On 03/12/2014 09:05 AM, Felipe Franciosi wrote:
If the buffers are unmapped after completing a request, then stale data
might be in the request.
Good find, Felipe, thank you. I would prefer something along the lines
of this patch to make sure to avoid double completions / dma_unmap_sg()
calls during surprise removal and/or timeout conditions.
Jens: note that this patch also fixes a regression in the unaligned
workaround implementation that was introduced by the SRSI patch.
Signed-off-by: Sam Bradshaw <[email protected]>
diff --git a/drivers/block/mtip32xx/mtip32xx.c
b/drivers/block/mtip32xx/mtip32xx.c
index 5160269..390ac6f 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -252,38 +252,45 @@ static void mtip_async_complete(struct mtip_port
*port,
void *data,
int status)
{
- struct mtip_cmd *command;
+ struct mtip_cmd *cmd;
struct driver_data *dd = data;
- int cb_status = status ? -EIO : 0;
+ int unaligned, cb_status = status ? -EIO : 0;
+ void (*func)(void *, int);
if (unlikely(!dd) || unlikely(!port))
return;
- command = &port->commands[tag];
+ cmd = &port->commands[tag];
if (unlikely(status == PORT_IRQ_TF_ERR)) {
dev_warn(&port->dd->pdev->dev,
"Command tag %d failed due to TFE\n", tag);
}
+ /* Clear the active flag */
+ atomic_set(&port->commands[tag].active, 0);
+
/* Upper layer callback */
- if (likely(command->async_callback))
- command->async_callback(command->async_data, cb_status);
+ func = cmd->async_callback;
+ if (likely(func && cmpxchg(&cmd->async_callback, func, 0) == func)) {
- command->async_callback = NULL;
- command->comp_func = NULL;
+ /* Unmap the DMA scatter list entries */
+ dma_unmap_sg(&dd->pdev->dev,
+ cmd->sg,
+ cmd->scatter_ents,
+ cmd->direction);
- /* Unmap the DMA scatter list entries */
- dma_unmap_sg(&dd->pdev->dev,
- command->sg,
- command->scatter_ents,
- command->direction);
+ func(cmd->async_data, cb_status);
+ unaligned = cmd->unaligned;
- /* Clear the allocated and active bits for the command */
- atomic_set(&port->commands[tag].active, 0);
- release_slot(port, tag);
+ /* Clear the allocated bit for the command */
+ release_slot(port, tag);
- up(&port->cmd_slot);
+ if (unlikely(unaligned))
+ up(&port->cmd_slot_unal);
+ else
+ up(&port->cmd_slot);
+ }
}
/*
@@ -660,11 +667,12 @@ static void mtip_timeout_function(unsigned long
int data)
{
struct mtip_port *port = (struct mtip_port *) data;
struct host_to_dev_fis *fis;
- struct mtip_cmd *command;
- int tag, cmdto_cnt = 0;
+ struct mtip_cmd *cmd;
+ int unaligned, tag, cmdto_cnt = 0;
unsigned int bit, group;
unsigned int num_command_slots;
unsigned long to, tagaccum[SLOTBITS_IN_LONGS];
+ void (*func)(void *, int);
if (unlikely(!port))
return;
@@ -694,8 +702,8 @@ static void mtip_timeout_function(unsigned long int
data)
group = tag >> 5;
bit = tag & 0x1F;
- command = &port->commands[tag];
- fis = (struct host_to_dev_fis *) command->command;
+ cmd = &port->commands[tag];
+ fis = (struct host_to_dev_fis *) cmd->command;
set_bit(tag, tagaccum);
cmdto_cnt++;
@@ -709,27 +717,30 @@ static void mtip_timeout_function(unsigned long
int data)
*/
writel(1 << bit, port->completed[group]);
- /* Call the async completion callback. */
- if (likely(command->async_callback))
- command->async_callback(command->async_data,
- -EIO);
- command->async_callback = NULL;
- command->comp_func = NULL;
+ /* Clear the active flag for the command */
+ atomic_set(&port->commands[tag].active, 0);
- /* Unmap the DMA scatter list entries */
- dma_unmap_sg(&port->dd->pdev->dev,
- command->sg,
- command->scatter_ents,
- command->direction);
+ func = cmd->async_callback;
+ if (func &&
+ cmpxchg(&cmd->async_callback, func, 0) == func) {
- /*
- * Clear the allocated bit and active tag for the
- * command.
- */
- atomic_set(&port->commands[tag].active, 0);
- release_slot(port, tag);
+ /* Unmap the DMA scatter list entries */
+ dma_unmap_sg(&port->dd->pdev->dev,
+ cmd->sg,
+ cmd->scatter_ents,
+ cmd->direction);
- up(&port->cmd_slot);
+ func(cmd->async_data, -EIO);
+ unaligned = cmd->unaligned;
+
+ /* Clear the allocated bit for the command. */
+ release_slot(port, tag);
+
+ if (unaligned)
+ up(&port->cmd_slot_unal);
+ else
+ up(&port->cmd_slot);
+ }
}
}
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