu pte entry
681 * @da: iommu device virtual address
682 * @ppgd: iommu pgd entry pointer to be returned
683 * @ppte: iommu pte entry pointer to be returned
686 iopgtable_lookup_entry(struct omap_iommu *obj, u32 da, u32 **ppgd, u32 **ppte)
688 u32 *iopgd, *iopte = NULL;
690 iopgd = iopgd_offset(obj, da);
694 if (iopgd_is_table(*iopgd))
695 iopte = iopte_offset(iopgd, da);
701 static size_t iopgtable_clear_entry_core(struct omap_iommu *obj, u32 da)
704 u32 *iopgd = iopgd_offset(obj, da);
707 unsigned long pd_offset = iopgd_index(da) * sizeof(da);
708 unsigned long pt_offset = iopte_index(da) * sizeof(da);
713 if (iopgd_is_table(*iopgd)) {
715 u32 *iopte = iopte_offset(iopgd, da);
718 if (*iopte & IOPTE_LARGE) {
720 /* rewind to the 1st entry */
721 iopte = iopte_offset(iopgd, (da & IOLARGE_MASK));
724 memset(iopte, 0, nent * sizeof(*iopte));
725 pt_dma = iopgd_page_paddr(iopgd);
726 flush_iopte_range(obj->dev, pt_dma, pt_offset, nent);
729 * do table walk to check if this table is necessary or not
731 iopte = iopte_offset(iopgd, 0);
732 for (i = 0; i < PTRS_PER_IOPTE; i++)
736 iopte_free(obj, iopte, true);
737 nent = 1; /* for the next L1 entry */
740 if ((*iopgd & IOPGD_SUPER) == IOPGD_SUPER) {
742 /* rewind to the 1st entry */
743 iopgd = iopgd_offset(obj, (da & IOSUPER_MASK));
747 memset(iopgd, 0, nent * sizeof(*iopgd));
748 flush_iopte_range(obj->dev, obj->pd_dma, pd_offset, nent);
754 * iopgtable_clear_entry - Remove an iommu pte entry
756 * @da: iommu device virtual address
758 static size_t iopgtable_clear_entry(struct omap_iommu *obj, u32 da)
762 spin_lock(&obj->page_table_lock);
764 bytes = iopgtable_clear_entry_core(obj, da);
765 flush_iotlb_page(obj, da);
767 spin_unlock(&obj->page_table_lock);
772 static void iopgtable_clear_entry_all(struct omap_iommu *obj)
774 unsigned long offset;
777 spin_lock(&obj->page_table_lock);
779 for (i = 0; i < PTRS_PER_IOPGD; i++) {
783 da = i << IOPGD_SHIFT;
784 iopgd = iopgd_offset(obj, da);
785 offset = iopgd_index(da) * sizeof(da);
790 if (iopgd_is_table(*iopgd))
791 iopte_free(obj, iopte_offset(iopgd, 0), true);
794 flush_iopte_range(obj->dev, obj->pd_dma, offset, 1);
797 flush_iotlb_all(obj);
799 spin_unlock(&obj->page_table_lock);
803 * Device IOMMU generic operations
805 static irqreturn_t iommu_fault_handler(int irq, void *data)
809 struct omap_iommu *obj = data;
810 struct iommu_domain *domain = obj->domain;
811 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
813 if (!omap_domain->dev)
816 errs = iommu_report_fault(obj, &da);
820 /* Fault callback or TLB/PTE Dynamic loading */
821 if (!report_iommu_fault(domain, obj->dev, da, 0))
824 iommu_write_reg(obj, 0, MMU_IRQENABLE);
826 iopgd = iopgd_offset(obj, da);
828 if (!iopgd_is_table(*iopgd)) {
829 dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:px%08x\n",
830 obj->name, errs, da, iopgd, *iopgd);
834 iopte = iopte_offset(iopgd, da);
836 dev_err(obj->dev, "%s: errs:0x%08x da:0x%08x pgd:0x%p *pgd:0x%08x pte:0x%p *pte:0x%08x\n",
837 obj->name, errs, da, iopgd, *iopgd, iopte, *iopte);
843 * omap_iommu_attach() - attach iommu device to an iommu domain
844 * @obj: target omap iommu device
847 static int omap_iommu_attach(struct omap_iommu *obj, u32 *iopgd)
851 spin_lock(&obj->iommu_lock);
853 obj->pd_dma = dma_map_single(obj->dev, iopgd, IOPGD_TABLE_SIZE,
