[PATCH 06/11] IB,usnic: convert usnic_uiom_interval_tree to half closed intervals

Davidlohr Bueso
2019-10-03T20:20:28Z

The usnic_uiom interval tree really wants [a, b) intervals,
not fully closed. As such convert it to use the new
interval_tree_gen.h, and also rename the 'last' endpoint
in the node to 'end', which both a more suitable name for
the half closed interval and also reduces the chances of some
caller being missed.

The conversion can get non-trivial when calling into things like:

- find_intervals_intersection_sorted()
- usnic_uiom_insert_interval()

which have been converted to no longer subtracting one from the
interval->end, hoping that the semantics of ad-hoc usage remain
untouched.

Cc: Christian Benvenuti <benve@cisco.com>
Cc: Nelson Escobar <neescoba@cisco.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
drivers/infiniband/hw/usnic/usnic_uiom.c | 8 +++----
.../infiniband/hw/usnic/usnic_uiom_interval_tree.c | 26 ++++++++++------------
.../infiniband/hw/usnic/usnic_uiom_interval_tree.h | 2 +-
3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/infiniband/hw/usnic/usnic_uiom.c b/drivers/infiniband/hw/usnic/usnic_uiom.c
index 62e6ffa9ad78..14f607c398a8 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom.c
@@ -200,7 +200,7 @@ static void usnic_uiom_unmap_sorted_intervals(struct list_head *intervals,

list_for_each_entry_safe(interval, tmp, intervals, link) {
va = interval->start << PAGE_SHIFT;
- size = ((interval->last - interval->start) + 1) << PAGE_SHIFT;
+ size = (interval->end - interval->start) << PAGE_SHIFT;
while (size > 0) {
/* Workaround for RH 970401 */
usnic_dbg("va 0x%lx size 0x%lx", va, PAGE_SIZE);
@@ -223,7 +223,7 @@ static void __usnic_uiom_reg_release(struct usnic_uiom_pd *pd,

npages = PAGE_ALIGN(uiomr->length + uiomr->offset) >> PAGE_SHIFT;
vpn_start = (uiomr->va & PAGE_MASK) >> PAGE_SHIFT;
- vpn_last = vpn_start + npages - 1;
+ vpn_last = vpn_start + npages;

spin_lock(&pd->lock);
usnic_uiom_remove_interval(&pd->root, vpn_start,
@@ -293,7 +293,7 @@ static int usnic_uiom_map_sorted_intervals(struct list_head *intervals,
pa_end = pa;
}

- if ((va >> PAGE_SHIFT) == interval_node->last) {
+ if ((va >> PAGE_SHIFT) == interval_node->end) {
/* Last page of the interval */
size = pa - pa_start + PAGE_SIZE;
usnic_dbg("va 0x%lx pa %pa size 0x%zx flags 0x%x\n",
@@ -354,7 +354,7 @@ struct usnic_uiom_reg *usnic_uiom_reg_get(struct usnic_uiom_pd *pd,
offset = addr & ~PAGE_MASK;
npages = PAGE_ALIGN(size + offset) >> PAGE_SHIFT;
vpn_start = (addr & PAGE_MASK) >> PAGE_SHIFT;
- vpn_last = vpn_start + npages - 1;
+ vpn_last = vpn_start + npages;

uiomr = kmalloc(sizeof(*uiomr), GFP_KERNEL);
if (!uiomr)
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
index d399523206c7..12c968447673 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
+++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c
@@ -36,11 +36,11 @@
#include <linux/slab.h>
#include <linux/list_sort.h>

-#include <linux/interval_tree_generic.h>
+#include <linux/interval_tree_gen.h>
#include "usnic_uiom_interval_tree.h"

#define START(node) ((node)->start)
-#define LAST(node) ((node)->last)
+#define END(node) ((node)->end)

#define MAKE_NODE(node, start, end, ref_cnt, flags, err, err_out) \
do { \
@@ -76,7 +76,7 @@ usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt,
return NULL;

interval->start = start;
- interval->last = last;
+ interval->end = last;
interval->flags = flags;
interval->ref_cnt = ref_cnt;

@@ -133,7 +133,7 @@ int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,

list_for_each_entry(interval, &intersection_set, link) {
if (pivot < interval->start) {
- MAKE_NODE_AND_APPEND(tmp, pivot, interval->start - 1,
+ MAKE_NODE_AND_APPEND(tmp, pivot, interval->start,
1, flags, err, err_out,
diff_set);
pivot = interval->start;
@@ -144,12 +144,10 @@ int usnic_uiom_get_intervals_diff(unsigned long start, unsigned long last,
* but not in both.
*/

- if (pivot > interval->last) {
+ if (pivot > interval->end - 1) {
continue;
- } else if (pivot <= interval->last &&
- FLAGS_EQUAL(interval->flags, flags,
- flag_mask)) {
- pivot = interval->last + 1;
+ } else if (FLAGS_EQUAL(interval->flags, flags, flag_mask)) {
+ pivot = interval->end;
}
}

@@ -195,15 +193,15 @@ int usnic_uiom_insert_interval(struct rb_root_cached *root, unsigned long start,
* inserted
*/
istart = interval->start;
- ilast = interval->last;
+ ilast = interval->end - 1;
iref_cnt = interval->ref_cnt;
iflags = interval->flags;

if (istart < lpivot) {
- MAKE_NODE_AND_APPEND(tmp, istart, lpivot - 1, iref_cnt,
+ MAKE_NODE_AND_APPEND(tmp, istart, lpivot, iref_cnt,
iflags, err, err_out, &to_add);
} else if (istart > lpivot) {
- MAKE_NODE_AND_APPEND(tmp, lpivot, istart - 1, 1, flags,
+ MAKE_NODE_AND_APPEND(tmp, lpivot, istart, 1, flags,
err, err_out, &to_add);
lpivot = istart;
} else {
@@ -222,7 +220,7 @@ int usnic_uiom_insert_interval(struct rb_root_cached *root, unsigned long start,
&to_add);
}

- lpivot = ilast + 1;
+ lpivot = interval->end;
}

if (lpivot <= last)
@@ -267,4 +265,4 @@ void usnic_uiom_remove_interval(struct rb_root_cached *root,

INTERVAL_TREE_DEFINE(struct usnic_uiom_interval_node, rb,
unsigned long, __subtree_last,
- START, LAST, , usnic_uiom_interval_tree)
+ START, END, , usnic_uiom_interval_tree)
diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
index 1d7fc3226bca..496edc9758c1 100644
--- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
+++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.h
@@ -40,7 +40,7 @@ struct usnic_uiom_interval_node {
struct rb_node rb;
struct list_head link;
unsigned long start;
- unsigned long last;
+ unsigned long end;
unsigned long __subtree_last;
unsigned int ref_cnt;
int flags;
--
2.16.4