@@ -23,16 +23,19 @@
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
-#include <linux/dmapool.h>
#include <linux/platform_device.h>
#include <cpu/dma.h>
#include <asm/dma-sh.h>
#include "shdma.h"
/* DMA descriptor control */
-#define DESC_LAST (-1)
-#define DESC_COMP (1)
-#define DESC_NCOMP (0)
+enum sh_dmae_desc_status {
+ DESC_IDLE,
+ DESC_PREPARED,
+ DESC_SUBMITTED,
+ DESC_COMPLETED, /* completed, have to call callback */
+ DESC_WAITING, /* callback called, waiting for ack / re-submit */
+};
#define NR_DESCS_PER_CHANNEL 32
/*
@@ -45,6 +48,8 @@
*/
#define RS_DEFAULT (RS_DUAL)
+static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
+
#define SH_DMAC_CHAN_BASE(id) (dma_base_addr[id])
static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
{
@@ -106,11 +111,11 @@ static inline unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan)
return ts_shift[(chcr & CHCR_TS_MASK) >> CHCR_TS_SHIFT];
}
-static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs hw)
+static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
{
- sh_dmae_writel(sh_chan, hw.sar, SAR);
- sh_dmae_writel(sh_chan, hw.dar, DAR);
- sh_dmae_writel(sh_chan, hw.tcr >> calc_xmit_shift(sh_chan), TCR);
+ sh_dmae_writel(sh_chan, hw->sar, SAR);
+ sh_dmae_writel(sh_chan, hw->dar, DAR);
+ sh_dmae_writel(sh_chan, hw->tcr >> calc_xmit_shift(sh_chan), TCR);
}
static void dmae_start(struct sh_dmae_chan *sh_chan)
@@ -184,8 +189,9 @@ static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
{
- struct sh_desc *desc = tx_to_sh_desc(tx);
+ struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
+ dma_async_tx_callback callback = tx->callback;
dma_cookie_t cookie;
spin_lock_bh(&sh_chan->desc_lock);
@@ -195,45 +201,53 @@ static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
if (cookie < 0)
cookie = 1;
- /* If desc only in the case of 1 */
- if (desc->async_tx.cookie != -EBUSY)
- desc->async_tx.cookie = cookie;
- sh_chan->common.cookie = desc->async_tx.cookie;
+ sh_chan->common.cookie = cookie;
+ tx->cookie = cookie;
+
+ /* Mark all chunks of this descriptor as submitted, move to the queue */
+ list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
+ /*
+ * All chunks are on the global ld_free, so, we have to find
+ * the end of the chain ourselves
+ */
+ if (chunk != desc && (chunk->mark == DESC_IDLE ||
+ chunk->async_tx.cookie > 0 ||
+ chunk->async_tx.cookie == -EBUSY ||
+ &chunk->node == &sh_chan->ld_free))
+ break;
+ chunk->mark = DESC_SUBMITTED;
+ /* Callback goes to the last chunk */
+ chunk->async_tx.callback = NULL;
+ chunk->cookie = cookie;
+ list_move_tail(&chunk->node, &sh_chan->ld_queue);
+ last = chunk;
+ }
+
+ last->async_tx.callback = callback;
+ last->async_tx.callback_param = tx->callback_param;
- list_splice_init(&desc->tx_list, sh_chan->ld_queue.prev);
+ dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
+ tx->cookie, &last->async_tx, sh_chan->id,
+ desc->hw.sar, desc->hw.tcr, desc->hw.dar);
spin_unlock_bh(&sh_chan->desc_lock);
return cookie;
}
+/* Called with desc_lock held */
static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
{
- struct sh_desc *desc, *_desc, *ret = NULL;
+ struct sh_desc *desc;
- spin_lock_bh(&sh_chan->desc_lock);
- list_for_each_entry_safe(desc, _desc, &sh_chan->ld_free, node) {
- if (async_tx_test_ack(&desc->async_tx)) {
+ list_for_each_entry(desc, &sh_chan->ld_free, node)
+ if (desc->mark != DESC_PREPARED) {
+ BUG_ON(desc->mark != DESC_IDLE);
list_del(&desc->node);
- ret = desc;
- break;
+ return desc;
}
- }
- spin_unlock_bh(&sh_chan->desc_lock);
-
- return ret;
-}
-
-static void sh_dmae_put_desc(struct sh_dmae_chan *sh_chan, struct sh_desc *desc)
-{
- if (desc) {
- spin_lock_bh(&sh_chan->desc_lock);
-
- list_splice_init(&desc->tx_list, &sh_chan->ld_free);
- list_add(&desc->node, &sh_chan->ld_free);
- spin_unlock_bh(&sh_chan->desc_lock);
