[IA64] hotplug/ia64: SN Hotplug Driver - SN Hotplug Driver code

This patch is the SGI hotplug driver and additional changes required for
the driver.  These modifications include changes to the SN io_init.c code
for memory management, the inclusion of new SAL calls to enable and disable
PCI slots, and a hotplug-style driver.

Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

8 files changed, 754 insertions, 50 deletions

diff --git a/arch/ia64/sn/kernel/io_init.c b/arch/ia64/sn/kernel/io_init.c
index 041c4be02b2a..a67f39e448cb 100644
--- a/arch/ia64/sn/kernel/io_init.c
+++ b/arch/ia64/sn/kernel/io_init.c
@@ -23,6 +23,14 @@
 
 nasid_t master_nasid = INVALID_NASID;   /* Partition Master */
 
+static struct list_head sn_sysdata_list;
+
+/* sysdata list struct */
+struct sysdata_el {
+        struct list_head entry;
+        void *sysdata;
+};
+
 struct slab_info {
         struct hubdev_info hubdev;
 };
@@ -137,23 +145,6 @@ sal_get_pcidev_info(u64 segment, u64 bus_number, u64 devfn, u64 pci_dev,
 }
 
 /*
- * sn_alloc_pci_sysdata() - This routine allocates a pci controller
- *      which is expected as the pci_dev and pci_bus sysdata by the Linux
- *      PCI infrastructure.
- */
-static inline struct pci_controller *sn_alloc_pci_sysdata(void)
-{
-        struct pci_controller *pci_sysdata;
-
-        pci_sysdata = kmalloc(sizeof(*pci_sysdata), GFP_KERNEL);
-        if (!pci_sysdata)
-                BUG();
-
-        memset(pci_sysdata, 0, sizeof(*pci_sysdata));
-        return pci_sysdata;
-}
-
-/*
  * sn_fixup_ionodes() - This routine initializes the HUB data strcuture for 
  *      each node in the system.
  */
@@ -220,6 +211,15 @@ static void sn_fixup_ionodes(void)
 
 }
 
+void sn_pci_unfixup_slot(struct pci_dev *dev)
+{
+        struct pci_dev *host_pci_dev = SN_PCIDEV_INFO(dev)->host_pci_dev;
+
+        sn_irq_unfixup(dev);
+        pci_dev_put(host_pci_dev);
+        pci_dev_put(dev);
+}
+
 /*
  * sn_pci_fixup_slot() - This routine sets up a slot's resources
  * consistent with the Linux PCI abstraction layer.  Resources acquired
@@ -238,6 +238,7 @@ void sn_pci_fixup_slot(struct pci_dev *dev)
         unsigned long size;
         unsigned int bus_no, devfn;
 
+        pci_dev_get(dev); /* for the sysdata pointer */
         dev->sysdata = kmalloc(sizeof(struct pcidev_info), GFP_KERNEL);
         if (SN_PCIDEV_INFO(dev) <= 0)
                 BUG();          /* Cannot afford to run out of memory */
@@ -276,7 +277,8 @@ void sn_pci_fixup_slot(struct pci_dev *dev)
                         dev->resource[idx].parent = &iomem_resource;
         }
 
-        /* Using the PROMs values for the PCI host bus, get the Linux
+        /*
+         * Using the PROMs values for the PCI host bus, get the Linux
          * PCI host_pci_dev struct and set up host bus linkages
          */
 
@@ -313,55 +315,57 @@ void sn_pci_fixup_slot(struct pci_dev *dev)
  * sn_pci_controller_fixup() - This routine sets up a bus's resources
  * consistent with the Linux PCI abstraction layer.
  */
-static void sn_pci_controller_fixup(int segment, int busnum)
+void sn_pci_controller_fixup(int segment, int busnum, struct pci_bus *bus)
 {
         int status = 0;
         int nasid, cnode;
-        struct pci_bus *bus;
         struct pci_controller *controller;
         struct pcibus_bussoft *prom_bussoft_ptr;
         struct hubdev_info *hubdev_info;
         void *provider_soft;
         struct sn_pcibus_provider *provider;
 
-        status =
-            sal_get_pcibus_info((u64) segment, (u64) busnum,
-                                (u64) ia64_tpa(&prom_bussoft_ptr));
-        if (status > 0) {
-                return;         /* bus # does not exist */
-        }
-
+        status = sal_get_pcibus_info((u64) segment, (u64) busnum,
+                                     (u64) ia64_tpa(&prom_bussoft_ptr));
+        if (status > 0)
+                return;         /*bus # does not exist */
         prom_bussoft_ptr = __va(prom_bussoft_ptr);
-        controller = sn_alloc_pci_sysdata();
-        /* controller non-zero is BUG'd in sn_alloc_pci_sysdata */
 
-        bus = pci_scan_bus(busnum, &pci_root_ops, controller);
+        controller = kcalloc(1,sizeof(struct pci_controller), GFP_KERNEL);
+        if (!controller)
+                BUG();
+
         if (bus == NULL) {
-                return;         /* error, or bus already scanned */
+                bus = pci_scan_bus(busnum, &pci_root_ops, controller);
+                if (bus == NULL)
+                        return; /* error, or bus already scanned */
+                bus->sysdata = NULL;
         }
 
+        if (bus->sysdata)
+                goto error_return; /* sysdata already alloc'd */
+
         /*
          * Per-provider fixup.  Copies the contents from prom to local
          * area and links SN_PCIBUS_BUSSOFT().
          */
 
-        if (prom_bussoft_ptr->bs_asic_type >= PCIIO_ASIC_MAX_TYPES) {
+        if (prom_bussoft_ptr->bs_asic_type >= PCIIO_ASIC_MAX_TYPES)
                 return;         /* unsupported asic type */
-        }
+
+        if (prom_bussoft_ptr->bs_asic_type == PCIIO_ASIC_TYPE_PPB)
+                goto error_return; /* no further fixup necessary */
 
         provider = sn_pci_provider[prom_bussoft_ptr->bs_asic_type];
-        if (provider == NULL) {
+        if (provider == NULL)
                 return;         /* no provider registerd for this asic */
-        }
 
         provider_soft = NULL;
-        if (provider->bus_fixup) {
+        if (provider->bus_fixup)
                 provider_soft = (*provider->bus_fixup) (prom_bussoft_ptr);
-        }
 
-        if (provider_soft == NULL) {
+        if (provider_soft == NULL)
                 return;         /* fixup failed or not applicable */
-        }
 
         /*
          * Generic bus fixup goes here.  Don't reference prom_bussoft_ptr
@@ -370,12 +374,47 @@ static void sn_pci_controller_fixup(int segment, int busnum)
 
         bus->sysdata = controller;
         PCI_CONTROLLER(bus)->platform_data = provider_soft;
-
         nasid = NASID_GET(SN_PCIBUS_BUSSOFT(bus)->bs_base);
         cnode = nasid_to_cnodeid(nasid);
         hubdev_info = (struct hubdev_info *)(NODEPDA(cnode)->pdinfo);
         SN_PCIBUS_BUSSOFT(bus)->bs_xwidget_info =
             &(hubdev_info->hdi_xwidget_info[SN_PCIBUS_BUSSOFT(bus)->bs_xid]);
+
+        return;
+
+error_return:
+
+        kfree(controller);
+        return;
+}
+
+void sn_bus_store_sysdata(struct pci_dev *dev)
+{
+        struct sysdata_el *element;
+
+        element = kcalloc(1, sizeof(struct sysdata_el), GFP_KERNEL);
+        if (!element) {
+                dev_dbg(dev, "%s: out of memory!\n", __FUNCTION__);
+                return;
+        }
+        element->sysdata = dev->sysdata;
+        list_add(&element->entry, &sn_sysdata_list);
+}
+
+void sn_bus_free_sysdata(void)
+{
+        struct sysdata_el *element;
+        struct list_head *list;
+
+sn_sysdata_free_start:
+        list_for_each(list, &sn_sysdata_list) {
+                element = list_entry(list, struct sysdata_el, entry);
+                list_del(&element->entry);
+                kfree(element->sysdata);
+                kfree(element);
+                goto sn_sysdata_free_start;
+        }
+        return;
 }
 
 /*
@@ -413,15 +452,16 @@ static int __init sn_pci_init(void)
         ia64_max_iommu_merge_mask = ~PAGE_MASK;
         sn_fixup_ionodes();
         sn_irq_lh_init();
+        INIT_LIST_HEAD(&sn_sysdata_list);
         sn_init_cpei_timer();
 
 #ifdef CONFIG_PROC_FS
         register_sn_procfs();
 #endif
 
-        for (i = 0; i < PCI_BUSES_TO_SCAN; i++) {
-                sn_pci_controller_fixup(0, i);
-        }
+        /* busses are not known yet ... */
+        for (i = 0; i < PCI_BUSES_TO_SCAN; i++)
+                sn_pci_controller_fixup(0, i, NULL);
 
