sgi-xp: prepare xpc_rsvd_page to work on either sn2 or uv hardware

Prepare XPC's reserved page header to work for either sn2 or uv.

Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 267 insertions, 133 deletions

diff --git a/drivers/misc/sgi-xp/Makefile b/drivers/misc/sgi-xp/Makefile
index b50f2921781..b3eeff31ebf 100644
--- a/drivers/misc/sgi-xp/Makefile
+++ b/drivers/misc/sgi-xp/Makefile
@@ -7,6 +7,7 @@ xp-y				:= xp_main.o xp_uv.o
 xp-$(CONFIG_IA64)               += xp_sn2.o xp_nofault.o
 
 obj-$(CONFIG_SGI_XP)            += xpc.o
-xpc-y                           := xpc_main.o xpc_channel.o xpc_partition.o
+xpc-y                           := xpc_main.o xpc_uv.o xpc_channel.o xpc_partition.o
+xpc-$(CONFIG_IA64)              += xpc_sn2.o
 
 obj-$(CONFIG_SGI_XP)            += xpnet.o
diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h
index c42196a1a6b..0f75592896d 100644
--- a/drivers/misc/sgi-xp/xp.h
+++ b/drivers/misc/sgi-xp/xp.h
@@ -220,9 +220,10 @@ enum xp_retval {
 
         xpBteCopyError,         /* 52: bte_copy() returned error */
         xpSalError,             /* 53: sn SAL error */
+        xpRsvdPageNotSet,       /* 54: the reserved page is not set up */
 
-        xpUnsupported,          /* 54: unsupported functionality or resource */
-        xpUnknownReason         /* 55: unknown reason - must be last in enum */
+        xpUnsupported,          /* 55: unsupported functionality or resource */
+        xpUnknownReason         /* 56: unknown reason - must be last in enum */
 };
 
 /*
diff --git a/drivers/misc/sgi-xp/xpc.h b/drivers/misc/sgi-xp/xpc.h
index 60388bed770..94b52bb8151 100644
--- a/drivers/misc/sgi-xp/xpc.h
+++ b/drivers/misc/sgi-xp/xpc.h
@@ -71,11 +71,11 @@
  *
  *   reserved page header
  *
- *     The first cacheline of the reserved page contains the header
- *     (struct xpc_rsvd_page). Before SAL initialization has completed,
+ *     The first two 64-byte cachelines of the reserved page contain the
+ *     header (struct xpc_rsvd_page). Before SAL initialization has completed,
  *     SAL has set up the following fields of the reserved page header:
- *     SAL_signature, SAL_version, partid, and nasids_size. The other
- *     fields are set up by XPC. (xpc_rsvd_page points to the local
+ *     SAL_signature, SAL_version, SAL_partid, and SAL_nasids_size. The
+ *     other fields are set up by XPC. (xpc_rsvd_page points to the local
  *     partition's reserved page.)
  *
  *   part_nasids mask
@@ -89,11 +89,11 @@
  *     nasids. The part_nasids mask is located starting at the first cacheline
  *     following the reserved page header. The mach_nasids mask follows right
  *     after the part_nasids mask. The size in bytes of each mask is reflected
- *     by the reserved page header field 'nasids_size'. (Local partition's
+ *     by the reserved page header field 'SAL_nasids_size'. (Local partition's
  *     mask pointers are xpc_part_nasids and xpc_mach_nasids.)
  *
- *   vars
- *   vars part
+ *   vars       (ia64-sn2 only)
+ *   vars part  (ia64-sn2 only)
  *
  *     Immediately following the mach_nasids mask are the XPC variables
  *     required by other partitions. First are those that are generic to all
@@ -101,25 +101,31 @@
  *     which are partition specific (vars part). These are setup by XPC.
  *     (Local partition's vars pointers are xpc_vars and xpc_vars_part.)
  *
- * Note: Until vars_pa is set, the partition XPC code has not been initialized.
+ * Note: Until 'stamp' is set non-zero, the partition XPC code has not been
+ *       initialized.
  */
 struct xpc_rsvd_page {
         u64 SAL_signature;      /* SAL: unique signature */
         u64 SAL_version;        /* SAL: version */
-        u8 partid;              /* SAL: partition ID */
+        short SAL_partid;       /* SAL: partition ID */
+        short max_npartitions;  /* value of XPC_MAX_PARTITIONS */
         u8 version;
-        u8 pad1[6];             /* align to next u64 in cacheline */
-        u64 vars_pa;            /* physical address of struct xpc_vars */
+        u8 pad1[3];             /* align to next u64 in 1st 64-byte cacheline */
+        union {
+                u64 vars_pa;    /* physical address of struct xpc_vars */
+                u64 activate_mq_gpa;    /* global phys address of activate_mq */
+        } sn;
         struct timespec stamp;  /* time when reserved page was setup by XPC */
-        u64 pad2[9];            /* align to last u64 in cacheline */
-        u64 nasids_size;        /* SAL: size of each nasid mask in bytes */
+        u64 pad2[9];            /* align to last u64 in 2nd 64-byte cacheline */
+        u64 SAL_nasids_size;    /* SAL: size of each nasid mask in bytes */
 };
 
