Merge tag 'isci-for-3.5' into misc

isci update for 3.5

1/ Rework remote-node-context (RNC) handling for proper management of
   the silicon state machine in error handling and hot-plug conditions.
   Further details below, suffice to say if the RNC is mismanaged the
   silicon state machines may lock up.

2/ Refactor the initialization code to be reused for suspend/resume support

3/ Miscellaneous bug fixes to address discovery issues and hardware
   compatibility.

RNC rework details from Jeff Skirvin:

In the controller, devices as they appear on a SAS domain (or
direct-attached SATA devices) are represented by memory structures known
as "Remote Node Contexts" (RNCs).  These structures are transferred from
main memory to the controller using a set of register commands; these
commands include setting up the context ("posting"), removing the
context ("invalidating"), and commands to control the scheduling of
commands and connections to that remote device ("suspensions" and
"resumptions").  There is a similar path to control RNC scheduling from
the protocol engine, which interprets the results of command and data
transmission and reception.

In general, the controller chooses among non-suspended RNCs to find one
that has work requiring scheduling the transmission of command and data
frames to a target.  Likewise, when a target tries to return data back
to the initiator, the state of the RNC is used by the controller to
determine how to treat the incoming request. As an example, if the RNC
is in the state "TX/RX Suspended", incoming SSP connection requests from
the target will be rejected by the controller hardware.  When an RNC is
"TX Suspended", it will not be selected by the controller hardware to
start outgoing command or data operations (with certain priority-based
exceptions).

As mentioned above, there are two sources for management of the RNC
states: commands from driver software, and the result of transmission
and reception conditions of commands and data signaled by the controller
hardware.  As an example of the latter, if an outgoing SSP command ends
with a OPEN_REJECT(BAD_DESTINATION) status, the RNC state will
transition to the "TX Suspended" state, and this is signaled by the
controller hardware in the status to the completion of the pending
command as well as signaled in a controller hardware event.  Examples of
the former are included in the patch changelogs.

Driver software is required to suspend the RNC in a "TX/RX Suspended"
condition before any outstanding commands can be terminated.  Failure to
guarantee this can lead to a complete hardware hang condition.  Earlier
versions of the driver software did not guarantee that an RNC was
correctly managed before I/O termination, and so operated in an unsafe
way.

Further, the driver performed unnecessary contortions to preserve the
remote device command state and so was more complicated than it needed
to be.  A simplifying driver assumption is that once an I/O has entered
the error handler path without having completed in the target, the
requirement on the driver is that all use of the sas_task must end.
Beyond that, recovery of operation is dependent on libsas and other
components to reset, rediscover and reconfigure the device before normal
operation can restart.  In the driver, this simplifying assumption meant
that the RNC management could be reduced to entry into the suspended
state, terminating the targeted I/O request, and resuming the RNC as
needed for device-specific management such as an SSP Abort Task or LUN
Reset Management request.

1 files changed, 201 insertions, 122 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index bdd41d4bfa8..2ed1ac3513f 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -18,6 +18,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/err.h>
 #include <linux/amba/bus.h>
+#include <linux/regulator/consumer.h>
 
 #include <plat/ste_dma40.h>
 
@@ -69,6 +70,22 @@ enum d40_command {
 };
 
 /*
+ * enum d40_events - The different Event Enables for the event lines.
+ *
+ * @D40_DEACTIVATE_EVENTLINE: De-activate Event line, stopping the logical chan.
+ * @D40_ACTIVATE_EVENTLINE: Activate the Event line, to start a logical chan.
+ * @D40_SUSPEND_REQ_EVENTLINE: Requesting for suspending a event line.
+ * @D40_ROUND_EVENTLINE: Status check for event line.
+ */
+
+enum d40_events {
+	D40_DEACTIVATE_EVENTLINE	= 0,
+	D40_ACTIVATE_EVENTLINE		= 1,
+	D40_SUSPEND_REQ_EVENTLINE	= 2,
+	D40_ROUND_EVENTLINE		= 3
+};
+
+/*
  * These are the registers that has to be saved and later restored
  * when the DMA hw is powered off.
  * TODO: Add save/restore of D40_DREG_GCC on dma40 v3 or later, if that works.
@@ -870,8 +887,8 @@ static void d40_save_restore_registers(struct d40_base *base, bool save)
 }
 #endif
 
