1 files changed, 441 insertions, 126 deletions

diff --git a/drivers/infiniband/hw/hfi1/affinity.c b/drivers/infiniband/hw/hfi1/affinity.c
index 14d7eeb09be6..79575ee873f2 100644
--- a/drivers/infiniband/hw/hfi1/affinity.c
+++ b/drivers/infiniband/hw/hfi1/affinity.c
@@ -47,12 +47,18 @@
 #include <linux/topology.h>
 #include <linux/cpumask.h>
 #include <linux/module.h>
+#include <linux/cpumask.h>
 
 #include "hfi.h"
 #include "affinity.h"
 #include "sdma.h"
 #include "trace.h"
 
+struct hfi1_affinity_node_list node_affinity = {
+	.list = LIST_HEAD_INIT(node_affinity.list),
+	.lock = __SPIN_LOCK_UNLOCKED(&node_affinity.lock),
+};
+
 /* Name of IRQ types, indexed by enum irq_type */
 static const char * const irq_type_names[] = {
 	"SDMA",
@@ -61,6 +67,9 @@ static const char * const irq_type_names[] = {
 	"OTHER",
 };
 
+/* Per NUMA node count of HFI devices */
+static unsigned int *hfi1_per_node_cntr;
+
 static inline void init_cpu_mask_set(struct cpu_mask_set *set)
 {
 	cpumask_clear(&set->mask);
@@ -69,47 +78,136 @@ static inline void init_cpu_mask_set(struct cpu_mask_set *set)
 }
 
 /* Initialize non-HT cpu cores mask */
-int init_real_cpu_mask(struct hfi1_devdata *dd)
+void init_real_cpu_mask(void)
 {
-	struct hfi1_affinity *info;
 	int possible, curr_cpu, i, ht;
 
-	info = kzalloc(sizeof(*info), GFP_KERNEL);
-	if (!info)
-		return -ENOMEM;
-
-	cpumask_clear(&info->real_cpu_mask);
+	cpumask_clear(&node_affinity.real_cpu_mask);
 
 	/* Start with cpu online mask as the real cpu mask */
-	cpumask_copy(&info->real_cpu_mask, cpu_online_mask);
+	cpumask_copy(&node_affinity.real_cpu_mask, cpu_online_mask);
 
 	/*
 	 * Remove HT cores from the real cpu mask.  Do this in two steps below.
 	 */
-	possible = cpumask_weight(&info->real_cpu_mask);
+	possible = cpumask_weight(&node_affinity.real_cpu_mask);
 	ht = cpumask_weight(topology_sibling_cpumask(
-					cpumask_first(&info->real_cpu_mask)));
+				cpumask_first(&node_affinity.real_cpu_mask)));
 	/*
 	 * Step 1.  Skip over the first N HT siblings and use them as the
 	 * "real" cores.  Assumes that HT cores are not enumerated in
 	 * succession (except in the single core case).
 	 */
-	curr_cpu = cpumask_first(&info->real_cpu_mask);
+	curr_cpu = cpumask_first(&node_affinity.real_cpu_mask);
 	for (i = 0; i < possible / ht; i++)
-		curr_cpu = cpumask_next(curr_cpu, &info->real_cpu_mask);
+		curr_cpu = cpumask_next(curr_cpu, &node_affinity.real_cpu_mask);
 	/*
 	 * Step 2.  Remove the remaining HT siblings.  Use cpumask_next() to
 	 * skip any gaps.
 	 */
 	for (; i < possible; i++) {
-		cpumask_clear_cpu(curr_cpu, &info->real_cpu_mask);
-		curr_cpu = cpumask_next(curr_cpu, &info->real_cpu_mask);
+		cpumask_clear_cpu(curr_cpu, &node_affinity.real_cpu_mask);
+		curr_cpu = cpumask_next(curr_cpu, &node_affinity.real_cpu_mask);
+	}
+}
+
+int node_affinity_init(void)
+{
+	int node;
+	struct pci_dev *dev = NULL;
+	const struct pci_device_id *ids = hfi1_pci_tbl;
+
+	cpumask_clear(&node_affinity.proc.used);
+	cpumask_copy(&node_affinity.proc.mask, cpu_online_mask);
+
+	node_affinity.proc.gen = 0;
+	node_affinity.num_core_siblings =
+				cpumask_weight(topology_sibling_cpumask(
+					cpumask_first(&node_affinity.proc.mask)
+					));
+	node_affinity.num_online_nodes = num_online_nodes();
+	node_affinity.num_online_cpus = num_online_cpus();
+
+	/*
+	 * The real cpu mask is part of the affinity struct but it has to be
+	 * initialized early. It is needed to calculate the number of user
+	 * contexts in set_up_context_variables().
+	 */
+	init_real_cpu_mask();
+
+	hfi1_per_node_cntr = kcalloc(num_possible_nodes(),
+				     sizeof(*hfi1_per_node_cntr), GFP_KERNEL);
+	if (!hfi1_per_node_cntr)
+		return -ENOMEM;
+
+	while (ids->vendor) {
+		dev = NULL;
+		while ((dev = pci_get_device(ids->vendor, ids->device, dev))) {
+			node = pcibus_to_node(dev->bus);
+			if (node < 0)
+				node = numa_node_id();
+
+			hfi1_per_node_cntr[node]++;
+		}
+		ids++;
 	}
 
-	dd->affinity = info;
 	return 0;
 }
 
+void node_affinity_destroy(void)
+{
+	struct list_head *pos, *q;
+	struct hfi1_affinity_node *entry;
+
+	spin_lock(&node_affinity.lock);
+	list_for_each_safe(pos, q, &node_affinity.list) {
+		entry = list_entry(pos, struct hfi1_affinity_node,
+				   list);
+		list_del(pos);
+		kfree(entry);
+	}
+	spin_unlock(&node_affinity.lock);
+	kfree(hfi1_per_node_cntr);
+}
+
+static struct hfi1_affinity_node *node_affinity_allocate(int node)
+{
+	struct hfi1_affinity_node *entry;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return NULL;
+	entry->node = node;
+	INIT_LIST_HEAD(&entry->list);
+
+	return entry;
+}
+
+/*
+ * It appends an entry to the list.
+ * It *must* be called with node_affinity.lock held.
+ */
+static void node_affinity_add_tail(struct hfi1_affinity_node *entry)
+{
+	list_add_tail(&entry->list, &node_affinity.list);
+}
+
+/* It must be called with node_affinity.lock held */
+static struct hfi1_affinity_node *node_affinity_lookup(int node)
+{
+	struct list_head *pos;
+	struct hfi1_affinity_node *entry;
+
+	list_for_each(pos, &node_affinity.list) {
+		entry = list_entry(pos, struct hfi1_affinity_node, list);
+		if (entry->node == node)
+			return entry;
+	}
+
+	return NULL;
+}
+
 /*
  * Interrupt affinity.
  *
@@ -121,10 +219,10 @@ int init_real_cpu_mask(struct hfi1_devdata *dd)
  * to the node relative 1 as necessary.
  *
  */
-void hfi1_dev_affinity_init(struct hfi1_devdata *dd)
+int hfi1_dev_affinity_init(struct hfi1_devdata *dd)
 {
 	int node = pcibus_to_node(dd->pcidev->bus);
-	struct hfi1_affinity *info = dd->affinity;
+	struct hfi1_affinity_node *entry;
 	const struct cpumask *local_mask;
 	int curr_cpu, possible, i;
 
@@ -132,56 +230,93 @@ void hfi1_dev_affinity_init(struct hfi1_devdata *dd)
 		node = numa_node_id();
 	dd->node = node;
 