-#define XPC_RP_VERSION _XPC_VERSION(1, 1) /* version 1.1 of the reserved page */
+#define XPC_RP_VERSION _XPC_VERSION(2, 0) /* version 2.0 of the reserved page */
 
 #define XPC_SUPPORTS_RP_STAMP(_version) \
                         (_version >= _XPC_VERSION(1, 1))
 
+#define ZERO_STAMP      ((struct timespec){0, 0})
 /*
  * compare stamps - the return value is:
  *
@@ -218,10 +224,10 @@ xpc_disallow_hb(short partid, struct xpc_vars *vars)
  *
  * An array of these structures, one per partition, will be defined. As a
  * partition becomes active XPC will copy the array entry corresponding to
- * itself from that partition. It is desirable that the size of this
- * structure evenly divide into a cacheline, such that none of the entries
- * in this array crosses a cacheline boundary. As it is now, each entry
- * occupies half a cacheline.
+ * itself from that partition. It is desirable that the size of this structure
+ * evenly divides into a 128-byte cacheline, such that none of the entries in
+ * this array crosses a 128-byte cacheline boundary. As it is now, each entry
+ * occupies a 64-byte cacheline.
  */
 struct xpc_vars_part {
         u64 magic;
@@ -632,16 +638,25 @@ extern void xpc_activate_kthreads(struct xpc_channel *, int);
 extern void xpc_create_kthreads(struct xpc_channel *, int, int);
 extern void xpc_disconnect_wait(int);
 
+extern enum xp_retval (*xpc_rsvd_page_init) (struct xpc_rsvd_page *);
+
+/* found in xpc_sn2.c */
+extern void xpc_init_sn2(void);
+extern struct xpc_vars *xpc_vars;               /*>>> eliminate from here */
+extern struct xpc_vars_part *xpc_vars_part;     /*>>> eliminate from here */
+
+/* found in xpc_uv.c */
+extern void xpc_init_uv(void);
+
 /* found in xpc_partition.c */
 extern int xpc_exiting;
-extern struct xpc_vars *xpc_vars;
+extern int xp_nasid_mask_words;
 extern struct xpc_rsvd_page *xpc_rsvd_page;
-extern struct xpc_vars_part *xpc_vars_part;
 extern struct xpc_partition *xpc_partitions;
 extern char *xpc_remote_copy_buffer;
 extern void *xpc_remote_copy_buffer_base;
 extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **);
-extern struct xpc_rsvd_page *xpc_rsvd_page_init(void);
+extern struct xpc_rsvd_page *xpc_setup_rsvd_page(void);
 extern void xpc_allow_IPI_ops(void);
 extern void xpc_restrict_IPI_ops(void);
 extern int xpc_identify_act_IRQ_sender(void);
diff --git a/drivers/misc/sgi-xp/xpc_main.c b/drivers/misc/sgi-xp/xpc_main.c
index a05c7c7da22..2180f1f7e08 100644
--- a/drivers/misc/sgi-xp/xpc_main.c
+++ b/drivers/misc/sgi-xp/xpc_main.c
@@ -175,6 +175,8 @@ static struct notifier_block xpc_die_notifier = {
         .notifier_call = xpc_system_die,
 };
 
+enum xp_retval (*xpc_rsvd_page_init) (struct xpc_rsvd_page *rp);
+
 /*
  * Timer function to enforce the timelimit on the partition disengage request.
  */
@@ -949,7 +951,7 @@ xpc_do_exit(enum xp_retval reason)
         DBUG_ON(xpc_partition_engaged(-1UL));
 