855 if (dma_mapping_error(obj->dev, obj->pd_dma)) {
856 dev_err(obj->dev, "DMA map error for L1 table\n");
862 err = iommu_enable(obj);
865 flush_iotlb_all(obj);
867 spin_unlock(&obj->iommu_lock);
869 dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
874 spin_unlock(&obj->iommu_lock);
880 * omap_iommu_detach - release iommu device
883 static void omap_iommu_detach(struct omap_iommu *obj)
885 if (!obj || IS_ERR(obj))
888 spin_lock(&obj->iommu_lock);
890 dma_unmap_single(obj->dev, obj->pd_dma, IOPGD_TABLE_SIZE,
896 spin_unlock(&obj->iommu_lock);
898 dev_dbg(obj->dev, "%s: %s\n", __func__, obj->name);
901 static void omap_iommu_save_tlb_entries(struct omap_iommu *obj)
903 struct iotlb_lock lock;
908 /* check if there are any locked tlbs to save */
909 iotlb_lock_get(obj, &lock);
910 obj->num_cr_ctx = lock.base;
911 if (!obj->num_cr_ctx)
915 for_each_iotlb_cr(obj, obj->num_cr_ctx, i, cr)
919 static void omap_iommu_restore_tlb_entries(struct omap_iommu *obj)
925 /* no locked tlbs to restore */
926 if (!obj->num_cr_ctx)
931 for (i = 0; i < obj->num_cr_ctx; i++, tmp++) {
933 iotlb_lock_set(obj, &l);
934 iotlb_load_cr(obj, tmp);
936 l.base = obj->num_cr_ctx;
938 iotlb_lock_set(obj, &l);
942 * omap_iommu_domain_deactivate - deactivate attached iommu devices
943 * @domain: iommu domain attached to the target iommu device
945 * This API allows the client devices of IOMMU devices to suspend
946 * the IOMMUs they control at runtime, after they are idled and
947 * suspended all activity. System Suspend will leverage the PM
948 * driver late callbacks.
950 int omap_iommu_domain_deactivate(struct iommu_domain *domain)
952 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
953 struct omap_iommu_device *iommu;
954 struct omap_iommu *oiommu;
957 if (!omap_domain->dev)
960 iommu = omap_domain->iommus;
961 iommu += (omap_domain->num_iommus - 1);
962 for (i = 0; i < omap_domain->num_iommus; i++, iommu--) {
963 oiommu = iommu->iommu_dev;
964 pm_runtime_put_sync(oiommu->dev);
969 EXPORT_SYMBOL_GPL(omap_iommu_domain_deactivate);
972 * omap_iommu_domain_activate - activate attached iommu devices
973 * @domain: iommu domain attached to the target iommu device
975 * This API allows the client devices of IOMMU devices to resume the
976 * IOMMUs they control at runtime, before they can resume operations.
977 * System Resume will leverage the PM driver late callbacks.
979 int omap_iommu_domain_activate(struct iommu_domain *domain)
981 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
982 struct omap_iommu_device *iommu;
983 struct omap_iommu *oiommu;
986 if (!omap_domain->dev)
989 iommu = omap_domain->iommus;
990 for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
991 oiommu = iommu->iommu_dev;
992 pm_runtime_get_sync(oiommu->dev);
997 EXPORT_SYMBOL_GPL(omap_iommu_domain_activate);
1000 * omap_iommu_runtime_suspend - disable an iommu device
1001 * @dev: iommu device
1003 * This function performs all that is necessary to disable an
1004 * IOMMU device, either during final detachment from a client
1005 * device, or during system/runtime suspend of the device. This
1006 * includes programming all the appropriate IOMMU registers, and
1007 * managing the associated omap_hwmod's state and the device's
1008 * reset line. This function also saves the context of any
1009 * locked TLBs if suspending.