-static int d40_channel_execute_command(struct d40_chan *d40c,
-				       enum d40_command command)
+static int __d40_execute_command_phy(struct d40_chan *d40c,
+				     enum d40_command command)
 {
 	u32 status;
 	int i;
@@ -880,6 +897,12 @@ static int d40_channel_execute_command(struct d40_chan *d40c,
 	unsigned long flags;
 	u32 wmask;
 
+	if (command == D40_DMA_STOP) {
+		ret = __d40_execute_command_phy(d40c, D40_DMA_SUSPEND_REQ);
+		if (ret)
+			return ret;
+	}
+
 	spin_lock_irqsave(&d40c->base->execmd_lock, flags);
 
 	if (d40c->phy_chan->num % 2 == 0)
@@ -973,67 +996,109 @@ static void d40_term_all(struct d40_chan *d40c)
 		}
 
 	d40c->pending_tx = 0;
-	d40c->busy = false;
 }
 
-static void __d40_config_set_event(struct d40_chan *d40c, bool enable,
-				   u32 event, int reg)
+static void __d40_config_set_event(struct d40_chan *d40c,
+				   enum d40_events event_type, u32 event,
+				   int reg)
 {
 	void __iomem *addr = chan_base(d40c) + reg;
 	int tries;
+	u32 status;
+
+	switch (event_type) {
+
+	case D40_DEACTIVATE_EVENTLINE:
 
-	if (!enable) {
 		writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
 		       | ~D40_EVENTLINE_MASK(event), addr);
-		return;
-	}
+		break;
+
+	case D40_SUSPEND_REQ_EVENTLINE:
+		status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+			  D40_EVENTLINE_POS(event);
+
+		if (status == D40_DEACTIVATE_EVENTLINE ||
+		    status == D40_SUSPEND_REQ_EVENTLINE)
+			break;
 
+		writel((D40_SUSPEND_REQ_EVENTLINE << D40_EVENTLINE_POS(event))
+		       | ~D40_EVENTLINE_MASK(event), addr);
+
+		for (tries = 0 ; tries < D40_SUSPEND_MAX_IT; tries++) {
+
+			status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+				  D40_EVENTLINE_POS(event);
+
+			cpu_relax();
+			/*
+			 * Reduce the number of bus accesses while
+			 * waiting for the DMA to suspend.
+			 */
+			udelay(3);
+
+			if (status == D40_DEACTIVATE_EVENTLINE)
+				break;
+		}
+
+		if (tries == D40_SUSPEND_MAX_IT) {
+			chan_err(d40c,
+				"unable to stop the event_line chl %d (log: %d)"
+				"status %x\n", d40c->phy_chan->num,
+				 d40c->log_num, status);
+		}
+		break;
+
+	case D40_ACTIVATE_EVENTLINE:
 	/*
 	 * The hardware sometimes doesn't register the enable when src and dst
 	 * event lines are active on the same logical channel.  Retry to ensure
 	 * it does.  Usually only one retry is sufficient.
 	 */
-	tries = 100;
-	while (--tries) {
-		writel((D40_ACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
-		       | ~D40_EVENTLINE_MASK(event), addr);
+		tries = 100;
+		while (--tries) {
+			writel((D40_ACTIVATE_EVENTLINE <<
+				D40_EVENTLINE_POS(event)) |
+				~D40_EVENTLINE_MASK(event), addr);
 
-		if (readl(addr) & D40_EVENTLINE_MASK(event))
-			break;
-	}
+			if (readl(addr) & D40_EVENTLINE_MASK(event))
+				break;
+		}
 