-	spin_lock_init(&info->lock);
-
-	init_cpu_mask_set(&info->def_intr);
-	init_cpu_mask_set(&info->rcv_intr);
-	init_cpu_mask_set(&info->proc);
-
 	local_mask = cpumask_of_node(dd->node);
 	if (cpumask_first(local_mask) >= nr_cpu_ids)
 		local_mask = topology_core_cpumask(0);
-	/* Use the "real" cpu mask of this node as the default */
-	cpumask_and(&info->def_intr.mask, &info->real_cpu_mask, local_mask);
-
-	/*  fill in the receive list */
-	possible = cpumask_weight(&info->def_intr.mask);
-	curr_cpu = cpumask_first(&info->def_intr.mask);
-	if (possible == 1) {
-		/*  only one CPU, everyone will use it */
-		cpumask_set_cpu(curr_cpu, &info->rcv_intr.mask);
-	} else {
-		/*
-		 * Retain the first CPU in the default list for the control
-		 * context.
-		 */
-		curr_cpu = cpumask_next(curr_cpu, &info->def_intr.mask);
-		/*
-		 * Remove the remaining kernel receive queues from
-		 * the default list and add them to the receive list.
-		 */
-		for (i = 0; i < dd->n_krcv_queues - 1; i++) {
-			cpumask_clear_cpu(curr_cpu, &info->def_intr.mask);
-			cpumask_set_cpu(curr_cpu, &info->rcv_intr.mask);
-			curr_cpu = cpumask_next(curr_cpu, &info->def_intr.mask);
-			if (curr_cpu >= nr_cpu_ids)
-				break;
+
+	spin_lock(&node_affinity.lock);
+	entry = node_affinity_lookup(dd->node);
+	spin_unlock(&node_affinity.lock);
+
+	/*
+	 * If this is the first time this NUMA node's affinity is used,
+	 * create an entry in the global affinity structure and initialize it.
+	 */
+	if (!entry) {
+		entry = node_affinity_allocate(node);
+		if (!entry) {
+			dd_dev_err(dd,
+				   "Unable to allocate global affinity node\n");
+			return -ENOMEM;
 		}
-	}
+		init_cpu_mask_set(&entry->def_intr);
+		init_cpu_mask_set(&entry->rcv_intr);
+		cpumask_clear(&entry->general_intr_mask);
+		/* Use the "real" cpu mask of this node as the default */
+		cpumask_and(&entry->def_intr.mask, &node_affinity.real_cpu_mask,
+			    local_mask);
+
+		/* fill in the receive list */
+		possible = cpumask_weight(&entry->def_intr.mask);
+		curr_cpu = cpumask_first(&entry->def_intr.mask);
+
+		if (possible == 1) {
+			/* only one CPU, everyone will use it */
+			cpumask_set_cpu(curr_cpu, &entry->rcv_intr.mask);
+			cpumask_set_cpu(curr_cpu, &entry->general_intr_mask);
+		} else {
+			/*
+			 * The general/control context will be the first CPU in
+			 * the default list, so it is removed from the default
+			 * list and added to the general interrupt list.
+			 */
+			cpumask_clear_cpu(curr_cpu, &entry->def_intr.mask);
+			cpumask_set_cpu(curr_cpu, &entry->general_intr_mask);
+			curr_cpu = cpumask_next(curr_cpu,
+						&entry->def_intr.mask);
 
-	cpumask_copy(&info->proc.mask, cpu_online_mask);
-}
+			/*
+			 * Remove the remaining kernel receive queues from
+			 * the default list and add them to the receive list.
+			 */
+			for (i = 0;
+			     i < (dd->n_krcv_queues - 1) *
+				  hfi1_per_node_cntr[dd->node];
+			     i++) {
+				cpumask_clear_cpu(curr_cpu,
+						  &entry->def_intr.mask);
+				cpumask_set_cpu(curr_cpu,
+						&entry->rcv_intr.mask);
+				curr_cpu = cpumask_next(curr_cpu,
+							&entry->def_intr.mask);
+				if (curr_cpu >= nr_cpu_ids)
+					break;
+			}
 
