MFC 290414,290415:

Additional PCI helper functions.

290414:
Add helper routines for PCI device drivers to read, write, and modify
PCI-Express capability registers (that is, PCI config registers in the
standard PCI config space belonging to the PCI-Express capability
register set).

Note that all of the current PCI-e registers are either 16 or 32-bits,
so only widths of 2 or 4 bytes are supported.

290415:
Add a new helper function for PCI devices to locate the upstream
PCI-express root port of a given PCI device.

2 files changed, 103 insertions, 0 deletions

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index e5db8e2..fb9a202 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -1895,6 +1895,63 @@ pci_set_max_read_req(device_t dev, int size)
 	return (size);
 }
 
+uint32_t
+pcie_read_config(device_t dev, int reg, int width)
+{
+	struct pci_devinfo *dinfo = device_get_ivars(dev);
+	int cap;
+
+	cap = dinfo->cfg.pcie.pcie_location;
+	if (cap == 0) {
+		if (width == 2)
+			return (0xffff);
+		return (0xffffffff);
+	}
+
+	return (pci_read_config(dev, cap + reg, width));
+}
+
+void
+pcie_write_config(device_t dev, int reg, uint32_t value, int width)
+{
+	struct pci_devinfo *dinfo = device_get_ivars(dev);
+	int cap;
+
+	cap = dinfo->cfg.pcie.pcie_location;
+	if (cap == 0)
+		return;
+	pci_write_config(dev, cap + reg, value, width);
+}
+
+/*
+ * Adjusts a PCI-e capability register by clearing the bits in mask
+ * and setting the bits in (value & mask).  Bits not set in mask are
+ * not adjusted.
+ *
+ * Returns the old value on success or all ones on failure.
+ */
+uint32_t
+pcie_adjust_config(device_t dev, int reg, uint32_t mask, uint32_t value,
+    int width)
+{
+	struct pci_devinfo *dinfo = device_get_ivars(dev);
+	uint32_t old, new;
+	int cap;
+
+	cap = dinfo->cfg.pcie.pcie_location;
+	if (cap == 0) {
+		if (width == 2)
+			return (0xffff);
+		return (0xffffffff);
+	}
+
+	old = pci_read_config(dev, cap + reg, width);
+	new = old & ~mask;
+	new |= (value & mask);
+	pci_write_config(dev, cap + reg, new, width);
+	return (old);
+}
+
 /*
  * Support for MSI message signalled interrupts.
  */
@@ -5139,3 +5196,44 @@ pci_get_rid_method(device_t dev, device_t child)
 
 	return (PCIB_GET_RID(device_get_parent(dev), child));
 }
+
+/* Find the upstream port of a given PCI device in a root complex. */
+device_t
+pci_find_pcie_root_port(device_t dev)
+{
+	struct pci_devinfo *dinfo;
+	devclass_t pci_class;
+	device_t pcib, bus;
+
+	pci_class = devclass_find("pci");
+	KASSERT(device_get_devclass(device_get_parent(dev)) == pci_class,
+	    ("%s: non-pci device %s", __func__, device_get_nameunit(dev)));
+
+	/*
+	 * Walk the bridge hierarchy until we find a PCI-e root
+	 * port or a non-PCI device.
+	 */
+	for (;;) {
+		bus = device_get_parent(dev);
+		KASSERT(bus != NULL, ("%s: null parent of %s", __func__,
+		    device_get_nameunit(dev)));
+
+		pcib = device_get_parent(bus);
+		KASSERT(pcib != NULL, ("%s: null bridge of %s", __func__,
+		    device_get_nameunit(bus)));
+
+		/*
+		 * pcib's parent must be a PCI bus for this to be a
+		 * PCI-PCI bridge.
+		 */
+		if (device_get_devclass(device_get_parent(pcib)) != pci_class)
+			return (NULL);
+
+		dinfo = device_get_ivars(pcib);
+		if (dinfo->cfg.pcie.pcie_location != 0 &&
+		    dinfo->cfg.pcie.pcie_type == PCIEM_TYPE_ROOT_PORT)
+			return (pcib);
+
+		dev = pcib;
+	}
+}
diff --git a/sys/dev/pci/pcivar.h b/sys/dev/pci/pcivar.h
index 0157ee7..4b570d0 100644
--- a/sys/dev/pci/pcivar.h
+++ b/sys/dev/pci/pcivar.h
@@ -501,10 +501,15 @@ int	pci_msix_device_blacklisted(device_t dev);
 
 void	pci_ht_map_msi(device_t dev, uint64_t addr);
 
+device_t pci_find_pcie_root_port(device_t dev);
 int	pci_get_max_read_req(device_t dev);
 void	pci_restore_state(device_t dev);
 void	pci_save_state(device_t dev);
 int	pci_set_max_read_req(device_t dev, int size);
+uint32_t pcie_read_config(device_t dev, int reg, int width);
+void	pcie_write_config(device_t dev, int reg, uint32_t value, int width);
+uint32_t pcie_adjust_config(device_t dev, int reg, uint32_t mask,
+	    uint32_t value, int width);
 
 
 #ifdef BUS_SPACE_MAXADDR