1011 static __maybe_unused int omap_iommu_runtime_suspend(struct device *dev)
1013 struct platform_device *pdev = to_platform_device(dev);
1014 struct iommu_platform_data *pdata = dev_get_platdata(dev);
1015 struct omap_iommu *obj = to_iommu(dev);
1018 /* save the TLBs only during suspend, and not for power down */
1019 if (obj->domain && obj->iopgd)
1020 omap_iommu_save_tlb_entries(obj);
1022 omap2_iommu_disable(obj);
1024 if (pdata && pdata->device_idle)
1025 pdata->device_idle(pdev);
1027 if (pdata && pdata->assert_reset)
1028 pdata->assert_reset(pdev, pdata->reset_name);
1030 if (pdata && pdata->set_pwrdm_constraint) {
1031 ret = pdata->set_pwrdm_constraint(pdev, false, &obj->pwrst);
1033 dev_warn(obj->dev, "pwrdm_constraint failed to be reset, status = %d\n",
1042 * omap_iommu_runtime_resume - enable an iommu device
1043 * @dev: iommu device
1045 * This function performs all that is necessary to enable an
1046 * IOMMU device, either during initial attachment to a client
1047 * device, or during system/runtime resume of the device. This
1048 * includes programming all the appropriate IOMMU registers, and
1049 * managing the associated omap_hwmod's state and the device's
1050 * reset line. The function also restores any locked TLBs if
1051 * resuming after a suspend.
1053 static __maybe_unused int omap_iommu_runtime_resume(struct device *dev)
1055 struct platform_device *pdev = to_platform_device(dev);
1056 struct iommu_platform_data *pdata = dev_get_platdata(dev);
1057 struct omap_iommu *obj = to_iommu(dev);
1060 if (pdata && pdata->set_pwrdm_constraint) {
1061 ret = pdata->set_pwrdm_constraint(pdev, true, &obj->pwrst);
1063 dev_warn(obj->dev, "pwrdm_constraint failed to be set, status = %d\n",
1068 if (pdata && pdata->deassert_reset) {
1069 ret = pdata->deassert_reset(pdev, pdata->reset_name);
1071 dev_err(dev, "deassert_reset failed: %d\n", ret);
1076 if (pdata && pdata->device_enable)
1077 pdata->device_enable(pdev);
1079 /* restore the TLBs only during resume, and not for power up */
1081 omap_iommu_restore_tlb_entries(obj);
1083 ret = omap2_iommu_enable(obj);
1089 * omap_iommu_suspend_prepare - prepare() dev_pm_ops implementation
1090 * @dev: iommu device
1092 * This function performs the necessary checks to determine if the IOMMU
1093 * device needs suspending or not. The function checks if the runtime_pm
1094 * status of the device is suspended, and returns 1 in that case. This
1095 * results in the PM core to skip invoking any of the Sleep PM callbacks
1096 * (suspend, suspend_late, resume, resume_early etc).
1098 static int omap_iommu_prepare(struct device *dev)
1100 if (pm_runtime_status_suspended(dev))
1105 static bool omap_iommu_can_register(struct platform_device *pdev)
1107 struct device_node *np = pdev->dev.of_node;
1109 if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
1113 * restrict IOMMU core registration only for processor-port MDMA MMUs
1116 if ((!strcmp(dev_name(&pdev->dev), "40d01000.mmu")) ||
1117 (!strcmp(dev_name(&pdev->dev), "41501000.mmu")))
1123 static int omap_iommu_dra7_get_dsp_system_cfg(struct platform_device *pdev,
1124 struct omap_iommu *obj)
1126 struct device_node *np = pdev->dev.of_node;
1129 if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
1132 if (!of_property_read_bool(np, "ti,syscon-mmuconfig")) {
1133 dev_err(&pdev->dev, "ti,syscon-mmuconfig property is missing\n");
1138 syscon_regmap_lookup_by_phandle(np, "ti,syscon-mmuconfig");
1139 if (IS_ERR(obj->syscfg)) {
1140 /* can fail with -EPROBE_DEFER */
1141 ret = PTR_ERR(obj->syscfg);
1145 if (of_property_read_u32_index(np, "ti,syscon-mmuconfig", 1,
1147 dev_err(&pdev->dev, "couldn't get the IOMMU instance id within subsystem\n");
1151 if (obj->id != 0 && obj->id != 1) {