         /* indicate to others that our reserved page is uninitialized */
-        xpc_rsvd_page->vars_pa = 0;
+        xpc_rsvd_page->stamp = ZERO_STAMP;
 
         /* now it's time to eliminate our heartbeat */
         del_timer_sync(&xpc_hb_timer);
@@ -1128,8 +1130,24 @@ xpc_init(void)
         struct task_struct *kthread;
         size_t buf_size;
 
-        if (!ia64_platform_is("sn2"))
+        if (is_shub()) {
+                /*
+                 * The ia64-sn2 architecture supports at most 64 partitions.
+                 * And the inability to unregister remote AMOs restricts us
+                 * further to only support exactly 64 partitions on this
+                 * architecture, no less.
+                 */
+                if (xp_max_npartitions != 64)
+                        return -EINVAL;
+
+                xpc_init_sn2();
+
+        } else if (is_uv()) {
+                xpc_init_uv();
+
+        } else {
                 return -ENODEV;
+        }
 
         snprintf(xpc_part->bus_id, BUS_ID_SIZE, "part");
         snprintf(xpc_chan->bus_id, BUS_ID_SIZE, "chan");
@@ -1214,7 +1232,7 @@ xpc_init(void)
          * other partitions to discover we are alive and establish initial
          * communications.
          */
-        xpc_rsvd_page = xpc_rsvd_page_init();
+        xpc_rsvd_page = xpc_setup_rsvd_page();
         if (xpc_rsvd_page == NULL) {
                 dev_err(xpc_part, "can't setup our reserved page\n");
                 ret = -EBUSY;
@@ -1273,7 +1291,8 @@ xpc_init(void)
         /* initialization was not successful */
 out_4:
         /* indicate to others that our reserved page is uninitialized */
-        xpc_rsvd_page->vars_pa = 0;
+        xpc_rsvd_page->stamp = ZERO_STAMP;
+
         del_timer_sync(&xpc_hb_timer);
         (void)unregister_die_notifier(&xpc_die_notifier);
         (void)unregister_reboot_notifier(&xpc_reboot_notifier);
diff --git a/drivers/misc/sgi-xp/xpc_partition.c b/drivers/misc/sgi-xp/xpc_partition.c
index 6c82f205097..1db84cb4914 100644
--- a/drivers/misc/sgi-xp/xpc_partition.c
+++ b/drivers/misc/sgi-xp/xpc_partition.c
@@ -20,7 +20,6 @@
 #include <linux/cache.h>
 #include <linux/mmzone.h>
 #include <linux/nodemask.h>
-#include <asm/uncached.h>
 #include <asm/sn/intr.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/nodepda.h>
@@ -44,11 +43,10 @@ u64 xpc_prot_vec[MAX_NUMNODES];
 struct xpc_rsvd_page *xpc_rsvd_page;
 static u64 *xpc_part_nasids;
 static u64 *xpc_mach_nasids;
-struct xpc_vars *xpc_vars;
-struct xpc_vars_part *xpc_vars_part;
 
-static int xp_nasid_mask_bytes; /* actual size in bytes of nasid mask */
-static int xp_nasid_mask_words; /* actual size in words of nasid mask */
+/* >>> next two variables should be 'xpc_' if they remain here */
+static int xp_sizeof_nasid_mask;        /* actual size in bytes of nasid mask */
+int xp_nasid_mask_words;        /* actual size in words of nasid mask */
 
 struct xpc_partition *xpc_partitions;
 
@@ -150,12 +148,10 @@ xpc_get_rsvd_page_pa(int nasid)
  * communications.
  */
 struct xpc_rsvd_page *
-xpc_rsvd_page_init(void)
+xpc_setup_rsvd_page(void)
 {
         struct xpc_rsvd_page *rp;
-        AMO_t *amos_page;
-        u64 rp_pa, nasid_array = 0;
-        int i, ret;
+        u64 rp_pa;
 
         /* get the local reserved page's address */
 
@@ -168,110 +164,44 @@ xpc_rsvd_page_init(void)
         }
         rp = (struct xpc_rsvd_page *)__va(rp_pa);
 
