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Diffstat (limited to 'src/southbridge/intel/lynxpoint/pcie.c')
-rw-r--r--src/southbridge/intel/lynxpoint/pcie.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/src/southbridge/intel/lynxpoint/pcie.c b/src/southbridge/intel/lynxpoint/pcie.c
index a3b84e3c3f..28f4b6ad15 100644
--- a/src/southbridge/intel/lynxpoint/pcie.c
+++ b/src/southbridge/intel/lynxpoint/pcie.c
@@ -25,6 +25,191 @@
#include <device/pci_ids.h>
#include "pch.h"
+/* Check if any port in set X to X+3 is enabled */
+static int pch_pcie_check_set_enabled(device_t dev)
+{
+ device_t port;
+ int port_func;
+ int dev_func = PCI_FUNC(dev->path.pci.devfn);
+
+ printk(BIOS_DEBUG, "%s: check set enabled\n", dev_path(dev));
+
+ /* Go through static device tree list of devices
+ * because enumeration is still in progress */
+ for (port = all_devices; port; port = port->next) {
+ /* Only care about PCIe root ports */
+ if (PCI_SLOT(port->path.pci.devfn) !=
+ PCI_SLOT(dev->path.pci.devfn))
+ continue;
+
+ /* Check if port is in range and enabled */
+ port_func = PCI_FUNC(port->path.pci.devfn);
+ if (port_func >= dev_func &&
+ port_func < (dev_func + 4) &&
+ port->enabled)
+ return 1;
+ }
+
+ /* None of the ports in this set are enabled */
+ return 0;
+}
+
+/* RPFN is a write-once register so keep a copy until it is written */
+static u32 new_rpfn;
+
+/* Swap function numbers assigned to two PCIe Root Ports */
+static void pch_pcie_function_swap(u8 old_fn, u8 new_fn)
+{
+ u32 old_rpfn = new_rpfn;
+
+ printk(BIOS_DEBUG, "PCH: Remap PCIe function %d to %d\n",
+ old_fn, new_fn);
+
+ new_rpfn &= ~(RPFN_FNMASK(old_fn) | RPFN_FNMASK(new_fn));
+
+ /* Old function set to new function and disabled */
+ new_rpfn |= RPFN_FNSET(old_fn, RPFN_FNGET(old_rpfn, new_fn));
+ new_rpfn |= RPFN_FNSET(new_fn, RPFN_FNGET(old_rpfn, old_fn));
+}
+
+/* Update devicetree with new Root Port function number assignment */
+static void pch_pcie_devicetree_update(void)
+{
+ device_t dev;
+
+ /* Update the function numbers in the static devicetree */
+ for (dev = all_devices; dev; dev = dev->next) {
+ u8 new_devfn;
+
+ /* Only care about PCH PCIe root ports */
+ if (PCI_SLOT(dev->path.pci.devfn) !=
+ PCH_PCIE_DEV_SLOT)
+ continue;
+
+ /* Determine the new devfn for this port */
+ new_devfn = PCI_DEVFN(PCH_PCIE_DEV_SLOT,
+ RPFN_FNGET(new_rpfn,
+ PCI_FUNC(dev->path.pci.devfn)));
+
+ if (dev->path.pci.devfn != new_devfn) {
+ printk(BIOS_DEBUG,
+ "PCH: PCIe map %02x.%1x -> %02x.%1x\n",
+ PCI_SLOT(dev->path.pci.devfn),
+ PCI_FUNC(dev->path.pci.devfn),
+ PCI_SLOT(new_devfn), PCI_FUNC(new_devfn));
+
+ dev->path.pci.devfn = new_devfn;
+ }
+ }
+}
+
+/* Special handling for PCIe Root Port devices */
+void pch_pcie_enable_dev(device_t dev)
+{
+ struct southbridge_intel_lynxpoint_config *config = dev->chip_info;
+ u32 reg32;
+
+ /*
+ * Save a copy of the Root Port Function Number map when
+ * starting to walk the list of PCIe Root Ports so it can
+ * be updated locally and written out when the last port
+ * has been processed.