         /*
          * Generic Linux PCI Layer has created the pci_bus and pci_dev 
@@ -430,9 +470,8 @@ static int __init sn_pci_init(void)
          */
 
         while ((pci_dev =
-                pci_find_device(PCI_ANY_ID, PCI_ANY_ID, pci_dev)) != NULL) {
+                pci_get_device(PCI_ANY_ID, PCI_ANY_ID, pci_dev)) != NULL)
                 sn_pci_fixup_slot(pci_dev);
-        }
 
         sn_ioif_inited = 1;     /* sn I/O infrastructure now initialized */
 
@@ -474,3 +513,8 @@ cnodeid_get_geoid(cnodeid_t cnode)
 }
 
 subsys_initcall(sn_pci_init);
+EXPORT_SYMBOL(sn_pci_fixup_slot);
+EXPORT_SYMBOL(sn_pci_unfixup_slot);
+EXPORT_SYMBOL(sn_pci_controller_fixup);
+EXPORT_SYMBOL(sn_bus_store_sysdata);
+EXPORT_SYMBOL(sn_bus_free_sysdata);
diff --git a/arch/ia64/sn/kernel/irq.c b/arch/ia64/sn/kernel/irq.c
index cf4dbf9645f1..84d276a14ecb 100644
--- a/arch/ia64/sn/kernel/irq.c
+++ b/arch/ia64/sn/kernel/irq.c
@@ -284,7 +284,6 @@ void sn_irq_fixup(struct pci_dev *pci_dev, struct sn_irq_info *sn_irq_info)
         int cpu = nasid_slice_to_cpuid(nasid, slice);
 
         pci_dev_get(pci_dev);
-
         sn_irq_info->irq_cpuid = cpu;
         sn_irq_info->irq_pciioinfo = SN_PCIDEV_INFO(pci_dev);
 
@@ -305,15 +304,16 @@ void sn_irq_unfixup(struct pci_dev *pci_dev)
                 return;
 
         sn_irq_info = SN_PCIDEV_INFO(pci_dev)->pdi_sn_irq_info;
-        if (!sn_irq_info || !sn_irq_info->irq_irq)
+        if (!sn_irq_info || !sn_irq_info->irq_irq) {
+                kfree(sn_irq_info);
                 return;
+        }
 
         unregister_intr_pda(sn_irq_info);
         spin_lock(&sn_irq_info_lock);
         list_del_rcu(&sn_irq_info->list);
         spin_unlock(&sn_irq_info_lock);
         call_rcu(&sn_irq_info->rcu, sn_irq_info_free);
-
         pci_dev_put(pci_dev);
 }
 
diff --git a/arch/ia64/sn/pci/pcibr/pcibr_provider.c b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
index 9bc4de4a3ec0..9813da56d311 100644
--- a/arch/ia64/sn/pci/pcibr/pcibr_provider.c
+++ b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
@@ -18,6 +18,40 @@
 #include "xtalk/xwidgetdev.h"
 #include "xtalk/hubdev.h"
 
+int
+sal_pcibr_slot_enable(struct pcibus_info *soft, int device, void *resp)
+{
+        struct ia64_sal_retval ret_stuff;
+        uint64_t busnum;
+
+        ret_stuff.status = 0;
+        ret_stuff.v0 = 0;
+
+        busnum = soft->pbi_buscommon.bs_persist_busnum;
+        SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_SLOT_ENABLE, (u64) busnum,
+                        (u64) device, (u64) resp, 0, 0, 0, 0);
+
+        return (int)ret_stuff.v0;
+}
+
+int
+sal_pcibr_slot_disable(struct pcibus_info *soft, int device, int action,
+                       void *resp)
+{
+        struct ia64_sal_retval ret_stuff;
+        uint64_t busnum;
+
+        ret_stuff.status = 0;
+        ret_stuff.v0 = 0;
+
+        busnum = soft->pbi_buscommon.bs_persist_busnum;
+        SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_SLOT_DISABLE,
+                        (u64) busnum, (u64) device, (u64) action,
+                        (u64) resp, 0, 0, 0);
+
+        return (int)ret_stuff.v0;
+}
+
 static int sal_pcibr_error_interrupt(struct pcibus_info *soft)
 {
         struct ia64_sal_retval ret_stuff;
@@ -187,3 +221,6 @@ pcibr_init_provider(void)
 
         return 0;
 }
+
+EXPORT_SYMBOL_GPL(sal_pcibr_slot_enable);
+EXPORT_SYMBOL_GPL(sal_pcibr_slot_disable);
diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
index 1a4d4ca2a4dc..9c4a39ee89b5 100644
--- a/drivers/pci/hotplug/Kconfig
+++ b/drivers/pci/hotplug/Kconfig
@@ -187,9 +187,10 @@ config HOTPLUG_PCI_RPA_DLPAR
 
 config HOTPLUG_PCI_SGI
         tristate "SGI PCI Hotplug Support"
-        depends on HOTPLUG_PCI && IA64_SGI_SN2
+        depends on HOTPLUG_PCI && (IA64_SGI_SN2 || IA64_GENERIC)
         help
-          Say Y here if you have an SGI IA64 Altix system.
+          Say Y here if you want to use the SGI Altix Hotplug
+          Driver for PCI devices.
 