1152 dev_err(&pdev->dev, "invalid IOMMU instance id\n");
1160 * OMAP Device MMU(IOMMU) detection
1162 static int omap_iommu_probe(struct platform_device *pdev)
1166 struct omap_iommu *obj;
1167 struct resource *res;
1168 struct device_node *of = pdev->dev.of_node;
1171 pr_err("%s: only DT-based devices are supported\n", __func__);
1175 obj = devm_kzalloc(&pdev->dev, sizeof(*obj) + MMU_REG_SIZE, GFP_KERNEL);
1180 * self-manage the ordering dependencies between omap_device_enable/idle
1181 * and omap_device_assert/deassert_hardreset API
1183 if (pdev->dev.pm_domain) {
1184 dev_dbg(&pdev->dev, "device pm_domain is being reset\n");
1185 pdev->dev.pm_domain = NULL;
1188 obj->name = dev_name(&pdev->dev);
1189 obj->nr_tlb_entries = 32;
1190 err = of_property_read_u32(of, "ti,#tlb-entries", &obj->nr_tlb_entries);
1191 if (err && err != -EINVAL)
1193 if (obj->nr_tlb_entries != 32 && obj->nr_tlb_entries != 8)
1195 if (of_find_property(of, "ti,iommu-bus-err-back", NULL))
1196 obj->has_bus_err_back = MMU_GP_REG_BUS_ERR_BACK_EN;
1198 obj->dev = &pdev->dev;
1199 obj->ctx = (void *)obj + sizeof(*obj);
1200 obj->cr_ctx = devm_kzalloc(&pdev->dev,
1201 sizeof(*obj->cr_ctx) * obj->nr_tlb_entries,
1206 spin_lock_init(&obj->iommu_lock);
1207 spin_lock_init(&obj->page_table_lock);
1209 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1210 obj->regbase = devm_ioremap_resource(obj->dev, res);
1211 if (IS_ERR(obj->regbase))
1212 return PTR_ERR(obj->regbase);
1214 err = omap_iommu_dra7_get_dsp_system_cfg(pdev, obj);
1218 irq = platform_get_irq(pdev, 0);
1222 err = devm_request_irq(obj->dev, irq, iommu_fault_handler, IRQF_SHARED,
1223 dev_name(obj->dev), obj);
1226 platform_set_drvdata(pdev, obj);
1228 if (omap_iommu_can_register(pdev)) {
1229 obj->group = iommu_group_alloc();
1230 if (IS_ERR(obj->group))
1231 return PTR_ERR(obj->group);
1233 err = iommu_device_sysfs_add(&obj->iommu, obj->dev, NULL,
1238 iommu_device_set_ops(&obj->iommu, &omap_iommu_ops);
1239 iommu_device_set_fwnode(&obj->iommu, &of->fwnode);
1241 err = iommu_device_register(&obj->iommu);
1246 pm_runtime_enable(obj->dev);
1248 omap_iommu_debugfs_add(obj);
1250 dev_info(&pdev->dev, "%s registered\n", obj->name);
1252 /* Re-probe bus to probe device attached to this IOMMU */
1253 bus_iommu_probe(&platform_bus_type);
1258 iommu_device_sysfs_remove(&obj->iommu);
1260 iommu_group_put(obj->group);
1264 static int omap_iommu_remove(struct platform_device *pdev)
1266 struct omap_iommu *obj = platform_get_drvdata(pdev);
1269 iommu_group_put(obj->group);
1272 iommu_device_sysfs_remove(&obj->iommu);
1273 iommu_device_unregister(&obj->iommu);
1276 omap_iommu_debugfs_remove(obj);
1278 pm_runtime_disable(obj->dev);
1280 dev_info(&pdev->dev, "%s removed\n", obj->name);
1284 static const struct dev_pm_ops omap_iommu_pm_ops = {
1285 .prepare = omap_iommu_prepare,
1286 SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1287 pm_runtime_force_resume)
1288 SET_RUNTIME_PM_OPS(omap_iommu_runtime_suspend,
1289 omap_iommu_runtime_resume, NULL)
1292 static const struct of_device_id omap_iommu_of_match[] = {
1293 { .compatible = "ti,omap2-iommu" },
1294 { .compatible = "ti,omap4-iommu" },
1295 { .compatible = "ti,dra7-iommu" },
1296 { .compatible = "ti,dra7-dsp-iommu" },
1300 static struct platform_driver omap_iommu_driver = {
1301 .probe = omap_iommu_probe,
1302 .remove = omap_iommu_remove,
1304 .name = "omap-iommu",
1305 .pm = &omap_iommu_pm_ops,
1306 .of_match_table = of_match_ptr(omap_iommu_of_match),
1310 static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
1312 memset(e, 0, sizeof(*e));
1316 e->valid = MMU_CAM_V;
1318 e->endian = MMU_RAM_ENDIAN_LITTLE;
1319 e->elsz = MMU_RAM_ELSZ_8;
1322 return iopgsz_to_bytes(e->pgsz);
