[PATCH 4.1 098/159] IB/qib: Change lkey table allocation to support more MRs

Greg Kroah-Hartman
2015-09-26T21:17:55Z

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"
@@ -2089,10 +2090,16 @@ 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;
@@ -2265,7 +2272,7 @@ 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:
@@ -2319,8 +2326,7 @@ 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) */