Patch "IB/qib: Change lkey table allocation to support more MRs" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    IB/qib: Change lkey table allocation to support more MRs

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ib-qib-change-lkey-table-allocation-to-support-more-mrs.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d6f1c17e162b2a11e708f28fa93f2f79c164b442 Mon Sep 17 00:00:00 2001
From: Mike Marciniszyn <mike.marciniszyn@intel.com>
Date: Tue, 21 Jul 2015 08:36:07 -0400
Subject: IB/qib: Change lkey table allocation to support more MRs

From: Mike Marciniszyn <mike.marciniszyn@intel.com>

commit d6f1c17e162b2a11e708f28fa93f2f79c164b442 upstream.

The lkey table is allocated with with a get_user_pages() with an
order based on a number of index bits from a module parameter.

The underlying kernel code cannot allocate that many contiguous pages.

There is no reason the underlying memory needs to be physically
contiguous.

This patch:
- switches the allocation/deallocation to vmalloc/vfree
- caps the number of bits to 23 to insure at least 1 generation bit
  o this matches the module parameter description

Reviewed-by: Vinit Agnihotri <vinit.abhay.agnihotri@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/qib/qib_keys.c  |    4 ++++
 drivers/infiniband/hw/qib/qib_verbs.c |   14 ++++++++++----
 drivers/infiniband/hw/qib/qib_verbs.h |    2 ++
 3 files changed, 16 insertions(+), 4 deletions(-)

--- a/drivers/infiniband/hw/qib/qib_keys.c
+++ b/drivers/infiniband/hw/qib/qib_keys.c
@@ -86,6 +86,10 @@ int qib_alloc_lkey(struct qib_mregion *m
 	 * unrestricted LKEY.
 	 */
 	rkt->gen++;
+	/*
+	 * bits are capped in qib_verbs.c to insure enough bits
+	 * for generation number
+	 */
 	mr->lkey = (r << (32 - ib_qib_lkey_table_size)) |
 		((((1 << (24 - ib_qib_lkey_table_size)) - 1) & rkt->gen)
 		 << 8);
--- a/drivers/infiniband/hw/qib/qib_verbs.c
+++ b/drivers/infiniband/hw/qib/qib_verbs.c
@@ -40,6 +40,7 @@
 #include <linux/rculist.h>
 #include <linux/mm.h>
 #include <linux/random.h>
+#include <linux/vmalloc.h>
 
 #include "qib.h"
 #include "qib_common.h"
@@ -2109,10 +2110,16 @@ int qib_register_ib_device(struct qib_de
 	 * the LKEY).  The remaining bits act as a generation number or tag.
 	 */
 	spin_lock_init(&dev->lk_table.lock);
+	/* insure generation is at least 4 bits see keys.c */
+	if (ib_qib_lkey_table_size > MAX_LKEY_TABLE_BITS) {
+		qib_dev_warn(dd, "lkey bits %u too large, reduced to %u\n",
+			ib_qib_lkey_table_size, MAX_LKEY_TABLE_BITS);
+		ib_qib_lkey_table_size = MAX_LKEY_TABLE_BITS;
+	}
 	dev->lk_table.max = 1 << ib_qib_lkey_table_size;
 	lk_tab_size = dev->lk_table.max * sizeof(*dev->lk_table.table);
 	dev->lk_table.table = (struct qib_mregion __rcu **)
-		__get_free_pages(GFP_KERNEL, get_order(lk_tab_size));
+		vmalloc(lk_tab_size);
 	if (dev->lk_table.table == NULL) {
 		ret = -ENOMEM;
 		goto err_lk;
@@ -2286,7 +2293,7 @@ err_tx:
 					sizeof(struct qib_pio_header),
 				  dev->pio_hdrs, dev->pio_hdrs_phys);
 err_hdrs:
-	free_pages((unsigned long) dev->lk_table.table, get_order(lk_tab_size));
+	vfree(dev->lk_table.table);
 err_lk:
 	kfree(dev->qp_table);
 err_qpt:
@@ -2340,8 +2347,7 @@ void qib_unregister_ib_device(struct qib
 					sizeof(struct qib_pio_header),
 				  dev->pio_hdrs, dev->pio_hdrs_phys);
 	lk_tab_size = dev->lk_table.max * sizeof(*dev->lk_table.table);
-	free_pages((unsigned long) dev->lk_table.table,
-		   get_order(lk_tab_size));
+	vfree(dev->lk_table.table);
 	kfree(dev->qp_table);
 }
 
--- a/drivers/infiniband/hw/qib/qib_verbs.h
+++ b/drivers/infiniband/hw/qib/qib_verbs.h
@@ -647,6 +647,8 @@ struct qib_qpn_table {
 	struct qpn_map map[QPNMAP_ENTRIES];
 };
 
+#define MAX_LKEY_TABLE_BITS 23
+
 struct qib_lkey_table {
 	spinlock_t lock; /* protect changes in this struct */
 	u32 next;               /* next unused index (speeds search) */


Patches currently in stable-queue which might be from mike.marciniszyn@intel.com are

queue-4.2/ib-qib-change-lkey-table-allocation-to-support-more-mrs.patch