PCI hotplug: add pci_configure_slot()

This patch adds a new pci_configure_slot() function that programs the
PCI bus characteristics for a newly-added device.  This is based on
code in pciehp_pci.c, but should be generic enough to be used by pciehp,
shpchp, and acpiphp.

The hotplug_params struct and the program_hpp_typeX() functions are based
on the ACPI definitions, but they aren't really ACPI-specific, and there's
no alternate implementation, so I don't see the need to abstract them yet.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Alex Chiang <achiang@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 187 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/pcihp_slot.c b/drivers/pci/hotplug/pcihp_slot.c
new file mode 100644
index 00000000000..cc8ec3aa41a
--- /dev/null
+++ b/drivers/pci/hotplug/pcihp_slot.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 1995,2001 Compaq Computer Corporation
+ * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2001 IBM Corp.
+ * Copyright (C) 2003-2004 Intel Corporation
+ * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/pci.h>
+#include <linux/pci_hotplug.h>
+
+static struct hpp_type0 pci_default_type0 = {
+	.revision = 1,
+	.cache_line_size = 8,
+	.latency_timer = 0x40,
+	.enable_serr = 0,
+	.enable_perr = 0,
+};
+
+static void program_hpp_type0(struct pci_dev *dev, struct hpp_type0 *hpp)
+{
+	u16 pci_cmd, pci_bctl;
+
+	if (!hpp) {
+		/*
+		 * Perhaps we *should* use default settings for PCIe, but
+		 * pciehp didn't, so we won't either.
+		 */
+		if (dev->is_pcie)
+			return;
+		dev_info(&dev->dev, "using default PCI settings\n");
+		hpp = &pci_default_type0;
+	}
+
+	if (hpp->revision > 1) {
+		dev_warn(&dev->dev,
+			 "PCI settings rev %d not supported; using defaults\n",
+			 hpp->revision);
+		hpp = &pci_default_type0;
+	}
+
+	pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, hpp->cache_line_size);
+	pci_write_config_byte(dev, PCI_LATENCY_TIMER, hpp->latency_timer);
+	pci_read_config_word(dev, PCI_COMMAND, &pci_cmd);
+	if (hpp->enable_serr)
+		pci_cmd |= PCI_COMMAND_SERR;
+	else
+		pci_cmd &= ~PCI_COMMAND_SERR;
+	if (hpp->enable_perr)
+		pci_cmd |= PCI_COMMAND_PARITY;
+	else
+		pci_cmd &= ~PCI_COMMAND_PARITY;
+	pci_write_config_word(dev, PCI_COMMAND, pci_cmd);
+
+	/* Program bridge control value */
+	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
+		pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER,
+				      hpp->latency_timer);
+		pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl);
+		if (hpp->enable_serr)
+			pci_bctl |= PCI_BRIDGE_CTL_SERR;
+		else
+			pci_bctl &= ~PCI_BRIDGE_CTL_SERR;
+		if (hpp->enable_perr)
+			pci_bctl |= PCI_BRIDGE_CTL_PARITY;
+		else
+			pci_bctl &= ~PCI_BRIDGE_CTL_PARITY;
+		pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl);
+	}
+}
+
+static void program_hpp_type1(struct pci_dev *dev, struct hpp_type1 *hpp)
+{
+	if (hpp)
+		dev_warn(&dev->dev, "PCI-X settings not supported\n");
+}
+
+static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
+{
+	int pos;
+	u16 reg16;
+	u32 reg32;
+
+	if (!hpp)
+		return;
+
+	/* Find PCI Express capability */
+	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
+	if (!pos)
+		return;
+
+	if (hpp->revision > 1) {
+		dev_warn(&dev->dev, "PCIe settings rev %d not supported\n",
+			 hpp->revision);
+		return;
+	}
+
+	/* Initialize Device Control Register */
+	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &reg16);
+	reg16 = (reg16 & hpp->pci_exp_devctl_and) | hpp->pci_exp_devctl_or;
+	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, reg16);
+
+	/* Initialize Link Control Register */
+	if (dev->subordinate) {
+		pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &reg16);
+		reg16 = (reg16 & hpp->pci_exp_lnkctl_and)
+			| hpp->pci_exp_lnkctl_or;
+		pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, reg16);
+	}
+
+	/* Find Advanced Error Reporting Enhanced Capability */
+	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
+	if (!pos)
+		return;
+
+	/* Initialize Uncorrectable Error Mask Register */
+	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &reg32);
+	reg32 = (reg32 & hpp->unc_err_mask_and) | hpp->unc_err_mask_or;
+	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, reg32);
+
+	/* Initialize Uncorrectable Error Severity Register */
+	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &reg32);
+	reg32 = (reg32 & hpp->unc_err_sever_and) | hpp->unc_err_sever_or;
+	pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, reg32);
+
+	/* Initialize Correctable Error Mask Register */
+	pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &reg32);
+	reg32 = (reg32 & hpp->cor_err_mask_and) | hpp->cor_err_mask_or;
+	pci_write_config_dword(dev, pos + PCI_ERR_COR_MASK, reg32);
+
+	/* Initialize Advanced Error Capabilities and Control Register */
+	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
+	reg32 = (reg32 & hpp->adv_err_cap_and) | hpp->adv_err_cap_or;
+	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);
+
+	/*
+	 * FIXME: The following two registers are not supported yet.
+	 *
+	 *   o Secondary Uncorrectable Error Severity Register
+	 *   o Secondary Uncorrectable Error Mask Register
+	 */
+}
+
+void pci_configure_slot(struct pci_dev *dev)
+{
+	struct pci_dev *cdev;
+	struct hotplug_params hpp;
+	int ret;
+
+	if (!(dev->hdr_type == PCI_HEADER_TYPE_NORMAL ||
+			(dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
+			(dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)))
+		return;
+
+	memset(&hpp, 0, sizeof(hpp));
+	ret = pci_get_hp_params(dev, &hpp);
+	if (ret)
+		dev_warn(&dev->dev, "no hotplug settings from platform\n");
+
+	program_hpp_type2(dev, hpp.t2);
+	program_hpp_type1(dev, hpp.t1);
+	program_hpp_type0(dev, hpp.t0);
+
+	if (dev->subordinate) {
+		list_for_each_entry(cdev, &dev->subordinate->devices,
+				    bus_list)
+			pci_configure_slot(cdev);
+	}
+}
+EXPORT_SYMBOL_GPL(pci_configure_slot);