4 * Privileged Space Mapping Buffer (PMB) Support.
6 * Copyright (C) 2005 - 2010 Paul Mundt
7 * Copyright (C) 2010 Matt Fleming
9 * This file is subject to the terms and conditions of the GNU General Public
10 * License. See the file "COPYING" in the main directory of this archive
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/sysdev.h>
16 #include <linux/cpu.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/bitops.h>
20 #include <linux/debugfs.h>
22 #include <linux/seq_file.h>
23 #include <linux/err.h>
25 #include <linux/spinlock.h>
26 #include <linux/vmalloc.h>
27 #include <asm/cacheflush.h>
28 #include <asm/sizes.h>
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <asm/pgtable.h>
34 #include <asm/mmu_context.h>
47 * 0 .. NR_PMB_ENTRIES for specific entry selection, or
48 * PMB_NO_ENTRY to search for a free one
52 /* Adjacent entry link for contiguous multi-entry mappings */
53 struct pmb_entry *link;
60 { .size = SZ_512M, .flag = PMB_SZ_512M, },
61 { .size = SZ_128M, .flag = PMB_SZ_128M, },
62 { .size = SZ_64M, .flag = PMB_SZ_64M, },
63 { .size = SZ_16M, .flag = PMB_SZ_16M, },
66 static void pmb_unmap_entry(struct pmb_entry *, int depth);
68 static DEFINE_RWLOCK(pmb_rwlock);
69 static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
70 static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);
72 static unsigned int pmb_iomapping_enabled;
74 static __always_inline unsigned long mk_pmb_entry(unsigned int entry)
76 return (entry & PMB_E_MASK) << PMB_E_SHIFT;
79 static __always_inline unsigned long mk_pmb_addr(unsigned int entry)
81 return mk_pmb_entry(entry) | PMB_ADDR;
84 static __always_inline unsigned long mk_pmb_data(unsigned int entry)
86 return mk_pmb_entry(entry) | PMB_DATA;
89 static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
91 return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
95 * Ensure that the PMB entries match our cache configuration.
97 * When we are in 32-bit address extended mode, CCR.CB becomes
98 * invalid, so care must be taken to manually adjust cacheable
101 static __always_inline unsigned long pmb_cache_flags(void)
103 unsigned long flags = 0;
105 #if defined(CONFIG_CACHE_OFF)
106 flags |= PMB_WT | PMB_UB;
107 #elif defined(CONFIG_CACHE_WRITETHROUGH)
108 flags |= PMB_C | PMB_WT | PMB_UB;
109 #elif defined(CONFIG_CACHE_WRITEBACK)
117 * Convert typical pgprot value to the PMB equivalent
119 static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
121 unsigned long pmb_flags = 0;
122 u64 flags = pgprot_val(prot);
124 if (flags & _PAGE_CACHABLE)
126 if (flags & _PAGE_WT)
127 pmb_flags |= PMB_WT | PMB_UB;
132 static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
134 return (b->vpn == (a->vpn + a->size)) &&
135 (b->ppn == (a->ppn + a->size)) &&
136 (b->flags == a->flags);
139 static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys,
144 read_lock(&pmb_rwlock);
146 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
147 struct pmb_entry *pmbe, *iter;
150 if (!test_bit(i, pmb_map))
153 pmbe = &pmb_entry_list[i];
156 * See if VPN and PPN are bounded by an existing mapping.
158 if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
160 if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
164 * Now see if we're in range of a simple mapping.
166 if (size <= pmbe->size) {
167 read_unlock(&pmb_rwlock);
174 * Finally for sizes that involve compound mappings, walk
177 for (iter = pmbe->link; iter; iter = iter->link)
181 * Nothing else to do if the range requirements are met.
184 read_unlock(&pmb_rwlock);
189 read_unlock(&pmb_rwlock);
193 static bool pmb_size_valid(unsigned long size)
197 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
198 if (pmb_sizes[i].size == size)
204 static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
206 return (addr >= P1SEG && (addr + size - 1) < P3SEG);
209 static inline bool pmb_prot_valid(pgprot_t prot)
211 return (pgprot_val(prot) & _PAGE_USER) == 0;
214 static int pmb_size_to_flags(unsigned long size)
218 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
219 if (pmb_sizes[i].size == size)
220 return pmb_sizes[i].flag;
225 static int pmb_alloc_entry(void)
229 pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES);
230 if (pos >= 0 && pos < NR_PMB_ENTRIES)
231 __set_bit(pos, pmb_map);
238 static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
239 unsigned long flags, int entry)
241 struct pmb_entry *pmbe;
242 unsigned long irqflags;
246 write_lock_irqsave(&pmb_rwlock, irqflags);
248 if (entry == PMB_NO_ENTRY) {
249 pos = pmb_alloc_entry();
250 if (unlikely(pos < 0)) {
255 if (__test_and_set_bit(entry, pmb_map)) {
256 ret = ERR_PTR(-ENOSPC);
263 write_unlock_irqrestore(&pmb_rwlock, irqflags);
265 pmbe = &pmb_entry_list[pos];
267 memset(pmbe, 0, sizeof(struct pmb_entry));
269 spin_lock_init(&pmbe->lock);
279 write_unlock_irqrestore(&pmb_rwlock, irqflags);
283 static void pmb_free(struct pmb_entry *pmbe)
285 __clear_bit(pmbe->entry, pmb_map);
287 pmbe->entry = PMB_NO_ENTRY;
292 * Must be run uncached.
