Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / misc / sgi-xp / xpc_partition.c
diff --git a/kernel/drivers/misc/sgi-xp/xpc_partition.c b/kernel/drivers/misc/sgi-xp/xpc_partition.c
new file mode 100644 (file)
index 0000000..6956f7e
--- /dev/null
@@ -0,0 +1,541 @@
+/*
+ * 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) 2004-2008 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+/*
+ * Cross Partition Communication (XPC) partition support.
+ *
+ *     This is the part of XPC that detects the presence/absence of
+ *     other partitions. It provides a heartbeat and monitors the
+ *     heartbeats of other partitions.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/hardirq.h>
+#include <linux/slab.h>
+#include "xpc.h"
+#include <asm/uv/uv_hub.h>
+
+/* XPC is exiting flag */
+int xpc_exiting;
+
+/* this partition's reserved page pointers */
+struct xpc_rsvd_page *xpc_rsvd_page;
+static unsigned long *xpc_part_nasids;
+unsigned long *xpc_mach_nasids;
+
+static int xpc_nasid_mask_nbytes;      /* #of bytes in nasid mask */
+int xpc_nasid_mask_nlongs;     /* #of longs in nasid mask */
+
+struct xpc_partition *xpc_partitions;
+
+/*
+ * Guarantee that the kmalloc'd memory is cacheline aligned.
+ */
+void *
+xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
+{
+       /* see if kmalloc will give us cachline aligned memory by default */
+       *base = kmalloc(size, flags);
+       if (*base == NULL)
+               return NULL;
+
+       if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
+               return *base;
+
+       kfree(*base);
+
+       /* nope, we'll have to do it ourselves */
+       *base = kmalloc(size + L1_CACHE_BYTES, flags);
+       if (*base == NULL)
+               return NULL;
+
+       return (void *)L1_CACHE_ALIGN((u64)*base);
+}
+
+/*
+ * Given a nasid, get the physical address of the  partition's reserved page
+ * for that nasid. This function returns 0 on any error.
+ */
+static unsigned long
+xpc_get_rsvd_page_pa(int nasid)
+{
+       enum xp_retval ret;
+       u64 cookie = 0;
+       unsigned long rp_pa = nasid;    /* seed with nasid */
+       size_t len = 0;
+       size_t buf_len = 0;
+       void *buf = buf;
+       void *buf_base = NULL;
+       enum xp_retval (*get_partition_rsvd_page_pa)
+               (void *, u64 *, unsigned long *, size_t *) =
+               xpc_arch_ops.get_partition_rsvd_page_pa;
+
+       while (1) {
+
+               /* !!! rp_pa will need to be _gpa on UV.
+                * ??? So do we save it into the architecture specific parts
+                * ??? of the xpc_partition structure? Do we rename this
+                * ??? function or have two versions? Rename rp_pa for UV to
+                * ??? rp_gpa?
+                */
+               ret = get_partition_rsvd_page_pa(buf, &cookie, &rp_pa, &len);
+
+               dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
+                       "address=0x%016lx, len=0x%016lx\n", ret,
+                       (unsigned long)cookie, rp_pa, len);
+
+               if (ret != xpNeedMoreInfo)
+                       break;
+
+               /* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
+               if (is_shub())
+                       len = L1_CACHE_ALIGN(len);
+
+               if (len > buf_len) {
+                       if (buf_base != NULL)
+                               kfree(buf_base);
+                       buf_len = L1_CACHE_ALIGN(len);
+                       buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
+                                                           &buf_base);
+                       if (buf_base == NULL) {
+                               dev_err(xpc_part, "unable to kmalloc "
+                                       "len=0x%016lx\n", buf_len);
+                               ret = xpNoMemory;
+                               break;
+                       }
+               }
+
+               ret = xp_remote_memcpy(xp_pa(buf), rp_pa, len);
+               if (ret != xpSuccess) {
+                       dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
+                       break;
+               }
+       }
+
+       kfree(buf_base);
+
+       if (ret != xpSuccess)
+               rp_pa = 0;
+
+       dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
+       return rp_pa;
+}
+
+/*
+ * Fill the partition reserved page with the information needed by
+ * other partitions to discover we are alive and establish initial
+ * communications.