           When in doubt, say N.
 
diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
index 3e632ff8c717..31a307004b94 100644
--- a/drivers/pci/hotplug/Makefile
+++ b/drivers/pci/hotplug/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_HOTPLUG_PCI_PCIE)		+= pciehp.o
 obj-$(CONFIG_HOTPLUG_PCI_SHPC)          += shpchp.o
 obj-$(CONFIG_HOTPLUG_PCI_RPA)           += rpaphp.o
 obj-$(CONFIG_HOTPLUG_PCI_RPA_DLPAR)     += rpadlpar_io.o
+obj-$(CONFIG_HOTPLUG_PCI_SGI)           += sgi_hotplug.o
 
 pci_hotplug-objs        :=      pci_hotplug_core.o
 
diff --git a/drivers/pci/hotplug/sgi_hotplug.c b/drivers/pci/hotplug/sgi_hotplug.c
new file mode 100644
index 000000000000..323041fd41dc
--- /dev/null
+++ b/drivers/pci/hotplug/sgi_hotplug.c
@@ -0,0 +1,611 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005 Silicon Graphics, Inc. All rights reserved.
+ *
+ * This work was based on the 2.4/2.6 kernel development by Dick Reigner.
+ * Work to add BIOS PROM support was completed by Mike Habeck.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/proc_fs.h>
+#include <linux/types.h>
+
+#include <asm/sn/addrs.h>
+#include <asm/sn/l1.h>
+#include <asm/sn/module.h>
+#include <asm/sn/pcibr_provider.h>
+#include <asm/sn/pcibus_provider_defs.h>
+#include <asm/sn/pcidev.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/types.h>
+
+#include "../pci.h"
+#include "pci_hotplug.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
+MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
+
+#define PCIIO_ASIC_TYPE_TIOCA     4
+#define PCI_SLOT_ALREADY_UP       2     /* slot already up */
+#define PCI_SLOT_ALREADY_DOWN     3     /* slot already down */
+#define PCI_L1_ERR                7     /* L1 console command error */
+#define PCI_EMPTY_33MHZ          15     /* empty 33 MHz bus */
+#define PCI_L1_QSIZE            128     /* our L1 message buffer size */
+#define SN_MAX_HP_SLOTS          32     /* max number of hotplug slots */
+#define SGI_HOTPLUG_PROM_REV    0x0420  /* Min. required PROM version */
+
+/* internal list head */
+static struct list_head sn_hp_list;
+
+/* hotplug_slot struct's private pointer */
+struct slot {
+        int device_num;
+        struct pci_bus *pci_bus;
+        /* this struct for glue internal only */
+        struct hotplug_slot *hotplug_slot;
+        struct list_head hp_list;
+};
+
+struct pcibr_slot_enable_resp {
+        int resp_sub_errno;
+        char resp_l1_msg[PCI_L1_QSIZE + 1];
+};
+
+struct pcibr_slot_disable_resp {
+        int resp_sub_errno;
+        char resp_l1_msg[PCI_L1_QSIZE + 1];
+};
+
+enum sn_pci_req_e {
+        PCI_REQ_SLOT_ELIGIBLE,
+        PCI_REQ_SLOT_DISABLE
+};
+
+static int enable_slot(struct hotplug_slot *slot);
+static int disable_slot(struct hotplug_slot *slot);
+static int get_power_status(struct hotplug_slot *slot, u8 *value);
+
+static struct hotplug_slot_ops sn_hotplug_slot_ops = {
+        .owner                  = THIS_MODULE,
+        .enable_slot            = enable_slot,
+        .disable_slot           = disable_slot,
+        .get_power_status       = get_power_status,
+};
+
+static DECLARE_MUTEX(sn_hotplug_sem);
+
+static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
+{
+        struct pcibus_info *pcibus_info;
+        int bricktype;
+        int bus_num;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
+
+        /* Check to see if this is a valid slot on 'pci_bus' */
+        if (!(pcibus_info->pbi_valid_devices & (1 << device)))
+                return -EPERM;
+
+        bricktype = MODULE_GET_BTYPE(pcibus_info->pbi_moduleid);
+        bus_num = pcibus_info->pbi_buscommon.bs_persist_busnum & 0xf;
+
+        /* Do not allow hotplug operations on base I/O cards */
+        if ((bricktype == L1_BRICKTYPE_IX ||  bricktype == L1_BRICKTYPE_IA) &&
+            (bus_num == 1 && device != 1))
+                return -EPERM;
+
+        return 1;
+}
+
+static int sn_pci_bus_valid(struct pci_bus *pci_bus)
+{
+        struct pcibus_info *pcibus_info;
+        int asic_type;
+        int bricktype;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
+
+        /* Don't register slots hanging off the TIOCA bus */
+        asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
+        if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
+                return -EPERM;
+
+        /* Only register slots in I/O Bricks that support hotplug */
+        bricktype = MODULE_GET_BTYPE(pcibus_info->pbi_moduleid);
+        switch (bricktype) {
+        case L1_BRICKTYPE_IX:
+        case L1_BRICKTYPE_PX:
+        case L1_BRICKTYPE_IA:
+        case L1_BRICKTYPE_PA:
+                return 1;
+                break;
+        default:
+                return -EPERM;
+                break;
+        }
+
+        return -EIO;
+}
+
+static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
+                                    struct pci_bus *pci_bus, int device)
+{
+        struct pcibus_info *pcibus_info;
+        struct slot *slot;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
+
+        bss_hotplug_slot->private = kcalloc(1, sizeof(struct slot),
+                                            GFP_KERNEL);
+        if (!bss_hotplug_slot->private)
+                return -ENOMEM;
+        slot = (struct slot *)bss_hotplug_slot->private;
+
+        bss_hotplug_slot->name = kmalloc(33, GFP_KERNEL);
+        if (!bss_hotplug_slot->name) {
+                kfree(bss_hotplug_slot->private);
+                return -ENOMEM;
+        }
+
+        slot->device_num = device;
+        slot->pci_bus = pci_bus;
+
+        sprintf(bss_hotplug_slot->name, "module_%c%c%c%c%.2d_b_%d_s_%d",
+                '0'+RACK_GET_CLASS(MODULE_GET_RACK(pcibus_info->pbi_moduleid)),
+                '0'+RACK_GET_GROUP(MODULE_GET_RACK(pcibus_info->pbi_moduleid)),
+                '0'+RACK_GET_NUM(MODULE_GET_RACK(pcibus_info->pbi_moduleid)),
+                MODULE_GET_BTCHAR(pcibus_info->pbi_moduleid),
+                MODULE_GET_BPOS(pcibus_info->pbi_moduleid),
+                ((int)pcibus_info->pbi_buscommon.bs_persist_busnum) & 0xf,
+                device + 1);
+
+        slot->hotplug_slot = bss_hotplug_slot;
+        list_add(&slot->hp_list, &sn_hp_list);
+
+        return 0;
+}
+
+static struct hotplug_slot * sn_hp_destroy(void)
+{
+        struct slot *slot;
+        struct list_head *list;
+        struct hotplug_slot *bss_hotplug_slot = NULL;
+
+        list_for_each(list, &sn_hp_list) {
+                slot = list_entry(list, struct slot, hp_list);
+                bss_hotplug_slot = slot->hotplug_slot;
+                list_del(&((struct slot *)bss_hotplug_slot->private)->
+                         hp_list);
+                break;
+        }
+        return bss_hotplug_slot;
+}
+
+static void sn_bus_alloc_data(struct pci_dev *dev)
+{
+        struct list_head *node;
+        struct pci_bus *subordinate_bus;
+        struct pci_dev *child;
+
+        sn_pci_fixup_slot(dev);
+
+        /* Recursively sets up the sn_irq_info structs */
+        if (dev->subordinate) {
+                subordinate_bus = dev->subordinate;
+                list_for_each(node, &subordinate_bus->devices) {
+                        child = list_entry(node, struct pci_dev, bus_list);
+                        sn_bus_alloc_data(child);
+                }
+        }
+}
+
+static void sn_bus_free_data(struct pci_dev *dev)
+{
+        struct list_head *node;
+        struct pci_bus *subordinate_bus;
+        struct pci_dev *child;
+
+        /* Recursively clean up sn_irq_info structs */
+        if (dev->subordinate) {
+                subordinate_bus = dev->subordinate;
+                list_for_each(node, &subordinate_bus->devices) {
+                        child = list_entry(node, struct pci_dev, bus_list);
+                        sn_bus_free_data(child);
+                }
+        }
+        sn_pci_unfixup_slot(dev);
+}
+
+static u8 sn_power_status_get(struct hotplug_slot *bss_hotplug_slot)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pcibus_info *pcibus_info;
+        u8 retval;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
+        retval = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
+
+        return retval ? 1 : 0;
+}
+
+static void sn_slot_mark_enable(struct hotplug_slot *bss_hotplug_slot,
+                                int device_num)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pcibus_info *pcibus_info;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
+        pcibus_info->pbi_enabled_devices |= (1 << device_num);
+}
+
+static void sn_slot_mark_disable(struct hotplug_slot *bss_hotplug_slot,
+                                 int device_num)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pcibus_info *pcibus_info;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
+        pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
+}
+
+static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
+                          int device_num)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pcibus_info *pcibus_info;
+        struct pcibr_slot_enable_resp resp;
+        int rc;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
+
+        /*
+         * Power-on and initialize the slot in the SN
+         * PCI infrastructure.
+         */
+        rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp);
+
+        if (rc == PCI_SLOT_ALREADY_UP) {
+                dev_dbg(slot->pci_bus->self, "is already active\n");
+                return -EPERM;
+        }
+
+        if (rc == PCI_L1_ERR) {
+                dev_dbg(slot->pci_bus->self,
+                        "L1 failure %d with message: %s",
+                        resp.resp_sub_errno, resp.resp_l1_msg);
+                return -EPERM;
+        }
+
+        if (rc) {
+                dev_dbg(slot->pci_bus->self,
+                        "insert failed with error %d sub-error %d\n",
+                        rc, resp.resp_sub_errno);
+                return -EIO;
+        }
+
+        sn_slot_mark_enable(bss_hotplug_slot, device_num);
+
+        return 0;
+}
+
+static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
+                           int device_num, int action)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pcibus_info *pcibus_info;
+        struct pcibr_slot_disable_resp resp;
+        int rc;
+
+        pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
+
+        rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
+
+        if (action == PCI_REQ_SLOT_ELIGIBLE && rc == PCI_SLOT_ALREADY_DOWN) {
+                dev_dbg(slot->pci_bus->self, "Slot %s already inactive\n");
+                return -ENODEV;
+        }
+
+        if (action == PCI_REQ_SLOT_ELIGIBLE && rc == PCI_EMPTY_33MHZ) {
+                dev_dbg(slot->pci_bus->self,
+                        "Cannot remove last 33MHz card\n");
+                return -EPERM;
+        }
+
+        if (action == PCI_REQ_SLOT_ELIGIBLE && rc == PCI_L1_ERR) {
+                dev_dbg(slot->pci_bus->self,
+                        "L1 failure %d with message \n%s\n",
+                        resp.resp_sub_errno, resp.resp_l1_msg);
+                return -EPERM;
+        }
+
+        if (action == PCI_REQ_SLOT_ELIGIBLE && rc) {
+                dev_dbg(slot->pci_bus->self,
+                        "remove failed with error %d sub-error %d\n",
+                        rc, resp.resp_sub_errno);
+                return -EIO;
+        }
+
+        if (action == PCI_REQ_SLOT_ELIGIBLE && !rc)
+                return 0;
+
+        if (action == PCI_REQ_SLOT_DISABLE && !rc) {
+                sn_slot_mark_disable(bss_hotplug_slot, device_num);
+                dev_dbg(slot->pci_bus->self, "remove successful\n");
+                return 0;
+        }
+
+        if (action == PCI_REQ_SLOT_DISABLE && rc) {
+                dev_dbg(slot->pci_bus->self,"remove failed rc = %d\n", rc);
+                return rc;
+        }
+
+        return rc;
+}
+
+static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pci_bus *new_bus = NULL;
+        struct pci_dev *dev;
+        int func, num_funcs;
+        int new_ppb = 0;
+        int rc;
+
+        /* Serialize the Linux PCI infrastructure */
+        down(&sn_hotplug_sem);
+
+        /*
+         * Power-on and initialize the slot in the SN
+         * PCI infrastructure.
+         */
+        rc = sn_slot_enable(bss_hotplug_slot, slot->device_num);
+        if (rc) {
+                up(&sn_hotplug_sem);
+                return rc;
+        }
+
+        num_funcs = pci_scan_slot(slot->pci_bus, PCI_DEVFN(slot->device_num+1,
+                                                           PCI_FUNC(0)));
+        if (!num_funcs) {
+                dev_dbg(slot->pci_bus->self, "no device in slot\n");
+                up(&sn_hotplug_sem);
+                return -ENODEV;
+        }
+
+        sn_pci_controller_fixup(pci_domain_nr(slot->pci_bus),
+                                slot->pci_bus->number,
+                                slot->pci_bus);
+        /*
+         * Map SN resources for all functions on the card
+         * to the Linux PCI interface and tell the drivers
+         * about them.
+         */
+        for (func = 0; func < num_funcs;  func++) {
+                dev = pci_get_slot(slot->pci_bus,
+                                   PCI_DEVFN(slot->device_num + 1,
+                                             PCI_FUNC(func)));
+
+
+                if (dev) {
+                        if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+                                unsigned char sec_bus;