- }
+ return NULL;
}
static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
@@ -252,11 +266,10 @@ static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
dma_async_tx_descriptor_init(&desc->async_tx,
&sh_chan->common);
desc->async_tx.tx_submit = sh_dmae_tx_submit;
- desc->async_tx.flags = DMA_CTRL_ACK;
- INIT_LIST_HEAD(&desc->tx_list);
- sh_dmae_put_desc(sh_chan, desc);
+ desc->mark = DESC_IDLE;
spin_lock_bh(&sh_chan->desc_lock);
+ list_add(&desc->node, &sh_chan->ld_free);
sh_chan->descs_allocated++;
}
spin_unlock_bh(&sh_chan->desc_lock);
@@ -273,7 +286,10 @@ static void sh_dmae_free_chan_resources(struct dma_chan *chan)
struct sh_desc *desc, *_desc;
LIST_HEAD(list);
- BUG_ON(!list_empty(&sh_chan->ld_queue));
+ /* Prepared and not submitted descriptors can still be on the queue */
+ if (!list_empty(&sh_chan->ld_queue))
+ sh_dmae_chan_ld_cleanup(sh_chan, true);
+
spin_lock_bh(&sh_chan->desc_lock);
list_splice_init(&sh_chan->ld_free, &list);
@@ -292,6 +308,8 @@ static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
struct sh_dmae_chan *sh_chan;
struct sh_desc *first = NULL, *prev = NULL, *new;
size_t copy_size;
+ LIST_HEAD(tx_list);
+ int chunks = (len + SH_DMA_TCR_MAX) / (SH_DMA_TCR_MAX + 1);
if (!chan)
return NULL;
@@ -301,108 +319,189 @@ static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
sh_chan = to_sh_chan(chan);
+ /* Have to lock the whole loop to protect against concurrent release */
+ spin_lock_bh(&sh_chan->desc_lock);
+
+ /*
+ * Chaining:
+ * first descriptor is what user is dealing with in all API calls, its
+ * cookie is at first set to -EBUSY, at tx-submit to a positive
+ * number
+ * if more than one chunk is needed further chunks have cookie = -EINVAL
+ * the last chunk, if not equal to the first, has cookie = -ENOSPC
+ * all chunks are linked onto the tx_list head with their .node heads
+ * only during this function, then they are immediately spliced
+ * back onto the free list in form of a chain
+ */
do {
- /* Allocate the link descriptor from DMA pool */
+ /* Allocate the link descriptor from the free list */
new = sh_dmae_get_desc(sh_chan);
if (!new) {
dev_err(sh_chan->dev,
"No free memory for link descriptor\n");
- goto err_get_desc;
+ list_for_each_entry(new, &tx_list, node)
+ new->mark = DESC_IDLE;
+ list_splice(&tx_list, &sh_chan->ld_free);
+ spin_unlock_bh(&sh_chan->desc_lock);
+ return NULL;
}
- copy_size = min(len, (size_t)SH_DMA_TCR_MAX);
+ copy_size = min(len, (size_t)SH_DMA_TCR_MAX + 1);
new->hw.sar = dma_src;
new->hw.dar = dma_dest;
new->hw.tcr = copy_size;
- if (!first)
+ if (!first) {
+ /* First desc */
+ new->async_tx.cookie = -EBUSY;
first = new;
+ } else {
+ /* Other desc - invisible to the user */
+ new->async_tx.cookie = -EINVAL;
+ }
- new->mark = DESC_NCOMP;
- async_tx_ack(&new->async_tx);
+ dev_dbg(sh_chan->dev,
+ "chaining %u of %u with %p, dst %x, cookie %d\n",
+ copy_size, len, &new->async_tx, dma_dest,
+ new->async_tx.cookie);
+
+ new->mark = DESC_PREPARED;
+ new->async_tx.flags = flags;
+ new->chunks = chunks--;
prev = new;
len -= copy_size;
dma_src += copy_size;
dma_dest += copy_size;
/* Insert the link descriptor to the LD ring */
- list_add_tail(&new->node, &first->tx_list);
+ list_add_tail(&new->node, &tx_list);
} while (len);
- new->async_tx.flags = flags; /* client is in control of this ack */
- new->async_tx.cookie = -EBUSY; /* Last desc */
+ if (new != first)
+ new->async_tx.cookie = -ENOSPC;
- return &first->async_tx;
+ /* Put them back on the free list, so, they don't get lost */
+ list_splice_tail(&tx_list, &sh_chan->ld_free);
-err_get_desc:
- sh_dmae_put_desc(sh_chan, first);
- return NULL;
+ spin_unlock_bh(&sh_chan->desc_lock);
+ return &first->async_tx;
}
-/*
- * sh_chan_ld_cleanup - Clean up link descriptors
- *
- * This function clean up the ld_queue of DMA channel.
