ACPI: eviscerate pci_bind.c

Now that we can dynamically convert an ACPI CA handle to a
struct pci_dev at runtime, there's no need to statically bind
them during boot.

acpi_pci_bind/unbind are vastly simplified, and are only used
to evaluate _PRT methods on P2P bridges and non-bridge children.

This patch also changes the time-space tradeoff ever so slightly.

Looking up the ACPI-PCI binding is never in the performance path, and by
eliminating this caching, we save 24 bytes for each _ADR device in the
ACPI namespace.

This patch lays further groundwork to eventually eliminate
the acpi_driver_ops.bind callback.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

3 files changed, 39 insertions, 211 deletions

diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c
index c283c29662a7..703d2a3e8012 100644
--- a/drivers/acpi/pci_bind.c
+++ b/drivers/acpi/pci_bind.c
@@ -24,12 +24,7 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
 #include <linux/types.h>
-#include <linux/proc_fs.h>
-#include <linux/spinlock.h>
-#include <linux/pm.h>
 #include <linux/pci.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
@@ -111,238 +106,72 @@ EXPORT_SYMBOL(acpi_get_pci_id);
 
 static int acpi_pci_unbind(struct acpi_device *device)
 {
-        int result = 0;
-        acpi_status status;
-        struct acpi_pci_data *data;
-        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-
-
-        if (!device || !device->parent)
-                return -EINVAL;
-
-        status = acpi_get_name(device->handle, ACPI_FULL_PATHNAME, &buffer);
-        if (ACPI_FAILURE(status))
-                return -ENODEV;
-
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unbinding PCI device [%s]...\n",
-                          (char *) buffer.pointer));
-        kfree(buffer.pointer);
+        struct pci_dev *dev;
 
-        status =
-            acpi_get_data(device->handle, acpi_pci_data_handler,
-                          (void **)&data);
-        if (ACPI_FAILURE(status)) {
-                result = -ENODEV;
-                goto end;
-        }
+        dev = acpi_get_pci_dev(device->handle);
+        if (!dev)
+                return 0;
 
-        status = acpi_detach_data(device->handle, acpi_pci_data_handler);
-        if (ACPI_FAILURE(status)) {
-                ACPI_EXCEPTION((AE_INFO, status,
-                                "Unable to detach data from device %s",
-                                acpi_device_bid(device)));
-                result = -ENODEV;
-                goto end;
-        }
-        if (data->dev->subordinate) {
-                acpi_pci_irq_del_prt(data->id.segment, data->bus->number);
-        }
-        pci_dev_put(data->dev);
-        kfree(data);
+        if (dev->subordinate)
+                acpi_pci_irq_del_prt(pci_domain_nr(dev->bus),
+                                     dev->subordinate->number);
 
-      end:
-        return result;
+        pci_dev_put(dev);
+        return 0;
 }
 
 static int acpi_pci_bind(struct acpi_device *device)
 {
-        int result = 0;
         acpi_status status;
-        struct acpi_pci_data *data;
-        struct acpi_pci_data *pdata;
-        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
         acpi_handle handle;
+        unsigned char bus;
+        struct pci_dev *dev;
 
-        if (!device || !device->parent)
-                return -EINVAL;
-
-        data = kzalloc(sizeof(struct acpi_pci_data), GFP_KERNEL);
-        if (!data)
-                return -ENOMEM;
-
-        status = acpi_get_name(device->handle, ACPI_FULL_PATHNAME, &buffer);
-        if (ACPI_FAILURE(status)) {
-                kfree(data);
-                return -ENODEV;
-        }
-
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Binding PCI device [%s]...\n",
-                          (char *)buffer.pointer));
-
-        /* 
-         * Segment & Bus
-         * -------------
-         * These are obtained via the parent device's ACPI-PCI context.
-         */
-        status = acpi_get_data(device->parent->handle, acpi_pci_data_handler,
-                               (void **)&pdata);
-        if (ACPI_FAILURE(status) || !pdata || !pdata->bus) {
-                ACPI_EXCEPTION((AE_INFO, status,
-                                "Invalid ACPI-PCI context for parent device %s",
-                                acpi_device_bid(device->parent)));
-                result = -ENODEV;
-                goto end;
-        }
-        data->id.segment = pdata->id.segment;
-        data->id.bus = pdata->bus->number;
-
-        /*
-         * Device & Function
-         * -----------------
-         * These are simply obtained from the device's _ADR method.  Note
-         * that a value of zero is valid.
-         */
-        data->id.device = device->pnp.bus_address >> 16;
-        data->id.function = device->pnp.bus_address & 0xFFFF;
-
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "...to %04x:%02x:%02x.%d\n",
-                          data->id.segment, data->id.bus, data->id.device,
-                          data->id.function));
-
-        /*
-         * TBD: Support slot devices (e.g. function=0xFFFF).
-         */
-
-        /* 
-         * Locate PCI Device
-         * -----------------
-         * Locate matching device in PCI namespace.  If it doesn't exist
-         * this typically means that the device isn't currently inserted
-         * (e.g. docking station, port replicator, etc.).
-         */
-        data->dev = pci_get_slot(pdata->bus,
-                                PCI_DEVFN(data->id.device, data->id.function));
-        if (!data->dev) {
-                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                  "Device %04x:%02x:%02x.%d not present in PCI namespace\n",
-                                  data->id.segment, data->id.bus,
-                                  data->id.device, data->id.function));
-                result = -ENODEV;
-                goto end;
-        }
-        if (!data->dev->bus) {
-                printk(KERN_ERR PREFIX
-                            "Device %04x:%02x:%02x.%d has invalid 'bus' field\n",
-                            data->id.segment, data->id.bus,
-                            data->id.device, data->id.function);
-                result = -ENODEV;
-                goto end;
-        }
+        dev = acpi_get_pci_dev(device->handle);
+        if (!dev)
+                return 0;
 
