[POWERPC] Celleb: bug fix caused by not casting pointer types

This fixes a bug caused by changes of pointer type in
commit f1fda89522c5aaa1bd4ef69605e85e6ee9c85faf.

hose->cfg_addr type is "volatile unsigned int __iomem *", so
"hose->cfg_addr + X" will not make an intended address.

This patch also adds comments for usage of cfg_addr and cfg_data in
pci_controller structure.  We use them in irregular way, and the
original code is short of explanations about them.

Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 61 insertions, 21 deletions

diff --git a/arch/powerpc/platforms/celleb/scc_epci.c b/arch/powerpc/platforms/celleb/scc_epci.c
index c11b39c3776a..fb23d53eb09c 100644
--- a/arch/powerpc/platforms/celleb/scc_epci.c
+++ b/arch/powerpc/platforms/celleb/scc_epci.c
@@ -43,11 +43,34 @@
 
 #define iob()  __asm__ __volatile__("eieio; sync":::"memory")
 
+static inline volatile void __iomem *celleb_epci_get_epci_base(
+                                        struct pci_controller *hose)
+{
+        /*
+         * Note:
+         * Celleb epci uses cfg_addr as a base address for
+         * epci control registers.
+         */
+
+        return hose->cfg_addr;
+}
+
+static inline volatile void __iomem *celleb_epci_get_epci_cfg(
+                                        struct pci_controller *hose)
+{
+        /*
+         * Note:
+         * Celleb epci uses cfg_data as a base address for
+         * configuration area for epci devices.
+         */
+
+        return hose->cfg_data;
+}
 
 #if 0 /* test code for epci dummy read */
 static void celleb_epci_dummy_read(struct pci_dev *dev)
 {
-        void __iomem *epci_base;
+        volatile void __iomem *epci_base;
         struct device_node *node;
         struct pci_controller *hose;
         u32 val;
@@ -58,7 +81,7 @@ static void celleb_epci_dummy_read(struct pci_dev *dev)
         if (!hose)
                 return;
 
-        epci_base = hose->cfg_addr;
+        epci_base = celleb_epci_get_epci_base(hose);
 
         val = in_be32(epci_base + SCC_EPCI_WATRP);
         iosync();
@@ -70,19 +93,20 @@ static void celleb_epci_dummy_read(struct pci_dev *dev)
 static inline void clear_and_disable_master_abort_interrupt(
                                         struct pci_controller *hose)
 {
-        void __iomem *addr;
-        addr = hose->cfg_addr + PCI_COMMAND;
-        out_be32(addr, in_be32(addr) | (PCI_STATUS_REC_MASTER_ABORT << 16));
+        volatile void __iomem *epci_base, *reg;
+        epci_base = celleb_epci_get_epci_base(hose);
+        reg = epci_base + PCI_COMMAND;
+        out_be32(reg, in_be32(reg) | (PCI_STATUS_REC_MASTER_ABORT << 16));
 }
 
 static int celleb_epci_check_abort(struct pci_controller *hose,
-                                   void __iomem *addr)
+                                   volatile void __iomem *addr)
 {
-        void __iomem *reg, *epci_base;
+        volatile void __iomem *reg, *epci_base;
         u32 val;
 
         iob();
-        epci_base = hose->cfg_addr;
+        epci_base = celleb_epci_get_epci_base(hose);
 
         reg = epci_base + PCI_COMMAND;
         val = in_be32(reg);
@@ -108,20 +132,21 @@ static int celleb_epci_check_abort(struct pci_controller *hose,
         return PCIBIOS_SUCCESSFUL;
 }
 