-void hfi1_dev_affinity_free(struct hfi1_devdata *dd)
-{
-	kfree(dd->affinity);
+			/*
+			 * If there ends up being 0 CPU cores leftover for SDMA
+			 * engines, use the same CPU cores as general/control
+			 * context.
+			 */
+			if (cpumask_weight(&entry->def_intr.mask) == 0)
+				cpumask_copy(&entry->def_intr.mask,
+					     &entry->general_intr_mask);
+		}
+
+		spin_lock(&node_affinity.lock);
+		node_affinity_add_tail(entry);
+		spin_unlock(&node_affinity.lock);
+	}
+
+	return 0;
 }
 
 int hfi1_get_irq_affinity(struct hfi1_devdata *dd, struct hfi1_msix_entry *msix)
 {
 	int ret;
 	cpumask_var_t diff;
-	struct cpu_mask_set *set;
+	struct hfi1_affinity_node *entry;
+	struct cpu_mask_set *set = NULL;
 	struct sdma_engine *sde = NULL;
 	struct hfi1_ctxtdata *rcd = NULL;
 	char extra[64];
@@ -194,22 +329,25 @@ int hfi1_get_irq_affinity(struct hfi1_devdata *dd, struct hfi1_msix_entry *msix)
 	if (!ret)
 		return -ENOMEM;
 
+	spin_lock(&node_affinity.lock);
+	entry = node_affinity_lookup(dd->node);
+	spin_unlock(&node_affinity.lock);
+
 	switch (msix->type) {
 	case IRQ_SDMA:
 		sde = (struct sdma_engine *)msix->arg;
 		scnprintf(extra, 64, "engine %u", sde->this_idx);
-		/* fall through */
+		set = &entry->def_intr;
+		break;
 	case IRQ_GENERAL:
-		set = &dd->affinity->def_intr;
+		cpu = cpumask_first(&entry->general_intr_mask);
 		break;
 	case IRQ_RCVCTXT:
 		rcd = (struct hfi1_ctxtdata *)msix->arg;
-		if (rcd->ctxt == HFI1_CTRL_CTXT) {
-			set = &dd->affinity->def_intr;
-			cpu = cpumask_first(&set->mask);
-		} else {
-			set = &dd->affinity->rcv_intr;
-		}
+		if (rcd->ctxt == HFI1_CTRL_CTXT)
+			cpu = cpumask_first(&entry->general_intr_mask);
+		else
+			set = &entry->rcv_intr;
 		scnprintf(extra, 64, "ctxt %u", rcd->ctxt);
 		break;
 	default:
@@ -218,12 +356,12 @@ int hfi1_get_irq_affinity(struct hfi1_devdata *dd, struct hfi1_msix_entry *msix)
 	}
 
 	/*
-	 * The control receive context is placed on a particular CPU, which
-	 * is set above.  Skip accounting for it.  Everything else finds its
-	 * CPU here.
+	 * The general and control contexts are placed on a particular
+	 * CPU, which is set above. Skip accounting for it. Everything else
+	 * finds its CPU here.
 	 */
-	if (cpu == -1) {
-		spin_lock(&dd->affinity->lock);
+	if (cpu == -1 && set) {
+		spin_lock(&node_affinity.lock);
 		if (cpumask_equal(&set->mask, &set->used)) {
 			/*
 			 * We've used up all the CPUs, bump up the generation
@@ -235,7 +373,7 @@ int hfi1_get_irq_affinity(struct hfi1_devdata *dd, struct hfi1_msix_entry *msix)
 		cpumask_andnot(diff, &set->mask, &set->used);
 		cpu = cpumask_first(diff);
 		cpumask_set_cpu(cpu, &set->used);
-		spin_unlock(&dd->affinity->lock);
+		spin_unlock(&node_affinity.lock);
 	}
 
 	switch (msix->type) {
@@ -263,43 +401,84 @@ void hfi1_put_irq_affinity(struct hfi1_devdata *dd,
 {
 	struct cpu_mask_set *set = NULL;
 	struct hfi1_ctxtdata *rcd;
+	struct hfi1_affinity_node *entry;
+
+	spin_lock(&node_affinity.lock);
+	entry = node_affinity_lookup(dd->node);
+	spin_unlock(&node_affinity.lock);
 
