[PATCH 3.16.y-ckt 063/133] IB/qib: Change lkey table allocation to support more MRs

From: Luis Henriques
Date: Wed Sep 30 2015 - 06:22:25 EST


3.16.7-ckt18 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
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(-)

diff --git a/drivers/infiniband/hw/qib/qib_keys.c b/drivers/infiniband/hw/qib/qib_keys.c
index 3b9afccaaade..eabe54738be6 100644
--- 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 *mr, int dma_region)
* 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);
diff --git a/drivers/infiniband/hw/qib/qib_verbs.c b/drivers/infiniband/hw/qib/qib_verbs.c
index 9bcfbd842980..40afdfce2fbc 100644
--- 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"
@@ -2086,10 +2087,16 @@ int qib_register_ib_device(struct qib_devdata *dd)
* 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;
@@ -2262,7 +2269,7 @@ 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:
@@ -2316,8 +2323,7 @@ void qib_unregister_ib_device(struct qib_devdata *dd)
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);
}

diff --git a/drivers/infiniband/hw/qib/qib_verbs.h b/drivers/infiniband/hw/qib/qib_verbs.h
index bfc8948fdd35..44ca28c83fe6 100644
--- 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) */
--
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