---

yaml
---
r: 283334
b: refs/heads/master
c: a2e2778
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fb51ccbf217c1c994607b6519c7d85250928553d
+refs/heads/master: a2e27787f893621c5a6b865acf6b7766f8671328

trunk/drivers/pci/access.c

@@ -13,7 +13,7 @@
  * configuration space.
  */
 
-static DEFINE_RAW_SPINLOCK(pci_lock);
+DEFINE_RAW_SPINLOCK(pci_lock);
 
 /*
  *  Wrappers for all PCI configuration access functions.  They just check

trunk/drivers/pci/pci.c

@@ -2767,6 +2767,116 @@ pci_intx(struct pci_dev *pdev, int enable)
 	}
 }
 
+/**
+ * pci_intx_mask_supported - probe for INTx masking support
+ * @pdev: the PCI device to operate on
+ *
+ * Check if the device dev support INTx masking via the config space
+ * command word.
+ */
+bool pci_intx_mask_supported(struct pci_dev *dev)
+{
+	bool mask_supported = false;
+	u16 orig, new;
+
+	pci_cfg_access_lock(dev);
+
+	pci_read_config_word(dev, PCI_COMMAND, &orig);
+	pci_write_config_word(dev, PCI_COMMAND,
+			      orig ^ PCI_COMMAND_INTX_DISABLE);
+	pci_read_config_word(dev, PCI_COMMAND, &new);
+
+	/*
+	 * There's no way to protect against hardware bugs or detect them
+	 * reliably, but as long as we know what the value should be, let's
+	 * go ahead and check it.
+	 */
+	if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
+		dev_err(&dev->dev, "Command register changed from "
+			"0x%x to 0x%x: driver or hardware bug?\n", orig, new);
+	} else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
+		mask_supported = true;
+		pci_write_config_word(dev, PCI_COMMAND, orig);
+	}
+
+	pci_cfg_access_unlock(dev);
+	return mask_supported;
+}
+EXPORT_SYMBOL_GPL(pci_intx_mask_supported);
+
+static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
+{
+	struct pci_bus *bus = dev->bus;
+	bool mask_updated = true;
+	u32 cmd_status_dword;
+	u16 origcmd, newcmd;
+	unsigned long flags;
+	bool irq_pending;
+
+	/*
+	 * We do a single dword read to retrieve both command and status.
+	 * Document assumptions that make this possible.
+	 */
+	BUILD_BUG_ON(PCI_COMMAND % 4);
+	BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
+
+	raw_spin_lock_irqsave(&pci_lock, flags);
+
+	bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword);
+
+	irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT;
+
+	/*
+	 * Check interrupt status register to see whether our device
+	 * triggered the interrupt (when masking) or the next IRQ is
+	 * already pending (when unmasking).
+	 */
+	if (mask != irq_pending) {
+		mask_updated = false;
+		goto done;
+	}
+
+	origcmd = cmd_status_dword;
+	newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE;
+	if (mask)
+		newcmd |= PCI_COMMAND_INTX_DISABLE;
+	if (newcmd != origcmd)
+		bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd);
+
+done:
+	raw_spin_unlock_irqrestore(&pci_lock, flags);
+
+	return mask_updated;
+}
+
+/**
+ * pci_check_and_mask_intx - mask INTx on pending interrupt
+ * @pdev: the PCI device to operate on
+ *
+ * Check if the device dev has its INTx line asserted, mask it and
+ * return true in that case. False is returned if not interrupt was
+ * pending.
+ */
+bool pci_check_and_mask_intx(struct pci_dev *dev)
+{
+	return pci_check_and_set_intx_mask(dev, true);
+}
+EXPORT_SYMBOL_GPL(pci_check_and_mask_intx);
+
+/**
+ * pci_check_and_mask_intx - unmask INTx of no interrupt is pending
+ * @pdev: the PCI device to operate on
+ *
+ * Check if the device dev has its INTx line asserted, unmask it if not
+ * and return true. False is returned and the mask remains active if
+ * there was still an interrupt pending.
+ */
+bool pci_check_and_unmask_intx(struct pci_dev *dev)
+{
+	return pci_check_and_set_intx_mask(dev, false);
+}
+EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
+
 /**
  * pci_msi_off - disables any msi or msix capabilities
  * @dev: the PCI device to operate on

trunk/drivers/pci/pci.h

@@ -136,6 +136,8 @@ static inline void pci_remove_legacy_files(struct pci_bus *bus) { return; }
 /* Lock for read/write access to pci device and bus lists */
 extern struct rw_semaphore pci_bus_sem;
 
+extern raw_spinlock_t pci_lock;
+
 extern unsigned int pci_pm_d3_delay;
 
 #ifdef CONFIG_PCI_MSI

trunk/include/linux/pci.h

@@ -804,6 +804,9 @@ int __must_check pci_set_mwi(struct pci_dev *dev);
 int pci_try_set_mwi(struct pci_dev *dev);
 void pci_clear_mwi(struct pci_dev *dev);
 void pci_intx(struct pci_dev *dev, int enable);
+bool pci_intx_mask_supported(struct pci_dev *dev);
+bool pci_check_and_mask_intx(struct pci_dev *dev);
+bool pci_check_and_unmask_intx(struct pci_dev *dev);
 void pci_msi_off(struct pci_dev *dev);
 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size);
 int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask);