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path: root/drivers/cxl/core/region.c
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Diffstat (limited to 'drivers/cxl/core/region.c')
-rw-r--r--drivers/cxl/core/region.c282
1 files changed, 281 insertions, 1 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index a84b007df4be..51447458a522 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -24,6 +24,7 @@
* but is only visible for persistent regions.
* 1. Interleave granularity
* 2. Interleave size
+ * 3. Decoder targets
*/
/*
@@ -141,6 +142,8 @@ static ssize_t interleave_ways_show(struct device *dev,
return rc;
}
+static const struct attribute_group *get_cxl_region_target_group(void);
+
static ssize_t interleave_ways_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
@@ -149,7 +152,7 @@ static ssize_t interleave_ways_store(struct device *dev,
struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
struct cxl_region *cxlr = to_cxl_region(dev);
struct cxl_region_params *p = &cxlr->params;
- int rc, val;
+ int rc, val, save;
u8 iw;
rc = kstrtoint(buf, 0, &val);
@@ -178,7 +181,11 @@ static ssize_t interleave_ways_store(struct device *dev,
goto out;
}
+ save = p->interleave_ways;
p->interleave_ways = val;
+ rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group());
+ if (rc)
+ p->interleave_ways = save;
out:
up_write(&cxl_region_rwsem);
if (rc)
@@ -404,9 +411,262 @@ static const struct attribute_group cxl_region_group = {
.is_visible = cxl_region_visible,
};
+static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos)
+{
+ struct cxl_region_params *p = &cxlr->params;
+ struct cxl_endpoint_decoder *cxled;
+ int rc;
+
+ rc = down_read_interruptible(&cxl_region_rwsem);
+ if (rc)
+ return rc;
+
+ if (pos >= p->interleave_ways) {
+ dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
+ p->interleave_ways);
+ rc = -ENXIO;
+ goto out;
+ }
+
+ cxled = p->targets[pos];
+ if (!cxled)
+ rc = sysfs_emit(buf, "\n");
+ else
+ rc = sysfs_emit(buf, "%s\n", dev_name(&cxled->cxld.dev));
+out:
+ up_read(&cxl_region_rwsem);
+
+ return rc;
+}
+
+/*
+ * - Check that the given endpoint is attached to a host-bridge identified
+ * in the root interleave.
+ */
+static int cxl_region_attach(struct cxl_region *cxlr,
+ struct cxl_endpoint_decoder *cxled, int pos)
+{
+ struct cxl_region_params *p = &cxlr->params;
+
+ if (cxled->mode == CXL_DECODER_DEAD) {
+ dev_dbg(&cxlr->dev, "%s dead\n", dev_name(&cxled->cxld.dev));
+ return -ENODEV;
+ }
+
+ if (pos >= p->interleave_ways) {
+ dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
+ p->interleave_ways);
+ return -ENXIO;
+ }
+
+ if (p->targets[pos] == cxled)
+ return 0;
+
+ if (p->targets[pos]) {
+ struct cxl_endpoint_decoder *cxled_target = p->targets[pos];
+ struct cxl_memdev *cxlmd_target = cxled_to_memdev(cxled_target);
+
+ dev_dbg(&cxlr->dev, "position %d already assigned to %s:%s\n",
+ pos, dev_name(&cxlmd_target->dev),
+ dev_name(&cxled_target->cxld.dev));
+ return -EBUSY;
+ }
+
+ p->targets[pos] = cxled;
+ cxled->pos = pos;
+ p->nr_targets++;
+
+ return 0;
+}
+
+static void cxl_region_detach(struct cxl_endpoint_decoder *cxled)
+{
+ struct cxl_region *cxlr = cxled->cxld.region;
+ struct cxl_region_params *p;
+
+ lockdep_assert_held_write(&cxl_region_rwsem);
+
+ if (!cxlr)
+ return;
+
+ p = &cxlr->params;
+ get_device(&cxlr->dev);
+
+ if (cxled->pos < 0 || cxled->pos >= p->interleave_ways ||
+ p->targets[cxled->pos] != cxled) {
+ struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
+
+ dev_WARN_ONCE(&cxlr->dev, 1, "expected %s:%s at position %d\n",
+ dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev),
+ cxled->pos);
+ goto out;
+ }
+
+ p->targets[cxled->pos] = NULL;
+ p->nr_targets--;
+
+ /* notify the region driver that one of its targets has deparated */
+ up_write(&cxl_region_rwsem);
+ device_release_driver(&cxlr->dev);
+ down_write(&cxl_region_rwsem);
+out:
+ put_device(&cxlr->dev);
+}
+
+void cxl_decoder_kill_region(struct cxl_endpoint_decoder *cxled)
+{
