[PATCH] pSeries - read irqs dynamically

For I/O DLPAR to work properly, the kernel needs to allow for dynamic
assignment of the irq field of the pci_dev structure upon dynamic bus
addition.  This patch moves the assignment of that field from
pSeries_final_fixup() to pcibios_fixup_bus(), which enables dynamic
assignment for the children of a newly added bus.

Currently, pci_devs receive their irq numbers in one of two ways.  The
irq line is either read at boot for all pci_devs, or read by the rpaphp
module at slot enable time.  The latter is no longer sufficient for
DLPAR addition of slots that don't qualify as PCI-hotplug capable.
This solution handles the cases of boot and dynamic add.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

4 files changed, 29 insertions, 18 deletions

diff --git a/arch/ppc64/kernel/pSeries_pci.c b/arch/ppc64/kernel/pSeries_pci.c
index dfa6d3d3e9f0..1f5f141fb7a1 100644
--- a/arch/ppc64/kernel/pSeries_pci.c
+++ b/arch/ppc64/kernel/pSeries_pci.c
@@ -32,7 +32,7 @@
 
 #include "pci.h"
 
-static int __initdata s7a_workaround;
+static int __initdata s7a_workaround = -1;
 
 #if 0
 void pcibios_name_device(struct pci_dev *dev)
@@ -65,6 +65,7 @@ static void __init check_s7a(void)
         struct device_node *root;
         char *model;
 
+        s7a_workaround = 0;
         root = of_find_node_by_path("/");
         if (root) {
                 model = get_property(root, "model", NULL);
@@ -74,6 +75,24 @@ static void __init check_s7a(void)
         }
 }
 
+void __devinit pSeries_irq_bus_setup(struct pci_bus *bus)
+{
+        struct pci_dev *dev;
+
+        if (s7a_workaround < 0)
+                check_s7a();
+        list_for_each_entry(dev, &bus->devices, bus_list) {
+                pci_read_irq_line(dev);
+                if (s7a_workaround) {
+                        if (dev->irq > 16) {
+                                dev->irq -= 3;
+                                pci_write_config_byte(dev, PCI_INTERRUPT_LINE,
+                                        dev->irq);
+                        }
+                }
+        }
+}
+
 static void __init pSeries_request_regions(void)
 {
         if (!isa_io_base)
@@ -89,20 +108,6 @@ static void __init pSeries_request_regions(void)
 
 void __init pSeries_final_fixup(void)
 {
-        struct pci_dev *dev = NULL;
-
-        check_s7a();
-
-        for_each_pci_dev(dev) {
-                pci_read_irq_line(dev);
-                if (s7a_workaround) {
-                        if (dev->irq > 16) {
-                                dev->irq -= 3;
-                                pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
-                        }
-                }
-        }
-
         phbs_remap_io();
         pSeries_request_regions();
 
diff --git a/arch/ppc64/kernel/pSeries_setup.c b/arch/ppc64/kernel/pSeries_setup.c
index 41e6de2c9158..f2b41243342c 100644
--- a/arch/ppc64/kernel/pSeries_setup.c
+++ b/arch/ppc64/kernel/pSeries_setup.c
@@ -71,8 +71,6 @@
 #define DBG(fmt...)
 #endif
 
-extern void pSeries_final_fixup(void);
-
 extern void find_udbg_vterm(void);
 extern void system_reset_fwnmi(void);   /* from head.S */
 extern void machine_check_fwnmi(void);  /* from head.S */
@@ -425,6 +423,7 @@ struct machdep_calls __initdata pSeries_md = {
         .get_cpuinfo            = pSeries_get_cpuinfo,
         .log_error              = pSeries_log_error,
         .pcibios_fixup          = pSeries_final_fixup,
+        .irq_bus_setup          = pSeries_irq_bus_setup,
         .restart                = rtas_restart,
         .power_off              = rtas_power_off,
         .halt                   = rtas_halt,
diff --git a/arch/ppc64/kernel/pci.c b/arch/ppc64/kernel/pci.c
index 2bf0513f3eca..580676f87d23 100644
--- a/arch/ppc64/kernel/pci.c
+++ b/arch/ppc64/kernel/pci.c
@@ -902,6 +902,9 @@ void __devinit pcibios_fixup_bus(struct pci_bus *bus)
         list_for_each_entry(dev, &bus->devices, bus_list)
                 ppc_md.iommu_dev_setup(dev);
 
+        if (ppc_md.irq_bus_setup)
+                ppc_md.irq_bus_setup(bus);
+
         if (!pci_probe_only)
                 return;
 
diff --git a/arch/ppc64/kernel/pci.h b/arch/ppc64/kernel/pci.h
index 0fd7d849aa77..26be78b13af1 100644
--- a/arch/ppc64/kernel/pci.h
+++ b/arch/ppc64/kernel/pci.h
@@ -40,10 +40,14 @@ struct device_node *fetch_dev_dn(struct pci_dev *dev);
 void pci_addr_cache_insert_device(struct pci_dev *dev);
 void pci_addr_cache_remove_device(struct pci_dev *dev);
 
-/* From pSeries_pci.h */
+/* From rtas_pci.h */
 void init_pci_config_tokens (void);
 unsigned long get_phb_buid (struct device_node *);
 
+/* From pSeries_pci.h */
+extern void pSeries_final_fixup(void);
+extern void pSeries_irq_bus_setup(struct pci_bus *bus);
+
 extern unsigned long pci_probe_only;
 extern unsigned long pci_assign_all_buses;
 extern int pci_read_irq_line(struct pci_dev *pci_dev);