         /*
-         * PCI Bridge?
-         * -----------
-         * If so, set the 'bus' field and install the 'bind' function to 
-         * facilitate callbacks for all of its children.
+         * Install the 'bind' function to facilitate callbacks for
+         * children of the P2P bridge.
          */
-        if (data->dev->subordinate) {
+        if (dev->subordinate) {
                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                                   "Device %04x:%02x:%02x.%d is a PCI bridge\n",
-                                  data->id.segment, data->id.bus,
-                                  data->id.device, data->id.function));
-                data->bus = data->dev->subordinate;
+                                  pci_domain_nr(dev->bus), dev->bus->number,
+                                  PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)));
                 device->ops.bind = acpi_pci_bind;
                 device->ops.unbind = acpi_pci_unbind;
         }
 
         /*
-         * Attach ACPI-PCI Context
-         * -----------------------
-         * Thus binding the ACPI and PCI devices.
-         */
-        status = acpi_attach_data(device->handle, acpi_pci_data_handler, data);
-        if (ACPI_FAILURE(status)) {
-                ACPI_EXCEPTION((AE_INFO, status,
-                                "Unable to attach ACPI-PCI context to device %s",
-                                acpi_device_bid(device)));
-                result = -ENODEV;
-                goto end;
-        }
-
-        /*
-         * PCI Routing Table
-         * -----------------
-         * Evaluate and parse _PRT, if exists.  This code is independent of 
-         * PCI bridges (above) to allow parsing of _PRT objects within the
-         * scope of non-bridge devices.  Note that _PRTs within the scope of
-         * a PCI bridge assume the bridge's subordinate bus number.
+         * Evaluate and parse _PRT, if exists.  This code allows parsing of
+         * _PRT objects within the scope of non-bridge devices.  Note that
+         * _PRTs within the scope of a PCI bridge assume the bridge's
+         * subordinate bus number.
          *
          * TBD: Can _PRTs exist within the scope of non-bridge PCI devices?
          */
         status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
-        if (ACPI_SUCCESS(status)) {
-                if (data->bus)  /* PCI-PCI bridge */
-                        acpi_pci_irq_add_prt(device->handle, data->id.segment,
-                                             data->bus->number);
-                else            /* non-bridge PCI device */
-                        acpi_pci_irq_add_prt(device->handle, data->id.segment,
-                                             data->id.bus);
-        }
-
-      end:
-        kfree(buffer.pointer);
-        if (result) {
-                pci_dev_put(data->dev);
-                kfree(data);
-        }
-        return result;
-}
+        if (ACPI_FAILURE(status))
+                goto out;
 
-int
-acpi_pci_bind_root(struct acpi_device *device,
-                   struct acpi_pci_id *id, struct pci_bus *bus)
-{
-        int result = 0;
-        acpi_status status;
-        struct acpi_pci_data *data = NULL;
-        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+        if (dev->subordinate)
+                bus = dev->subordinate->number;
+        else
+                bus = dev->bus->number;
 
-        if (!device || !id || !bus) {
-                return -EINVAL;
-        }
+        acpi_pci_irq_add_prt(device->handle, pci_domain_nr(dev->bus), bus);
 
-        data = kzalloc(sizeof(struct acpi_pci_data), GFP_KERNEL);
-        if (!data)
-                return -ENOMEM;
+out:
+        pci_dev_put(dev);
+        return 0;
+}
 
-        data->id = *id;
-        data->bus = bus;
+int acpi_pci_bind_root(struct acpi_device *device)
+{
         device->ops.bind = acpi_pci_bind;
         device->ops.unbind = acpi_pci_unbind;
 
-        status = acpi_get_name(device->handle, ACPI_FULL_PATHNAME, &buffer);
-        if (ACPI_FAILURE(status)) {
-                kfree (data);
-                return -ENODEV;
-        }
-
-        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Binding PCI root bridge [%s] to "
-                        "%04x:%02x\n", (char *)buffer.pointer,
-                        id->segment, id->bus));
-
-        status = acpi_attach_data(device->handle, acpi_pci_data_handler, data);
-        if (ACPI_FAILURE(status)) {
-                ACPI_EXCEPTION((AE_INFO, status,
-                                "Unable to attach ACPI-PCI context to device %s",
-                                (char *)buffer.pointer));
-                result = -ENODEV;
-                goto end;
-        }
-
-      end:
-        kfree(buffer.pointer);
-        if (result != 0)
-                kfree(data);
-
-        return result;
+        return 0;
 }
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index e5099919e574..f23fcc5c9674 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -603,7 +603,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
          * -----------------------
          * Thus binding the ACPI and PCI devices.
          */
-        result = acpi_pci_bind_root(device, &root->id, root->bus);
+        result = acpi_pci_bind_root(device);
         if (result)
                 goto end;
 
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index dbe3989952ee..2740a2894837 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -100,8 +100,7 @@ struct pci_bus;
 
 struct pci_dev *acpi_get_pci_dev(acpi_handle);
 acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id);
-int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id,
-                       struct pci_bus *bus);
+int acpi_pci_bind_root(struct acpi_device *device);
 
 /* Arch-defined function to add a bus to the system */