/* * Copyright (C) 2008 Advanced Micro Devices, Inc. * * Author: Joerg Roedel <joerg.roedel@amd.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #define pr_fmt(fmt) "DMA-API: " fmt #include <linux/sched/task_stack.h>#include <linux/scatterlist.h>#include <linux/dma-mapping.h>#include <linux/sched/task.h>#include <linux/stacktrace.h>#include <linux/dma-debug.h>#include <linux/spinlock.h>#include <linux/vmalloc.h>#include <linux/debugfs.h>#include <linux/uaccess.h>#include <linux/export.h>#include <linux/device.h>#include <linux/types.h>#include <linux/sched.h>#include <linux/ctype.h>#include <linux/list.h>#include <linux/slab.h> #include <asm/sections.h> #define HASH_SIZE 1024ULL#define HASH_FN_SHIFT 13#define HASH_FN_MASK (HASH_SIZE - 1) #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)/* If the pool runs out, add this many new entries at once */#define DMA_DEBUG_DYNAMIC_ENTRIES (PAGE_SIZE / sizeof(struct dma_debug_entry)) enum { dma_debug_single, dma_debug_sg, dma_debug_coherent, dma_debug_resource,}; enum map_err_types { MAP_ERR_CHECK_NOT_APPLICABLE, MAP_ERR_NOT_CHECKED, MAP_ERR_CHECKED,}; #define DMA_DEBUG_STACKTRACE_ENTRIES 5 /** * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping * @list: node on pre-allocated free_entries list * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent * @type: single, page, sg, coherent * @pfn: page frame of the start address * @offset: offset of mapping relative to pfn * @size: length of the mapping * @direction: enum dma_data_direction * @sg_call_ents: 'nents' from dma_map_sg * @sg_mapped_ents: 'mapped_ents' from dma_map_sg * @map_err_type: track whether dma_mapping_error() was checked * @stacktrace: support backtraces when a violation is detected */struct dma_debug_entry { struct list_head list; struct device *dev; int type; unsigned long pfn; size_t offset; u64 dev_addr; u64 size; int direction; int sg_call_ents; int sg_mapped_ents; enum map_err_types map_err_type;#ifdef CONFIG_STACKTRACE struct stack_trace stacktrace; unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];#endif}; typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *); struct hash_bucket { struct list_head list; spinlock_t lock;} ____cacheline_aligned_in_smp; /* Hash list to save the allocated dma addresses */static struct hash_bucket dma_entry_hash[HASH_SIZE];/* List of pre-allocated dma_debug_entry's */static LIST_HEAD(free_entries);/* Lock for the list above */static DEFINE_SPINLOCK(free_entries_lock); /* Global disable flag - will be set in case of an error */static bool global_disable __read_mostly; /* Early initialization disable flag, set at the end of dma_debug_init */static bool dma_debug_initialized __read_mostly; static inline bool dma_debug_disabled(void){ return global_disable || !dma_debug_initialized;} /* Global error count */static u32 error_count; /* Global error show enable*/static u32 show_all_errors __read_mostly;/* Number of errors to show */static u32 show_num_errors = 1; static u32 num_free_entries;static u32 min_free_entries;static u32 nr_total_entries; /* number of preallocated entries requested by kernel cmdline */static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; /* debugfs dentry's for the stuff above */static struct dentry *dma_debug_dent __read_mostly;static struct dentry *global_disable_dent __read_mostly;static struct dentry *error_count_dent __read_mostly;static struct dentry *show_all_errors_dent __read_mostly;static struct dentry *show_num_errors_dent __read_mostly;static struct dentry *num_free_entries_dent __read_mostly;static struct dentry *min_free_entries_dent __read_mostly;static struct dentry *nr_total_entries_dent __read_mostly;static struct dentry *filter_dent __read_mostly; /* per-driver filter related state */ #define NAME_MAX_LEN 64 static char current_driver_name[NAME_MAX_LEN] __read_mostly;static struct device_driver *current_driver __read_mostly; static DEFINE_RWLOCK(driver_name_lock); static const char *const maperr2str[] = { [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable", [MAP_ERR_NOT_CHECKED] = "dma map error not checked", [MAP_ERR_CHECKED] = "dma map error checked",}; static const char *type2name[5] = { "single", "page", "scather-gather", "coherent", "resource" }; static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE", "DMA_FROM_DEVICE", "DMA_NONE" }; /* * The