We mark command as huge by using meta->flags from other (non huge) command,
but flags can be possibly overridden, when non huge command is enqueued,
what can lead to:
WARNING: at lib/dma-debug.c:696 dma_debug_device_change+0x1a3/0x1f0()
DMA-API: device driver has pending DMA allocations while released from device [count=1]
To fix introduce additional CMD_MAPPED to mark command as mapped and
serialize iwl_enqueue_hcmd() with iwl_tx_cmd_complete() using
hcmd_lock. Serialization will also fix possible race conditions,
because q->read_ptr, q->write_ptr are modified/used in parallel.
On the way fix whitespace.
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
---
drivers/net/wireless/iwlwifi/iwl-dev.h | 1 +
drivers/net/wireless/iwlwifi/iwl-tx.c | 62 +++++++++++++++++---------------
2 files changed, 34 insertions(+), 29 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 68b953f..9e63bd8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -309,6 +309,7 @@ enum {
CMD_SIZE_HUGE = (1 << 0),
CMD_ASYNC = (1 << 1),
CMD_WANT_SKB = (1 << 2),
+ CMD_MAPPED = (1 << 3),
};
#define DEF_CMD_PAYLOAD_SIZE 320
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 277c917..39a4180 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -149,32 +149,31 @@ void iwl_cmd_queue_unmap(struct iwl_priv *priv)
struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
struct iwl_queue *q = &txq->q;
int i;
- bool huge = false;
if (q->n_bd == 0)
return;
while (q->read_ptr != q->write_ptr) {
- /* we have no way to tell if it is a huge cmd ATM */
i = get_cmd_index(q, q->read_ptr, 0);
- if (txq->meta[i].flags & CMD_SIZE_HUGE)
- huge = true;
- else
+ if (txq->meta[i].flags & CMD_MAPPED) {
pci_unmap_single(priv->pci_dev,
dma_unmap_addr(&txq->meta[i], mapping),
dma_unmap_len(&txq->meta[i], len),
PCI_DMA_BIDIRECTIONAL);
+ txq->meta[i].flags = 0;
+ }
- q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
+ q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd);
}
- if (huge) {
- i = q->n_window;
+ i = q->n_window;
+ if (txq->meta[i].flags & CMD_MAPPED) {
pci_unmap_single(priv->pci_dev,
dma_unmap_addr(&txq->meta[i], mapping),
dma_unmap_len(&txq->meta[i], len),
PCI_DMA_BIDIRECTIONAL);
+ txq->meta[i].flags = 0;
}
}
@@ -463,7 +462,11 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
return -EIO;
}
+ spin_lock_irqsave(&priv->hcmd_lock, flags);
+
if (iwl_queue_space(q) < ((cmd->flags & CMD_ASYNC) ? 2 : 1)) {
+ spin_unlock_irqrestore(&priv->hcmd_lock, flags);
+
IWL_ERR(priv, "No space in command queue\n");
if (priv->cfg->ops->lib->tt_ops.ct_kill_check) {
is_ct_kill =
@@ -476,22 +479,17 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
return -ENOSPC;
}
- spin_lock_irqsave(&priv->hcmd_lock, flags);
-
- /* If this is a huge cmd, mark the huge flag also on the meta.flags
- * of the _original_ cmd. This is used for DMA mapping clean up.
- */
- if (cmd->flags & CMD_SIZE_HUGE) {
- idx = get_cmd_index(q, q->write_ptr, 0);
- txq->meta[idx].flags = CMD_SIZE_HUGE;
- }
-
idx = get_cmd_index(q, q->write_ptr, cmd->flags & CMD_SIZE_HUGE);
out_cmd = txq->cmd[idx];
out_meta = &txq->meta[idx];
+ if (WARN_ON(out_meta->flags & CMD_MAPPED)) {
+ spin_unlock_irqrestore(&priv->hcmd_lock, flags);
+ return -ENOSPC;
+ }
+
memset(out_meta, 0, sizeof(*out_meta)); /* re-initialize to NULL */
- out_meta->flags = cmd->flags;
+ out_meta->flags = cmd->flags | CMD_MAPPED;
if (cmd->flags & CMD_WANT_SKB)
out_meta->source = cmd;
if (cmd->flags & CMD_ASYNC)
@@ -609,6 +607,10 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
struct iwl_device_cmd *cmd;
struct iwl_cmd_meta *meta;
struct iwl_tx_queue *txq = &priv->txq[priv->cmd_queue];
+ unsigned long flags;
+ void (*callback) (struct iwl_priv *priv, struct iwl_device_cmd *cmd,
+ struct iwl_rx_packet *pkt);
+
/* If a Tx command is being handled and it isn't in the actual
* command queue then there a command routing bug has been introduced
@@ -622,14 +624,8 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
return;
}
- /* If this is a huge cmd, clear the huge flag on the meta.flags
- * of the _original_ cmd. So that iwl_cmd_queue_free won't unmap
- * the DMA buffer for the scan (huge) command.
- */
- if (huge) {
- cmd_index = get_cmd_index(&txq->q, index, 0);
- txq->meta[cmd_index].flags = 0;
- }
+ spin_lock_irqsave(&priv->hcmd_lock, flags);
+
cmd_index = get_cmd_index(&txq->q, index, huge);
cmd = txq->cmd[cmd_index];
meta = &txq->meta[cmd_index];
@@ -639,12 +635,13 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
dma_unmap_len(meta, len),
PCI_DMA_BIDIRECTIONAL);
+ callback = NULL;
/* Input error checking is done when commands are added to queue. */
if (meta->flags & CMD_WANT_SKB) {
meta->source->reply_page = (unsigned long)rxb_addr(rxb);
rxb->page = NULL;
- } else if (meta->callback)
- meta->callback(priv, cmd, pkt);
+ } else
+ callback = meta->callback;
iwl_hcmd_queue_reclaim(priv, txq_id, index, cmd_index);
@@ -654,5 +651,12 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
get_cmd_string(cmd->hdr.cmd));
wake_up_interruptible(&priv->wait_command_queue);
}
+
+ /* Mark as unmapped */
meta->flags = 0;
+
+ spin_unlock_irqrestore(&priv->hcmd_lock, flags);
+
+ if (callback)
+ callback(priv, cmd, pkt);
}
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