+ */
+ if (PCI_FUNC(dev->path.pci.devfn) == 0) {
+ new_rpfn = RCBA32(RPFN);
+
+ /*
+ * Enable Root Port coalescing if the first port is disabled
+ * or the other devices will not be enumerated by the OS.
+ */
+ if (!dev->enabled)
+ config->pcie_port_coalesce = 1;
+
+ if (config->pcie_port_coalesce)
+ printk(BIOS_INFO,
+ "PCH: PCIe Root Port coalescing is enabled\n");
+ }
+
+ if (!dev->enabled) {
+ printk(BIOS_DEBUG, "%s: Disabling device\n", dev_path(dev));
+
+ /*
+ * PCIE Power Savings for PantherPoint and CougarPoint/B1+
+ *
+ * If PCIe 0-3 disabled set Function 0 0xE2[0] = 1
+ * If PCIe 4-7 disabled set Function 4 0xE2[0] = 1
+ *
+ * This check is done here instead of pcie driver
+ * because the pcie driver enable() handler is not
+ * called unless the device is enabled.
+ */
+ if ((PCI_FUNC(dev->path.pci.devfn) == 0 ||
+ PCI_FUNC(dev->path.pci.devfn) == 4)) {
+ /* Handle workaround for PPT and CPT/B1+ */
+ if (!pch_pcie_check_set_enabled(dev)) {
+ u8 reg8 = pci_read_config8(dev, 0xe2);
+ reg8 |= 1;
+ pci_write_config8(dev, 0xe2, reg8);
+ }
+
+ /*
+ * Enable Clock Gating for shared PCIe resources
+ * before disabling this particular port.
+ */
+ pci_write_config8(dev, 0xe1, 0x3c);
+ }
+
+ /* Ensure memory, io, and bus master are all disabled */
+ reg32 = pci_read_config32(dev, PCI_COMMAND);
+ reg32 &= ~(PCI_COMMAND_MASTER |
+ PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+ pci_write_config32(dev, PCI_COMMAND, reg32);
+
+ /* Do not claim downstream transactions for PCIe ports */
+ new_rpfn |= RPFN_HIDE(PCI_FUNC(dev->path.pci.devfn));
+
+ /* Disable this device if possible */
+ pch_disable_devfn(dev);
+ } else {
+ int fn;
+
+ /*
+ * Check if there is a lower disabled port to swap with this
+ * port in order to maintain linear order starting at zero.
+ */
+ if (config->pcie_port_coalesce) {
+ for (fn=0; fn < PCI_FUNC(dev->path.pci.devfn); fn++) {
+ if (!(new_rpfn & RPFN_HIDE(fn)))
+ continue;
+
+ /* Swap places with this function */
+ pch_pcie_function_swap(
+ PCI_FUNC(dev->path.pci.devfn), fn);
+ break;
+ }
+ }
+
+ /* Enable SERR */
+ reg32 = pci_read_config32(dev, PCI_COMMAND);
+ reg32 |= PCI_COMMAND_SERR;
+ pci_write_config32(dev, PCI_COMMAND, reg32);
+ }
+
+ /*
+ * When processing the last PCIe root port we can now
+ * update the Root Port Function Number and Hide register.
+ */
+ if (PCI_FUNC(dev->path.pci.devfn) == 7) {
+ printk(BIOS_SPEW, "PCH: RPFN 0x%08x -> 0x%08x\n",
+ RCBA32(RPFN), new_rpfn);
+ RCBA32(RPFN) = new_rpfn;
+
+ /* Update static devictree with new function numbers */
+ if (config->pcie_port_coalesce)
+ pch_pcie_devicetree_update();
+ }
+}
+
static void pch_pcie_pm_early(struct device *dev)
{
/* RPC has been moved. It is in PCI config space now. */