294 static void __set_pmb_entry(struct pmb_entry *pmbe)
296 unsigned long addr, data;
298 addr = mk_pmb_addr(pmbe->entry);
299 data = mk_pmb_data(pmbe->entry);
304 __raw_writel(pmbe->vpn | PMB_V, addr);
305 __raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data);
310 static void __clear_pmb_entry(struct pmb_entry *pmbe)
312 unsigned long addr, data;
313 unsigned long addr_val, data_val;
315 addr = mk_pmb_addr(pmbe->entry);
316 data = mk_pmb_data(pmbe->entry);
318 addr_val = __raw_readl(addr);
319 data_val = __raw_readl(data);
322 writel_uncached(addr_val & ~PMB_V, addr);
323 writel_uncached(data_val & ~PMB_V, data);
326 static void set_pmb_entry(struct pmb_entry *pmbe)
330 spin_lock_irqsave(&pmbe->lock, flags);
331 __set_pmb_entry(pmbe);
332 spin_unlock_irqrestore(&pmbe->lock, flags);
335 int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
336 unsigned long size, pgprot_t prot)
338 struct pmb_entry *pmbp, *pmbe;
339 unsigned long orig_addr, orig_size;
340 unsigned long flags, pmb_flags;
343 if (!pmb_addr_valid(vaddr, size))
345 if (pmb_mapping_exists(vaddr, phys, size))
351 flush_tlb_kernel_range(vaddr, vaddr + size);
353 pmb_flags = pgprot_to_pmb_flags(prot);
357 for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
358 if (size < pmb_sizes[i].size)
361 pmbe = pmb_alloc(vaddr, phys, pmb_flags |
362 pmb_sizes[i].flag, PMB_NO_ENTRY);
364 pmb_unmap_entry(pmbp, mapped);
365 return PTR_ERR(pmbe);
368 spin_lock_irqsave(&pmbe->lock, flags);
370 pmbe->size = pmb_sizes[i].size;
372 __set_pmb_entry(pmbe);
379 * Link adjacent entries that span multiple PMB
380 * entries for easier tear-down.
383 spin_lock(&pmbp->lock);
385 spin_unlock(&pmbp->lock);
391 * Instead of trying smaller sizes on every
392 * iteration (even if we succeed in allocating
393 * space), try using pmb_sizes[i].size again.
398 spin_unlock_irqrestore(&pmbe->lock, flags);
400 } while (size >= SZ_16M);
402 flush_cache_vmap(orig_addr, orig_addr + orig_size);
407 void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
408 pgprot_t prot, void *caller)
411 phys_addr_t offset, last_addr;
412 phys_addr_t align_mask;
413 unsigned long aligned;
414 struct vm_struct *area;
417 if (!pmb_iomapping_enabled)
421 * Small mappings need to go through the TLB.
424 return ERR_PTR(-EINVAL);
425 if (!pmb_prot_valid(prot))
426 return ERR_PTR(-EINVAL);
428 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
429 if (size >= pmb_sizes[i].size)
432 last_addr = phys + size;
433 align_mask = ~(pmb_sizes[i].size - 1);
434 offset = phys & ~align_mask;
436 aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;
439 * XXX: This should really start from uncached_end, but this
440 * causes the MMU to reset, so for now we restrict it to the
441 * 0xb000...0xc000 range.