access to some variables in this macro is racy. We can't use atomic_t * here because all these variables are exported to debugfs. Some of them even * writeable. This is also the reason why a lock won't help much. But anyway, * the races are no big deal. Here is why: * * error_count: the addition is racy, but the worst thing that can happen is * that we don't count some errors * show_num_errors: the subtraction is racy. Also no big deal because in * worst case this will result in one warning more in the * system log than the user configured. This variable is * writeable via debugfs. */static inline void dump_entry_trace(struct dma_debug_entry *entry){#ifdef CONFIG_STACKTRACE if (entry) { pr_warning("Mapped at:\n"); print_stack_trace(&entry->stacktrace, 0); }#endif} static bool driver_filter(struct device *dev){ struct device_driver *drv; unsigned long flags; bool ret; /* driver filter off */ if (likely(!current_driver_name[0])) return true; /* driver filter on and initialized */ if (current_driver && dev && dev->driver == current_driver) return true; /* driver filter on, but we can't filter on a NULL device... */ if (!dev) return false; if (current_driver || !current_driver_name[0]) return false; /* driver filter on but not yet initialized */ drv = dev->driver; if (!drv) return false; /* lock to protect against change of current_driver_name */ read_lock_irqsave(&driver_name_lock, flags); ret = false; if (drv->name && strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) { current_driver = drv; ret = true; } read_unlock_irqrestore(&driver_name_lock, flags); return ret;} #define err_printk(dev, entry, format, arg...) do { \ error_count += 1; \ if (driver_filter(dev) && \ (show_all_errors || show_num_errors > 0)) { \ WARN(1, pr_fmt("%s %s: ") format, \ dev ? dev_driver_string(dev) : "NULL", \ dev ? dev_name(dev) : "NULL", ## arg); \ dump_entry_trace(entry); \ } \ if (!show_all_errors && show_num_errors > 0) \ show_num_errors -= 1; \ } while (0); /* * Hash related functions * * Every DMA-API request is saved into a struct dma_debug_entry. To * have quick access to these structs they are stored into a hash. */static int hash_fn(struct dma_debug_entry *entry){ /* * Hash function is based on the dma address. * We use bits 20-27 here as the index into the hash */ return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;} /* * Request exclusive access to a hash bucket for a given dma_debug_entry. */static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, unsigned long *flags) __acquires(&dma_entry_hash[idx].lock){ int idx = hash_fn(entry); unsigned long __flags; spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); *flags = __flags; return &dma_entry_hash[idx];} /* * Give up exclusive access to the hash bucket */static void put_hash_bucket(struct hash_bucket *bucket, unsigned long *flags) __releases(&bucket->lock){ unsigned long __flags = *flags; spin_unlock_irqrestore(&bucket->lock, __flags);} static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b){ return ((a->dev_addr == b->dev_addr) && (a->dev == b->dev)) ? true : false;} static bool containing_match(struct dma_debug_entry *a, struct dma_debug_entry *b){ if (a->dev != b->dev) return false; if ((b->dev_addr <= a->dev_addr) && ((b->dev_addr + b->size) >= (a->dev_addr + a->size))) return true; return false;} /* * Search a given entry in the hash bucket list */static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket, struct dma_debug_entry *ref, match_fn match){ struct dma_debug_entry *entry, *ret = NULL; int matches = 0, match_lvl, last_lvl = -1; list_for_each_entry(entry, &bucket->list, list) { if (!match(ref, entry)) continue; /* * Some drivers map the same physical address multiple * times. Without a hardware IOMMU this results in the * same device addresses being put into the dma-debug * hash multiple times too. This can result in false * positives being reported. Therefore we implement a * best-fit algorithm here which returns the entry from * the hash which fits best to the reference value * instead of the first-fit. */ matches += 1; match_lvl = 0; entry->size == ref->size ? ++match_lvl : 0; entry->type == ref->type ? ++match_lvl : 0; entry->direction == ref->direction ? ++match_lvl : 0; entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0; if (match_lvl == 4) { /* perfect-fit - return the result */ return entry; } else if (match_lvl > last_lvl) { /* * We found an entry that fits better then the * previous one or it is the 1st match. */ last_lvl = match_lvl; ret = entry; } } /* * If we have multiple matches but no perfect-fit, just return * NULL. */ ret = (matches == 1) ? ret : NULL; return ret;} static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket, struct dma_debug_entry *ref){ return __hash_bucket_find(bucket, ref, exact_match);} static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, struct dma_debug_entry *ref, unsigned long *flags){ unsigned int max_range = dma_get_max_seg_size(ref->dev); struct dma_debug_entry *entry, index = *ref; unsigned int range = 0; while (range <= max_range) { entry = __hash_bucket_find(*bucket, ref, containing_match); if (entry) return entry; /* * Nothing found, go back a hash bucket */ put_hash_bucket(*bucket, flags); range += (1 << HASH_FN_SHIFT); index.dev_addr -= (1 << HASH_FN_SHIFT); *bucket = get_hash_bucket(&index, flags); } return NULL;} /* * Add an entry to a hash bucket */static void hash_bucket_add(struct hash_bucket *bucket, struct dma_debug_entry *entry){ list_add_tail(&entry->list, &bucket->list);} /* * Remove entry from a hash bucket list */static void hash_bucket_del(struct dma_debug_entry *entry){ list_del(&entry->list);} static unsigned long long phys_addr(struct dma_debug_entry *entry){ if (entry->type == dma_debug_resource) return __pfn_to_phys(entry->pfn) + entry->offset; return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;} /* * Dump mapping entries for debugging purposes */void debug_dma_dump_mappings(struct device *dev){ int idx; for (idx = 0; idx < HASH_SIZE; idx++) { struct hash_bucket *bucket = &dma_entry_hash[idx]; struct dma_debug_entry *entry; unsigned long flags; spin_lock_irqsave(&bucket->lock, flags); list_for_each_entry(entry, &bucket->list, list) { if (!dev || dev == entry->dev) { dev_info(entry->dev, "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n", type2name[entry->type], idx, phys_addr(entry), entry->pfn, entry->dev_addr, entry->size, dir2name[entry->direction], maperr2str[entry->map_err_type]); } } spin_unlock_irqrestore(&bucket->lock, flags); }} /* * For each mapping (initial cacheline in the case of * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a * scatterlist, or the cacheline specified in dma_map_single) insert * into this tree using the cacheline as the key. At * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If * the entry already exists at insertion time add a tag as a reference * count for the overlapping mappings. For now, the overlap tracking * just ensures that 'unmaps' balance 'maps' before marking the * cacheline idle, but we should also be flagging overlaps as an API * violation. * * Memory usage is mostly constrained by the maximum number of available * dma-debug entries in that we need a free dma_debug_entry before * inserting into the tree. In the case of dma_map_page and * dma_alloc_coherent there is only one dma_debug_entry and one * dma_active_cacheline entry to track per event. dma_map_sg(), on the * other hand, consumes a single dma_debug_entry, but inserts 'nents' * entries into the tree. * * At any time debug_dma_assert_idle() can be called to trigger a * warning if any cachelines in the given page are in the active set. */static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);static DEFINE_SPINLOCK(radix_lock);#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT) static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry){ return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) + (entry->offset >> L1_CACHE_SHIFT);} static int active_cacheline_read_overlap(phys_addr_t cln){ int overlap = 0, i; for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--) if (radix_tree_tag_get(&dma_active_cacheline, cln, i)) overlap |= 1 << i; return overlap;} static int active_cacheline_set_overlap(phys_addr_t cln, int overlap){ int i; if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0) return overlap; Lines 1–500 of 1707. 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/* * Copyright (C) 2008 Advanced Micro Devices, Inc. * * Author: Joerg Roedel <joerg.roedel@amd.