---

yaml
---
r: 283333
b: refs/heads/master
c: fb51ccb
h: refs/heads/master
i:
  283331: 20d37b6
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: ae5cd86455381282ece162966183d3f208c6fad7
+refs/heads/master: fb51ccbf217c1c994607b6519c7d85250928553d

trunk/drivers/pci/access.c

@@ -127,20 +127,20 @@ EXPORT_SYMBOL(pci_write_vpd);
  * We have a bit per device to indicate it's blocked and a global wait queue
  * for callers to sleep on until devices are unblocked.
  */
-static DECLARE_WAIT_QUEUE_HEAD(pci_ucfg_wait);
+static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
 
-static noinline void pci_wait_ucfg(struct pci_dev *dev)
+static noinline void pci_wait_cfg(struct pci_dev *dev)
 {
 	DECLARE_WAITQUEUE(wait, current);
 
-	__add_wait_queue(&pci_ucfg_wait, &wait);
+	__add_wait_queue(&pci_cfg_wait, &wait);
 	do {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		raw_spin_unlock_irq(&pci_lock);
 		schedule();
 		raw_spin_lock_irq(&pci_lock);
-	} while (dev->block_ucfg_access);
-	__remove_wait_queue(&pci_ucfg_wait, &wait);
+	} while (dev->block_cfg_access);
+	__remove_wait_queue(&pci_cfg_wait, &wait);
 }
 
 /* Returns 0 on success, negative values indicate error. */
@@ -153,7 +153,8 @@ int pci_user_read_config_##size						\
 	if (PCI_##size##_BAD)						\
 		return -EINVAL;						\
 	raw_spin_lock_irq(&pci_lock);				\
-	if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);	\
+	if (unlikely(dev->block_cfg_access))				\
+		pci_wait_cfg(dev);					\
 	ret = dev->bus->ops->read(dev->bus, dev->devfn,			\
 					pos, sizeof(type), &data);	\
 	raw_spin_unlock_irq(&pci_lock);				\
@@ -172,7 +173,8 @@ int pci_user_write_config_##size					\
 	if (PCI_##size##_BAD)						\
 		return -EINVAL;						\
 	raw_spin_lock_irq(&pci_lock);				\
-	if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);	\
+	if (unlikely(dev->block_cfg_access))				\
+		pci_wait_cfg(dev);					\
 	ret = dev->bus->ops->write(dev->bus, dev->devfn,		\
 					pos, sizeof(type), val);	\
 	raw_spin_unlock_irq(&pci_lock);				\
@@ -401,47 +403,67 @@ int pci_vpd_truncate(struct pci_dev *dev, size_t size)
 EXPORT_SYMBOL(pci_vpd_truncate);
 
 /**
- * pci_block_user_cfg_access - Block userspace PCI config reads/writes
+ * pci_cfg_access_lock - Lock PCI config reads/writes
  * @dev:	pci device struct
  *
- * When user access is blocked, any reads or writes to config space will
- * sleep until access is unblocked again.  We don't allow nesting of
- * block/unblock calls.
+ * When access is locked, any userspace reads or writes to config
+ * space and concurrent lock requests will sleep until access is
+ * allowed via pci_cfg_access_unlocked again.
  */
-void pci_block_user_cfg_access(struct pci_dev *dev)
+void pci_cfg_access_lock(struct pci_dev *dev)
+{
+	might_sleep();
+
+	raw_spin_lock_irq(&pci_lock);
+	if (dev->block_cfg_access)
+		pci_wait_cfg(dev);
+	dev->block_cfg_access = 1;
+	raw_spin_unlock_irq(&pci_lock);
+}
+EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
+
+/**
+ * pci_cfg_access_trylock - try to lock PCI config reads/writes
+ * @dev:	pci device struct
+ *
+ * Same as pci_cfg_access_lock, but will return 0 if access is
+ * already locked, 1 otherwise. This function can be used from
+ * atomic contexts.
+ */
+bool pci_cfg_access_trylock(struct pci_dev *dev)
 {
 	unsigned long flags;
-	int was_blocked;
+	bool locked = true;
 
 	raw_spin_lock_irqsave(&pci_lock, flags);
-	was_blocked = dev->block_ucfg_access;
-	dev->block_ucfg_access = 1;
+	if (dev->block_cfg_access)
+		locked = false;
+	else
+		dev->block_cfg_access = 1;
 	raw_spin_unlock_irqrestore(&pci_lock, flags);
 
