Merge branch 'pci/switchtec'

- Return error to application when command execution fails because an
  out-of-band reset has cleared the device BARs, Memory Space Enable, etc
  (Kelvin Cao)

- Fix MRPC error status handling issue (Kelvin Cao)

- Mask out other bits when reading of management VEP instance ID (Kelvin
  Cao)

- Return EOPNOTSUPP instead of ENOTSUPP from sysfs show functions (Kelvin
  Cao)

- Add check of event support (Logan Gunthorpe)

* pci/switchtec:
  PCI/switchtec: Add check of event support
  PCI/switchtec: Replace ENOTSUPP with EOPNOTSUPP
  PCI/switchtec: Update the way of getting management VEP instance ID
  PCI/switchtec: Fix a MRPC error status handling issue
  PCI/switchtec: Error out MRPC execution when MMIO reads fail

drivers/pci/switch/switchtec.c

@@ -45,6 +45,7 @@ enum mrpc_state {
 	MRPC_QUEUED,
 	MRPC_RUNNING,
 	MRPC_DONE,
+	MRPC_IO_ERROR,
 };
 
 struct switchtec_user {
@@ -66,6 +67,19 @@ struct switchtec_user {
 	int event_cnt;
 };
 
+/*
+ * The MMIO reads to the device_id register should always return the device ID
+ * of the device, otherwise the firmware is probably stuck or unreachable
+ * due to a firmware reset which clears PCI state including the BARs and Memory
+ * Space Enable bits.
+ */
+static int is_firmware_running(struct switchtec_dev *stdev)
+{
+	u32 device = ioread32(&stdev->mmio_sys_info->device_id);
+
+	return stdev->pdev->device == device;
+}
+
 static struct switchtec_user *stuser_create(struct switchtec_dev *stdev)
 {
 	struct switchtec_user *stuser;
@@ -113,6 +127,7 @@ static void stuser_set_state(struct switchtec_user *stuser,
 		[MRPC_QUEUED] = "QUEUED",
 		[MRPC_RUNNING] = "RUNNING",
 		[MRPC_DONE] = "DONE",
+		[MRPC_IO_ERROR] = "IO_ERROR",
 	};
 
 	stuser->state = state;
@@ -184,9 +199,26 @@ static int mrpc_queue_cmd(struct switchtec_user *stuser)
 	return 0;
 }
 
+static void mrpc_cleanup_cmd(struct switchtec_dev *stdev)
+{
+	/* requires the mrpc_mutex to already be held when called */
+
+	struct switchtec_user *stuser = list_entry(stdev->mrpc_queue.next,
+						   struct switchtec_user, list);
+
+	stuser->cmd_done = true;
+	wake_up_interruptible(&stuser->cmd_comp);
+	list_del_init(&stuser->list);
+	stuser_put(stuser);
+	stdev->mrpc_busy = 0;
+
+	mrpc_cmd_submit(stdev);
+}
+
 static void mrpc_complete_cmd(struct switchtec_dev *stdev)
 {
 	/* requires the mrpc_mutex to already be held when called */
+
 	struct switchtec_user *stuser;
 
 	if (list_empty(&stdev->mrpc_queue))
@@ -206,7 +238,8 @@ static void mrpc_complete_cmd(struct switchtec_dev *stdev)
 	stuser_set_state(stuser, MRPC_DONE);
 	stuser->return_code = 0;
 
-	if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE)
+	if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE &&
+	    stuser->status != SWITCHTEC_MRPC_STATUS_ERROR)
 		goto out;
 
 	if (stdev->dma_mrpc)
@@ -223,13 +256,7 @@ static void mrpc_complete_cmd(struct switchtec_dev *stdev)
 		memcpy_fromio(stuser->data, &stdev->mmio_mrpc->output_data,
 			      stuser->read_len);
 out:
-	stuser->cmd_done = true;
-	wake_up_interruptible(&stuser->cmd_comp);
-	list_del_init(&stuser->list);
-	stuser_put(stuser);
-	stdev->mrpc_busy = 0;
-
-	mrpc_cmd_submit(stdev);
+	mrpc_cleanup_cmd(stdev);
 }
 
 static void mrpc_event_work(struct work_struct *work)
@@ -246,6 +273,23 @@ static void mrpc_event_work(struct work_struct *work)
 	mutex_unlock(&stdev->mrpc_mutex);
 }
 
+static void mrpc_error_complete_cmd(struct switchtec_dev *stdev)
+{
+	/* requires the mrpc_mutex to already be held when called */
+
+	struct switchtec_user *stuser;
+
+	if (list_empty(&stdev->mrpc_queue))
+		return;
+
+	stuser = list_entry(stdev->mrpc_queue.next,
+			    struct switchtec_user, list);
+
+	stuser_set_state(stuser, MRPC_IO_ERROR);
+
+	mrpc_cleanup_cmd(stdev);
+}
+
 static void mrpc_timeout_work(struct work_struct *work)
 {
 	struct switchtec_dev *stdev;
@@ -257,6 +301,11 @@ static void mrpc_timeout_work(struct work_struct *work)
 
 	mutex_lock(&stdev->mrpc_mutex);
 