 	switch (msix->type) {
 	case IRQ_SDMA:
+		set = &entry->def_intr;
+		break;
 	case IRQ_GENERAL:
-		set = &dd->affinity->def_intr;
+		/* Don't do accounting for general contexts */
 		break;
 	case IRQ_RCVCTXT:
 		rcd = (struct hfi1_ctxtdata *)msix->arg;
-		/* only do accounting for non control contexts */
+		/* Don't do accounting for control contexts */
 		if (rcd->ctxt != HFI1_CTRL_CTXT)
-			set = &dd->affinity->rcv_intr;
+			set = &entry->rcv_intr;
 		break;
 	default:
 		return;
 	}
 
 	if (set) {
-		spin_lock(&dd->affinity->lock);
+		spin_lock(&node_affinity.lock);
 		cpumask_andnot(&set->used, &set->used, &msix->mask);
 		if (cpumask_empty(&set->used) && set->gen) {
 			set->gen--;
 			cpumask_copy(&set->used, &set->mask);
 		}
-		spin_unlock(&dd->affinity->lock);
+		spin_unlock(&node_affinity.lock);
 	}
 
 	irq_set_affinity_hint(msix->msix.vector, NULL);
 	cpumask_clear(&msix->mask);
 }
 
-int hfi1_get_proc_affinity(struct hfi1_devdata *dd, int node)
+/* This should be called with node_affinity.lock held */
+static void find_hw_thread_mask(uint hw_thread_no, cpumask_var_t hw_thread_mask,
+				struct hfi1_affinity_node_list *affinity)
 {
-	int cpu = -1, ret;
-	cpumask_var_t diff, mask, intrs;
+	int possible, curr_cpu, i;
+	uint num_cores_per_socket = node_affinity.num_online_cpus /
+					affinity->num_core_siblings /
+						node_affinity.num_online_nodes;
+
+	cpumask_copy(hw_thread_mask, &affinity->proc.mask);
+	if (affinity->num_core_siblings > 0) {
+		/* Removing other siblings not needed for now */
+		possible = cpumask_weight(hw_thread_mask);
+		curr_cpu = cpumask_first(hw_thread_mask);
+		for (i = 0;
+		     i < num_cores_per_socket * node_affinity.num_online_nodes;
+		     i++)
+			curr_cpu = cpumask_next(curr_cpu, hw_thread_mask);
+
+		for (; i < possible; i++) {
+			cpumask_clear_cpu(curr_cpu, hw_thread_mask);
+			curr_cpu = cpumask_next(curr_cpu, hw_thread_mask);
+		}
+
+		/* Identifying correct HW threads within physical cores */
+		cpumask_shift_left(hw_thread_mask, hw_thread_mask,
+				   num_cores_per_socket *
+				   node_affinity.num_online_nodes *
+				   hw_thread_no);
+	}
+}
+
+int hfi1_get_proc_affinity(int node)
+{
+	int cpu = -1, ret, i;
+	struct hfi1_affinity_node *entry;
+	cpumask_var_t diff, hw_thread_mask, available_mask, intrs_mask;
 	const struct cpumask *node_mask,
 		*proc_mask = tsk_cpus_allowed(current);
-	struct cpu_mask_set *set = &dd->affinity->proc;
+	struct hfi1_affinity_node_list *affinity = &node_affinity;
+	struct cpu_mask_set *set = &affinity->proc;
 
 	/*
 	 * check whether process/context affinity has already
@@ -325,22 +504,41 @@ int hfi1_get_proc_affinity(struct hfi1_devdata *dd, int node)
 