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #define pr_fmt(fmt) "DMA-API: " fmt #include <linux/sched/task_stack.h> #include <linux/scatterlist.h> #include <linux/dma-mapping.h> #include <linux/sched/task.h> #include <linux/stacktrace.h> #include <linux/dma-debug.h> #include <linux/spinlock.h> #include <linux/vmalloc.h> #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/export.h> #include <linux/device.h> #include <linux/types.h> #include <linux/sched.h> #include <linux/ctype.h> #include <linux/list.h> #include <linux/slab.h> #include <asm/sections.h> #define HASH_SIZE 1024ULL #define HASH_FN_SHIFT 13 #define HASH_FN_MASK (HASH_SIZE - 1) #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) /* If the pool runs out, add this many new entries at once */ #define DMA_DEBUG_DYNAMIC_ENTRIES (PAGE_SIZE / sizeof(struct dma_debug_entry)) enum { dma_debug_single, dma_debug_sg, dma_debug_coherent, dma_debug_resource, }; enum map_err_types { MAP_ERR_CHECK_NOT_APPLICABLE, MAP_ERR_NOT_CHECKED, MAP_ERR_CHECKED, }; #define DMA_DEBUG_STACKTRACE_ENTRIES 5 /** * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping * @list: node on pre-allocated free_entries list * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent * @type: single, page, sg, coherent * @pfn: page frame of the start address * @offset: offset of mapping relative to pfn * @size: length of the mapping * @direction: enum dma_data_direction * @sg_call_ents: 'nents' from dma_map_sg * @sg_mapped_ents: 'mapped_ents' from dma_map_sg * @map_err_type: track whether dma_mapping_error() was checked * @stacktrace: support backtraces when a violation is detected */ struct dma_debug_entry { struct list_head list; struct device *dev; int type; unsigned long pfn; size_t offset; u64 dev_addr; u64 size; int direction; int sg_call_ents; int sg_mapped_ents; enum map_err_types map_err_type; #ifdef CONFIG_STACKTRACE struct stack_trace stacktrace; unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; #endif }; typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *); struct hash_bucket { struct list_head list; spinlock_t lock; } ____cacheline_aligned_in_smp; /* Hash list to save the allocated dma addresses */ static struct hash_bucket dma_entry_hash[HASH_SIZE]; /* List of pre-allocated dma_debug_entry's */ static LIST_HEAD(free_entries); /* Lock for the list above */ static DEFINE_SPINLOCK(free_entries_lock); /* Global disable flag - will be set in case of an error */ static bool global_disable __read_mostly; /* Early initialization disable flag, set at the end of dma_debug_init */ static bool dma_debug_initialized __read_mostly; static inline bool dma_debug_disabled(void) { return global_disable || !dma_debug_initialized; } /* Global error count */ static u32 error_count; /* Global error show enable*/ static u32 show_all_errors __read_mostly; /* Number of errors to show */ static u32 show_num_errors = 1; static u32 num_free_entries; static u32 min_free_entries; static u32 nr_total_entries; /* number of preallocated entries requested by kernel cmdline */ static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; /* debugfs dentry's for the stuff above */ static struct dentry *dma_debug_dent __read_mostly; static struct dentry *global_disable_dent __read_mostly; static struct dentry *error_count_dent __read_mostly; static struct dentry *show_all_errors_dent __read_mostly; static struct dentry *show_num_errors_dent __read_mostly; static struct dentry *num_free_entries_dent __read_mostly; static struct dentry *min_free_entries_dent __read_mostly; static struct dentry *nr_total_entries_dent __read_mostly; static struct dentry *filter_dent __read_mostly; /* per-driver filter related state */ #define NAME_MAX_LEN 64 static char current_driver_name[NAME_MAX_LEN] __read_mostly; static struct device_driver *current_driver __read_mostly; static DEFINE_RWLOCK(driver_name_lock); static const char *const maperr2str[] = { [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable", [MAP_ERR_NOT_CHECKED] = "dma map error not checked", [MAP_ERR_CHECKED] = "dma map error checked", }; static const char *type2name[5] = { "single", "page", "scather-gather", "coherent", "resource" }; static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE", "DMA_FROM_DEVICE", "DMA_NONE" }; /* * The