-	/* If we BUG() inside the pci_lock, we're guaranteed to hose
-	 * the machine */
-	BUG_ON(was_blocked);
+	return locked;
 }
-EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
+EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
 
 /**
- * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
+ * pci_cfg_access_unlock - Unlock PCI config reads/writes
  * @dev:	pci device struct
  *
- * This function allows userspace PCI config accesses to resume.
+ * This function allows PCI config accesses to resume.
  */
-void pci_unblock_user_cfg_access(struct pci_dev *dev)
+void pci_cfg_access_unlock(struct pci_dev *dev)
 {
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&pci_lock, flags);
 
 	/* This indicates a problem in the caller, but we don't need
 	 * to kill them, unlike a double-block above. */
-	WARN_ON(!dev->block_ucfg_access);
+	WARN_ON(!dev->block_cfg_access);
 
-	dev->block_ucfg_access = 0;
-	wake_up_all(&pci_ucfg_wait);
+	dev->block_cfg_access = 0;
+	wake_up_all(&pci_cfg_wait);
 	raw_spin_unlock_irqrestore(&pci_lock, flags);
 }
-EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);
+EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);

trunk/drivers/pci/iov.c

@@ -348,10 +348,10 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 	}
 
 	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
-	pci_block_user_cfg_access(dev);
+	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	msleep(100);
-	pci_unblock_user_cfg_access(dev);
+	pci_cfg_access_unlock(dev);
 
 	iov->initial = initial;
 	if (nr_virtfn < initial)
@@ -379,10 +379,10 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
 		virtfn_remove(dev, j, 0);
 
 	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
-	pci_block_user_cfg_access(dev);
+	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	ssleep(1);
-	pci_unblock_user_cfg_access(dev);
+	pci_cfg_access_unlock(dev);
 
 	if (iov->link != dev->devfn)
 		sysfs_remove_link(&dev->dev.kobj, "dep_link");
@@ -405,10 +405,10 @@ static void sriov_disable(struct pci_dev *dev)
 		virtfn_remove(dev, i, 0);
 
 	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
-	pci_block_user_cfg_access(dev);
+	pci_cfg_access_lock(dev);
 	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
 	ssleep(1);
-	pci_unblock_user_cfg_access(dev);
+	pci_cfg_access_unlock(dev);
 
 	if (iov->link != dev->devfn)
 		sysfs_remove_link(&dev->dev.kobj, "dep_link");

trunk/drivers/pci/pci.c

@@ -2965,7 +2965,7 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
 	might_sleep();
 
 	if (!probe) {
-		pci_block_user_cfg_access(dev);
+		pci_cfg_access_lock(dev);
 		/* block PM suspend, driver probe, etc. */
 		device_lock(&dev->dev);
 	}
@@ -2990,7 +2990,7 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
 done:
 	if (!probe) {
 		device_unlock(&dev->dev);
-		pci_unblock_user_cfg_access(dev);
+		pci_cfg_access_unlock(dev);
 	}
 
 	return rc;

trunk/drivers/scsi/ipr.c

@@ -7638,8 +7638,12 @@ static int ipr_reset_restore_cfg_space(struct ipr_cmnd *ipr_cmd)
  **/
 static int ipr_reset_bist_done(struct ipr_cmnd *ipr_cmd)
 {
+	struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+
 	ENTER;
-	pci_unblock_user_cfg_access(ipr_cmd->ioa_cfg->pdev);
+	if (ioa_cfg->cfg_locked)
+		pci_cfg_access_unlock(ioa_cfg->pdev);
+	ioa_cfg->cfg_locked = 0;
 	ipr_cmd->job_step = ipr_reset_restore_cfg_space;
 	LEAVE;
 	return IPR_RC_JOB_CONTINUE;
@@ -7660,8 +7664,6 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd)
 	int rc = PCIBIOS_SUCCESSFUL;
 