 	/*
 	 * The process does not have a preset CPU affinity so find one to
-	 * recommend. We prefer CPUs on the same NUMA as the device.
+	 * recommend using the following algorithm:
+	 *
+	 * For each user process that is opening a context on HFI Y:
+	 *  a) If all cores are filled, reinitialize the bitmask
+	 *  b) Fill real cores first, then HT cores (First set of HT
+	 *     cores on all physical cores, then second set of HT core,
+	 *     and, so on) in the following order:
+	 *
+	 *     1. Same NUMA node as HFI Y and not running an IRQ
+	 *        handler
+	 *     2. Same NUMA node as HFI Y and running an IRQ handler
+	 *     3. Different NUMA node to HFI Y and not running an IRQ
+	 *        handler
+	 *     4. Different NUMA node to HFI Y and running an IRQ
+	 *        handler
+	 *  c) Mark core as filled in the bitmask. As user processes are
+	 *     done, clear cores from the bitmask.
 	 */
 
 	ret = zalloc_cpumask_var(&diff, GFP_KERNEL);
 	if (!ret)
 		goto done;
-	ret = zalloc_cpumask_var(&mask, GFP_KERNEL);
+	ret = zalloc_cpumask_var(&hw_thread_mask, GFP_KERNEL);
 	if (!ret)
 		goto free_diff;
-	ret = zalloc_cpumask_var(&intrs, GFP_KERNEL);
+	ret = zalloc_cpumask_var(&available_mask, GFP_KERNEL);
+	if (!ret)
+		goto free_hw_thread_mask;
+	ret = zalloc_cpumask_var(&intrs_mask, GFP_KERNEL);
 	if (!ret)
-		goto free_mask;
+		goto free_available_mask;
 
-	spin_lock(&dd->affinity->lock);
+	spin_lock(&affinity->lock);
 	/*
-	 * If we've used all available CPUs, clear the mask and start
+	 * If we've used all available HW threads, clear the mask and start
 	 * overloading.
 	 */
 	if (cpumask_equal(&set->mask, &set->used)) {
@@ -348,81 +546,198 @@ int hfi1_get_proc_affinity(struct hfi1_devdata *dd, int node)
 		cpumask_clear(&set->used);
 	}
 
-	/* CPUs used by interrupt handlers */
-	cpumask_copy(intrs, (dd->affinity->def_intr.gen ?
-			     &dd->affinity->def_intr.mask :
-			     &dd->affinity->def_intr.used));
-	cpumask_or(intrs, intrs, (dd->affinity->rcv_intr.gen ?
-				  &dd->affinity->rcv_intr.mask :
-				  &dd->affinity->rcv_intr.used));
+	/*
+	 * If NUMA node has CPUs used by interrupt handlers, include them in the
+	 * interrupt handler mask.
+	 */
+	entry = node_affinity_lookup(node);
+	if (entry) {
+		cpumask_copy(intrs_mask, (entry->def_intr.gen ?
+					  &entry->def_intr.mask :
+					  &entry->def_intr.used));
+		cpumask_or(intrs_mask, intrs_mask, (entry->rcv_intr.gen ?
+						    &entry->rcv_intr.mask :
+						    &entry->rcv_intr.used));
+		cpumask_or(intrs_mask, intrs_mask, &entry->general_intr_mask);
+	}
 	hfi1_cdbg(PROC, "CPUs used by interrupts: %*pbl",
-		  cpumask_pr_args(intrs));
+		  cpumask_pr_args(intrs_mask));
+
+	cpumask_copy(hw_thread_mask, &set->mask);
 
