1 files changed, 86 insertions, 5 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index cab05f31223f..460d046ab6fe 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -10,6 +10,8 @@
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_pci.h>
 #include <linux/pci.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
@@ -3197,7 +3199,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 {
         u16 csr;
 
-        if (!dev->pm_cap)
+        if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
                 return -ENOTTY;
 
         pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr);
@@ -3271,7 +3273,8 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 {
         struct pci_dev *pdev;
 
-        if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
+        if (pci_is_root_bus(dev->bus) || dev->subordinate ||
+            !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
                 return -ENOTTY;
 
         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3305,7 +3308,8 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
 {
         struct pci_dev *pdev;
 
-        if (dev->subordinate || !dev->slot)
+        if (dev->subordinate || !dev->slot ||
+            dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
                 return -ENOTTY;
 
         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3557,6 +3561,20 @@ int pci_try_reset_function(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_try_reset_function);
 
+/* Do any devices on or below this bus prevent a bus reset? */
+static bool pci_bus_resetable(struct pci_bus *bus)
+{
+        struct pci_dev *dev;
+
+        list_for_each_entry(dev, &bus->devices, bus_list) {
+                if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+                    (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+                        return false;
+        }
+
+        return true;
+}
+
 /* Lock devices from the top of the tree down */
 static void pci_bus_lock(struct pci_bus *bus)
 {
@@ -3607,6 +3625,22 @@ unlock:
         return 0;
 }
 
+/* Do any devices on or below this slot prevent a bus reset? */
+static bool pci_slot_resetable(struct pci_slot *slot)
+{
+        struct pci_dev *dev;
+
+        list_for_each_entry(dev, &slot->bus->devices, bus_list) {
+                if (!dev->slot || dev->slot != slot)
+                        continue;
+                if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+                    (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+                        return false;
+        }
+
+        return true;
+}
+
 /* Lock devices from the top of the tree down */
 static void pci_slot_lock(struct pci_slot *slot)
 {
@@ -3728,7 +3762,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
 {
         int rc;
 
-        if (!slot)
+        if (!slot || !pci_slot_resetable(slot))
                 return -ENOTTY;
 
         if (!probe)
@@ -3820,7 +3854,7 @@ EXPORT_SYMBOL_GPL(pci_try_reset_slot);
 
 static int pci_bus_reset(struct pci_bus *bus, int probe)
 {
-        if (!bus->self)
+        if (!bus->self || !pci_bus_resetable(bus))
                 return -ENOTTY;
 
         if (probe)
@@ -4439,6 +4473,53 @@ int pci_get_new_domain_nr(void)
 {
         return atomic_inc_return(&__domain_nr);
 }
+
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+        static int use_dt_domains = -1;
+        int domain = of_get_pci_domain_nr(parent->of_node);
+
+        /*
+         * Check DT domain and use_dt_domains values.
+         *
+         * If DT domain property is valid (domain >= 0) and
+         * use_dt_domains != 0, the DT assignment is valid since this means
+         * we have not previously allocated a domain number by using
+         * pci_get_new_domain_nr(); we should also update use_dt_domains to
+         * 1, to indicate that we have just assigned a domain number from
+         * DT.
+         *
+         * If DT domain property value is not valid (ie domain < 0), and we
+         * have not previously assigned a domain number from DT
+         * (use_dt_domains != 1) we should assign a domain number by
+         * using the:
+         *
+         * pci_get_new_domain_nr()
+         *
+         * API and update the use_dt_domains value to keep track of method we
+         * are using to assign domain numbers (use_dt_domains = 0).
+         *
+         * All other combinations imply we have a platform that is trying
+         * to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
+         * which is a recipe for domain mishandling and it is prevented by
+         * invalidating the domain value (domain = -1) and printing a
+         * corresponding error.
+         */
+        if (domain >= 0 && use_dt_domains) {
+                use_dt_domains = 1;
+        } else if (domain < 0 && use_dt_domains != 1) {
+                use_dt_domains = 0;
+                domain = pci_get_new_domain_nr();
+        } else {
+                dev_err(parent, "Node %s has inconsistent \"linux,pci-domain\" property in DT\n",
+                        parent->of_node->full_name);
+                domain = -1;
+        }
+
+        bus->domain_nr = domain;
+}
+#endif
 #endif
 
 /**