PCI/PM: Fix config reg access for D3cold and bridge suspending

[cascardo/linux.git] / drivers / pci / pci-sysfs.c

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 86c63fe..02d107b 100644 (file)
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -28,6 +28,7 @@
 #include <linux/pci-aspm.h>
 #include <linux/slab.h>
 #include <linux/vgaarb.h>
+#include <linux/pm_runtime.h>
 #include "pci.h"
 
 static int sysfs_initialized;  /* = 0 */
@@ -378,6 +379,31 @@ dev_bus_rescan_store(struct device *dev, struct device_attribute *attr,
 
 #endif
 
+#if defined(CONFIG_PM_RUNTIME) && defined(CONFIG_ACPI)
+static ssize_t d3cold_allowed_store(struct device *dev,
+                                   struct device_attribute *attr,
+                                   const char *buf, size_t count)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       unsigned long val;
+
+       if (strict_strtoul(buf, 0, &val) < 0)
+               return -EINVAL;
+
+       pdev->d3cold_allowed = !!val;
+       pm_runtime_resume(dev);
+
+       return count;
+}
+
+static ssize_t d3cold_allowed_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+       struct pci_dev *pdev = to_pci_dev(dev);
+       return sprintf (buf, "%u\n", pdev->d3cold_allowed);
+}
+#endif
+
 struct device_attribute pci_dev_attrs[] = {
        __ATTR_RO(resource),
        __ATTR_RO(vendor),
@@ -401,6 +427,9 @@ struct device_attribute pci_dev_attrs[] = {
 #ifdef CONFIG_HOTPLUG
        __ATTR(remove, (S_IWUSR|S_IWGRP), NULL, remove_store),
        __ATTR(rescan, (S_IWUSR|S_IWGRP), NULL, dev_rescan_store),
+#endif
+#if defined(CONFIG_PM_RUNTIME) && defined(CONFIG_ACPI)
+       __ATTR(d3cold_allowed, 0644, d3cold_allowed_show, d3cold_allowed_store),
 #endif
        __ATTR_NULL,
 };
@@ -429,6 +458,40 @@ boot_vga_show(struct device *dev, struct device_attribute *attr, char *buf)
 }
 struct device_attribute vga_attr = __ATTR_RO(boot_vga);
 
+static void
+pci_config_pm_runtime_get(struct pci_dev *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device *parent = dev->parent;
+
+       if (parent)
+               pm_runtime_get_sync(parent);
+       pm_runtime_get_noresume(dev);
+       /*
+        * pdev->current_state is set to PCI_D3cold during suspending,
+        * so wait until suspending completes
+        */
+       pm_runtime_barrier(dev);
+       /*
+        * Only need to resume devices in D3cold, because config
+        * registers are still accessible for devices suspended but
+        * not in D3cold.
+        */
+       if (pdev->current_state == PCI_D3cold)
+               pm_runtime_resume(dev);
+}
+
+static void
+pci_config_pm_runtime_put(struct pci_dev *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device *parent = dev->parent;
+
+       pm_runtime_put(dev);
+       if (parent)
+               pm_runtime_put_sync(parent);
+}
+
 static ssize_t
 pci_read_config(struct file *filp, struct kobject *kobj,
                struct bin_attribute *bin_attr,
@@ -455,6 +518,8 @@ pci_read_config(struct file *filp, struct kobject *kobj,
                size = count;
        }
 
+       pci_config_pm_runtime_get(dev);
+
        if ((off & 1) && size) {
                u8 val;
                pci_user_read_config_byte(dev, off, &val);
@@ -500,6 +565,8 @@ pci_read_config(struct file *filp, struct kobject *kobj,
                --size;
        }
 
+       pci_config_pm_runtime_put(dev);
+
        return count;
 }
 
@@ -520,6 +587,8 @@ pci_write_config(struct file* filp, struct kobject *kobj,
                count = size;
        }
        
+       pci_config_pm_runtime_get(dev);
+
        if ((off & 1) && size) {
                pci_user_write_config_byte(dev, off, data[off - init_off]);
                off++;
@@ -558,6 +627,8 @@ pci_write_config(struct file* filp, struct kobject *kobj,
                --size;
        }
 
+       pci_config_pm_runtime_put(dev);
+
        return count;
 }
 
@@ -1112,7 +1183,7 @@ static struct bin_attribute pcie_config_attr = {
        .write = pci_write_config,
 };
 
-int __attribute__ ((weak)) pcibios_add_platform_entries(struct pci_dev *dev)
+int __weak pcibios_add_platform_entries(struct pci_dev *dev)
 {
        return 0;
 }