Make prealloc_memory() a little more general and robust so that it serves for runtime reallocations too. The first thing we can do with that is clean up dma_debug_resize_entries() quite a bit.
Signed-off-by: Robin Murphy <[email protected]> --- kernel/dma/debug.c | 95 +++++++++++++++++++--------------------------- 1 file changed, 40 insertions(+), 55 deletions(-) diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 91b84140e4a5..de5db800dbfc 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -645,6 +645,39 @@ static void add_dma_entry(struct dma_debug_entry *entry) */ } +static int prealloc_memory(u32 num_entries) +{ + struct dma_debug_entry *entry, *next_entry; + unsigned long flags; + LIST_HEAD(tmp); + int i; + + for (i = 0; i < num_entries; ++i) { + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + goto out_err; + + list_add_tail(&entry->list, &tmp); + } + + spin_lock_irqsave(&free_entries_lock, flags); + list_splice(&tmp, &free_entries); + num_free_entries += num_entries; + nr_total_entries += num_entries; + spin_unlock_irqrestore(&free_entries_lock, flags); + + return 0; + +out_err: + + list_for_each_entry_safe(entry, next_entry, &tmp, list) { + list_del(&entry->list); + kfree(entry); + } + + return -ENOMEM; +} + static struct dma_debug_entry *__dma_entry_alloc(void) { struct dma_debug_entry *entry; @@ -714,44 +747,25 @@ int dma_debug_resize_entries(u32 num_entries) int i, delta, ret = 0; unsigned long flags; struct dma_debug_entry *entry; - LIST_HEAD(tmp); - - spin_lock_irqsave(&free_entries_lock, flags); if (nr_total_entries < num_entries) { delta = num_entries - nr_total_entries; - spin_unlock_irqrestore(&free_entries_lock, flags); - - for (i = 0; i < delta; i++) { - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - break; - - list_add_tail(&entry->list, &tmp); - } - - spin_lock_irqsave(&free_entries_lock, flags); - - list_splice(&tmp, &free_entries); - nr_total_entries += i; - num_free_entries += i; + ret = prealloc_memory(delta); } else { delta = nr_total_entries - num_entries; + spin_lock_irqsave(&free_entries_lock, flags); for (i = 0; i < delta && !list_empty(&free_entries); i++) { entry = __dma_entry_alloc(); kfree(entry); } + spin_unlock_irqrestore(&free_entries_lock, flags); nr_total_entries -= i; + if (nr_total_entries != num_entries) + ret = -EBUSY; } - - if (nr_total_entries != num_entries) - ret = 1; - - spin_unlock_irqrestore(&free_entries_lock, flags); - return ret; } @@ -763,36 +777,6 @@ int dma_debug_resize_entries(u32 num_entries) * 2. Preallocate a given number of dma_debug_entry structs */ -static int prealloc_memory(u32 num_entries) -{ - struct dma_debug_entry *entry, *next_entry; - int i; - - for (i = 0; i < num_entries; ++i) { - entry = kzalloc(sizeof(*entry), GFP_KERNEL); - if (!entry) - goto out_err; - - list_add_tail(&entry->list, &free_entries); - } - - num_free_entries = num_entries; - min_free_entries = num_entries; - - pr_info("preallocated %d debug entries\n", num_entries); - - return 0; - -out_err: - - list_for_each_entry_safe(entry, next_entry, &free_entries, list) { - list_del(&entry->list); - kfree(entry); - } - - return -ENOMEM; -} - static ssize_t filter_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { @@ -1038,7 +1022,8 @@ static int dma_debug_init(void) return 0; } - nr_total_entries = num_free_entries; + min_free_entries = num_free_entries; + pr_info("preallocated %d debug entries\n", nr_total_entries); dma_debug_initialized = true; -- 2.19.1.dirty _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
