[PATCH] I/OAT: fixups from code comments

From: Shannon Nelson
Date: Fri Nov 16 2007 - 17:57:55 EST

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A few fixups from Andrew's code comments.
- removed "static inline" forward-declares
- changed use of min() to min_t()
- removed some unnecessary NULL initializations
- removed a couple of BUG() calls

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Shannon Nelson <shannon.nelson@xxxxxxxxx>
---

drivers/dma/ioat_dma.c | 142 ++++++++++++++++++++++++++----------------------
drivers/dma/ioatdma.h | 2 -
2 files changed, 78 insertions(+), 66 deletions(-)

diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index c1c2dcc..c17ec32 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -173,10 +173,47 @@ static void ioat_set_dest(dma_addr_t addr,
tx_to_ioat_desc(tx)->dst = addr;
}

+/**
+ * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
+ * descriptors to hw
+ * @chan: DMA channel handle
+ */
static inline void __ioat1_dma_memcpy_issue_pending(
- struct ioat_dma_chan *ioat_chan);
+ struct ioat_dma_chan *ioat_chan)
+{
+ ioat_chan->pending = 0;
+ writeb(IOAT_CHANCMD_APPEND, ioat_chan->reg_base + IOAT1_CHANCMD_OFFSET);
+}
+
+static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
+{
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+ if (ioat_chan->pending != 0) {
+ spin_lock_bh(&ioat_chan->desc_lock);
+ __ioat1_dma_memcpy_issue_pending(ioat_chan);
+ spin_unlock_bh(&ioat_chan->desc_lock);
+ }
+}
+
static inline void __ioat2_dma_memcpy_issue_pending(
- struct ioat_dma_chan *ioat_chan);
+ struct ioat_dma_chan *ioat_chan)
+{
+ ioat_chan->pending = 0;
+ writew(ioat_chan->dmacount,
+ ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
+}
+
+static void ioat2_dma_memcpy_issue_pending(struct dma_chan *chan)
+{
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+
+ if (ioat_chan->pending != 0) {
+ spin_lock_bh(&ioat_chan->desc_lock);
+ __ioat2_dma_memcpy_issue_pending(ioat_chan);
+ spin_unlock_bh(&ioat_chan->desc_lock);
+ }
+}

static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
{
@@ -203,7 +240,7 @@ static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
prev = to_ioat_desc(ioat_chan->used_desc.prev);
prefetch(prev->hw);
do {
- copy = min((u32) len, ioat_chan->xfercap);
+ copy = min_t(size_t, len, ioat_chan->xfercap);

new->async_tx.ack = 1;

@@ -291,10 +328,12 @@ static dma_cookie_t ioat2_tx_submit(struct dma_async_tx_descriptor *tx)
orig_ack = first->async_tx.ack;
new = first;

- /* ioat_chan->desc_lock is still in force in version 2 path */
-
+ /*
+ * ioat_chan->desc_lock is still in force in version 2 path
+ * it gets unlocked at end of this function
+ */
do {
- copy = min((u32) len, ioat_chan->xfercap);
+ copy = min_t(size_t, len, ioat_chan->xfercap);

new->async_tx.ack = 1;

@@ -432,7 +471,7 @@ static void ioat2_dma_massage_chan_desc(struct ioat_dma_chan *ioat_chan)
static int ioat_dma_alloc_chan_resources(struct dma_chan *chan)
{
struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
- struct ioat_desc_sw *desc = NULL;
+ struct ioat_desc_sw *desc;
u16 chanctrl;
u32 chanerr;
int i;
@@ -575,7 +614,7 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan)
static struct ioat_desc_sw *
ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
{
- struct ioat_desc_sw *new = NULL;
+ struct ioat_desc_sw *new;

if (!list_empty(&ioat_chan->free_desc)) {
new = to_ioat_desc(ioat_chan->free_desc.next);
@@ -583,9 +622,11 @@ ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
} else {
/* try to get another desc */
new = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
- /* will this ever happen? */
- /* TODO add upper limit on these */
- BUG_ON(!new);
+ if (!new) {
+ dev_err(&ioat_chan->device->pdev->dev,
+ "alloc failed\n");
+ return NULL;
+ }
}

prefetch(new->hw);
@@ -595,7 +636,7 @@ ioat1_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
static struct ioat_desc_sw *
ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
{
- struct ioat_desc_sw *new = NULL;
+ struct ioat_desc_sw *new;

/*
* used.prev points to where to start processing
@@ -609,8 +650,8 @@ ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
if (ioat_chan->used_desc.prev &&
ioat_chan->used_desc.next == ioat_chan->used_desc.prev->prev) {

- struct ioat_desc_sw *desc = NULL;
- struct ioat_desc_sw *noop_desc = NULL;
+ struct ioat_desc_sw *desc;
+ struct ioat_desc_sw *noop_desc;
int i;