 	/*
-	 * If we don't have a NUMA node requested, preference is towards
-	 * device NUMA node
+	 * If HT cores are enabled, identify which HW threads within the
+	 * physical cores should be used.
 	 */
-	if (node == -1)
-		node = dd->node;
+	if (affinity->num_core_siblings > 0) {
+		for (i = 0; i < affinity->num_core_siblings; i++) {
+			find_hw_thread_mask(i, hw_thread_mask, affinity);
+
+			/*
+			 * If there's at least one available core for this HW
+			 * thread number, stop looking for a core.
+			 *
+			 * diff will always be not empty at least once in this
+			 * loop as the used mask gets reset when
+			 * (set->mask == set->used) before this loop.
+			 */
+			cpumask_andnot(diff, hw_thread_mask, &set->used);
+			if (!cpumask_empty(diff))
+				break;
+		}
+	}
+	hfi1_cdbg(PROC, "Same available HW thread on all physical CPUs: %*pbl",
+		  cpumask_pr_args(hw_thread_mask));
+
 	node_mask = cpumask_of_node(node);
-	hfi1_cdbg(PROC, "device on NUMA %u, CPUs %*pbl", node,
+	hfi1_cdbg(PROC, "Device on NUMA %u, CPUs %*pbl", node,
 		  cpumask_pr_args(node_mask));
 
-	/* diff will hold all unused cpus */
-	cpumask_andnot(diff, &set->mask, &set->used);
-	hfi1_cdbg(PROC, "unused CPUs (all) %*pbl", cpumask_pr_args(diff));
-
-	/* get cpumask of available CPUs on preferred NUMA */
-	cpumask_and(mask, diff, node_mask);
-	hfi1_cdbg(PROC, "available cpus on NUMA %*pbl", cpumask_pr_args(mask));
+	/* Get cpumask of available CPUs on preferred NUMA */
+	cpumask_and(available_mask, hw_thread_mask, node_mask);
+	cpumask_andnot(available_mask, available_mask, &set->used);
+	hfi1_cdbg(PROC, "Available CPUs on NUMA %u: %*pbl", node,
+		  cpumask_pr_args(available_mask));
 
 	/*
 	 * At first, we don't want to place processes on the same
-	 * CPUs as interrupt handlers.
+	 * CPUs as interrupt handlers. Then, CPUs running interrupt
+	 * handlers are used.
+	 *
+	 * 1) If diff is not empty, then there are CPUs not running
+	 *    non-interrupt handlers available, so diff gets copied
+	 *    over to available_mask.
+	 * 2) If diff is empty, then all CPUs not running interrupt
+	 *    handlers are taken, so available_mask contains all
+	 *    available CPUs running interrupt handlers.
+	 * 3) If available_mask is empty, then all CPUs on the
+	 *    preferred NUMA node are taken, so other NUMA nodes are
+	 *    used for process assignments using the same method as
+	 *    the preferred NUMA node.
 	 */
-	cpumask_andnot(diff, mask, intrs);
+	cpumask_andnot(diff, available_mask, intrs_mask);
 	if (!cpumask_empty(diff))
-		cpumask_copy(mask, diff);
+		cpumask_copy(available_mask, diff);
 
-	/*
-	 * if we don't have a cpu on the preferred NUMA, get
-	 * the list of the remaining available CPUs
-	 */
-	if (cpumask_empty(mask)) {
-		cpumask_andnot(diff, &set->mask, &set->used);
-		cpumask_andnot(mask, diff, node_mask);
+	/* If we don't have CPUs on the preferred node, use other NUMA nodes */
+	if (cpumask_empty(available_mask)) {
+		cpumask_andnot(available_mask, hw_thread_mask, &set->used);
+		/* Excluding preferred NUMA cores */
+		cpumask_andnot(available_mask, available_mask, node_mask);
+		hfi1_cdbg(PROC,
+			  "Preferred NUMA node cores are taken, cores available in other NUMA nodes: %*pbl",
+			  cpumask_pr_args(available_mask));
+
+		/*
+		 * At first, we don't want to place processes on the same
+		 * CPUs as interrupt handlers.
+		 */
+		cpumask_andnot(diff, available_mask, intrs_mask);
+		if (!cpumask_empty(diff))
+			cpumask_copy(available_mask, diff);
 	}
-	hfi1_cdbg(PROC, "possible CPUs for process %*pbl",
-		  cpumask_pr_args(mask));
+	hfi1_cdbg(PROC, "Possible CPUs for process: %*pbl",
+		  cpumask_pr_args(available_mask));
 