 	ENTER;
-	pci_block_user_cfg_access(ioa_cfg->pdev);
-
 	if (ioa_cfg->ipr_chip->bist_method == IPR_MMIO)
 		writel(IPR_UPROCI_SIS64_START_BIST,
 		       ioa_cfg->regs.set_uproc_interrupt_reg32);
@@ -7673,7 +7675,9 @@ static int ipr_reset_start_bist(struct ipr_cmnd *ipr_cmd)
 		ipr_reset_start_timer(ipr_cmd, IPR_WAIT_FOR_BIST_TIMEOUT);
 		rc = IPR_RC_JOB_RETURN;
 	} else {
-		pci_unblock_user_cfg_access(ipr_cmd->ioa_cfg->pdev);
+		if (ioa_cfg->cfg_locked)
+			pci_cfg_access_unlock(ipr_cmd->ioa_cfg->pdev);
+		ioa_cfg->cfg_locked = 0;
 		ipr_cmd->s.ioasa.hdr.ioasc = cpu_to_be32(IPR_IOASC_PCI_ACCESS_ERROR);
 		rc = IPR_RC_JOB_CONTINUE;
 	}
@@ -7716,14 +7720,63 @@ static int ipr_reset_slot_reset(struct ipr_cmnd *ipr_cmd)
 	struct pci_dev *pdev = ioa_cfg->pdev;
 
 	ENTER;
-	pci_block_user_cfg_access(pdev);
 	pci_set_pcie_reset_state(pdev, pcie_warm_reset);
 	ipr_cmd->job_step = ipr_reset_slot_reset_done;
 	ipr_reset_start_timer(ipr_cmd, IPR_PCI_RESET_TIMEOUT);
 	LEAVE;
 	return IPR_RC_JOB_RETURN;
 }
 
+/**
+ * ipr_reset_block_config_access_wait - Wait for permission to block config access
+ * @ipr_cmd:	ipr command struct
+ *
+ * Description: This attempts to block config access to the IOA.
+ *
+ * Return value:
+ * 	IPR_RC_JOB_CONTINUE / IPR_RC_JOB_RETURN
+ **/
+static int ipr_reset_block_config_access_wait(struct ipr_cmnd *ipr_cmd)
+{
+	struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
+	int rc = IPR_RC_JOB_CONTINUE;
+
+	if (pci_cfg_access_trylock(ioa_cfg->pdev)) {
+		ioa_cfg->cfg_locked = 1;
+		ipr_cmd->job_step = ioa_cfg->reset;
+	} else {
+		if (ipr_cmd->u.time_left) {
+			rc = IPR_RC_JOB_RETURN;
+			ipr_cmd->u.time_left -= IPR_CHECK_FOR_RESET_TIMEOUT;
+			ipr_reset_start_timer(ipr_cmd,
+					      IPR_CHECK_FOR_RESET_TIMEOUT);
+		} else {
+			ipr_cmd->job_step = ioa_cfg->reset;
+			dev_err(&ioa_cfg->pdev->dev,
+				"Timed out waiting to lock config access. Resetting anyway.\n");
+		}
+	}
+
+	return rc;
+}
+
+/**
+ * ipr_reset_block_config_access - Block config access to the IOA
+ * @ipr_cmd:	ipr command struct
+ *
+ * Description: This attempts to block config access to the IOA
+ *
+ * Return value:
+ * 	IPR_RC_JOB_CONTINUE
+ **/
+static int ipr_reset_block_config_access(struct ipr_cmnd *ipr_cmd)
+{
+	ipr_cmd->ioa_cfg->cfg_locked = 0;
+	ipr_cmd->job_step = ipr_reset_block_config_access_wait;
+	ipr_cmd->u.time_left = IPR_WAIT_FOR_RESET_TIMEOUT;
+	return IPR_RC_JOB_CONTINUE;
+}
+
 /**
  * ipr_reset_allowed - Query whether or not IOA can be reset
  * @ioa_cfg:	ioa config struct
@@ -7763,7 +7816,7 @@ static int ipr_reset_wait_to_start_bist(struct ipr_cmnd *ipr_cmd)
 		ipr_cmd->u.time_left -= IPR_CHECK_FOR_RESET_TIMEOUT;
 		ipr_reset_start_timer(ipr_cmd, IPR_CHECK_FOR_RESET_TIMEOUT);
 	} else {
-		ipr_cmd->job_step = ioa_cfg->reset;
+		ipr_cmd->job_step = ipr_reset_block_config_access;
 		rc = IPR_RC_JOB_CONTINUE;
 	}
 