-        if (rp->partid != sn_partition_id) {
-                dev_err(xpc_part, "the reserved page's partid of %d should be "
-                        "%d\n", rp->partid, sn_partition_id);
+        if (rp->SAL_version < 3) {
+                /* SAL_versions < 3 had a SAL_partid defined as a u8 */
+                rp->SAL_partid &= 0xff;
+        }
+        BUG_ON(rp->SAL_partid != sn_partition_id);
+
+        if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
+                dev_err(xpc_part, "the reserved page's partid of %d is outside "
+                        "supported range (< 0 || >= %d)\n", rp->SAL_partid,
+                        xp_max_npartitions);
                 return NULL;
         }
 
         rp->version = XPC_RP_VERSION;
+        rp->max_npartitions = xp_max_npartitions;
 
         /* establish the actual sizes of the nasid masks */
         if (rp->SAL_version == 1) {
                 /* SAL_version 1 didn't set the nasids_size field */
-                rp->nasids_size = 128;
+                rp->SAL_nasids_size = 128;
         }
-        xp_nasid_mask_bytes = rp->nasids_size;
-        xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
+        xp_sizeof_nasid_mask = rp->SAL_nasids_size;
+        xp_nasid_mask_words = DIV_ROUND_UP(xp_sizeof_nasid_mask,
+                                           BYTES_PER_WORD);
 
         /* setup the pointers to the various items in the reserved page */
         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
-        xpc_vars = XPC_RP_VARS(rp);
-        xpc_vars_part = XPC_RP_VARS_PART(rp);
 
-        /*
-         * Before clearing xpc_vars, see if a page of AMOs had been previously
-         * allocated. If not we'll need to allocate one and set permissions
-         * so that cross-partition AMOs are allowed.
-         *
-         * The allocated AMO page needs MCA reporting to remain disabled after
-         * XPC has unloaded.  To make this work, we keep a copy of the pointer
-         * to this page (i.e., amos_page) in the struct xpc_vars structure,
-         * which is pointed to by the reserved page, and re-use that saved copy
-         * on subsequent loads of XPC. This AMO page is never freed, and its
-         * memory protections are never restricted.
-         */
-        amos_page = xpc_vars->amos_page;
-        if (amos_page == NULL) {
-                amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0, 1));
-                if (amos_page == NULL) {
-                        dev_err(xpc_part, "can't allocate page of AMOs\n");
-                        return NULL;
-                }
-
-                /*
-                 * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
-                 * when xpc_allow_IPI_ops() is called via xpc_hb_init().
-                 */
-                if (!enable_shub_wars_1_1()) {
-                        ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
-                                                   PAGE_SIZE,
-                                                   SN_MEMPROT_ACCESS_CLASS_1,
-                                                   &nasid_array);
-                        if (ret != 0) {
-                                dev_err(xpc_part, "can't change memory "
-                                        "protections\n");
-                                uncached_free_page(__IA64_UNCACHED_OFFSET |
-                                                   TO_PHYS((u64)amos_page), 1);
-                                return NULL;
-                        }
-                }
-        } else if (!IS_AMO_ADDRESS((u64)amos_page)) {
-                /*
-                 * EFI's XPBOOT can also set amos_page in the reserved page,
-                 * but it happens to leave it as an uncached physical address
-                 * and we need it to be an uncached virtual, so we'll have to
-                 * convert it.
-                 */
-                if (!IS_AMO_PHYS_ADDRESS((u64)amos_page)) {
-                        dev_err(xpc_part, "previously used amos_page address "
-                                "is bad = 0x%p\n", (void *)amos_page);
-                        return NULL;
-                }
-                amos_page = (AMO_t *)TO_AMO((u64)amos_page);
-        }
-
-        /* clear xpc_vars */
-        memset(xpc_vars, 0, sizeof(struct xpc_vars));
-
-        xpc_vars->version = XPC_V_VERSION;
-        xpc_vars->act_nasid = cpuid_to_nasid(0);
-        xpc_vars->act_phys_cpuid = cpu_physical_id(0);
-        xpc_vars->vars_part_pa = __pa(xpc_vars_part);
-        xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
-        xpc_vars->amos_page = amos_page;        /* save for next load of XPC */
-
-        /* clear xpc_vars_part */
-        memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
-               xp_max_npartitions);
-
-        /* initialize the activate IRQ related AMO variables */
-        for (i = 0; i < xp_nasid_mask_words; i++)
-                (void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
-
-        /* initialize the engaged remote partitions related AMO variables */
-        (void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
-        (void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
-
-        /* timestamp of when reserved page was setup by XPC */
-        rp->stamp = CURRENT_TIME;
+        if (xpc_rsvd_page_init(rp) != xpSuccess)
+                return NULL;
 