/* set up the noop descriptor */
@@ -624,10 +665,14 @@ ioat2_dma_get_next_descriptor(struct ioat_dma_chan *ioat_chan)
ioat_chan->pending++;
ioat_chan->dmacount++;

- /* get a few more descriptors */
+ /* try to get a few more descriptors */
for (i = 16; i; i--) {
desc = ioat_dma_alloc_descriptor(ioat_chan, GFP_ATOMIC);
- BUG_ON(!desc);
+ if (!desc) {
+ dev_err(&ioat_chan->device->pdev->dev,
+ "alloc failed\n");
+ break;
+ }
list_add_tail(&desc->node, ioat_chan->used_desc.next);

desc->hw->next
@@ -677,10 +722,13 @@ static struct dma_async_tx_descriptor *ioat1_dma_prep_memcpy(

spin_lock_bh(&ioat_chan->desc_lock);
new = ioat_dma_get_next_descriptor(ioat_chan);
- new->len = len;
spin_unlock_bh(&ioat_chan->desc_lock);

- return new ? &new->async_tx : NULL;
+ if (new) {
+ new->len = len;
+ return &new->async_tx;
+ } else
+ return NULL;
}

static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy(
@@ -693,53 +741,17 @@ static struct dma_async_tx_descriptor *ioat2_dma_prep_memcpy(

spin_lock_bh(&ioat_chan->desc_lock);
new = ioat2_dma_get_next_descriptor(ioat_chan);
- new->len = len;
-
- /* leave ioat_chan->desc_lock set in version 2 path */
- return new ? &new->async_tx : NULL;
-}
-
-
-/**
- * ioat_dma_memcpy_issue_pending - push potentially unrecognized appended
- * descriptors to hw
- * @chan: DMA channel handle
- */
-static inline void __ioat1_dma_memcpy_issue_pending(
- struct ioat_dma_chan *ioat_chan)
-{
- ioat_chan->pending = 0;
- writeb(IOAT_CHANCMD_APPEND, ioat_chan->reg_base + IOAT1_CHANCMD_OFFSET);
-}
-
-static void ioat1_dma_memcpy_issue_pending(struct dma_chan *chan)
-{
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
-
- if (ioat_chan->pending != 0) {
- spin_lock_bh(&ioat_chan->desc_lock);
- __ioat1_dma_memcpy_issue_pending(ioat_chan);
- spin_unlock_bh(&ioat_chan->desc_lock);
- }
-}
-
-static inline void __ioat2_dma_memcpy_issue_pending(
- struct ioat_dma_chan *ioat_chan)
-{
- ioat_chan->pending = 0;
- writew(ioat_chan->dmacount,
- ioat_chan->reg_base + IOAT_CHAN_DMACOUNT_OFFSET);
-}

-static void ioat2_dma_memcpy_issue_pending(struct dma_chan *chan)
-{
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ /*
+ * leave ioat_chan->desc_lock set in ioat 2 path
+ * it will get unlocked at end of tx_submit
+ */

- if (ioat_chan->pending != 0) {
- spin_lock_bh(&ioat_chan->desc_lock);
- __ioat2_dma_memcpy_issue_pending(ioat_chan);
- spin_unlock_bh(&ioat_chan->desc_lock);
- }
+ if (new) {
+ new->len = len;
+ return &new->async_tx;
+ } else
+ return NULL;
}

static void ioat_dma_cleanup_tasklet(unsigned long data)
@@ -1019,7 +1031,7 @@ static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
static void ioat_dma_test_callback(void *dma_async_param)
{
printk(KERN_ERR "ioatdma: ioat_dma_test_callback(%p)\n",
- dma_async_param);
+ dma_async_param);
}

/**
@@ -1032,7 +1044,7 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
u8 *src;
u8 *dest;
struct dma_chan *dma_chan;
- struct dma_async_tx_descriptor *tx = NULL;
+ struct dma_async_tx_descriptor *tx;
dma_addr_t addr;
dma_cookie_t cookie;
int err = 0;
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index b668234..f2c7fed 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -76,7 +76,7 @@ struct ioat_dma_chan {
dma_cookie_t completed_cookie;
unsigned long last_completion;

- u32 xfercap; /* XFERCAP register value expanded out */
+ size_t xfercap; /* XFERCAP register value expanded out */

spinlock_t cleanup_lock;
spinlock_t desc_lock;
-
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Next message: H. Peter Anvin: "Re: Kconfig: ARCH=x86 causes wrong utsname.machine"
Previous message: Jonas Stare: "[PATCH] drivers/ide/ide-probe.c Skip ide_wait_not_busy on noprobe-disks. was: [PATCH][RESUBMIT] drivers/ide/ide-probe.c, kernel 2.6.23.1"
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