-	if (tries != 99)
-		dev_dbg(chan2dev(d40c),
-			"[%s] workaround enable S%cLNK (%d tries)\n",
-			__func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
-			100 - tries);
+		if (tries != 99)
+			dev_dbg(chan2dev(d40c),
+				"[%s] workaround enable S%cLNK (%d tries)\n",
+				__func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
+				100 - tries);
 
-	WARN_ON(!tries);
-}
+		WARN_ON(!tries);
+		break;
 
-static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
-{
-	unsigned long flags;
+	case D40_ROUND_EVENTLINE:
+		BUG();
+		break;
 
-	spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+	}
+}
 
+static void d40_config_set_event(struct d40_chan *d40c,
+				 enum d40_events event_type)
+{
 	/* Enable event line connected to device (or memcpy) */
 	if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
 	    (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH)) {
 		u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
 
-		__d40_config_set_event(d40c, do_enable, event,
+		__d40_config_set_event(d40c, event_type, event,
 				       D40_CHAN_REG_SSLNK);
 	}
 
 	if (d40c->dma_cfg.dir !=  STEDMA40_PERIPH_TO_MEM) {
 		u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
 
-		__d40_config_set_event(d40c, do_enable, event,
+		__d40_config_set_event(d40c, event_type, event,
 				       D40_CHAN_REG_SDLNK);
 	}
-
-	spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
 }
 
 static u32 d40_chan_has_events(struct d40_chan *d40c)
@@ -1047,6 +1112,64 @@ static u32 d40_chan_has_events(struct d40_chan *d40c)
 	return val;
 }
 
+static int
+__d40_execute_command_log(struct d40_chan *d40c, enum d40_command command)
+{
+	unsigned long flags;
+	int ret = 0;
+	u32 active_status;
+	void __iomem *active_reg;
+
+	if (d40c->phy_chan->num % 2 == 0)
+		active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
+	else
+		active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;
+
+
+	spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+
+	switch (command) {
+	case D40_DMA_STOP:
+	case D40_DMA_SUSPEND_REQ:
+
+		active_status = (readl(active_reg) &
+				 D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
+				 D40_CHAN_POS(d40c->phy_chan->num);
+
+		if (active_status == D40_DMA_RUN)
+			d40_config_set_event(d40c, D40_SUSPEND_REQ_EVENTLINE);
+		else
+			d40_config_set_event(d40c, D40_DEACTIVATE_EVENTLINE);
+
+		if (!d40_chan_has_events(d40c) && (command == D40_DMA_STOP))
+			ret = __d40_execute_command_phy(d40c, command);
+
+		break;
+
+	case D40_DMA_RUN:
+
+		d40_config_set_event(d40c, D40_ACTIVATE_EVENTLINE);
+		ret = __d40_execute_command_phy(d40c, command);
+		break;
+
+	case D40_DMA_SUSPENDED:
+		BUG();
+		break;
+	}
+
+	spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
+	return ret;
+}
+
+static int d40_channel_execute_command(struct d40_chan *d40c,
+				       enum d40_command command)
+{
+	if (chan_is_logical(d40c))
+		return __d40_execute_command_log(d40c, command);
+	else
+		return __d40_execute_command_phy(d40c, command);
+}
+
 static u32 d40_get_prmo(struct d40_chan *d40c)
 {
 	static const unsigned int phy_map[] = {
@@ -1149,15 +1272,7 @@ static int d40_pause(struct d40_chan *d40c)
 	spin_lock_irqsave(&d40c->lock, flags);
 
 	res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
-	if (res == 0) {
-		if (chan_is_logical(d40c)) {
-			d40_config_set_event(d40c, false);
-			/* Resume the other logical channels if any */
-			if (d40_chan_has_events(d40c))
-				res = d40_channel_execute_command(d40c,
-								  D40_DMA_RUN);
-		}
-	}
+
 	pm_runtime_mark_last_busy(d40c->base->dev);
 	pm_runtime_put_autosuspend(d40c->base->dev);
 	spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1174,45 +1289,17 @@ static int d40_resume(struct d40_chan *d40c)
 
 	spin_lock_irqsave(&d40c->lock, flags);
 	pm_runtime_get_sync(d40c->base->dev);
-	if (d40c->base->rev == 0)
-		if (chan_is_logical(d40c)) {
-			res = d40_channel_execute_command(d40c,
-							  D40_DMA_SUSPEND_REQ);
-			goto no_suspend;
-		}
 