access to some variables in this macro is racy. We can't use atomic_t * here because all these variables are exported to debugfs. Some of them even * writeable. This is also the reason why a lock won't help much. But anyway, * the races are no big deal. Here is why: * * error_count: the addition is racy, but the worst thing that can happen is * that we don't count some errors * show_num_errors: the subtraction is racy. Also no big deal because in * worst case this will result in one warning more in the * system log than the user configured. This variable is * writeable via debugfs. */ static inline void dump_entry_trace(struct dma_debug_entry *entry) { #ifdef CONFIG_STACKTRACE if (entry) { pr_warning("Mapped at:\n"); print_stack_trace(&entry->stacktrace, 0); } #endif } static bool driver_filter(struct device *dev) { struct device_driver *drv; unsigned long flags; bool ret; /* driver filter off */ if (likely(!current_driver_name[0])) return true; /* driver filter on and initialized */ if (current_driver && dev && dev->driver == current_driver) return true; /* driver filter on, but we can't filter on a NULL device... */ if (!dev) return false; if (current_driver || !current_driver_name[0]) return false; /* driver filter on but not yet initialized */ drv = dev->driver; if (!drv) return false; /* lock to protect against change of current_driver_name */ read_lock_irqsave(&driver_name_lock, flags); ret = false; if (drv->name && strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) { current_driver = drv; ret = true; } read_unlock_irqrestore(&driver_name_lock, flags); return ret; } #define err_printk(dev, entry, format, arg...) do { \ error_count += 1; \ if (driver_filter(dev) && \ (show_all_errors || show_num_errors > 0)) { \ WARN(1, pr_fmt("%s %s: ") format, \ dev ? dev_driver_string(dev) : "NULL", \ dev ? dev_name(dev) : "NULL", ## arg); \ dump_entry_trace(entry); \ } \ if (!show_all_errors && show_num_errors > 0) \ show_num_errors -= 1; \ } while (0); /* * Hash related functions * * Every DMA-API request is saved into a struct dma_debug_entry. To * have quick access to these structs they are stored into a hash. */ static int hash_fn(struct dma_debug_entry *entry) { /* * Hash function is based on the dma address. * We use bits 20-27 here as the index into the hash */ return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK; } /* * Request exclusive access to a hash bucket for a given dma_debug_entry. */ static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry, unsigned long *flags) __acquires(&dma_entry_hash[idx].lock) { int idx = hash_fn(entry); unsigned long __flags; spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags); *flags = __flags; return &dma_entry_hash[idx]; } /* * Give up exclusive access to the hash bucket */ static void put_hash_bucket(struct hash_bucket *bucket, unsigned long *flags) __releases(&bucket->lock) { unsigned long __flags = *flags; spin_unlock_irqrestore(&bucket->lock, __flags); } static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b) { return ((a->dev_addr == b->dev_addr) && (a->dev == b->dev)) ? true : false; } static bool containing_match(struct dma_debug_entry *a, struct dma_debug_entry *b) { if (a->dev != b->dev) return false; if ((b->dev_addr <= a->dev_addr) && ((b->dev_addr + b->size) >= (a->dev_addr + a->size))) return true; return false; } /* * Search a given entry in the hash bucket list */ static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket, struct dma_debug_entry *ref, match_fn match) { struct dma_debug_entry *entry, *ret = NULL; int matches = 0, match_lvl, last_lvl = -1; list_for_each_entry(entry, &bucket->list, list) { if (!match(ref, entry)) continue; /* * Some drivers map the same physical address multiple * times. Without a hardware IOMMU this results in the * same device addresses being put into the dma-debug * hash multiple times too. This can result in false * positives being reported. Therefore we implement a * best-fit algorithm here which returns the entry from * the hash which fits best to the reference value * instead of the first-fit. */ matches += 1; match_lvl = 0; entry->size == ref->size ? ++match_lvl : 0; entry->type == ref->type ? ++match_lvl : 0; entry->direction == ref->direction ? ++match_lvl : 0; entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0; if (match_lvl == 4) { /* perfect-fit - return the result */ return entry; } else if (match_lvl > last_lvl) { /* * We found an entry that fits better then the * previous one or it is the 1st match. */ last_lvl = match_lvl; ret = entry; } } /* * If we have multiple matches but no perfect-fit, just return * NULL. */ ret = (matches == 1) ? ret : NULL; return ret; } static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket, struct dma_debug_entry *ref) { return __hash_bucket_find(bucket, ref, exact_match); } static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket, struct dma_debug_entry *ref, unsigned long *flags) { unsigned int max_range = dma_get_max_seg_size(ref->dev); struct dma_debug_entry *entry, index = *ref; unsigned int range = 0; while (range <= max_range) { entry = __hash_bucket_find(*bucket, ref, containing_match); if (entry) return entry; /* * Nothing found, go back a hash bucket */ put_hash_bucket(*bucket, flags); range += (1 << HASH_FN_SHIFT); index.dev_addr -= (1 << HASH_FN_SHIFT); *bucket = get_hash_bucket(&index, flags); } return NULL; } /* * Add an entry to a hash bucket */ static void hash_bucket_add(struct hash_bucket *bucket, struct dma_debug_entry *entry) { list_add_tail(&entry->list, &bucket->list); } /* * Remove entry from a hash bucket list */ static void hash_bucket_del(struct dma_debug_entry *entry) { list_del(&entry->list); } static unsigned long long phys_addr(struct dma_debug_entry *entry) { if (entry->type == dma_debug_resource) return __pfn_to_phys(entry->pfn) + entry->offset; return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset; } /* * Dump mapping entries for debugging purposes */ void debug_dma_dump_mappings(struct device *dev) { int idx; for (idx = 0; idx < HASH_SIZE; idx++) { struct hash_bucket *bucket = &dma_entry_hash[idx]; struct dma_debug_entry *entry; unsigned long flags; spin_lock_irqsave(&bucket->lock, flags); list_for_each_entry(entry, &bucket->list, list) { if (!dev || dev == entry->dev) { dev_info(entry->dev, "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n", type2name[entry->type], idx, phys_addr(entry), entry->pfn, entry->dev_addr, entry->size, dir2name[entry->direction], maperr2str[entry->map_err_type]); } } spin_unlock_irqrestore(&bucket->lock, flags); } } /* * For each mapping (initial cacheline in the case of * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a * scatterlist, or the cacheline specified in dma_map_single) insert * into this tree using the cacheline as the key. At * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry. If * the entry already exists at insertion time add a tag as a reference * count for the overlapping mappings. For now, the overlap tracking * just ensures that 'unmaps' balance 'maps' before marking the * cacheline idle, but we should also be flagging overlaps as an API * violation. * * Memory usage is mostly constrained by the maximum number of available * dma-debug entries in that we need a free dma_debug_entry before * inserting into the tree. In the case of dma_map_page and * dma_alloc_coherent there is only one dma_debug_entry and one * dma_active_cacheline entry to track per event. dma_map_sg(), on the * other hand, consumes a single dma_debug_entry, but inserts 'nents' * entries into the tree. * * At any time debug_dma_assert_idle() can be called to trigger a * warning if any cachelines in the given page are in the active set. */ static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT); static DEFINE_SPINLOCK(radix_lock); #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1) #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT) #define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT) static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry) { return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) + (entry->offset >> L1_CACHE_SHIFT); } static int active_cacheline_read_overlap(phys_addr_t cln) { int overlap = 0, i; for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--) if (radix_tree_tag_get(&dma_active_cacheline, cln, i)) overlap |= 1 << i; return overlap; } static int active_cacheline_set_overlap(phys_addr_t cln, int overlap) { int i; if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0) return overlap;