diff options
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/devio.c | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index fa66e6e58792..6abb7294e919 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -139,30 +139,42 @@ MODULE_PARM_DESC(usbfs_memory_mb, /* Hard limit, necessary to avoid arithmetic overflow */ #define USBFS_XFER_MAX (UINT_MAX / 2 - 1000000) -static atomic64_t usbfs_memory_usage; /* Total memory currently allocated */ +static DEFINE_SPINLOCK(usbfs_memory_usage_lock); +static u64 usbfs_memory_usage; /* Total memory currently allocated */ /* Check whether it's okay to allocate more memory for a transfer */ static int usbfs_increase_memory_usage(u64 amount) { - u64 lim; + u64 lim, total_mem; + unsigned long flags; + int ret; lim = READ_ONCE(usbfs_memory_mb); lim <<= 20; - atomic64_add(amount, &usbfs_memory_usage); - - if (lim > 0 && atomic64_read(&usbfs_memory_usage) > lim) { - atomic64_sub(amount, &usbfs_memory_usage); - return -ENOMEM; - } + ret = 0; + spin_lock_irqsave(&usbfs_memory_usage_lock, flags); + total_mem = usbfs_memory_usage + amount; + if (lim > 0 && total_mem > lim) + ret = -ENOMEM; + else + usbfs_memory_usage = total_mem; + spin_unlock_irqrestore(&usbfs_memory_usage_lock, flags); - return 0; + return ret; } /* Memory for a transfer is being deallocated */ static void usbfs_decrease_memory_usage(u64 amount) { - atomic64_sub(amount, &usbfs_memory_usage); + unsigned long flags; + + spin_lock_irqsave(&usbfs_memory_usage_lock, flags); + if (amount > usbfs_memory_usage) + usbfs_memory_usage = 0; + else + usbfs_memory_usage -= amount; + spin_unlock_irqrestore(&usbfs_memory_usage_lock, flags); } static int connected(struct usb_dev_state *ps) |