ASoC: soc-cache: Introduce raw bulk write support
[linux-2.6.git] / kernel / res_counter.c
index 722c484..c7eaa37 100644 (file)
 #include <linux/fs.h>
 #include <linux/res_counter.h>
 #include <linux/uaccess.h>
+#include <linux/mm.h>
 
-void res_counter_init(struct res_counter *counter)
+void res_counter_init(struct res_counter *counter, struct res_counter *parent)
 {
        spin_lock_init(&counter->lock);
-       counter->limit = (unsigned long)LONG_MAX;
+       counter->limit = RESOURCE_MAX;
+       counter->soft_limit = RESOURCE_MAX;
+       counter->parent = parent;
 }
 
 int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
@@ -27,17 +30,39 @@ int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
        }
 
        counter->usage += val;
+       if (counter->usage > counter->max_usage)
+               counter->max_usage = counter->usage;
        return 0;
 }
 
-int res_counter_charge(struct res_counter *counter, unsigned long val)
+int res_counter_charge(struct res_counter *counter, unsigned long val,
+                       struct res_counter **limit_fail_at)
 {
        int ret;
        unsigned long flags;
-
-       spin_lock_irqsave(&counter->lock, flags);
-       ret = res_counter_charge_locked(counter, val);
-       spin_unlock_irqrestore(&counter->lock, flags);
+       struct res_counter *c, *u;
+
+       *limit_fail_at = NULL;
+       local_irq_save(flags);
+       for (c = counter; c != NULL; c = c->parent) {
+               spin_lock(&c->lock);
+               ret = res_counter_charge_locked(c, val);
+               spin_unlock(&c->lock);
+               if (ret < 0) {
+                       *limit_fail_at = c;
+                       goto undo;
+               }
+       }
+       ret = 0;
+       goto done;
+undo:
+       for (u = counter; u != c; u = u->parent) {
+               spin_lock(&u->lock);
+               res_counter_uncharge_locked(u, val);
+               spin_unlock(&u->lock);
+       }
+done:
+       local_irq_restore(flags);
        return ret;
 }
 
@@ -52,23 +77,32 @@ void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
 void res_counter_uncharge(struct res_counter *counter, unsigned long val)
 {
        unsigned long flags;
+       struct res_counter *c;
 
-       spin_lock_irqsave(&counter->lock, flags);
-       res_counter_uncharge_locked(counter, val);
-       spin_unlock_irqrestore(&counter->lock, flags);
+       local_irq_save(flags);
+       for (c = counter; c != NULL; c = c->parent) {
+               spin_lock(&c->lock);
+               res_counter_uncharge_locked(c, val);
+               spin_unlock(&c->lock);
+       }
+       local_irq_restore(flags);
 }
 
 
-static inline unsigned long *res_counter_member(struct res_counter *counter,
-                                               int member)
+static inline unsigned long long *
+res_counter_member(struct res_counter *counter, int member)
 {
        switch (member) {
        case RES_USAGE:
                return &counter->usage;
+       case RES_MAX_USAGE:
+               return &counter->max_usage;
        case RES_LIMIT:
                return &counter->limit;
        case RES_FAILCNT:
                return &counter->failcnt;
+       case RES_SOFT_LIMIT:
+               return &counter->soft_limit;
        };
 
        BUG();
@@ -76,45 +110,68 @@ static inline unsigned long *res_counter_member(struct res_counter *counter,
 }
 
 ssize_t res_counter_read(struct res_counter *counter, int member,
-               const char __user *userbuf, size_t nbytes, loff_t *pos)
+               const char __user *userbuf, size_t nbytes, loff_t *pos,
+               int (*read_strategy)(unsigned long long val, char *st_buf))
 {
-       unsigned long *val;
+       unsigned long long *val;
        char buf[64], *s;
 
        s = buf;
        val = res_counter_member(counter, member);
-       s += sprintf(s, "%lu\n", *val);
+       if (read_strategy)
+               s += read_strategy(*val, s);
+       else
+               s += sprintf(s, "%llu\n", *val);
        return simple_read_from_buffer((void __user *)userbuf, nbytes,
                        pos, buf, s - buf);
 }
 
-ssize_t res_counter_write(struct res_counter *counter, int member,
-               const char __user *userbuf, size_t nbytes, loff_t *pos)
+u64 res_counter_read_u64(struct res_counter *counter, int member)
 {
-       int ret;
-       char *buf, *end;
-       unsigned long tmp, *val;
-
-       buf = kmalloc(nbytes + 1, GFP_KERNEL);
-       ret = -ENOMEM;
-       if (buf == NULL)
-               goto out;
+       return *res_counter_member(counter, member);
+}
 
-       buf[nbytes] = '\0';
-       ret = -EFAULT;
-       if (copy_from_user(buf, userbuf, nbytes))
-               goto out_free;
+int res_counter_memparse_write_strategy(const char *buf,
+                                       unsigned long long *res)
+{
+       char *end;
+
+       /* return RESOURCE_MAX(unlimited) if "-1" is specified */
+       if (*buf == '-') {
+               *res = simple_strtoull(buf + 1, &end, 10);
+               if (*res != 1 || *end != '\0')
+                       return -EINVAL;
+               *res = RESOURCE_MAX;
+               return 0;
+       }
 
-       ret = -EINVAL;
-       tmp = simple_strtoul(buf, &end, 10);
+       /* FIXME - make memparse() take const char* args */
+       *res = memparse((char *)buf, &end);
        if (*end != '\0')
-               goto out_free;
+               return -EINVAL;
+
+       *res = PAGE_ALIGN(*res);
+       return 0;
+}
 
+int res_counter_write(struct res_counter *counter, int member,
+                     const char *buf, write_strategy_fn write_strategy)
+{
+       char *end;
+       unsigned long flags;
+       unsigned long long tmp, *val;
+
+       if (write_strategy) {
+               if (write_strategy(buf, &tmp))
+                       return -EINVAL;
+       } else {
+               tmp = simple_strtoull(buf, &end, 10);
+               if (*end != '\0')
+                       return -EINVAL;
+       }
+       spin_lock_irqsave(&counter->lock, flags);
        val = res_counter_member(counter, member);
        *val = tmp;
-       ret = nbytes;
-out_free:
-       kfree(buf);
-out:
-       return ret;
+       spin_unlock_irqrestore(&counter->lock, flags);
+       return 0;
 }