1 files changed, 541 insertions, 0 deletions

diff --git a/drivers/misc/sgi-xp/xpc_partition.c b/drivers/misc/sgi-xp/xpc_partition.c
new file mode 100644
index 000000000..6956f7e7d
--- /dev/null
+++ b/drivers/misc/sgi-xp/xpc_partition.c
@@ -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);
+}