         /*
+         * Set timestamp of when reserved page was setup by XPC.
          * This signifies to the remote partition that our reserved
          * page is initialized.
          */
-        rp->vars_pa = __pa(xpc_vars);
+        rp->stamp = CURRENT_TIME;
 
         return rp;
 }
@@ -465,7 +395,7 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 
         /* pull over the reserved page header and part_nasids mask */
         ret = xp_remote_memcpy(remote_rp, (void *)*remote_rp_pa,
-                               XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes);
+                               XPC_RP_HEADER_SIZE + xp_sizeof_nasid_mask);
         if (ret != xpSuccess)
                 return ret;
 
@@ -476,19 +406,28 @@ xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
                         discovered_nasids[i] |= remote_part_nasids[i];
         }
 
-        /* check that the partid is for another partition */
+        /* check that the partid is valid and is for another partition */
 
-        if (remote_rp->partid < 0 || remote_rp->partid >= xp_max_npartitions)
+        if (remote_rp->SAL_partid < 0 ||
+            remote_rp->SAL_partid >= xp_max_npartitions) {
                 return xpInvalidPartid;
+        }
 
-        if (remote_rp->partid == sn_partition_id)
+        if (remote_rp->SAL_partid == sn_partition_id)
                 return xpLocalPartid;
 
+        /* see if the rest of the reserved page has been set up by XPC */
+        if (timespec_equal(&remote_rp->stamp, &ZERO_STAMP))
+                return xpRsvdPageNotSet;
+
         if (XPC_VERSION_MAJOR(remote_rp->version) !=
             XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
                 return xpBadVersion;
         }
 
+        if (remote_rp->max_npartitions <= sn_partition_id)
+                return xpInvalidPartid;
+
         return xpSuccess;
 }
 
@@ -592,7 +531,7 @@ xpc_identify_act_IRQ_req(int nasid)
         int remote_rp_version;
         int reactivate = 0;
         int stamp_diff;
-        struct timespec remote_rp_stamp = { 0, 0 };
+        struct timespec remote_rp_stamp = { 0, 0 }; /*>>> ZERO_STAMP */
         short partid;
         struct xpc_partition *part;
         enum xp_retval ret;
@@ -608,12 +547,12 @@ xpc_identify_act_IRQ_req(int nasid)
                 return;
         }
 
-        remote_vars_pa = remote_rp->vars_pa;
+        remote_vars_pa = remote_rp->sn.vars_pa;
         remote_rp_version = remote_rp->version;
         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version))
                 remote_rp_stamp = remote_rp->stamp;
 
-        partid = remote_rp->partid;
+        partid = remote_rp->SAL_partid;
         part = &xpc_partitions[partid];
 
         /* pull over the cross partition variables */
@@ -977,7 +916,7 @@ xpc_discovery(void)
         enum xp_retval ret;
 
         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
-                                                  xp_nasid_mask_bytes,
+                                                  xp_sizeof_nasid_mask,
                                                   GFP_KERNEL, &remote_rp_base);
         if (remote_rp == NULL)
                 return;
@@ -1063,9 +1002,9 @@ xpc_discovery(void)
                                 continue;
                         }
 
-                        remote_vars_pa = remote_rp->vars_pa;
+                        remote_vars_pa = remote_rp->sn.vars_pa;
 
-                        partid = remote_rp->partid;
+                        partid = remote_rp->SAL_partid;
                         part = &xpc_partitions[partid];
 
                         /* pull over the cross partition variables */
@@ -1155,5 +1094,5 @@ xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
         part_nasid_pa = (u64)XPC_RP_PART_NASIDS(part->remote_rp_pa);
 