+ down_write(&cxl_region_rwsem);
+ cxled->mode = CXL_DECODER_DEAD;
+ cxl_region_detach(cxled);
+ up_write(&cxl_region_rwsem);
+}
+
+static int attach_target(struct cxl_region *cxlr, const char *decoder, int pos)
+{
+ struct device *dev;
+ int rc;
+
+ dev = bus_find_device_by_name(&cxl_bus_type, NULL, decoder);
+ if (!dev)
+ return -ENODEV;
+
+ if (!is_endpoint_decoder(dev)) {
+ put_device(dev);
+ return -EINVAL;
+ }
+
+ rc = down_write_killable(&cxl_region_rwsem);
+ if (rc)
+ goto out;
+ down_read(&cxl_dpa_rwsem);
+ rc = cxl_region_attach(cxlr, to_cxl_endpoint_decoder(dev), pos);
+ up_read(&cxl_dpa_rwsem);
+ up_write(&cxl_region_rwsem);
+out:
+ put_device(dev);
+ return rc;
+}
+
+static int detach_target(struct cxl_region *cxlr, int pos)
+{
+ struct cxl_region_params *p = &cxlr->params;
+ int rc;
+
+ rc = down_write_killable(&cxl_region_rwsem);
+ if (rc)
+ return rc;
+
+ if (pos >= p->interleave_ways) {
+ dev_dbg(&cxlr->dev, "position %d out of range %d\n", pos,
+ p->interleave_ways);
+ rc = -ENXIO;
+ goto out;
+ }
+
+ if (!p->targets[pos]) {
+ rc = 0;
+ goto out;
+ }
+
+ cxl_region_detach(p->targets[pos]);
+ rc = 0;
+out:
+ up_write(&cxl_region_rwsem);
+ return rc;
+}
+
+static size_t store_targetN(struct cxl_region *cxlr, const char *buf, int pos,
+ size_t len)
+{
+ int rc;
+
+ if (sysfs_streq(buf, "\n"))
+ rc = detach_target(cxlr, pos);
+ else
+ rc = attach_target(cxlr, buf, pos);
+
+ if (rc < 0)
+ return rc;
+ return len;
+}
+
+#define TARGET_ATTR_RW(n) \
+static ssize_t target##n##_show( \
+ struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+ return show_targetN(to_cxl_region(dev), buf, (n)); \
+} \
+static ssize_t target##n##_store(struct device *dev, \
+ struct device_attribute *attr, \
+ const char *buf, size_t len) \
+{ \
+ return store_targetN(to_cxl_region(dev), buf, (n), len); \
+} \
+static DEVICE_ATTR_RW(target##n)
+
+TARGET_ATTR_RW(0);
+TARGET_ATTR_RW(1);
+TARGET_ATTR_RW(2);
+TARGET_ATTR_RW(3);
+TARGET_ATTR_RW(4);
+TARGET_ATTR_RW(5);
+TARGET_ATTR_RW(6);
+TARGET_ATTR_RW(7);
+TARGET_ATTR_RW(8);
+TARGET_ATTR_RW(9);
+TARGET_ATTR_RW(10);
+TARGET_ATTR_RW(11);
+TARGET_ATTR_RW(12);
+TARGET_ATTR_RW(13);
+TARGET_ATTR_RW(14);
+TARGET_ATTR_RW(15);
+
+static struct attribute *target_attrs[] = {
+ &dev_attr_target0.attr,
+ &dev_attr_target1.attr,
+ &dev_attr_target2.attr,
+ &dev_attr_target3.attr,
+ &dev_attr_target4.attr,
+ &dev_attr_target5.attr,
+ &dev_attr_target6.attr,
+ &dev_attr_target7.attr,
+ &dev_attr_target8.attr,
+ &dev_attr_target9.attr,
+ &dev_attr_target10.attr,
+ &dev_attr_target11.attr,
+ &dev_attr_target12.attr,
+ &dev_attr_target13.attr,
+ &dev_attr_target14.attr,
+ &dev_attr_target15.attr,
+ NULL,
+};
+
+static umode_t cxl_region_target_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct cxl_region *cxlr = to_cxl_region(dev);
+ struct cxl_region_params *p = &cxlr->params;
+
+ if (n < p->interleave_ways)
+ return a->mode;
+ return 0;
+}
+
+static const struct attribute_group cxl_region_target_group = {
+ .attrs = target_attrs,
+ .is_visible = cxl_region_target_visible,
+};
+
+static const struct attribute_group *get_cxl_region_target_group(void)
+{
+ return &cxl_region_target_group;
+}
+
static const struct attribute_group *region_groups[] = {
&cxl_base_attribute_group,
&cxl_region_group,
+ &cxl_region_target_group,
NULL,
};
@@ -566,6 +826,26 @@ static ssize_t create_pmem_region_store(struct device *dev,
}
DEVICE_ATTR_RW(create_pmem_region);
+static ssize_t region_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct cxl_decoder *cxld = to_cxl_decoder(dev);
+ ssize_t rc;
+
+ rc = down_read_interruptible(&cxl_region_rwsem);
+ if (rc)
+ return rc;
+
+ if (cxld->region)
+ rc = sysfs_emit(buf, "%s\n", dev_name(&cxld->region->dev));
+ else
+ rc = sysfs_emit(buf, "\n");
+ up_read(&cxl_region_rwsem);
+
+ return rc;
+}
+DEVICE_ATTR_RO(region);
+
static struct cxl_region *
cxl_find_region_by_name(struct cxl_root_decoder *cxlrd, const char *name)
{
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-17 02:07:06 +0300