/* 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)