+ */
+int
+xpc_setup_rsvd_page(void)
+{
+       int ret;
+       struct xpc_rsvd_page *rp;
+       unsigned long rp_pa;
+       unsigned long new_ts_jiffies;
+
+       /* get the local reserved page's address */
+
+       preempt_disable();
+       rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
+       preempt_enable();
+       if (rp_pa == 0) {
+               dev_err(xpc_part, "SAL failed to locate the reserved page\n");
+               return -ESRCH;
+       }
+       rp = (struct xpc_rsvd_page *)__va(xp_socket_pa(rp_pa));
+
+       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 != xp_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 -EINVAL;
+       }
+
+       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->SAL_nasids_size = 128;
+       }
+       xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
+       xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
+                                             BITS_PER_BYTE);
+
+       /* 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);
+
+       ret = xpc_arch_ops.setup_rsvd_page(rp);
+       if (ret != 0)
+               return ret;
+
+       /*
+        * Set timestamp of when reserved page was setup by XPC.
+        * This signifies to the remote partition that our reserved
+        * page is initialized.
+        */
+       new_ts_jiffies = jiffies;
+       if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
+               new_ts_jiffies++;
+       rp->ts_jiffies = new_ts_jiffies;
+
+       xpc_rsvd_page = rp;
+       return 0;
+}
+
+void
+xpc_teardown_rsvd_page(void)
+{
+       /* a zero timestamp indicates our rsvd page is not initialized */
+       xpc_rsvd_page->ts_jiffies = 0;
+}
+
+/*
+ * Get a copy of a portion of the remote partition's rsvd page.
+ *
+ * remote_rp points to a buffer that is cacheline aligned for BTE copies and
+ * is large enough to contain a copy of their reserved page header and
+ * part_nasids mask.
+ */
+enum xp_retval
+xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
+                 struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
+{
+       int l;
+       enum xp_retval ret;
+
+       /* get the reserved page's physical address */
+
+       *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
+       if (*remote_rp_pa == 0)
+               return xpNoRsvdPageAddr;
+
+       /* pull over the reserved page header and part_nasids mask */
+       ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
+                              XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
+       if (ret != xpSuccess)
+               return ret;
+
+       if (discovered_nasids != NULL) {
+               unsigned long *remote_part_nasids =
+                   XPC_RP_PART_NASIDS(remote_rp);
+
+               for (l = 0; l < xpc_nasid_mask_nlongs; l++)
+                       discovered_nasids[l] |= remote_part_nasids[l];
+       }
+
+       /* zero timestamp indicates the reserved page has not been setup */
+       if (remote_rp->ts_jiffies == 0)
+               return xpRsvdPageNotSet;
+
+       if (XPC_VERSION_MAJOR(remote_rp->version) !=
+           XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
+               return xpBadVersion;
+       }
+
+       /* check that both remote and local partids are valid for each side */
+       if (remote_rp->SAL_partid < 0 ||
+           remote_rp->SAL_partid >= xp_max_npartitions ||
+           remote_rp->max_npartitions <= xp_partition_id) {
+               return xpInvalidPartid;
+       }
+
+       if (remote_rp->SAL_partid == xp_partition_id)
+               return xpLocalPartid;
+
+       return xpSuccess;
+}
+
+/*
+ * See if the other side has responded to a partition deactivate request
+ * from us. Though we requested the remote partition to deactivate with regard
+ * to us, we really only need to wait for the other side to disengage from us.
+ */
+int
+xpc_partition_disengaged(struct xpc_partition *part)
+{
+       short partid = XPC_PARTID(part);
+       int disengaged;
+
+       disengaged = !xpc_arch_ops.partition_engaged(partid);
+       if (part->disengage_timeout) {
+               if (!disengaged) {
+                       if (time_is_after_jiffies(part->disengage_timeout)) {
+                               /* timelimit hasn't been reached yet */
+                               return 0;
+                       }
+
+                       /*
+                        * Other side hasn't responded to our deactivate
+                        * request in a timely fashion, so assume it's dead.