-	cpu = cpumask_first(mask);
+	cpu = cpumask_first(available_mask);
 	if (cpu >= nr_cpu_ids) /* empty */
 		cpu = -1;
 	else
 		cpumask_set_cpu(cpu, &set->used);
-	spin_unlock(&dd->affinity->lock);
-
-	free_cpumask_var(intrs);
-free_mask:
-	free_cpumask_var(mask);
+	spin_unlock(&affinity->lock);
+	hfi1_cdbg(PROC, "Process assigned to CPU %d", cpu);
+
+	free_cpumask_var(intrs_mask);
+free_available_mask:
+	free_cpumask_var(available_mask);
+free_hw_thread_mask:
+	free_cpumask_var(hw_thread_mask);
 free_diff:
 	free_cpumask_var(diff);
 done:
 	return cpu;
 }
 
-void hfi1_put_proc_affinity(struct hfi1_devdata *dd, int cpu)
+void hfi1_put_proc_affinity(int cpu)
 {
-	struct cpu_mask_set *set = &dd->affinity->proc;
+	struct hfi1_affinity_node_list *affinity = &node_affinity;
+	struct cpu_mask_set *set = &affinity->proc;
 
 	if (cpu < 0)
 		return;
-	spin_lock(&dd->affinity->lock);
+	spin_lock(&affinity->lock);
 	cpumask_clear_cpu(cpu, &set->used);
+	hfi1_cdbg(PROC, "Returning CPU %d for future process assignment", cpu);
 	if (cpumask_empty(&set->used) && set->gen) {
 		set->gen--;
 		cpumask_copy(&set->used, &set->mask);
 	}
-	spin_unlock(&dd->affinity->lock);
+	spin_unlock(&affinity->lock);
 }
 
+/* Prevents concurrent reads and writes of the sdma_affinity attrib */
+static DEFINE_MUTEX(sdma_affinity_mutex);
+
+int hfi1_set_sdma_affinity(struct hfi1_devdata *dd, const char *buf,
+			   size_t count)
+{
+	struct hfi1_affinity_node *entry;
+	struct cpumask mask;
+	int ret, i;
+
+	spin_lock(&node_affinity.lock);
+	entry = node_affinity_lookup(dd->node);
+	spin_unlock(&node_affinity.lock);
+
+	if (!entry)
+		return -EINVAL;
+
+	ret = cpulist_parse(buf, &mask);
+	if (ret)
+		return ret;
+
+	if (!cpumask_subset(&mask, cpu_online_mask) || cpumask_empty(&mask)) {
+		dd_dev_warn(dd, "Invalid CPU mask\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&sdma_affinity_mutex);
+	/* reset the SDMA interrupt affinity details */
+	init_cpu_mask_set(&entry->def_intr);
+	cpumask_copy(&entry->def_intr.mask, &mask);
+	/*
+	 * Reassign the affinity for each SDMA interrupt.
+	 */
+	for (i = 0; i < dd->num_msix_entries; i++) {
+		struct hfi1_msix_entry *msix;
+
+		msix = &dd->msix_entries[i];
+		if (msix->type != IRQ_SDMA)
+			continue;
+
+		ret = hfi1_get_irq_affinity(dd, msix);
+
+		if (ret)
+			break;
+	}
+
+	mutex_unlock(&sdma_affinity_mutex);
+	return ret ? ret : strnlen(buf, PAGE_SIZE);
+}
+
+int hfi1_get_sdma_affinity(struct hfi1_devdata *dd, char *buf)
+{
+	struct hfi1_affinity_node *entry;
+
+	spin_lock(&node_affinity.lock);
+	entry = node_affinity_lookup(dd->node);
+	spin_unlock(&node_affinity.lock);
+
+	if (!entry)
+		return -EINVAL;
+
+	mutex_lock(&sdma_affinity_mutex);
+	cpumap_print_to_pagebuf(true, buf, &entry->def_intr.mask);
+	mutex_unlock(&sdma_affinity_mutex);
+	return strnlen(buf, PAGE_SIZE);
+}