1325 static int omap_iommu_map(struct iommu_domain *domain, unsigned long da,
1326 phys_addr_t pa, size_t bytes, int prot, gfp_t gfp)
1328 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1329 struct device *dev = omap_domain->dev;
1330 struct omap_iommu_device *iommu;
1331 struct omap_iommu *oiommu;
1332 struct iotlb_entry e;
1337 omap_pgsz = bytes_to_iopgsz(bytes);
1338 if (omap_pgsz < 0) {
1339 dev_err(dev, "invalid size to map: %zu\n", bytes);
1343 dev_dbg(dev, "mapping da 0x%lx to pa %pa size 0x%zx\n", da, &pa, bytes);
1345 iotlb_init_entry(&e, da, pa, omap_pgsz);
1347 iommu = omap_domain->iommus;
1348 for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
1349 oiommu = iommu->iommu_dev;
1350 ret = omap_iopgtable_store_entry(oiommu, &e);
1352 dev_err(dev, "omap_iopgtable_store_entry failed: %d\n",
1361 oiommu = iommu->iommu_dev;
1362 iopgtable_clear_entry(oiommu, da);
1369 static size_t omap_iommu_unmap(struct iommu_domain *domain, unsigned long da,
1370 size_t size, struct iommu_iotlb_gather *gather)
1372 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1373 struct device *dev = omap_domain->dev;
1374 struct omap_iommu_device *iommu;
1375 struct omap_iommu *oiommu;
1380 dev_dbg(dev, "unmapping da 0x%lx size %zu\n", da, size);
1382 iommu = omap_domain->iommus;
1383 for (i = 0; i < omap_domain->num_iommus; i++, iommu++) {
1384 oiommu = iommu->iommu_dev;
1385 bytes = iopgtable_clear_entry(oiommu, da);
1391 * simplify return - we are only checking if any of the iommus
1392 * reported an error, but not if all of them are unmapping the
1393 * same number of entries. This should not occur due to the
1394 * mirror programming.
1396 return error ? 0 : bytes;
1399 static int omap_iommu_count(struct device *dev)
1401 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1404 while (arch_data->iommu_dev) {
1412 /* caller should call cleanup if this function fails */
1413 static int omap_iommu_attach_init(struct device *dev,
1414 struct omap_iommu_domain *odomain)
1416 struct omap_iommu_device *iommu;
1419 odomain->num_iommus = omap_iommu_count(dev);
1420 if (!odomain->num_iommus)
1423 odomain->iommus = kcalloc(odomain->num_iommus, sizeof(*iommu),
1425 if (!odomain->iommus)
1428 iommu = odomain->iommus;
1429 for (i = 0; i < odomain->num_iommus; i++, iommu++) {
1430 iommu->pgtable = kzalloc(IOPGD_TABLE_SIZE, GFP_ATOMIC);
1431 if (!iommu->pgtable)
1435 * should never fail, but please keep this around to ensure
1436 * we keep the hardware happy
1438 if (WARN_ON(!IS_ALIGNED((long)iommu->pgtable,
1446 static void omap_iommu_detach_fini(struct omap_iommu_domain *odomain)
1449 struct omap_iommu_device *iommu = odomain->iommus;
1451 for (i = 0; iommu && i < odomain->num_iommus; i++, iommu++)
1452 kfree(iommu->pgtable);
1454 kfree(odomain->iommus);
1455 odomain->num_iommus = 0;
1456 odomain->iommus = NULL;
1460 omap_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
1462 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1463 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1464 struct omap_iommu_device *iommu;
1465 struct omap_iommu *oiommu;
1469 if (!arch_data || !arch_data->iommu_dev) {
1470 dev_err(dev, "device doesn't have an associated iommu\n");
1474 spin_lock(&omap_domain->lock);
1476 /* only a single client device can be attached to a domain */
1477 if (omap_domain->dev) {
1478 dev_err(dev, "iommu domain is already attached\n");
1483 ret = omap_iommu_attach_init(dev, omap_domain);
1485 dev_err(dev, "failed to allocate required iommu data %d\n",
1490 iommu = omap_domain->iommus;
1491 for (i = 0; i < omap_domain->num_iommus; i++, iommu++, arch_data++) {
1492 /* configure and enable the omap iommu */
1493 oiommu = arch_data->iommu_dev;
