[MTD] Simplify NAND locking
Replace the chip lock by a the controller lock. For simple drivers a
dummy controller structure is created by the scan code.
This simplifies the locking algorithm in nand_get/release_chip().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 08dffb7..7933ca2 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -172,20 +172,12 @@
/* De-select the NAND device */
this->select_chip(mtd, -1);
- if (this->controller) {
- /* Release the controller and the chip */
- spin_lock(&this->controller->lock);
- this->controller->active = NULL;
- this->state = FL_READY;
- wake_up(&this->controller->wq);
- spin_unlock(&this->controller->lock);
- } else {
- /* Release the chip */
- spin_lock(&this->chip_lock);
- this->state = FL_READY;
- wake_up(&this->wq);
- spin_unlock(&this->chip_lock);
- }
+ /* Release the controller and the chip */
+ spin_lock(&this->controller->lock);
+ this->controller->active = NULL;
+ this->state = FL_READY;
+ wake_up(&this->controller->wq);
+ spin_unlock(&this->controller->lock);
}
/**
@@ -765,25 +757,18 @@
*/
static int nand_get_device(struct nand_chip *this, struct mtd_info *mtd, int new_state)
{
- struct nand_chip *active;
- spinlock_t *lock;
- wait_queue_head_t *wq;
+ spinlock_t *lock = &this->controller->lock;
+ wait_queue_head_t *wq = &this->controller->wq;
DECLARE_WAITQUEUE(wait, current);
-
- lock = (this->controller) ? &this->controller->lock : &this->chip_lock;
- wq = (this->controller) ? &this->controller->wq : &this->wq;
retry:
- active = this;
spin_lock(lock);
/* Hardware controller shared among independend devices */
- if (this->controller) {
- if (this->controller->active)
- active = this->controller->active;
- else
- this->controller->active = this;
- }
- if (active == this && this->state == FL_READY) {
+ /* Hardware controller shared among independend devices */
+ if (!this->controller->active)
+ this->controller->active = this;
+
+ if (this->controller->active == this && this->state == FL_READY) {
this->state = new_state;
spin_unlock(lock);
return 0;
@@ -2312,6 +2297,22 @@
}
+/*
+ * Free allocated data structures
+ */
+static void nand_free_kmem(struct nand_chip *this)
+{
+ /* Buffer allocated by nand_scan ? */
+ if (this->options & NAND_OOBBUF_ALLOC)
+ kfree(this->oob_buf);
+ /* Buffer allocated by nand_scan ? */
+ if (this->options & NAND_DATABUF_ALLOC)
+ kfree(this->data_buf);
+ /* Controller allocated by nand_scan ? */
+ if (this->options & NAND_CONTROLLER_ALLOC)
+ kfree(this->controller);
+}
+
/* module_text_address() isn't exported, and it's mostly a pointless
test if this is a module _anyway_ -- they'd have to try _really_ hard
to call us from in-kernel code if the core NAND support is modular. */
@@ -2522,9 +2523,8 @@
len = mtd->oobblock + mtd->oobsize;
this->data_buf = kmalloc(len, GFP_KERNEL);
if (!this->data_buf) {
- if (this->options & NAND_OOBBUF_ALLOC)
- kfree(this->oob_buf);
printk(KERN_ERR "nand_scan(): Cannot allocate data_buf\n");
+ nand_free_kmem(this);
return -ENOMEM;
}
this->options |= NAND_DATABUF_ALLOC;
@@ -2657,8 +2657,17 @@
/* Initialize state, waitqueue and spinlock */
this->state = FL_READY;
- init_waitqueue_head(&this->wq);
- spin_lock_init(&this->chip_lock);
+ if (!this->controller) {
+ this->controller = kzalloc(sizeof(struct nand_hw_control),
+ GFP_KERNEL);
+ if (!this->controller) {
+ nand_free_kmem(this);
+ return -ENOMEM;
+ }
+ this->options |= NAND_CONTROLLER_ALLOC;
+ }
+ init_waitqueue_head(&this->controller->wq);
+ spin_lock_init(&this->controller->lock);
/* De-select the device */
this->select_chip(mtd, -1);
@@ -2718,12 +2727,8 @@
/* Free bad block table memory */
kfree(this->bbt);
- /* Buffer allocated by nand_scan ? */
- if (this->options & NAND_OOBBUF_ALLOC)
- kfree(this->oob_buf);
- /* Buffer allocated by nand_scan ? */
- if (this->options & NAND_DATABUF_ALLOC)
- kfree(this->data_buf);
+ /* Free buffers */
+ nand_free_kmem(this);
}
EXPORT_SYMBOL_GPL(nand_scan);