+                        */
+
+                       dev_info(xpc_part, "deactivate request to remote "
+                                "partition %d timed out\n", partid);
+                       xpc_disengage_timedout = 1;
+                       xpc_arch_ops.assume_partition_disengaged(partid);
+                       disengaged = 1;
+               }
+               part->disengage_timeout = 0;
+
+               /* cancel the timer function, provided it's not us */
+               if (!in_interrupt())
+                       del_singleshot_timer_sync(&part->disengage_timer);
+
+               DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
+                       part->act_state != XPC_P_AS_INACTIVE);
+               if (part->act_state != XPC_P_AS_INACTIVE)
+                       xpc_wakeup_channel_mgr(part);
+
+               xpc_arch_ops.cancel_partition_deactivation_request(part);
+       }
+       return disengaged;
+}
+
+/*
+ * Mark specified partition as active.
+ */
+enum xp_retval
+xpc_mark_partition_active(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+       enum xp_retval ret;
+
+       dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
+
+       spin_lock_irqsave(&part->act_lock, irq_flags);
+       if (part->act_state == XPC_P_AS_ACTIVATING) {
+               part->act_state = XPC_P_AS_ACTIVE;
+               ret = xpSuccess;
+       } else {
+               DBUG_ON(part->reason == xpSuccess);
+               ret = part->reason;
+       }
+       spin_unlock_irqrestore(&part->act_lock, irq_flags);
+
+       return ret;
+}
+
+/*
+ * Start the process of deactivating the specified partition.
+ */
+void
+xpc_deactivate_partition(const int line, struct xpc_partition *part,
+                        enum xp_retval reason)
+{
+       unsigned long irq_flags;
+
+       spin_lock_irqsave(&part->act_lock, irq_flags);
+
+       if (part->act_state == XPC_P_AS_INACTIVE) {
+               XPC_SET_REASON(part, reason, line);
+               spin_unlock_irqrestore(&part->act_lock, irq_flags);
+               if (reason == xpReactivating) {
+                       /* we interrupt ourselves to reactivate partition */
+                       xpc_arch_ops.request_partition_reactivation(part);
+               }
+               return;
+       }
+       if (part->act_state == XPC_P_AS_DEACTIVATING) {
+               if ((part->reason == xpUnloading && reason != xpUnloading) ||
+                   reason == xpReactivating) {
+                       XPC_SET_REASON(part, reason, line);
+               }
+               spin_unlock_irqrestore(&part->act_lock, irq_flags);
+               return;
+       }
+
+       part->act_state = XPC_P_AS_DEACTIVATING;
+       XPC_SET_REASON(part, reason, line);
+
+       spin_unlock_irqrestore(&part->act_lock, irq_flags);
+
+       /* ask remote partition to deactivate with regard to us */
+       xpc_arch_ops.request_partition_deactivation(part);
+
+       /* set a timelimit on the disengage phase of the deactivation request */
+       part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
+       part->disengage_timer.expires = part->disengage_timeout;
+       add_timer(&part->disengage_timer);
+
+       dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
+               XPC_PARTID(part), reason);
+
+       xpc_partition_going_down(part, reason);
+}
+
+/*
+ * Mark specified partition as inactive.
+ */
+void
+xpc_mark_partition_inactive(struct xpc_partition *part)
+{
+       unsigned long irq_flags;
+
+       dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
+               XPC_PARTID(part));
+
+       spin_lock_irqsave(&part->act_lock, irq_flags);
+       part->act_state = XPC_P_AS_INACTIVE;
+       spin_unlock_irqrestore(&part->act_lock, irq_flags);
+       part->remote_rp_pa = 0;
+}
+
+/*
+ * SAL has provided a partition and machine mask.  The partition mask
+ * contains a bit for each even nasid in our partition.  The machine
+ * mask contains a bit for each even nasid in the entire machine.