-static void __iomem *celleb_epci_make_config_addr(struct pci_controller *hose,
+static volatile void __iomem *celleb_epci_make_config_addr(
+                                        struct pci_controller *hose,
                                         unsigned int devfn, int where)
 {
-        void __iomem *addr;
+        volatile void __iomem *addr;
         struct pci_bus *bus = hose->bus;
 
         if (bus->self)
-                addr = hose->cfg_data +
+                addr = celleb_epci_get_epci_cfg(hose) +
                        (((bus->number & 0xff) << 16)
                         | ((devfn & 0xff) << 8)
                         | (where & 0xff)
                         | 0x01000000);
         else
-                addr = hose->cfg_data +
+                addr = celleb_epci_get_epci_cfg(hose) +
                        (((devfn & 0xff) << 8) | (where & 0xff));
 
         pr_debug("EPCI: config_addr = 0x%p\n", addr);
@@ -132,7 +157,7 @@ static void __iomem *celleb_epci_make_config_addr(struct pci_controller *hose,
 static int celleb_epci_read_config(struct pci_bus *bus,
                         unsigned int devfn, int where, int size, u32 * val)
 {
-        void __iomem *addr;
+        volatile void __iomem *epci_base, *addr;
         struct device_node *node;
         struct pci_controller *hose;
 
@@ -142,13 +167,14 @@ static int celleb_epci_read_config(struct pci_bus *bus,
         node = (struct device_node *)bus->sysdata;
         hose = pci_find_hose_for_OF_device(node);
 
-        if (!hose->cfg_data)
+        if (!celleb_epci_get_epci_cfg(hose))
                 return PCIBIOS_DEVICE_NOT_FOUND;
 
         if (bus->number == hose->first_busno && devfn == 0) {
                 /* EPCI controller self */
 
-                addr = hose->cfg_addr + where;
+                epci_base = celleb_epci_get_epci_base(hose);
+                addr = epci_base + where;
 
                 switch (size) {
                 case 1:
@@ -185,7 +211,7 @@ static int celleb_epci_read_config(struct pci_bus *bus,
         }
 
         pr_debug("EPCI: "
-                 "addr=0x%lx, devfn=0x%x, where=0x%x, size=0x%x, val=0x%x\n",
+                 "addr=0x%p, devfn=0x%x, where=0x%x, size=0x%x, val=0x%x\n",
                  addr, devfn, where, size, *val);
 
         return celleb_epci_check_abort(hose, NULL);
@@ -194,7 +220,7 @@ static int celleb_epci_read_config(struct pci_bus *bus,
 static int celleb_epci_write_config(struct pci_bus *bus,
                         unsigned int devfn, int where, int size, u32 val)
 {
-        void __iomem *addr;
+        volatile void __iomem *epci_base, *addr;
         struct device_node *node;
         struct pci_controller *hose;
 
@@ -204,13 +230,15 @@ static int celleb_epci_write_config(struct pci_bus *bus,
         node = (struct device_node *)bus->sysdata;
         hose = pci_find_hose_for_OF_device(node);
 
-        if (!hose->cfg_data)
+
+        if (!celleb_epci_get_epci_cfg(hose))
                 return PCIBIOS_DEVICE_NOT_FOUND;
 
         if (bus->number == hose->first_busno && devfn == 0) {
                 /* EPCI controller self */
 
-                addr = hose->cfg_addr + where;
+                epci_base = celleb_epci_get_epci_base(hose);
+                addr = epci_base + where;
 
                 switch (size) {
                 case 1:
@@ -258,10 +286,10 @@ struct pci_ops celleb_epci_ops = {
 static int __devinit celleb_epci_init(struct pci_controller *hose)
 {
         u32 val;
-        void __iomem *reg, *epci_base;
+        volatile void __iomem *reg, *epci_base;
         int hwres = 0;
 
-        epci_base = hose->cfg_addr;
+        epci_base = celleb_epci_get_epci_base(hose);
 
         /* PCI core reset(Internal bus and PCI clock) */
         reg = epci_base + SCC_EPCI_CKCTRL;
@@ -382,6 +410,18 @@ int __devinit celleb_setup_epci(struct device_node *node,
 
         pr_debug("PCI: celleb_setup_epci()\n");
 
+        /*
+         * Note:
+         * Celleb epci uses cfg_addr and cfg_data member of
+         * pci_controller structure in irregular way.
+         *
+         * cfg_addr is used to map for control registers of
+         * celleb epci.
+         *
+         * cfg_data is used for configuration area of devices
+         * on Celleb epci buses.
+         */
+
         if (of_address_to_resource(node, 0, &r))
                 goto error;
         hose->cfg_addr = ioremap(r.start, (r.end - r.start + 1));