+                                pci_read_config_byte(dev, PCI_SECONDARY_BUS,
+                                                     &sec_bus);
+                                new_bus = pci_add_new_bus(dev->bus, dev,
+                                                          sec_bus);
+                                pci_scan_child_bus(new_bus);
+                                sn_pci_controller_fixup(pci_domain_nr(new_bus),
+                                                        new_bus->number,
+                                                        new_bus);
+                                new_ppb = 1;
+                        }
+                        sn_bus_alloc_data(dev);
+                        pci_dev_put(dev);
+                }
+        }
+
+        /* Call the driver for the new device */
+        pci_bus_add_devices(slot->pci_bus);
+        /* Call the drivers for the new devices subordinate to PPB */
+        if (new_ppb)
+                pci_bus_add_devices(new_bus);
+
+        up(&sn_hotplug_sem);
+
+        if (rc == 0)
+                dev_dbg(slot->pci_bus->self,
+                        "insert operation successful\n");
+        else
+                dev_dbg(slot->pci_bus->self,
+                        "insert operation failed rc = %d\n", rc);
+
+        return rc;
+}
+
+static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
+{
+        struct slot *slot = (struct slot *)bss_hotplug_slot->private;
+        struct pci_dev *dev;
+        int func;
+        int rc;
+
+        /* Acquire update access to the bus */
+        down(&sn_hotplug_sem);
+
+        /* is it okay to bring this slot down? */
+        rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
+                             PCI_REQ_SLOT_ELIGIBLE);
+        if (rc)
+                goto leaving;
+
+        /* Free the SN resources assigned to the Linux device.*/
+        for (func = 0; func < 8;  func++) {
+                dev = pci_get_slot(slot->pci_bus,
+                                   PCI_DEVFN(slot->device_num+1,
+                                             PCI_FUNC(func)));
+                if (dev) {
+                        /*
+                         * Some drivers may use dma accesses during the
+                         * driver remove function. We release the sysdata
+                         * areas after the driver remove functions have
+                         * been called.
+                         */
+                        sn_bus_store_sysdata(dev);
+                        sn_bus_free_data(dev);
+                        pci_remove_bus_device(dev);
+                        pci_dev_put(dev);
+                }
+        }
+
+        /* free the collected sysdata pointers */
+        sn_bus_free_sysdata();
+
+        /* Deactivate slot */
+        rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
+                             PCI_REQ_SLOT_DISABLE);
+ leaving:
+        /* Release the bus lock */
+        up(&sn_hotplug_sem);
+
+        return rc;
+}
+
+static int get_power_status(struct hotplug_slot *bss_hotplug_slot, u8 *value)
+{
+        down(&sn_hotplug_sem);
+        *value = sn_power_status_get(bss_hotplug_slot);
+        up(&sn_hotplug_sem);
+        return 0;
+}
+
+static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
+{
+        kfree(bss_hotplug_slot->info);
+        kfree(bss_hotplug_slot->name);
+        kfree(bss_hotplug_slot->private);
+        kfree(bss_hotplug_slot);
+}
+
+static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
+{
+        int device;
+        struct hotplug_slot *bss_hotplug_slot;
+        int rc = 0;
+
+        /*
+         * Currently only four devices are supported,
+         * in the future there maybe more -- up to 32.
+         */
+
+        for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
+                if (sn_pci_slot_valid(pci_bus, device) != 1)
+                        continue;
+
+                bss_hotplug_slot = kcalloc(1,sizeof(struct hotplug_slot),
+                                           GFP_KERNEL);
+                if (!bss_hotplug_slot) {
+                        rc = -ENOMEM;
+                        goto alloc_err;
+                }
+
+                bss_hotplug_slot->info =
+                        kcalloc(1,sizeof(struct hotplug_slot_info),
+                                GFP_KERNEL);
+                if (!bss_hotplug_slot->info) {
+                        rc = -ENOMEM;
+                        goto alloc_err;
+                }
+
+                if (sn_hp_slot_private_alloc(bss_hotplug_slot,
