ARM/PCI: Save MSI controller in pci_sys_data

Currently ARM associates an MSI controller with a PCI bus by defining
pcibios_add_bus() and using it to call a struct hw_pci.add_bus() method.
That method sets the struct pci_bus "msi" member.  That's unwieldy and
unnecessarily couples MSI with the PCI enumeration code.

On ARM, all devices under the same PCI host bridge share an MSI controller,
so add an msi_controller pointer to the struct pci_sys_data and implement
pcibios_msi_controller() to retrieve it.

This is a step toward moving the msi_controller pointer into the generic
struct pci_host_bridge.

[bhelgaas: changelog, take pci_dev instead of pci_bus]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 18 insertions, 0 deletions

diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h
index 7fc42784becb..8144d61e5693 100644
--- a/arch/arm/include/asm/mach/pci.h
+++ b/arch/arm/include/asm/mach/pci.h
@@ -22,6 +22,9 @@ struct hw_pci {
 #ifdef CONFIG_PCI_DOMAINS
         int             domain;
 #endif
+#ifdef CONFIG_PCI_MSI
+        struct msi_controller *msi_ctrl;
+#endif
         struct pci_ops  *ops;
         int             nr_controllers;
         void            **private_data;
@@ -47,6 +50,9 @@ struct pci_sys_data {
 #ifdef CONFIG_PCI_DOMAINS
         int             domain;
 #endif
+#ifdef CONFIG_PCI_MSI
+        struct msi_controller *msi_ctrl;
+#endif
         struct list_head node;
         int             busnr;          /* primary bus number                   */
         u64             mem_offset;     /* bus->cpu memory mapping offset       */
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 17a26c17f7f5..ff2be3a22e1d 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -18,6 +18,15 @@
 
 static int debug_pci;
 
+#ifdef CONFIG_PCI_MSI
+struct msi_controller *pcibios_msi_controller(struct pci_dev *dev)
+{
+        struct pci_sys_data *sysdata = dev->bus->sysdata;
+
+        return sysdata->msi_ctrl;
+}
+#endif
+
 /*
  * We can't use pci_get_device() here since we are
  * called from interrupt context.
@@ -471,6 +480,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 #ifdef CONFIG_PCI_DOMAINS
                 sys->domain  = hw->domain;
 #endif
+#ifdef CONFIG_PCI_MSI
+                sys->msi_ctrl = hw->msi_ctrl;
+#endif
                 sys->busnr   = busnr;
                 sys->swizzle = hw->swizzle;
                 sys->map_irq = hw->map_irq;