443 area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000,
448 area->phys_addr = phys;
449 vaddr = (unsigned long)area->addr;
451 ret = pmb_bolt_mapping(vaddr, phys, size, prot);
452 if (unlikely(ret != 0))
455 return (void __iomem *)(offset + (char *)vaddr);
458 int pmb_unmap(void __iomem *addr)
460 struct pmb_entry *pmbe = NULL;
461 unsigned long vaddr = (unsigned long __force)addr;
464 read_lock(&pmb_rwlock);
466 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
467 if (test_bit(i, pmb_map)) {
468 pmbe = &pmb_entry_list[i];
469 if (pmbe->vpn == vaddr) {
476 read_unlock(&pmb_rwlock);
479 pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
486 static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
489 struct pmb_entry *pmblink = pmbe;
492 * We may be called before this pmb_entry has been
493 * entered into the PMB table via set_pmb_entry(), but
494 * that's OK because we've allocated a unique slot for
495 * this entry in pmb_alloc() (even if we haven't filled
498 * Therefore, calling __clear_pmb_entry() is safe as no
499 * other mapping can be using that slot.
501 __clear_pmb_entry(pmbe);
503 flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size);
505 pmbe = pmblink->link;
508 } while (pmbe && --depth);
511 static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
518 write_lock_irqsave(&pmb_rwlock, flags);
519 __pmb_unmap_entry(pmbe, depth);
520 write_unlock_irqrestore(&pmb_rwlock, flags);
523 static void __init pmb_notify(void)
527 pr_info("PMB: boot mappings:\n");
529 read_lock(&pmb_rwlock);
531 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
532 struct pmb_entry *pmbe;
534 if (!test_bit(i, pmb_map))
537 pmbe = &pmb_entry_list[i];
539 pr_info(" 0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n",
540 pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT,
541 pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un");
544 read_unlock(&pmb_rwlock);
548 * Sync our software copy of the PMB mappings with those in hardware. The
549 * mappings in the hardware PMB were either set up by the bootloader or
550 * very early on by the kernel.
552 static void __init pmb_synchronize(void)
554 struct pmb_entry *pmbp = NULL;
558 * Run through the initial boot mappings, log the established
559 * ones, and blow away anything that falls outside of the valid
560 * PPN range. Specifically, we only care about existing mappings
561 * that impact the cached/uncached sections.
563 * Note that touching these can be a bit of a minefield; the boot
564 * loader can establish multi-page mappings with the same caching
565 * attributes, so we need to ensure that we aren't modifying a
566 * mapping that we're presently executing from, or may execute
567 * from in the case of straddling page boundaries.
569 * In the future we will have to tidy up after the boot loader by
570 * jumping between the cached and uncached mappings and tearing
571 * down alternating mappings while executing from the other.
573 for (i = 0; i < NR_PMB_ENTRIES; i++) {
574 unsigned long addr, data;
575 unsigned long addr_val, data_val;
576 unsigned long ppn, vpn, flags;
577 unsigned long irqflags;
579 struct pmb_entry *pmbe;
581 addr = mk_pmb_addr(i);
582 data = mk_pmb_data(i);
584 addr_val = __raw_readl(addr);
585 data_val = __raw_readl(data);
588 * Skip over any bogus entries
590 if (!(data_val & PMB_V) || !(addr_val & PMB_V))
593 ppn = data_val & PMB_PFN_MASK;
594 vpn = addr_val & PMB_PFN_MASK;
597 * Only preserve in-range mappings.
599 if (!pmb_ppn_in_range(ppn)) {
601 * Invalidate anything out of bounds.
603 writel_uncached(addr_val & ~PMB_V, addr);
604 writel_uncached(data_val & ~PMB_V, data);
609 * Update the caching attributes if necessary
611 if (data_val & PMB_C) {
612 data_val &= ~PMB_CACHE_MASK;
613 data_val |= pmb_cache_flags();
615 writel_uncached(data_val, data);
618 size = data_val & PMB_SZ_MASK;
619 flags = size | (data_val & PMB_CACHE_MASK);
621 pmbe = pmb_alloc(vpn, ppn, flags, i);
627 spin_lock_irqsave(&pmbe->lock, irqflags);
629 for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
630 if (pmb_sizes[j].flag == size)
631 pmbe->size = pmb_sizes[j].size;
634 spin_lock(&pmbp->lock);
637 * Compare the previous entry against the current one to
638 * see if the entries span a contiguous mapping. If so,
639 * setup the entry links accordingly. Compound mappings
640 * are later coalesced.
642 if (pmb_can_merge(pmbp, pmbe))
645 spin_unlock(&pmbp->lock);
650 spin_unlock_irqrestore(&pmbe->lock, irqflags);
654 static void __init pmb_merge(struct pmb_entry *head)
656 unsigned long span, newsize;
657 struct pmb_entry *tail;
658 int i = 1, depth = 0;
660 span = newsize = head->size;
666 if (pmb_size_valid(span)) {
671 /* This is the end of the line.. */
680 * The merged page size must be valid.
682 if (!pmb_size_valid(newsize))
685 head->flags &= ~PMB_SZ_MASK;
686 head->flags |= pmb_size_to_flags(newsize);
688 head->size = newsize;
690 __pmb_unmap_entry(head->link, depth);
691 __set_pmb_entry(head);
694 static void __init pmb_coalesce(void)
699 write_lock_irqsave(&pmb_rwlock, flags);
701 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
702 struct pmb_entry *pmbe;
704 if (!test_bit(i, pmb_map))
707 pmbe = &pmb_entry_list[i];
710 * We're only interested in compound mappings
716 * Nothing to do if it already uses the largest possible
719 if (pmbe->size == SZ_512M)
725 write_unlock_irqrestore(&pmb_rwlock, flags);
728 #ifdef CONFIG_UNCACHED_MAPPING
729 static void __init pmb_resize(void)
734 * If the uncached mapping was constructed by the kernel, it will
735 * already be a reasonable size.
737 if (uncached_size == SZ_16M)
740 read_lock(&pmb_rwlock);
742 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
743 struct pmb_entry *pmbe;
746 if (!test_bit(i, pmb_map))
749 pmbe = &pmb_entry_list[i];
751 if (pmbe->vpn != uncached_start)
755 * Found it, now resize it.
757 spin_lock_irqsave(&pmbe->lock, flags);
760 pmbe->flags &= ~PMB_SZ_MASK;
761 pmbe->flags |= pmb_size_to_flags(pmbe->size);
763 uncached_resize(pmbe->size);
765 __set_pmb_entry(pmbe);
767 spin_unlock_irqrestore(&pmbe->lock, flags);
770 read_lock(&pmb_rwlock);
774 static int __init early_pmb(char *p)
779 if (strstr(p, "iomap"))
780 pmb_iomapping_enabled = 1;
784 early_param("pmb", early_pmb);
786 void __init pmb_init(void)
788 /* Synchronize software state */
791 /* Attempt to combine compound mappings */
794 #ifdef CONFIG_UNCACHED_MAPPING
795 /* Resize initial mappings, if necessary */
802 writel_uncached(0, PMB_IRMCR);
804 /* Flush out the TLB */
805 __raw_writel(__raw_readl(MMUCR) | MMUCR_TI, MMUCR);
809 bool __in_29bit_mode(void)
811 return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0;
814 static int pmb_seq_show(struct seq_file *file, void *iter)
818 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
819 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
820 seq_printf(file, "ety vpn ppn size flags\n");
822 for (i = 0; i < NR_PMB_ENTRIES; i++) {
823 unsigned long addr, data;
827 addr = __raw_readl(mk_pmb_addr(i));
828 data = __raw_readl(mk_pmb_data(i));
830 size = data & PMB_SZ_MASK;
831 sz_str = (size == PMB_SZ_16M) ? " 16MB":
832 (size == PMB_SZ_64M) ? " 64MB":
833 (size == PMB_SZ_128M) ? "128MB":
836 /* 02: V 0x88 0x08 128MB C CB B */
837 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
838 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
839 (addr >> 24) & 0xff, (data >> 24) & 0xff,
840 sz_str, (data & PMB_C) ? 'C' : ' ',
841 (data & PMB_WT) ? "WT" : "CB",
842 (data & PMB_UB) ? "UB" : " B");
848 static int pmb_debugfs_open(struct inode *inode, struct file *file)
850 return single_open(file, pmb_seq_show, NULL);
853 static const struct file_operations pmb_debugfs_fops = {
854 .owner = THIS_MODULE,
855 .open = pmb_debugfs_open,
858 .release = single_release,
861 static int __init pmb_debugfs_init(void)
863 struct dentry *dentry;
865 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
866 sh_debugfs_root, NULL, &pmb_debugfs_fops);
870 return PTR_ERR(dentry);
874 subsys_initcall(pmb_debugfs_init);
877 static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state)
879 static pm_message_t prev_state;
882 /* Restore the PMB after a resume from hibernation */
883 if (state.event == PM_EVENT_ON &&
884 prev_state.event == PM_EVENT_FREEZE) {
885 struct pmb_entry *pmbe;
887 read_lock(&pmb_rwlock);
889 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
890 if (test_bit(i, pmb_map)) {
891 pmbe = &pmb_entry_list[i];
896 read_unlock(&pmb_rwlock);
904 static int pmb_sysdev_resume(struct sys_device *dev)
906 return pmb_sysdev_suspend(dev, PMSG_ON);
909 static struct sysdev_driver pmb_sysdev_driver = {
910 .suspend = pmb_sysdev_suspend,
911 .resume = pmb_sysdev_resume,
914 static int __init pmb_sysdev_init(void)
916 return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver);
918 subsys_initcall(pmb_sysdev_init);