+                                             pci_bus, device)) {
+                        rc = -ENOMEM;
+                        goto alloc_err;
+                }
+
+                bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
+                bss_hotplug_slot->release = &sn_release_slot;
+
+                rc = pci_hp_register(bss_hotplug_slot);
+                if (rc)
+                        goto register_err;
+        }
+        dev_dbg(pci_bus->self, "Registered bus with hotplug\n");
+        return rc;
+
+register_err:
+        dev_dbg(pci_bus->self, "bus failed to register with err = %d\n",
+                rc);
+
+alloc_err:
+        if (rc == -ENOMEM)
+                dev_dbg(pci_bus->self, "Memory allocation error\n");
+
+        /* destroy THIS element */
+        if (bss_hotplug_slot)
+                sn_release_slot(bss_hotplug_slot);
+
+        /* destroy anything else on the list */
+        while ((bss_hotplug_slot = sn_hp_destroy()))
+                pci_hp_deregister(bss_hotplug_slot);
+
+        return rc;
+}
+
+static int sn_pci_hotplug_init(void)
+{
+        struct pci_bus *pci_bus = NULL;
+        int rc;
+        int registered = 0;
+
+        INIT_LIST_HEAD(&sn_hp_list);
+
+        if (sn_sal_rev() < SGI_HOTPLUG_PROM_REV) {
+                printk(KERN_ERR "%s: PROM version must be greater than 4.05\n",
+                       __FUNCTION__);
+                return -EPERM;
+        }
+
+        while ((pci_bus = pci_find_next_bus(pci_bus))) {
+                if (!pci_bus->sysdata)
+                        continue;
+
+                rc = sn_pci_bus_valid(pci_bus);
+                if (rc != 1) {
+                        dev_dbg(pci_bus->self, "not a valid hotplug bus\n");
+                        continue;
+                }
+                dev_dbg(pci_bus->self, "valid hotplug bus\n");
+
+                rc = sn_hotplug_slot_register(pci_bus);
+                if (!rc)
+                        registered = 1;
+                else {
+                        registered = 0;
+                        break;
+                }
+        }
+
+        return registered == 1 ? 0 : -ENODEV;
+}
+
+static void sn_pci_hotplug_exit(void)
+{
+        struct hotplug_slot *bss_hotplug_slot;
+
+        while ((bss_hotplug_slot = sn_hp_destroy())) {
+                pci_hp_deregister(bss_hotplug_slot);
+        }
+
+        if (!list_empty(&sn_hp_list))
+                printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
+}
+
+module_init(sn_pci_hotplug_init);
+module_exit(sn_pci_hotplug_exit);
diff --git a/include/asm-ia64/sn/pcibr_provider.h b/include/asm-ia64/sn/pcibr_provider.h
index cbb4604c9349..2299c3ad2e33 100644
--- a/include/asm-ia64/sn/pcibr_provider.h
+++ b/include/asm-ia64/sn/pcibr_provider.h
@@ -151,4 +151,8 @@ extern void 		pcibr_change_devices_irq(struct sn_irq_info *sn_irq_info);
 extern int              pcibr_ate_alloc(struct pcibus_info *, int);
 extern void             pcibr_ate_free(struct pcibus_info *, int);
 extern void             ate_write(struct pcibus_info *, int, int, uint64_t);
+extern int sal_pcibr_slot_enable(struct pcibus_info *soft, int device,
+                                 void *resp);
+extern int sal_pcibr_slot_disable(struct pcibus_info *soft, int device,
+                                  int action, void *resp);
 #endif
diff --git a/include/asm-ia64/sn/pcidev.h b/include/asm-ia64/sn/pcidev.h
index 9610fcc63545..49711d00ad04 100644
--- a/include/asm-ia64/sn/pcidev.h
+++ b/include/asm-ia64/sn/pcidev.h
@@ -23,6 +23,8 @@
 #define SN_PCIBUS_BUSSOFT(pci_bus) \
         ((struct pcibus_bussoft *)(PCI_CONTROLLER((pci_bus))->platform_data))
 
+#define SN_PCIBUS_BUSSOFT_INFO(pci_bus) \
+        (struct pcibus_info *)((struct pcibus_bussoft *)(PCI_CONTROLLER((pci_bus))->platform_data))
 /*
  * Given a struct pci_dev, return the sn pcibus_bussoft struct.  Note
  * that this is not equivalent to SN_PCIBUS_BUSSOFT(pci_dev->bus) due
@@ -56,6 +58,10 @@ struct pcidev_info {
 extern void sn_irq_fixup(struct pci_dev *pci_dev,
                          struct sn_irq_info *sn_irq_info);
 extern void sn_irq_unfixup(struct pci_dev *pci_dev);
+extern void sn_pci_controller_fixup(int segment, int busnum,
+                                    struct pci_bus *bus);
+extern void sn_bus_store_sysdata(struct pci_dev *dev);
+extern void sn_bus_free_sysdata(void);
 extern void sn_pci_fixup_slot(struct pci_dev *dev);
 extern void sn_pci_unfixup_slot(struct pci_dev *dev);
 extern void sn_irq_lh_init(void);