- */
-static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan)
+static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
{
struct sh_desc *desc, *_desc;
+ /* Is the "exposed" head of a chain acked? */
+ bool head_acked = false;
+ dma_cookie_t cookie = 0;
+ dma_async_tx_callback callback = NULL;
+ void *param = NULL;
spin_lock_bh(&sh_chan->desc_lock);
list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
- dma_async_tx_callback callback;
- void *callback_param;
-
- /* non send data */
- if (desc->mark == DESC_NCOMP)
+ struct dma_async_tx_descriptor *tx = &desc->async_tx;
+
+ BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
+ BUG_ON(desc->mark != DESC_SUBMITTED &&
+ desc->mark != DESC_COMPLETED &&
+ desc->mark != DESC_WAITING);
+
+ /*
+ * queue is ordered, and we use this loop to (1) clean up all
+ * completed descriptors, and to (2) update descriptor flags of
+ * any chunks in a (partially) completed chain
+ */
+ if (!all && desc->mark == DESC_SUBMITTED &&
+ desc->cookie != cookie)
break;
- /* send data sesc */
- callback = desc->async_tx.callback;
- callback_param = desc->async_tx.callback_param;
+ if (tx->cookie > 0)
+ cookie = tx->cookie;
- /* Remove from ld_queue list */
- list_splice_init(&desc->tx_list, &sh_chan->ld_free);
+ if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
+ BUG_ON(sh_chan->completed_cookie != desc->cookie - 1);
+ sh_chan->completed_cookie = desc->cookie;
+ }
- dev_dbg(sh_chan->dev, "link descriptor %p will be recycle.\n",
- desc);
+ /* Call callback on the last chunk */
+ if (desc->mark == DESC_COMPLETED && tx->callback) {
+ desc->mark = DESC_WAITING;
+ callback = tx->callback;
+ param = tx->callback_param;
+ dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
+ tx->cookie, tx, sh_chan->id);
+ BUG_ON(desc->chunks != 1);
+ break;
+ }
- list_move(&desc->node, &sh_chan->ld_free);
- /* Run the link descriptor callback function */
- if (callback) {
- spin_unlock_bh(&sh_chan->desc_lock);
- dev_dbg(sh_chan->dev, "link descriptor %p callback\n",
- desc);
- callback(callback_param);
- spin_lock_bh(&sh_chan->desc_lock);
+ if (tx->cookie > 0 || tx->cookie == -EBUSY) {
+ if (desc->mark == DESC_COMPLETED) {
+ BUG_ON(tx->cookie < 0);
+ desc->mark = DESC_WAITING;
+ }
+ head_acked = async_tx_test_ack(tx);
+ } else {
+ switch (desc->mark) {
+ case DESC_COMPLETED:
+ desc->mark = DESC_WAITING;
+ /* Fall through */
+ case DESC_WAITING:
+ if (head_acked)
+ async_tx_ack(&desc->async_tx);
+ }
+ }
+
+ dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
+ tx, tx->cookie);
+
+ if (((desc->mark == DESC_COMPLETED ||
+ desc->mark == DESC_WAITING) &&
+ async_tx_test_ack(&desc->async_tx)) || all) {
+ /* Remove from ld_queue list */
+ desc->mark = DESC_IDLE;
+ list_move(&desc->node, &sh_chan->ld_free);
}
}
spin_unlock_bh(&sh_chan->desc_lock);
+
+ if (callback)
+ callback(param);
+
+ return callback;
+}
+
+/*
+ * sh_chan_ld_cleanup - Clean up link descriptors
+ *
+ * This function cleans up the ld_queue of DMA channel.