 	/* If bytes left to transfer or linked tx resume job */
-	if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
-
-		if (chan_is_logical(d40c))
-			d40_config_set_event(d40c, true);
-
+	if (d40_residue(d40c) || d40_tx_is_linked(d40c))
 		res = d40_channel_execute_command(d40c, D40_DMA_RUN);
-	}
 
-no_suspend:
 	pm_runtime_mark_last_busy(d40c->base->dev);
 	pm_runtime_put_autosuspend(d40c->base->dev);
 	spin_unlock_irqrestore(&d40c->lock, flags);
 	return res;
 }
 
-static int d40_terminate_all(struct d40_chan *chan)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	ret = d40_pause(chan);
-	if (!ret && chan_is_physical(chan))
-		ret = d40_channel_execute_command(chan, D40_DMA_STOP);
-
-	spin_lock_irqsave(&chan->lock, flags);
-	d40_term_all(chan);
-	spin_unlock_irqrestore(&chan->lock, flags);
-
-	return ret;
-}
-
 static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 {
 	struct d40_chan *d40c = container_of(tx->chan,
@@ -1232,20 +1319,6 @@ static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 
 static int d40_start(struct d40_chan *d40c)
 {
-	if (d40c->base->rev == 0) {
-		int err;
-
-		if (chan_is_logical(d40c)) {
-			err = d40_channel_execute_command(d40c,
-							  D40_DMA_SUSPEND_REQ);
-			if (err)
-				return err;
-		}
-	}
-
-	if (chan_is_logical(d40c))
-		d40_config_set_event(d40c, true);
-
 	return d40_channel_execute_command(d40c, D40_DMA_RUN);
 }
 
@@ -1258,10 +1331,10 @@ static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
 	d40d = d40_first_queued(d40c);
 
 	if (d40d != NULL) {
-		if (!d40c->busy)
+		if (!d40c->busy) {
 			d40c->busy = true;
-
-		pm_runtime_get_sync(d40c->base->dev);
+			pm_runtime_get_sync(d40c->base->dev);
+		}
 
 		/* Remove from queue */
 		d40_desc_remove(d40d);
@@ -1388,8 +1461,8 @@ static void dma_tasklet(unsigned long data)
 
 	return;
 
- err:
-	/* Rescue manoeuvre if receiving double interrupts */
+err:
+	/* Rescue manouver if receiving double interrupts */
 	if (d40c->pending_tx > 0)
 		d40c->pending_tx--;
 	spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1770,7 +1843,6 @@ static int d40_config_memcpy(struct d40_chan *d40c)
 	return 0;
 }
 
-
 static int d40_free_dma(struct d40_chan *d40c)
 {
 
@@ -1806,43 +1878,18 @@ static int d40_free_dma(struct d40_chan *d40c)
 	}
 
 	pm_runtime_get_sync(d40c->base->dev);
-	res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
+	res = d40_channel_execute_command(d40c, D40_DMA_STOP);
 	if (res) {
-		chan_err(d40c, "suspend failed\n");
+		chan_err(d40c, "stop failed\n");
 		goto out;
 	}
 
-	if (chan_is_logical(d40c)) {
-		/* Release logical channel, deactivate the event line */
+	d40_alloc_mask_free(phy, is_src, chan_is_logical(d40c) ? event : 0);
 