         return xp_remote_memcpy(nasid_mask, (void *)part_nasid_pa,
-                                xp_nasid_mask_bytes);
+                                xp_sizeof_nasid_mask);
 }
diff --git a/drivers/misc/sgi-xp/xpc_sn2.c b/drivers/misc/sgi-xp/xpc_sn2.c
new file mode 100644
index 00000000000..5a37348715c
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_sn2.c
@@ -0,0 +1,111 @@
+/*
+ * 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) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) sn2-based functions.
+ *
+ *     Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <asm/uncached.h>
+#include <asm/sn/sn_sal.h>
+#include "xpc.h"
+
+struct xpc_vars *xpc_vars;
+struct xpc_vars_part *xpc_vars_part;
+
+static enum xp_retval
+xpc_rsvd_page_init_sn2(struct xpc_rsvd_page *rp)
+{
+        AMO_t *amos_page;
+        u64 nasid_array = 0;
+        int i;
+        int ret;
+
+        xpc_vars = XPC_RP_VARS(rp);
+
+        rp->sn.vars_pa = __pa(xpc_vars);
+
+        xpc_vars_part = XPC_RP_VARS_PART(rp);
+
+        /*
+         * Before clearing xpc_vars, see if a page of AMOs had been previously
+         * allocated. If not we'll need to allocate one and set permissions
+         * so that cross-partition AMOs are allowed.
+         *
+         * The allocated AMO page needs MCA reporting to remain disabled after
+         * XPC has unloaded.  To make this work, we keep a copy of the pointer
+         * to this page (i.e., amos_page) in the struct xpc_vars structure,
+         * which is pointed to by the reserved page, and re-use that saved copy
+         * on subsequent loads of XPC. This AMO page is never freed, and its
+         * memory protections are never restricted.
+         */
+        amos_page = xpc_vars->amos_page;
+        if (amos_page == NULL) {
+                amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0, 1));
+                if (amos_page == NULL) {
+                        dev_err(xpc_part, "can't allocate page of AMOs\n");
+                        return xpNoMemory;
+                }
+
+                /*
+                 * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
+                 * when xpc_allow_IPI_ops() is called via xpc_hb_init().
+                 */
+                if (!enable_shub_wars_1_1()) {
+                        ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
+                                                   PAGE_SIZE,
+                                                   SN_MEMPROT_ACCESS_CLASS_1,
+                                                   &nasid_array);
+                        if (ret != 0) {
+                                dev_err(xpc_part, "can't change memory "
+                                        "protections\n");
+                                uncached_free_page(__IA64_UNCACHED_OFFSET |
+                                                   TO_PHYS((u64)amos_page), 1);
+                                return xpSalError;
+                        }
+                }
+        }
+
+        /* clear xpc_vars */
+        memset(xpc_vars, 0, sizeof(struct xpc_vars));
+
+        xpc_vars->version = XPC_V_VERSION;
+        xpc_vars->act_nasid = cpuid_to_nasid(0);
+        xpc_vars->act_phys_cpuid = cpu_physical_id(0);
+        xpc_vars->vars_part_pa = __pa(xpc_vars_part);
+        xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
+        xpc_vars->amos_page = amos_page;        /* save for next load of XPC */
+
+        /* clear xpc_vars_part */
+        memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
+               xp_max_npartitions);
+
+        /* initialize the activate IRQ related AMO variables */
+        for (i = 0; i < xp_nasid_mask_words; i++)
+                (void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
+
+        /* initialize the engaged remote partitions related AMO variables */
+        (void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
+        (void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
+
+        return xpSuccess;
+}
+
+void
+xpc_init_sn2(void)
+{
+        xpc_rsvd_page_init = xpc_rsvd_page_init_sn2;
+}
+
+void
+xpc_exit_sn2(void)
+{
+}
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c
new file mode 100644
index 00000000000..8327cd4017e
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_uv.c
@@ -0,0 +1,48 @@
+/*
+ * 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) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) uv-based functions.
+ *
+ *     Architecture specific implementation of common functions.
+ *
+ */
+
+#include <linux/kernel.h>
+
+/* >>> #include <gru/grukservices.h> */
+/* >>> uv_gpa() is defined in <gru/grukservices.h> */
+#define uv_gpa(_a)              ((unsigned long)_a)
+
+/* >>> temporarily define next three items for xpc.h */
+#define SGI_XPC_ACTIVATE        23
+#define SGI_XPC_NOTIFY          24
+#define sn_send_IPI_phys(_a, _b, _c, _d)
+
+#include "xpc.h"
+
+static void *xpc_activate_mq;
+
+static enum xp_retval
+xpc_rsvd_page_init_uv(struct xpc_rsvd_page *rp)
+{
+        /* >>> need to have established xpc_activate_mq earlier */
+        rp->sn.activate_mq_gpa = uv_gpa(xpc_activate_mq);
+        return xpSuccess;
+}
+
+void
+xpc_init_uv(void)
+{
+        xpc_rsvd_page_init = xpc_rsvd_page_init_uv;
+}
+
+void
+xpc_exit_uv(void)
+{
+}