+ *
+ * Using those two bit arrays, we can determine which nasids are
+ * known in the machine.  Each should also have a reserved page
+ * initialized if they are available for partitioning.
+ */
+void
+xpc_discovery(void)
+{
+       void *remote_rp_base;
+       struct xpc_rsvd_page *remote_rp;
+       unsigned long remote_rp_pa;
+       int region;
+       int region_size;
+       int max_regions;
+       int nasid;
+       struct xpc_rsvd_page *rp;
+       unsigned long *discovered_nasids;
+       enum xp_retval ret;
+
+       remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
+                                                 xpc_nasid_mask_nbytes,
+                                                 GFP_KERNEL, &remote_rp_base);
+       if (remote_rp == NULL)
+               return;
+
+       discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
+                                   GFP_KERNEL);
+       if (discovered_nasids == NULL) {
+               kfree(remote_rp_base);
+               return;
+       }
+
+       rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
+
+       /*
+        * The term 'region' in this context refers to the minimum number of
+        * nodes that can comprise an access protection grouping. The access
+        * protection is in regards to memory, IOI and IPI.
+        */
+       region_size = xp_region_size;
+
+       if (is_uv())
+               max_regions = 256;
+       else {
+               max_regions = 64;
+
+               switch (region_size) {
+               case 128:
+                       max_regions *= 2;
+               case 64:
+                       max_regions *= 2;
+               case 32:
+                       max_regions *= 2;
+                       region_size = 16;
+                       DBUG_ON(!is_shub2());
+               }
+       }
+
+       for (region = 0; region < max_regions; region++) {
+
+               if (xpc_exiting)
+                       break;
+
+               dev_dbg(xpc_part, "searching region %d\n", region);
+
+               for (nasid = (region * region_size * 2);
+                    nasid < ((region + 1) * region_size * 2); nasid += 2) {
+
+                       if (xpc_exiting)
+                               break;
+
+                       dev_dbg(xpc_part, "checking nasid %d\n", nasid);
+
+                       if (test_bit(nasid / 2, xpc_part_nasids)) {
+                               dev_dbg(xpc_part, "PROM indicates Nasid %d is "
+                                       "part of the local partition; skipping "
+                                       "region\n", nasid);
+                               break;
+                       }
+
+                       if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
+                               dev_dbg(xpc_part, "PROM indicates Nasid %d was "
+                                       "not on Numa-Link network at reset\n",
+                                       nasid);
+                               continue;
+                       }
+
+                       if (test_bit(nasid / 2, discovered_nasids)) {
+                               dev_dbg(xpc_part, "Nasid %d is part of a "
+                                       "partition which was previously "
+                                       "discovered\n", nasid);
+                               continue;
+                       }
+
+                       /* pull over the rsvd page header & part_nasids mask */
+
+                       ret = xpc_get_remote_rp(nasid, discovered_nasids,
+                                               remote_rp, &remote_rp_pa);
+                       if (ret != xpSuccess) {
+                               dev_dbg(xpc_part, "unable to get reserved page "
+                                       "from nasid %d, reason=%d\n", nasid,
+                                       ret);
+
+                               if (ret == xpLocalPartid)
+                                       break;
+
+                               continue;
+                       }
+
+                       xpc_arch_ops.request_partition_activation(remote_rp,
+                                                        remote_rp_pa, nasid);
+               }
+       }
+
+       kfree(discovered_nasids);
+       kfree(remote_rp_base);
+}
+
+/*
+ * Given a partid, get the nasids owned by that partition from the
+ * remote partition's reserved page.
+ */
+enum xp_retval
+xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
+{
+       struct xpc_partition *part;
+       unsigned long part_nasid_pa;
+
+       part = &xpc_partitions[partid];
+       if (part->remote_rp_pa == 0)
+               return xpPartitionDown;
+
+       memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
+
+       part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
+
+       return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
+                               xpc_nasid_mask_nbytes);
+}