-		d40_config_set_event(d40c, false);
+	if (chan_is_logical(d40c))
 		d40c->base->lookup_log_chans[d40c->log_num] = NULL;
-
-		/*
-		 * Check if there are more logical allocation
-		 * on this phy channel.
-		 */
-		if (!d40_alloc_mask_free(phy, is_src, event)) {
-			/* Resume the other logical channels if any */
-			if (d40_chan_has_events(d40c)) {
-				res = d40_channel_execute_command(d40c,
-								  D40_DMA_RUN);
-				if (res)
-					chan_err(d40c,
-						"Executing RUN command\n");
-			}
-			goto out;
-		}
-	} else {
-		(void) d40_alloc_mask_free(phy, is_src, 0);
-	}
-
-	/* Release physical channel */
-	res = d40_channel_execute_command(d40c, D40_DMA_STOP);
-	if (res) {
-		chan_err(d40c, "Failed to stop channel\n");
-		goto out;
-	}
+	else
+		d40c->base->lookup_phy_chans[phy->num] = NULL;
 
 	if (d40c->busy) {
 		pm_runtime_mark_last_busy(d40c->base->dev);
@@ -1852,7 +1899,6 @@ static int d40_free_dma(struct d40_chan *d40c)
 	d40c->busy = false;
 	d40c->phy_chan = NULL;
 	d40c->configured = false;
-	d40c->base->lookup_phy_chans[phy->num] = NULL;
 out:
 
 	pm_runtime_mark_last_busy(d40c->base->dev);
@@ -2070,7 +2116,7 @@ d40_prep_sg(struct dma_chan *dchan, struct scatterlist *sg_src,
 	if (sg_next(&sg_src[sg_len - 1]) == sg_src)
 		desc->cyclic = true;
 
-	if (direction != DMA_NONE) {
+	if (direction != DMA_TRANS_NONE) {
 		dma_addr_t dev_addr = d40_get_dev_addr(chan, direction);
 
 		if (direction == DMA_DEV_TO_MEM)
@@ -2371,6 +2417,31 @@ static void d40_issue_pending(struct dma_chan *chan)
 	spin_unlock_irqrestore(&d40c->lock, flags);
 }
 
+static void d40_terminate_all(struct dma_chan *chan)
+{
+	unsigned long flags;
+	struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
+	int ret;
+
+	spin_lock_irqsave(&d40c->lock, flags);
+
+	pm_runtime_get_sync(d40c->base->dev);
+	ret = d40_channel_execute_command(d40c, D40_DMA_STOP);
+	if (ret)
+		chan_err(d40c, "Failed to stop channel\n");
+
+	d40_term_all(d40c);
+	pm_runtime_mark_last_busy(d40c->base->dev);
+	pm_runtime_put_autosuspend(d40c->base->dev);
+	if (d40c->busy) {
+		pm_runtime_mark_last_busy(d40c->base->dev);
+		pm_runtime_put_autosuspend(d40c->base->dev);
+	}
+	d40c->busy = false;
+
+	spin_unlock_irqrestore(&d40c->lock, flags);
+}
+
 static int
 dma40_config_to_halfchannel(struct d40_chan *d40c,
 			    struct stedma40_half_channel_info *info,
@@ -2551,7 +2622,8 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 
 	switch (cmd) {
 	case DMA_TERMINATE_ALL:
-		return d40_terminate_all(d40c);
+		d40_terminate_all(chan);
+		return 0;
 	case DMA_PAUSE:
 		return d40_pause(d40c);
 	case DMA_RESUME:
@@ -2908,6 +2980,12 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
 	dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
 		 rev, res->start);
 
+	if (rev < 2) {
+		d40_err(&pdev->dev, "hardware revision: %d is not supported",
+			rev);
+		goto failure;
+	}
+
 	plat_data = pdev->dev.platform_data;
 
 	/* Count the number of logical channels in use */
@@ -2998,6 +3076,7 @@ failure:
 
 	if (base) {
 		kfree(base->lcla_pool.alloc_map);
+		kfree(base->reg_val_backup_chan);
 		kfree(base->lookup_log_chans);
 		kfree(base->lookup_phy_chans);
 		kfree(base->phy_res);