X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=lib%2Fdma-debug.c;h=3b93129a968c73b1d6eeff421abb76b38bc668dd;hb=a9d9058abab4ac17b79d500506e6c74bd16cecdc;hp=51f95e5b6265f0d4893acf8edfe064591494a866;hpb=884d05970bfbc3db368f23460dc4ce63257f240d;p=safe%2Fjmp%2Flinux-2.6 diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 51f95e5..3b93129 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -23,9 +23,11 @@ #include #include #include +#include #include #include #include +#include #include #include @@ -98,6 +100,16 @@ 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 *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 *type2name[4] = { "single", "page", "scather-gather", "coherent" }; @@ -127,15 +139,54 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) { #ifdef CONFIG_STACKTRACE if (entry) { - printk(KERN_WARNING "Mapped at:\n"); + 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->driver == current_driver) + return true; + + if (current_driver || !current_driver_name[0]) + return false; + + /* driver filter on but not yet initialized */ + drv = get_driver(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); + put_driver(drv); + + return ret; +} + #define err_printk(dev, entry, format, arg...) do { \ error_count += 1; \ - if (show_all_errors || show_num_errors > 0) { \ + if (driver_filter(dev) && \ + (show_all_errors || show_num_errors > 0)) { \ WARN(1, "%s %s: " format, \ dev_driver_string(dev), \ dev_name(dev) , ## arg); \ @@ -191,15 +242,51 @@ static void put_hash_bucket(struct hash_bucket *bucket, static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket, struct dma_debug_entry *ref) { - struct dma_debug_entry *entry; + struct dma_debug_entry *entry, *ret = NULL; + int matches = 0, match_lvl, last_lvl = 0; list_for_each_entry(entry, &bucket->list, list) { - if ((entry->dev_addr == ref->dev_addr) && - (entry->dev == ref->dev)) + if ((entry->dev_addr != ref->dev_addr) || + (entry->dev != ref->dev)) + 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. Therfore 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 + */ + last_lvl = match_lvl; + ret = entry; + } } - return NULL; + /* + * If we have multiple matches but no perfect-fit, just return + * NULL. + */ + ret = (matches == 1) ? ret : NULL; + + return ret; } /* @@ -291,8 +378,7 @@ static struct dma_debug_entry *dma_entry_alloc(void) spin_lock_irqsave(&free_entries_lock, flags); if (list_empty(&free_entries)) { - printk(KERN_ERR "DMA-API: debugging out of memory " - "- disabling\n"); + pr_err("DMA-API: debugging out of memory - disabling\n"); global_disable = true; goto out; } @@ -397,8 +483,7 @@ static int prealloc_memory(u32 num_entries) num_free_entries = num_entries; min_free_entries = num_entries; - printk(KERN_INFO "DMA-API: preallocated %d debug entries\n", - num_entries); + pr_info("DMA-API: preallocated %d debug entries\n", num_entries); return 0; @@ -412,11 +497,102 @@ out_err: return -ENOMEM; } +static ssize_t filter_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + char buf[NAME_MAX_LEN + 1]; + unsigned long flags; + int len; + + if (!current_driver_name[0]) + return 0; + + /* + * We can't copy to userspace directly because current_driver_name can + * only be read under the driver_name_lock with irqs disabled. So + * create a temporary copy first. + */ + read_lock_irqsave(&driver_name_lock, flags); + len = scnprintf(buf, NAME_MAX_LEN + 1, "%s\n", current_driver_name); + read_unlock_irqrestore(&driver_name_lock, flags); + + return simple_read_from_buffer(user_buf, count, ppos, buf, len); +} + +static ssize_t filter_write(struct file *file, const char __user *userbuf, + size_t count, loff_t *ppos) +{ + char buf[NAME_MAX_LEN]; + unsigned long flags; + size_t len; + int i; + + /* + * We can't copy from userspace directly. Access to + * current_driver_name is protected with a write_lock with irqs + * disabled. Since copy_from_user can fault and may sleep we + * need to copy to temporary buffer first + */ + len = min(count, (size_t)(NAME_MAX_LEN - 1)); + if (copy_from_user(buf, userbuf, len)) + return -EFAULT; + + buf[len] = 0; + + write_lock_irqsave(&driver_name_lock, flags); + + /* + * Now handle the string we got from userspace very carefully. + * The rules are: + * - only use the first token we got + * - token delimiter is everything looking like a space + * character (' ', '\n', '\t' ...) + * + */ + if (!isalnum(buf[0])) { + /* + * If the first character userspace gave us is not + * alphanumerical then assume the filter should be + * switched off. + */ + if (current_driver_name[0]) + pr_info("DMA-API: switching off dma-debug driver filter\n"); + current_driver_name[0] = 0; + current_driver = NULL; + goto out_unlock; + } + + /* + * Now parse out the first token and use it as the name for the + * driver to filter for. + */ + for (i = 0; i < NAME_MAX_LEN; ++i) { + current_driver_name[i] = buf[i]; + if (isspace(buf[i]) || buf[i] == ' ' || buf[i] == 0) + break; + } + current_driver_name[i] = 0; + current_driver = NULL; + + pr_info("DMA-API: enable driver filter for driver [%s]\n", + current_driver_name); + +out_unlock: + write_unlock_irqrestore(&driver_name_lock, flags); + + return count; +} + +const struct file_operations filter_fops = { + .read = filter_read, + .write = filter_write, +}; + static int dma_debug_fs_init(void) { dma_debug_dent = debugfs_create_dir("dma-api", NULL); if (!dma_debug_dent) { - printk(KERN_ERR "DMA-API: can not create debugfs directory\n"); + pr_err("DMA-API: can not create debugfs directory\n"); return -ENOMEM; } @@ -455,6 +631,11 @@ static int dma_debug_fs_init(void) if (!min_free_entries_dent) goto out_err; + filter_dent = debugfs_create_file("driver_filter", 0644, + dma_debug_dent, NULL, &filter_fops); + if (!filter_dent) + goto out_err; + return 0; out_err: @@ -469,15 +650,19 @@ static int device_dma_allocations(struct device *dev) unsigned long flags; int count = 0, i; + local_irq_save(flags); + for (i = 0; i < HASH_SIZE; ++i) { - spin_lock_irqsave(&dma_entry_hash[i].lock, flags); + spin_lock(&dma_entry_hash[i].lock); list_for_each_entry(entry, &dma_entry_hash[i].list, list) { if (entry->dev == dev) count += 1; } - spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags); + spin_unlock(&dma_entry_hash[i].lock); } + local_irq_restore(flags); + return count; } @@ -510,7 +695,7 @@ void dma_debug_add_bus(struct bus_type *bus) nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL); if (nb == NULL) { - printk(KERN_ERR "dma_debug_add_bus: out of memory\n"); + pr_err("dma_debug_add_bus: out of memory\n"); return; } @@ -535,8 +720,7 @@ void dma_debug_init(u32 num_entries) } if (dma_debug_fs_init() != 0) { - printk(KERN_ERR "DMA-API: error creating debugfs entries " - "- disabling\n"); + pr_err("DMA-API: error creating debugfs entries - disabling\n"); global_disable = true; return; @@ -546,8 +730,7 @@ void dma_debug_init(u32 num_entries) num_entries = req_entries; if (prealloc_memory(num_entries) != 0) { - printk(KERN_ERR "DMA-API: debugging out of memory error " - "- disabled\n"); + pr_err("DMA-API: debugging out of memory error - disabled\n"); global_disable = true; return; @@ -555,7 +738,7 @@ void dma_debug_init(u32 num_entries) nr_total_entries = num_free_entries; - printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n"); + pr_info("DMA-API: debugging enabled by kernel config\n"); } static __init int dma_debug_cmdline(char *str) @@ -564,8 +747,7 @@ static __init int dma_debug_cmdline(char *str) return -EINVAL; if (strncmp(str, "off", 3) == 0) { - printk(KERN_INFO "DMA-API: debugging disabled on kernel " - "command line\n"); + pr_info("DMA-API: debugging disabled on kernel command line\n"); global_disable = true; } @@ -692,72 +874,68 @@ static void check_for_illegal_area(struct device *dev, void *addr, u64 size) "[addr=%p] [size=%llu]\n", addr, size); } -static void check_sync(struct device *dev, dma_addr_t addr, - u64 size, u64 offset, int direction, bool to_cpu) +static void check_sync(struct device *dev, + struct dma_debug_entry *ref, + bool to_cpu) { - struct dma_debug_entry ref = { - .dev = dev, - .dev_addr = addr, - .size = size, - .direction = direction, - }; struct dma_debug_entry *entry; struct hash_bucket *bucket; unsigned long flags; - bucket = get_hash_bucket(&ref, &flags); + bucket = get_hash_bucket(ref, &flags); - entry = hash_bucket_find(bucket, &ref); + entry = hash_bucket_find(bucket, ref); if (!entry) { err_printk(dev, NULL, "DMA-API: device driver tries " "to sync DMA memory it has not allocated " "[device address=0x%016llx] [size=%llu bytes]\n", - (unsigned long long)addr, size); + (unsigned long long)ref->dev_addr, ref->size); goto out; } - if ((offset + size) > entry->size) { + if (ref->size > entry->size) { err_printk(dev, entry, "DMA-API: device driver syncs" " DMA memory outside allocated range " "[device address=0x%016llx] " - "[allocation size=%llu bytes] [sync offset=%llu] " - "[sync size=%llu]\n", entry->dev_addr, entry->size, - offset, size); + "[allocation size=%llu bytes] " + "[sync offset+size=%llu]\n", + entry->dev_addr, entry->size, + ref->size); } - if (direction != entry->direction) { + if (ref->direction != entry->direction) { err_printk(dev, entry, "DMA-API: device driver syncs " "DMA memory with different direction " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); } if (entry->direction == DMA_BIDIRECTIONAL) goto out; if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) && - !(direction == DMA_TO_DEVICE)) + !(ref->direction == DMA_TO_DEVICE)) err_printk(dev, entry, "DMA-API: device driver syncs " "device read-only DMA memory for cpu " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) && - !(direction == DMA_FROM_DEVICE)) + !