1494 ret = omap_iommu_attach(oiommu, iommu->pgtable);
1496 dev_err(dev, "can't get omap iommu: %d\n", ret);
1500 oiommu->domain = domain;
1501 iommu->iommu_dev = oiommu;
1504 omap_domain->dev = dev;
1512 oiommu = iommu->iommu_dev;
1513 omap_iommu_detach(oiommu);
1514 iommu->iommu_dev = NULL;
1515 oiommu->domain = NULL;
1518 omap_iommu_detach_fini(omap_domain);
1520 spin_unlock(&omap_domain->lock);
1524 static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
1527 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1528 struct omap_iommu_device *iommu = omap_domain->iommus;
1529 struct omap_iommu *oiommu;
1532 if (!omap_domain->dev) {
1533 dev_err(dev, "domain has no attached device\n");
1537 /* only a single device is supported per domain for now */
1538 if (omap_domain->dev != dev) {
1539 dev_err(dev, "invalid attached device\n");
1544 * cleanup in the reverse order of attachment - this addresses
1545 * any h/w dependencies between multiple instances, if any
1547 iommu += (omap_domain->num_iommus - 1);
1548 arch_data += (omap_domain->num_iommus - 1);
1549 for (i = 0; i < omap_domain->num_iommus; i++, iommu--, arch_data--) {
1550 oiommu = iommu->iommu_dev;
1551 iopgtable_clear_entry_all(oiommu);
1553 omap_iommu_detach(oiommu);
1554 iommu->iommu_dev = NULL;
1555 oiommu->domain = NULL;
1558 omap_iommu_detach_fini(omap_domain);
1560 omap_domain->dev = NULL;
1563 static void omap_iommu_detach_dev(struct iommu_domain *domain,
1566 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1568 spin_lock(&omap_domain->lock);
1569 _omap_iommu_detach_dev(omap_domain, dev);
1570 spin_unlock(&omap_domain->lock);
1573 static struct iommu_domain *omap_iommu_domain_alloc(unsigned type)
1575 struct omap_iommu_domain *omap_domain;
1577 if (type != IOMMU_DOMAIN_UNMANAGED)
1580 omap_domain = kzalloc(sizeof(*omap_domain), GFP_KERNEL);
1584 spin_lock_init(&omap_domain->lock);
1586 omap_domain->domain.geometry.aperture_start = 0;
1587 omap_domain->domain.geometry.aperture_end = (1ULL << 32) - 1;
1588 omap_domain->domain.geometry.force_aperture = true;
1590 return &omap_domain->domain;
1593 static void omap_iommu_domain_free(struct iommu_domain *domain)
1595 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1598 * An iommu device is still attached
1599 * (currently, only one device can be attached) ?
1601 if (omap_domain->dev)
1602 _omap_iommu_detach_dev(omap_domain, omap_domain->dev);
1607 static phys_addr_t omap_iommu_iova_to_phys(struct iommu_domain *domain,
1610 struct omap_iommu_domain *omap_domain = to_omap_domain(domain);
1611 struct omap_iommu_device *iommu = omap_domain->iommus;
1612 struct omap_iommu *oiommu = iommu->iommu_dev;
1613 struct device *dev = oiommu->dev;
1615 phys_addr_t ret = 0;
1618 * all the iommus within the domain will have identical programming,
1619 * so perform the lookup using just the first iommu
1621 iopgtable_lookup_entry(oiommu, da, &pgd, &pte);
1624 if (iopte_is_small(*pte))
1625 ret = omap_iommu_translate(*pte, da, IOPTE_MASK);
1626 else if (iopte_is_large(*pte))
1627 ret = omap_iommu_translate(*pte, da, IOLARGE_MASK);
1629 dev_err(dev, "bogus pte 0x%x, da 0x%llx", *pte,
1630 (unsigned long long)da);
1632 if (iopgd_is_section(*pgd))
1633 ret = omap_iommu_translate(*pgd, da, IOSECTION_MASK);
1634 else if (iopgd_is_super(*pgd))
1635 ret = omap_iommu_translate(*pgd, da, IOSUPER_MASK);
1637 dev_err(dev, "bogus pgd 0x%x, da 0x%llx", *pgd,
1638 (unsigned long long)da);
1644 static struct iommu_device *omap_iommu_probe_device(struct device *dev)
1646 struct omap_iommu_arch_data *arch_data, *tmp;
1647 struct platform_device *pdev;
1648 struct omap_iommu *oiommu;
1649 struct device_node *np;
1653 * Allocate the per-device iommu structure for DT-based devices.