@@ -7796,7 +7849,7 @@ static int ipr_reset_alert(struct ipr_cmnd *ipr_cmd)
 		writel(IPR_UPROCI_RESET_ALERT, ioa_cfg->regs.set_uproc_interrupt_reg32);
 		ipr_cmd->job_step = ipr_reset_wait_to_start_bist;
 	} else {
-		ipr_cmd->job_step = ioa_cfg->reset;
+		ipr_cmd->job_step = ipr_reset_block_config_access;
 	}
 
 	ipr_cmd->u.time_left = IPR_WAIT_FOR_RESET_TIMEOUT;

trunk/drivers/scsi/ipr.h

@@ -1387,6 +1387,7 @@ struct ipr_ioa_cfg {
 	u8 msi_received:1;
 	u8 sis64:1;
 	u8 dump_timeout:1;
+	u8 cfg_locked:1;
 
 	u8 revid;
 

trunk/drivers/uio/uio_pci_generic.c

@@ -55,7 +55,8 @@ static irqreturn_t irqhandler(int irq, struct uio_info *info)
 	BUILD_BUG_ON(PCI_COMMAND % 4);
 	BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
 
-	pci_block_user_cfg_access(pdev);
+	if (!pci_cfg_access_trylock(pdev))
+		goto error;
 
 	/* Read both command and status registers in a single 32-bit operation.
 	 * Note: we could cache the value for command and move the status read
@@ -79,7 +80,7 @@ static irqreturn_t irqhandler(int irq, struct uio_info *info)
 	ret = IRQ_HANDLED;
 done:
 
-	pci_unblock_user_cfg_access(pdev);
+	pci_cfg_access_lock(pdev);
 	return ret;
 }
 
@@ -91,7 +92,7 @@ static int __devinit verify_pci_2_3(struct pci_dev *pdev)
 	u16 orig, new;
 	int err = 0;
 
-	pci_block_user_cfg_access(pdev);
+	pci_cfg_access_lock(pdev);
 	pci_read_config_word(pdev, PCI_COMMAND, &orig);
 	pci_write_config_word(pdev, PCI_COMMAND,
 			      orig ^ PCI_COMMAND_INTX_DISABLE);
@@ -114,7 +115,7 @@ static int __devinit verify_pci_2_3(struct pci_dev *pdev)
 	/* Now restore the original value. */
 	pci_write_config_word(pdev, PCI_COMMAND, orig);
 err:
-	pci_unblock_user_cfg_access(pdev);
+	pci_cfg_access_unlock(pdev);
 	return err;
 }
 

trunk/include/linux/pci.h

@@ -308,7 +308,7 @@ struct pci_dev {
 	unsigned int	is_added:1;
 	unsigned int	is_busmaster:1; /* device is busmaster */
 	unsigned int	no_msi:1;	/* device may not use msi */
-	unsigned int	block_ucfg_access:1;	/* userspace config space access is blocked */
+	unsigned int	block_cfg_access:1;	/* config space access is blocked */
 	unsigned int	broken_parity_status:1;	/* Device generates false positive parity */
 	unsigned int	irq_reroute_variant:2;	/* device needs IRQ rerouting variant */
 	unsigned int 	msi_enabled:1;
@@ -1085,8 +1085,9 @@ int  ht_create_irq(struct pci_dev *dev, int idx);
 void ht_destroy_irq(unsigned int irq);
 #endif /* CONFIG_HT_IRQ */
 
-extern void pci_block_user_cfg_access(struct pci_dev *dev);
-extern void pci_unblock_user_cfg_access(struct pci_dev *dev);
+extern void pci_cfg_access_lock(struct pci_dev *dev);
+extern bool pci_cfg_access_trylock(struct pci_dev *dev);
+extern void pci_cfg_access_unlock(struct pci_dev *dev);
 
 /*
  * PCI domain support.  Sometimes called PCI segment (eg by ACPI),
@@ -1283,10 +1284,13 @@ static inline void pci_release_regions(struct pci_dev *dev)
 
 #define pci_dma_burst_advice(pdev, strat, strategy_parameter) do { } while (0)
 
-static inline void pci_block_user_cfg_access(struct pci_dev *dev)
+static inline void pci_block_cfg_access(struct pci_dev *dev)
 { }
 
-static inline void pci_unblock_user_cfg_access(struct pci_dev *dev)
+static inline int pci_block_cfg_access_in_atomic(struct pci_dev *dev)
+{ return 0; }
+
+static inline void pci_unblock_cfg_access(struct pci_dev *dev)
 { }
 
 static inline struct pci_bus *pci_find_next_bus(const struct pci_bus *from)