(ref->direction == DMA_FROM_DEVICE)) err_printk(dev, entry, "DMA-API: device driver syncs " "device write-only DMA memory to device " "[device address=0x%016llx] [size=%llu bytes] " "[mapped with %s] [synced with %s]\n", - (unsigned long long)addr, entry->size, + (unsigned long long)ref->dev_addr, entry->size, dir2name[entry->direction], - dir2name[direction]); + dir2name[ref->direction]); out: put_hash_bucket(bucket, &flags); @@ -855,13 +1033,30 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(debug_dma_map_sg); +static int get_nr_mapped_entries(struct device *dev, + struct dma_debug_entry *ref) +{ + struct dma_debug_entry *entry; + struct hash_bucket *bucket; + unsigned long flags; + int mapped_ents; + + bucket = get_hash_bucket(ref, &flags); + entry = hash_bucket_find(bucket, ref); + mapped_ents = 0; + + if (entry) + mapped_ents = entry->sg_mapped_ents; + put_hash_bucket(bucket, &flags); + + return mapped_ents; +} + void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, int dir) { - struct dma_debug_entry *entry; struct scatterlist *s; int mapped_ents = 0, i; - unsigned long flags; if (unlikely(global_disable)) return; @@ -875,21 +1070,14 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist, .dev_addr = sg_dma_address(s), .size = sg_dma_len(s), .direction = dir, - .sg_call_ents = 0, + .sg_call_ents = nelems, }; if (mapped_ents && i >= mapped_ents) break; - if (mapped_ents == 0) { - struct hash_bucket *bucket; - ref.sg_call_ents = nelems; - bucket = get_hash_bucket(&ref, &flags); - entry = hash_bucket_find(bucket, &ref); - if (entry) - mapped_ents = entry->sg_mapped_ents; - put_hash_bucket(bucket, &flags); - } + if (!i) + mapped_ents = get_nr_mapped_entries(dev, &ref); check_unmap(&ref); } @@ -944,10 +1132,19 @@ EXPORT_SYMBOL(debug_dma_free_coherent); void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, 0, direction, true); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, true); } EXPORT_SYMBOL(debug_dma_sync_single_for_cpu); @@ -955,10 +1152,19 @@ void debug_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, 0, direction, false); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, false); } EXPORT_SYMBOL(debug_dma_sync_single_for_device); @@ -967,10 +1173,19 @@ void debug_dma_sync_single_range_for_cpu(struct device *dev, unsigned long offset, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, offset, direction, true); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = offset + size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, true); } EXPORT_SYMBOL(debug_dma_sync_single_range_for_cpu); @@ -979,10 +1194,19 @@ void debug_dma_sync_single_range_for_device(struct device *dev, unsigned long offset, size_t size, int direction) { + struct dma_debug_entry ref; + if (unlikely(global_disable)) return; - check_sync(dev, dma_handle, size, offset, direction, false); + ref.type = dma_debug_single; + ref.dev = dev; + ref.dev_addr = dma_handle; + ref.size = offset + size; + ref.direction = direction; + ref.sg_call_ents = 0; + + check_sync(dev, &ref, false); } EXPORT_SYMBOL(debug_dma_sync_single_range_for_device); @@ -990,14 +1214,30 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems, int direction) { struct scatterlist *s; - int i; + int mapped_ents = 0, i; if (unlikely(global_disable)) return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, - direction, true); + + struct dma_debug_entry ref = { + .type = dma_debug_sg, + .dev = dev, + .paddr = sg_phys(s), + .dev_addr = sg_dma_address(s), + .size = sg_dma_len(s), + .direction = direction, + .sg_call_ents = nelems, + }; + + if (!i) + mapped_ents = get_nr_mapped_entries(dev, &ref); + + if (i >= mapped_ents) + break; + + check_sync(dev, &ref, true); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu); @@ -1006,15 +1246,48 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, int direction) { struct scatterlist *s; - int i; + int mapped_ents = 0, i; if (unlikely(global_disable)) return; for_each_sg(sg, s, nelems, i) { - check_sync(dev, sg_dma_address(s), sg_dma_len(s), 0, - direction, false); + + struct dma_debug_entry ref = { + .type = dma_debug_sg, + .dev = dev, + .paddr = sg_phys(s), + .dev_addr = sg_dma_address(s), + .size = sg_dma_len(s), + .direction = direction, + .sg_call_ents = nelems, + }; + if (!i) + mapped_ents = get_nr_mapped_entries(dev, &ref); + + if (i >= mapped_ents) + break; + + check_sync(dev, &ref, false); } } EXPORT_SYMBOL(debug_dma_sync_sg_for_device); +static int __init dma_debug_driver_setup(char *str) +{ + int i; + + for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) { + current_driver_name[i] = *str; + if (*str == 0) + break; + } + + if (current_driver_name[0]) + pr_info("DMA-API: enable driver filter for driver [%s]\n", + current_driver_name); + + + return 1; +} +__setup("dma_debug_driver=", dma_debug_driver_setup);