+	if (!is_firmware_running(stdev)) {
+		mrpc_error_complete_cmd(stdev);
+		goto out;
+	}
+
 	if (stdev->dma_mrpc)
 		status = stdev->dma_mrpc->status;
 	else
@@ -327,7 +376,7 @@ static ssize_t field ## _show(struct device *dev, \
 		return io_string_show(buf, &si->gen4.field, \
 				      sizeof(si->gen4.field)); \
 	else \
-		return -ENOTSUPP; \
+		return -EOPNOTSUPP; \
 } \
 \
 static DEVICE_ATTR_RO(field)
@@ -544,6 +593,11 @@ static ssize_t switchtec_dev_read(struct file *filp, char __user *data,
 	if (rc)
 		return rc;
 
+	if (stuser->state == MRPC_IO_ERROR) {
+		mutex_unlock(&stdev->mrpc_mutex);
+		return -EIO;
+	}
+
 	if (stuser->state != MRPC_DONE) {
 		mutex_unlock(&stdev->mrpc_mutex);
 		return -EBADE;
@@ -569,7 +623,8 @@ static ssize_t switchtec_dev_read(struct file *filp, char __user *data,
 out:
 	mutex_unlock(&stdev->mrpc_mutex);
 
-	if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE)
+	if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE ||
+	    stuser->status == SWITCHTEC_MRPC_STATUS_ERROR)
 		return size;
 	else if (stuser->status == SWITCHTEC_MRPC_STATUS_INTERRUPTED)
 		return -ENXIO;
@@ -613,7 +668,7 @@ static int ioctl_flash_info(struct switchtec_dev *stdev,
 		info.flash_length = ioread32(&fi->gen4.flash_length);
 		info.num_partitions = SWITCHTEC_NUM_PARTITIONS_GEN4;
 	} else {
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 	}
 
 	if (copy_to_user(uinfo, &info, sizeof(info)))
@@ -821,7 +876,7 @@ static int ioctl_flash_part_info(struct switchtec_dev *stdev,
 		if (ret)
 			return ret;
 	} else {
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 	}
 
 	if (copy_to_user(uinfo, &info, sizeof(info)))
@@ -969,6 +1024,9 @@ static int event_ctl(struct switchtec_dev *stdev,
 		return PTR_ERR(reg);
 
 	hdr = ioread32(reg);
+	if (hdr & SWITCHTEC_EVENT_NOT_SUPP)
+		return -EOPNOTSUPP;
+
 	for (i = 0; i < ARRAY_SIZE(ctl->data); i++)
 		ctl->data[i] = ioread32(&reg[i + 1]);
 
@@ -1041,7 +1099,7 @@ static int ioctl_event_ctl(struct switchtec_dev *stdev,
 		for (ctl.index = 0; ctl.index < nr_idxs; ctl.index++) {
 			ctl.flags = event_flags;
 			ret = event_ctl(stdev, &ctl);
-			if (ret < 0)
+			if (ret < 0 && ret != -EOPNOTSUPP)
 				return ret;
 		}
 	} else {
@@ -1078,7 +1136,7 @@ static int ioctl_pff_to_port(struct switchtec_dev *stdev,
 			break;
 		}
 
-		reg = ioread32(&pcfg->vep_pff_inst_id);
+		reg = ioread32(&pcfg->vep_pff_inst_id) & 0xFF;
 		if (reg == p.pff) {
 			p.port = SWITCHTEC_IOCTL_PFF_VEP;
 			break;
@@ -1124,7 +1182,7 @@ static int ioctl_port_to_pff(struct switchtec_dev *stdev,
 		p.pff = ioread32(&pcfg->usp_pff_inst_id);
 		break;
 	case SWITCHTEC_IOCTL_PFF_VEP:
-		p.pff = ioread32(&pcfg->vep_pff_inst_id);
+		p.pff = ioread32(&pcfg->vep_pff_inst_id) & 0xFF;
 		break;
 	default:
 		if (p.port > ARRAY_SIZE(pcfg->dsp_pff_inst_id))
@@ -1348,6 +1406,9 @@ static int mask_event(struct switchtec_dev *stdev, int eid, int idx)
 	hdr_reg = event_regs[eid].map_reg(stdev, off, idx);
 	hdr = ioread32(hdr_reg);
 
+	if (hdr & SWITCHTEC_EVENT_NOT_SUPP)
+		return 0;
+
 	if (!(hdr & SWITCHTEC_EVENT_OCCURRED && hdr & SWITCHTEC_EVENT_EN_IRQ))
 		return 0;
 
@@ -1498,7 +1559,7 @@ static void init_pff(struct switchtec_dev *stdev)
 	if (reg < stdev->pff_csr_count)
 		stdev->pff_local[reg] = 1;
 
-	reg = ioread32(&pcfg->vep_pff_inst_id);
+	reg = ioread32(&pcfg->vep_pff_inst_id) & 0xFF;
 	if (reg < stdev->pff_csr_count)
 		stdev->pff_local[reg] = 1;
 
@@ -1556,7 +1617,7 @@ static int switchtec_init_pci(struct switchtec_dev *stdev,
 	else if (stdev->gen == SWITCHTEC_GEN4)
 		part_id = &stdev->mmio_sys_info->gen4.partition_id;
 	else
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	stdev->partition = ioread8(part_id);
 	stdev->partition_count = ioread8(&stdev->mmio_ntb->partition_count);

include/linux/switchtec.h

@@ -19,6 +19,7 @@
 #define SWITCHTEC_EVENT_EN_CLI   BIT(2)
 #define SWITCHTEC_EVENT_EN_IRQ   BIT(3)
 #define SWITCHTEC_EVENT_FATAL    BIT(4)
+#define SWITCHTEC_EVENT_NOT_SUPP BIT(31)
 
 #define SWITCHTEC_DMA_MRPC_EN	BIT(0)