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-rw-r--r--drivers/pci/access.c2
-rw-r--r--drivers/pci/pci.c110
-rw-r--r--drivers/pci/pci.h2
-rw-r--r--include/linux/pci.h3
4 files changed, 116 insertions, 1 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 0c4c717..2a58164 100644
--- a/drivers/pci/access.c
+++ b/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
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c3cca7c..924193e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2768,6 +2768,116 @@ 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
*
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b74084e..3b6e4ed 100644
--- a/drivers/pci/pci.h
+++ b/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
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7240159..4286b85 100644
--- a/include/linux/pci.h
+++ b/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);
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