/* * arch/sh/mm/pmb.c * * Privileged Space Mapping Buffer (PMB) Support. * * Copyright (C) 2005 - 2011 Paul Mundt * Copyright (C) 2010 Matt Fleming * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/syscore_ops.h> #include <linux/cpu.h> #include <linux/module.h> #include <linux/bitops.h> #include <linux/debugfs.h> #include <linux/fs.h> #include <linux/seq_file.h> #include <linux/err.h> #include <linux/io.h> #include <linux/spinlock.h> #include <linux/vmalloc.h> #include <asm/cacheflush.h> #include <asm/sizes.h> #include <asm/uaccess.h> #include <asm/pgtable.h> #include <asm/page.h> #include <asm/mmu.h> #include <asm/mmu_context.h> struct pmb_entry; struct pmb_entry { unsigned long vpn; unsigned long ppn; unsigned long flags; unsigned long size; raw_spinlock_t lock; /* * 0 .. NR_PMB_ENTRIES for specific entry selection, or * PMB_NO_ENTRY to search for a free one */ int entry; /* Adjacent entry link for contiguous multi-entry mappings */ struct pmb_entry *link; }; static struct { unsigned long size; int flag; } pmb_sizes[] = { { .size = SZ_512M, .flag = PMB_SZ_512M, }, { .size = SZ_128M, .flag = PMB_SZ_128M, }, { .size = SZ_64M, .flag = PMB_SZ_64M, }, { .size = SZ_16M, .flag = PMB_SZ_16M, }, }; static void pmb_unmap_entry(struct pmb_entry *, int depth); static DEFINE_RWLOCK(pmb_rwlock); static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES]; static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES); static unsigned int pmb_iomapping_enabled; static __always_inline unsigned long mk_pmb_entry(unsigned int entry) { return (entry & PMB_E_MASK) << PMB_E_SHIFT; } static __always_inline unsigned long mk_pmb_addr(unsigned int entry) { return mk_pmb_entry(entry) | PMB_ADDR; } static __always_inline unsigned long mk_pmb_data(unsigned int entry) { return mk_pmb_entry(entry) | PMB_DATA; } static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn) { return ppn >= __pa(memory_start) && ppn < __pa(memory_end); } /* * Ensure that the PMB entries match our cache configuration. * * When we are in 32-bit address extended mode, CCR.CB becomes * invalid, so care must be taken to manually adjust cacheable * translations. */ static __always_inline unsigned long pmb_cache_flags(void) { unsigned long flags = 0; #if defined(CONFIG_CACHE_OFF) flags |= PMB_WT | PMB_UB; #elif defined(CONFIG_CACHE_WRITETHROUGH) flags |= PMB_C | PMB_WT | PMB_UB; #elif defined(CONFIG_CACHE_WRITEBACK) flags |= PMB_C; #endif return flags; } /* * Convert typical pgprot value to the PMB equivalent */ static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot) { unsigned long pmb_flags = 0; u64 flags = pgprot_val(prot); if (flags & _PAGE_CACHABLE) pmb_flags |= PMB_C; if (flags & _PAGE_WT) pmb_flags |= PMB_WT | PMB_UB; return pmb_flags; } static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b) { return (b->vpn == (a->vpn + a->size)) && (b->ppn == (a->ppn + a->size)) && (b->flags == a->flags); } static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys, unsigned long size) { int i; read_lock(&pmb_rwlock); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { struct pmb_entry *pmbe, *iter; unsigned long span; if (!test_bit(i, pmb_map)) continue; pmbe = &pmb_entry_list[i]; /* * See if VPN and PPN are bounded by an existing mapping. */ if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size))) continue; if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size))) continue; /* * Now see if we're in range of a simple mapping. */ if (size <= pmbe->size) { read_unlock(&pmb_rwlock); return true; } span = pmbe->size; /* * Finally for sizes that involve compound mappings, walk * the chain. */ for (iter = pmbe->link; iter; iter = iter->link) span += iter->size; /* * Nothing else to do if the range requirements are met. */ if (size <= span) { read_unlock(&pmb_rwlock); return true; } } read_unlock(&pmb_rwlock); return false; } static bool pmb_size_valid(unsigned long size) { int i; for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) if (pmb_sizes[i].size == size) return true; return false; } static inline bool pmb_addr_valid(unsigned long addr, unsigned long size) { return (addr >= P1SEG && (addr + size - 1) < P3SEG); } static inline bool pmb_prot_valid(pgprot_t prot) { return (pgprot_val(prot) & _PAGE_USER) == 0; } static int pmb_size_to_flags(unsigned long size) { int i; for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) if (pmb_sizes[i].size == size) return pmb_sizes[i].flag; return 0; } static int pmb_alloc_entry(void) { int pos; pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES); if (pos >= 0 && pos < NR_PMB_ENTRIES) __set_bit(pos, pmb_map); else pos = -ENOSPC; return pos; } static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn, unsigned long flags, int entry) { struct pmb_entry *pmbe; unsigned long irqflags; void *ret = NULL; int pos; write_lock_irqsave(&pmb_rwlock, irqflags); if (entry == PMB_NO_ENTRY) { pos = pmb_alloc_entry(); if (unlikely(pos < 0)) { ret = ERR_PTR(pos); goto out; } } else { if (__test_and_set_bit(entry, pmb_map)) { ret = ERR_PTR(-ENOSPC); goto out; } pos = entry; } write_unlock_irqrestore(&pmb_rwlock, irqflags); pmbe = &pmb_entry_list[pos]; memset(pmbe, 0, sizeof(struct pmb_entry)); raw_spin_lock_init(&pmbe->lock); pmbe->vpn = vpn; pmbe->ppn = ppn; pmbe->flags = flags; pmbe->entry = pos; return pmbe; out: write_unlock_irqrestore(&pmb_rwlock, irqflags); return ret; } static void pmb_free(struct pmb_entry *pmbe) { __clear_bit(pmbe->entry, pmb_map); pmbe->entry = PMB_NO_ENTRY; pmbe->link = NULL; } /* * Must be run uncached. */ static void __set_pmb_entry(struct pmb_entry *pmbe) { unsigned long addr, data; addr = mk_pmb_addr(pmbe->entry); data = mk_pmb_data(pmbe->entry); jump_to_uncached(); /* Set V-bit */ __raw_writel(pmbe->vpn | PMB_V, addr); __raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data); back_to_cached(); } static void __clear_pmb_entry(struct pmb_entry *pmbe) { unsigned long addr, data; unsigned long addr_val, data_val; addr = mk_pmb_addr(pmbe->entry); data = mk_pmb_data(pmbe->entry); addr_val = __raw_readl(addr); data_val = __raw_readl(data); /* Clear V-bit */ writel_uncached(addr_val & ~PMB_V, addr); writel_uncached(data_val & ~PMB_V, data); } #ifdef CONFIG_PM static void set_pmb_entry(struct pmb_entry *pmbe) { unsigned long flags; raw_spin_lock_irqsave(&pmbe->lock, flags); __set_pmb_entry(pmbe); raw_spin_unlock_irqrestore(&pmbe->lock, flags); } #endif /* CONFIG_PM */ int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys, unsigned long size, pgprot_t prot) { struct pmb_entry *pmbp, *pmbe; unsigned long orig_addr, orig_size; unsigned long flags, pmb_flags; int i, mapped; if (size < SZ_16M) return -EINVAL; if (!pmb_addr_valid(vaddr, size)) return -EFAULT; if (pmb_mapping_exists(vaddr, phys, size)) return 0; orig_addr = vaddr; orig_size = size; flush_tlb_kernel_range(vaddr, vaddr + size); pmb_flags = pgprot_to_pmb_flags(prot); pmbp = NULL; do { for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) { if (size < pmb_sizes[i].size) continue; pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag, PMB_NO_ENTRY); if (IS_ERR(pmbe)) { pmb_unmap_entry(pmbp, mapped); return PTR_ERR(pmbe); } raw_spin_lock_irqsave(&pmbe->lock, flags); pmbe->size = pmb_sizes[i].size; __set_pmb_entry(pmbe); phys += pmbe->size; vaddr += pmbe->size; size -= pmbe->size; /* * Link adjacent entries that span multiple PMB * entries for easier tear-down. */ if (likely(pmbp)) { raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING); pmbp->link = pmbe; raw_spin_unlock(&pmbp->lock); } pmbp = pmbe; /* * Instead of trying smaller sizes on every * iteration (even if we succeed in allocating * space), try using pmb_sizes[i].size again. */ i--; mapped++; raw_spin_unlock_irqrestore(&pmbe->lock, flags); } } while (size >= SZ_16M); flush_cache_vmap(orig_addr, orig_addr + orig_size); return 0; } void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size, pgprot_t prot, void *caller) { unsigned long vaddr; phys_addr_t offset, last_addr; phys_addr_t align_mask; unsigned long aligned; struct vm_struct *area; int i, ret; if (!pmb_iomapping_enabled) return NULL; /* * Small mappings need to go through the TLB. */ if (size < SZ_16M) return ERR_PTR(-EINVAL); if (!pmb_prot_valid(prot)) return ERR_PTR(-EINVAL); for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) if (size >= pmb_sizes[i].size) break; last_addr = phys + size; align_mask = ~(pmb_sizes[i].size - 1); offset = phys & ~align_mask; phys &= align_mask; aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys; /* * XXX: This should really start from uncached_end, but this * causes the MMU to reset, so for now we restrict it to the * 0xb000...0xc000 range. */ area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000, P3SEG, caller); if (!area) return NULL; area->phys_addr = phys; vaddr = (unsigned long)area->addr; ret = pmb_bolt_mapping(vaddr, phys, size, prot); if (unlikely(ret != 0)) return ERR_PTR(ret); return (void __iomem *)(offset + (char *)vaddr); } int pmb_unmap(void __iomem *addr) { struct pmb_entry *pmbe = NULL; unsigned long vaddr = (unsigned long __force)addr; int i, found = 0; read_lock(&pmb_rwlock); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { if (test_bit(i, pmb_map)) { pmbe = &pmb_entry_list[i]; if (pmbe->vpn == vaddr) { found = 1; break; } } } read_unlock(&pmb_rwlock); if (found) { pmb_unmap_entry(pmbe, NR_PMB_ENTRIES); return 0; } return -EINVAL; } static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth) { do { struct pmb_entry *pmblink = pmbe; /* * We may be called before this pmb_entry has been * entered into the PMB table via set_pmb_entry(), but * that's OK because we've allocated a unique slot for * this entry in pmb_alloc() (even if we haven't filled * it yet). * * Therefore, calling __clear_pmb_entry() is safe as no * other mapping can be using that slot. */ __clear_pmb_entry(pmbe); flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size); pmbe = pmblink->link; pmb_free(pmblink); } while (pmbe && --depth); } static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth) { unsigned long flags; if (unlikely(!pmbe)) return; write_lock_irqsave(&pmb_rwlock, flags); __pmb_unmap_entry(pmbe, depth); write_unlock_irqrestore(&pmb_rwlock, flags); } static void __init pmb_notify(void) { int i; pr_info("PMB: boot mappings:\n"); read_lock(&pmb_rwlock); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { struct pmb_entry *pmbe; if (!test_bit(i, pmb_map)) continue; pmbe = &pmb_entry_list[i]; pr_info(" 0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n", pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT, pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un"); } read_unlock(&pmb_rwlock); } /* * Sync our software copy of the PMB mappings with those in hardware. The * mappings in the hardware PMB were either set up by the bootloader or * very early on by the kernel. */ static void __init pmb_synchronize(void) { struct pmb_entry *pmbp = NULL; int i, j; /* * Run through the initial boot mappings, log the established * ones, and blow away anything that falls outside of the valid * PPN range. Specifically, we only care about existing mappings * that impact the cached/uncached sections. * * Note that touching these can be a bit of a minefield; the boot * loader can establish multi-page mappings with the same caching * attributes, so we need to ensure that we aren't modifying a * mapping that we're presently executing from, or may execute * from in the case of straddling page boundaries. * * In the future we will have to tidy up after the boot loader by * jumping between the cached and uncached mappings and tearing * down alternating mappings while executing from the other. */ for (i = 0; i < NR_PMB_ENTRIES; i++) { unsigned long addr, data; unsigned long addr_val, data_val; unsigned long ppn, vpn, flags; unsigned long irqflags; unsigned int size; struct pmb_entry *pmbe; addr = mk_pmb_addr(i); data = mk_pmb_data(i); addr_val = __raw_readl(addr); data_val = __raw_readl(data); /* * Skip over any bogus entries */ if (!(data_val & PMB_V) || !(addr_val & PMB_V)) continue; ppn = data_val & PMB_PFN_MASK; vpn = addr_val & PMB_PFN_MASK; /* * Only preserve in-range mappings. */ if (!pmb_ppn_in_range(ppn)) { /* * Invalidate anything out of bounds. */ writel_uncached(addr_val & ~PMB_V, addr); writel_uncached(data_val & ~PMB_V, data); continue; } /* * Update the caching attributes if necessary */ if (data_val & PMB_C) { data_val &= ~PMB_CACHE_MASK; data_val |= pmb_cache_flags(); writel_uncached(data_val, data); } size = data_val & PMB_SZ_MASK; flags = size | (data_val & PMB_CACHE_MASK); pmbe = pmb_alloc(vpn, ppn, flags, i); if (IS_ERR(pmbe)) { WARN_ON_ONCE(1); continue; } raw_spin_lock_irqsave(&pmbe->lock, irqflags); for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++) if (pmb_sizes[j].flag == size) pmbe->size = pmb_sizes[j].size; if (pmbp) { raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING); /* * Compare the previous entry against the current one to * see if the entries span a contiguous mapping. If so, * setup the entry links accordingly. Compound mappings * are later coalesced. */ if (pmb_can_merge(pmbp, pmbe)) pmbp->link = pmbe; raw_spin_unlock(&pmbp->lock); } pmbp = pmbe; raw_spin_unlock_irqrestore(&pmbe->lock, irqflags); } } static void __init pmb_merge(struct pmb_entry *head) { unsigned long span, newsize; struct pmb_entry *tail; int i = 1, depth = 0; span = newsize = head->size; tail = head->link; while (tail) { span += tail->size; if (pmb_size_valid(span)) { newsize = span; depth = i; } /* This is the end of the line.. */ if (!tail->link) break; tail = tail->link; i++; } /* * The merged page size must be valid. */ if (!depth || !pmb_size_valid(newsize)) return; head->flags &= ~PMB_SZ_MASK; head->flags |= pmb_size_to_flags(newsize); head->size = newsize; __pmb_unmap_entry(head->link, depth); __set_pmb_entry(head); } static void __init pmb_coalesce(void) { unsigned long flags; int i; write_lock_irqsave(&pmb_rwlock, flags); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { struct pmb_entry *pmbe; if (!test_bit(i, pmb_map)) continue; pmbe = &pmb_entry_list[i]; /* * We're only interested in compound mappings */ if (!pmbe->link) continue; /* * Nothing to do if it already uses the largest possible * page size. */ if (pmbe->size == SZ_512M) continue; pmb_merge(pmbe); } write_unlock_irqrestore(&pmb_rwlock, flags); } #ifdef CONFIG_UNCACHED_MAPPING static void __init pmb_resize(void) { int i; /* * If the uncached mapping was constructed by the kernel, it will * already be a reasonable size. */ if (uncached_size == SZ_16M) return; read_lock(&pmb_rwlock); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { struct pmb_entry *pmbe; unsigned long flags; if (!test_bit(i, pmb_map)) continue; pmbe = &pmb_entry_list[i]; if (pmbe->vpn != uncached_start) continue; /* * Found it, now resize it. */ raw_spin_lock_irqsave(&pmbe->lock, flags); pmbe->size = SZ_16M; pmbe->flags &= ~PMB_SZ_MASK; pmbe->flags |= pmb_size_to_flags(pmbe->size); uncached_resize(pmbe->size); __set_pmb_entry(pmbe); raw_spin_unlock_irqrestore(&pmbe->lock, flags); } read_unlock(&pmb_rwlock); } #endif static int __init early_pmb(char *p) { if (!p) return 0; if (strstr(p, "iomap")) pmb_iomapping_enabled = 1; return 0; } early_param("pmb", early_pmb); void __init pmb_init(void) { /* Synchronize software state */ pmb_synchronize(); /* Attempt to combine compound mappings */ pmb_coalesce(); #ifdef CONFIG_UNCACHED_MAPPING /* Resize initial mappings, if necessary */ pmb_resize(); #endif /* Log them */ pmb_notify(); writel_uncached(0, PMB_IRMCR); /* Flush out the TLB */ local_flush_tlb_all(); ctrl_barrier(); } bool __in_29bit_mode(void) { return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0; } static int pmb_seq_show(struct seq_file *file, void *iter) { int i; seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n" "CB: Copy-Back, B: Buffered, UB: Unbuffered\n"); seq_printf(file, "ety vpn ppn size flags\n"); for (i = 0; i < NR_PMB_ENTRIES; i++) { unsigned long addr, data; unsigned int size; char *sz_str = NULL; addr = __raw_readl(mk_pmb_addr(i)); data = __raw_readl(mk_pmb_data(i)); size = data & PMB_SZ_MASK; sz_str = (size == PMB_SZ_16M) ? " 16MB": (size == PMB_SZ_64M) ? " 64MB": (size == PMB_SZ_128M) ? "128MB": "512MB"; /* 02: V 0x88 0x08 128MB C CB B */ seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n", i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ', (addr >> 24) & 0xff, (data >> 24) & 0xff, sz_str, (data & PMB_C) ? 'C' : ' ', (data & PMB_WT) ? "WT" : "CB", (data & PMB_UB) ? "UB" : " B"); } return 0; } static int pmb_debugfs_open(struct inode *inode, struct file *file) { return single_open(file, pmb_seq_show, NULL); } static const struct file_operations pmb_debugfs_fops = { .owner = THIS_MODULE, .open = pmb_debugfs_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; static int __init pmb_debugfs_init(void) { struct dentry *dentry; dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO, arch_debugfs_dir, NULL, &pmb_debugfs_fops); if (!dentry) return -ENOMEM; return 0; } subsys_initcall(pmb_debugfs_init); #ifdef CONFIG_PM static void pmb_syscore_resume(void) { struct pmb_entry *pmbe; int i; read_lock(&pmb_rwlock); for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { if (test_bit(i, pmb_map)) { pmbe = &pmb_entry_list[i]; set_pmb_entry(pmbe); } } read_unlock(&pmb_rwlock); } static struct syscore_ops pmb_syscore_ops = { .resume = pmb_syscore_resume, }; static int __init pmb_sysdev_init(void) { register_syscore_ops(&pmb_syscore_ops); return 0; } subsys_initcall(pmb_sysdev_init); #endif