[PATCH 1/4] PCI: Add generic pcie_link_disable

[Dirk Gouders]

Remove not needed return value checking that Linus pointed out before.

Will use it from /sys/.../pcie/link_disable

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
 drivers/pci/Makefile    |  2 +-
 drivers/pci/pcie-link.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/pci.h     |  2 ++
 3 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 drivers/pci/pcie-link.c

diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index e04fe2d..eab9feb 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -4,7 +4,7 @@
 
 obj-y		+= access.o bus.o probe.o host-bridge.o remove.o pci.o \
 			pci-driver.o search.o pci-sysfs.o rom.o setup-res.o \
-			irq.o vpd.o setup-bus.o vc.o
+			irq.o vpd.o setup-bus.o pcie-link.o vc.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSFS) += slot.o
 
diff --git a/drivers/pci/pcie-link.c b/drivers/pci/pcie-link.c
new file mode 100644
index 0000000..e10d0ba
--- /dev/null
+++ b/drivers/pci/pcie-link.c
@@ -0,0 +1,42 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+
+int pcie_link_disable_get(struct pci_dev *dev)
+{
+	u16 lnk_ctrl;
+	if (!pci_is_pcie(dev))
+		return 0;
+
+	pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctrl);
+
+	return !!(lnk_ctrl & PCI_EXP_LNKCTL_LD);
+}
+
+void pcie_link_disable_set(struct pci_dev *dev, int bit)
+{
+	u16 lnk_ctrl, old_lnk_ctrl;
+
+	if (!pci_is_pcie(dev))
+		return;
+
+	pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &lnk_ctrl);
+	old_lnk_ctrl = lnk_ctrl;
+
+	if (!bit)
+		lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
+	else
+		lnk_ctrl |= PCI_EXP_LNKCTL_LD;
+
+	if (old_lnk_ctrl == lnk_ctrl)
+		return;
+
+	pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctrl);
+
+	dev_printk(KERN_DEBUG, &dev->dev, "%s: lnk_ctrl = %x\n", __func__,
+			 lnk_ctrl);
+}
+EXPORT_SYMBOL(pcie_link_disable_set);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 61978a4..926fcb4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -778,6 +778,8 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
 				int busnr);
 void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
+void pcie_link_disable_set(struct pci_dev *dev, int bit);
+int pcie_link_disable_get(struct pci_dev *dev);
 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name,
 				 struct hotplug_slot *hotplug);
-- 
2.1.0


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Content-Type: text/x-diff
Content-Disposition: inline;
 filename=0002-PCI-pciehp-Use-generic-pcie_link_disable.patch
Content-Description: patch2