1655 * TODO: Simplify this when removing non-DT support completely from the
1659 return ERR_PTR(-ENODEV);
1662 * retrieve the count of IOMMU nodes using phandle size as element size
1663 * since #iommu-cells = 0 for OMAP
1665 num_iommus = of_property_count_elems_of_size(dev->of_node, "iommus",
1670 arch_data = kcalloc(num_iommus + 1, sizeof(*arch_data), GFP_KERNEL);
1672 return ERR_PTR(-ENOMEM);
1674 for (i = 0, tmp = arch_data; i < num_iommus; i++, tmp++) {
1675 np = of_parse_phandle(dev->of_node, "iommus", i);
1678 return ERR_PTR(-EINVAL);
1681 pdev = of_find_device_by_node(np);
1685 return ERR_PTR(-ENODEV);
1688 oiommu = platform_get_drvdata(pdev);
1692 return ERR_PTR(-EINVAL);
1695 tmp->iommu_dev = oiommu;
1696 tmp->dev = &pdev->dev;
1701 dev_iommu_priv_set(dev, arch_data);
1704 * use the first IOMMU alone for the sysfs device linking.
1705 * TODO: Evaluate if a single iommu_group needs to be
1706 * maintained for both IOMMUs
1708 oiommu = arch_data->iommu_dev;
1710 return &oiommu->iommu;
1713 static void omap_iommu_release_device(struct device *dev)
1715 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1717 if (!dev->of_node || !arch_data)
1720 dev_iommu_priv_set(dev, NULL);
1725 static struct iommu_group *omap_iommu_device_group(struct device *dev)
1727 struct omap_iommu_arch_data *arch_data = dev_iommu_priv_get(dev);
1728 struct iommu_group *group = ERR_PTR(-EINVAL);
1731 return ERR_PTR(-ENODEV);
1733 if (arch_data->iommu_dev)
1734 group = iommu_group_ref_get(arch_data->iommu_dev->group);
1739 static const struct iommu_ops omap_iommu_ops = {
1740 .domain_alloc = omap_iommu_domain_alloc,
1741 .domain_free = omap_iommu_domain_free,
1742 .attach_dev = omap_iommu_attach_dev,
1743 .detach_dev = omap_iommu_detach_dev,
1744 .map = omap_iommu_map,
1745 .unmap = omap_iommu_unmap,
1746 .iova_to_phys = omap_iommu_iova_to_phys,
1747 .probe_device = omap_iommu_probe_device,
1748 .release_device = omap_iommu_release_device,
1749 .device_group = omap_iommu_device_group,
1750 .pgsize_bitmap = OMAP_IOMMU_PGSIZES,
1753 static int __init omap_iommu_init(void)
1755 struct kmem_cache *p;
1756 const slab_flags_t flags = SLAB_HWCACHE_ALIGN;
1757 size_t align = 1 << 10; /* L2 pagetable alignement */
1758 struct device_node *np;
1761 np = of_find_matching_node(NULL, omap_iommu_of_match);
1767 p = kmem_cache_create("iopte_cache", IOPTE_TABLE_SIZE, align, flags,
1773 omap_iommu_debugfs_init();
1775 ret = platform_driver_register(&omap_iommu_driver);
1777 pr_err("%s: failed to register driver\n", __func__);
1781 ret = bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
1788 platform_driver_unregister(&omap_iommu_driver);
1790 kmem_cache_destroy(iopte_cachep);
1793 subsys_initcall(omap_iommu_init);
1794 /* must be ready before omap3isp is probed */