+ */
+static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
+{
+ while (__ld_cleanup(sh_chan, all))
+ ;
}
static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
{
- struct list_head *ld_node;
- struct sh_dmae_regs hw;
+ struct sh_desc *sd;
+ spin_lock_bh(&sh_chan->desc_lock);
/* DMA work check */
- if (dmae_is_busy(sh_chan))
+ if (dmae_is_busy(sh_chan)) {
+ spin_unlock_bh(&sh_chan->desc_lock);
return;
+ }
/* Find the first un-transfer desciptor */
- for (ld_node = sh_chan->ld_queue.next;
- (ld_node != &sh_chan->ld_queue)
- && (to_sh_desc(ld_node)->mark == DESC_COMP);
- ld_node = ld_node->next)
- cpu_relax();
-
- if (ld_node != &sh_chan->ld_queue) {
- /* Get the ld start address from ld_queue */
- hw = to_sh_desc(ld_node)->hw;
- dmae_set_reg(sh_chan, hw);
- dmae_start(sh_chan);
- }
+ list_for_each_entry(sd, &sh_chan->ld_queue, node)
+ if (sd->mark == DESC_SUBMITTED) {
+ /* Get the ld start address from ld_queue */
+ dmae_set_reg(sh_chan, &sd->hw);
+ dmae_start(sh_chan);
+ break;
+ }
+
+ spin_unlock_bh(&sh_chan->desc_lock);
}
static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
@@ -420,12 +519,11 @@ static enum dma_status sh_dmae_is_complete(struct dma_chan *chan,
dma_cookie_t last_used;
dma_cookie_t last_complete;
- sh_dmae_chan_ld_cleanup(sh_chan);
+ sh_dmae_chan_ld_cleanup(sh_chan, false);
last_used = chan->cookie;
last_complete = sh_chan->completed_cookie;
- if (last_complete == -EBUSY)
- last_complete = last_used;
+ BUG_ON(last_complete < 0);
if (done)
*done = last_complete;
@@ -480,11 +578,13 @@ static irqreturn_t sh_dmae_err(int irq, void *data)
err = sh_dmae_rst(0);
if (err)
return err;
+#ifdef SH_DMAC_BASE1
if (shdev->pdata.mode & SHDMA_DMAOR1) {
err = sh_dmae_rst(1);
if (err)
return err;
}
+#endif
disable_irq(irq);
return IRQ_HANDLED;
}
@@ -494,35 +594,25 @@ static irqreturn_t sh_dmae_err(int irq, void *data)
static void dmae_do_tasklet(unsigned long data)
{
struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
- struct sh_desc *desc, *_desc, *cur_desc = NULL;
+ struct sh_desc *desc;
u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
- list_for_each_entry_safe(desc, _desc,
- &sh_chan->ld_queue, node) {
- if ((desc->hw.sar + desc->hw.tcr) == sar_buf) {
- cur_desc = desc;
+ spin_lock(&sh_chan->desc_lock);
+ list_for_each_entry(desc, &sh_chan->ld_queue, node) {
+ if ((desc->hw.sar + desc->hw.tcr) == sar_buf &&
+ desc->mark == DESC_SUBMITTED) {
+ dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
+ desc->async_tx.cookie, &desc->async_tx,
+ desc->hw.dar);
+ desc->mark = DESC_COMPLETED;
break;
}
}
+ spin_unlock(&sh_chan->desc_lock);
- if (cur_desc) {
- switch (cur_desc->async_tx.cookie) {
- case 0: /* other desc data */
- break;
- case -EBUSY: /* last desc */
- sh_chan->completed_cookie =
- cur_desc->async_tx.cookie;
- break;
- default: /* first desc ( 0 < )*/
- sh_chan->completed_cookie =
- cur_desc->async_tx.cookie - 1;
- break;
- }
- cur_desc->mark = DESC_COMP;
- }
/* Next desc */
sh_chan_xfer_ld_queue(sh_chan);
- sh_dmae_chan_ld_cleanup(sh_chan);
+ sh_dmae_chan_ld_cleanup(sh_chan, false);
}
static unsigned int get_dmae_irq(unsigned int id)
@@ -13,9 +13,9 @@
#ifndef __DMA_SHDMA_H
#define __DMA_SHDMA_H
-#include <linux/device.h>
-#include <linux/dmapool.h>
#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
#define SH_DMA_TCR_MAX 0x00FFFFFF /* 16MB */
@@ -26,13 +26,16 @@ struct sh_dmae_regs {
};
struct sh_desc {
- struct list_head tx_list;
struct sh_dmae_regs hw;
struct list_head node;
struct dma_async_tx_descriptor async_tx;
+ dma_cookie_t cookie;
+ int chunks;
int mark;
};
+struct device;
+
struct sh_dmae_chan {
dma_cookie_t completed_cookie; /* The maximum cookie completed */
spinlock_t desc_lock; /* Descriptor operation lock */