Currently 'struct cxl_decoder' contains the superset of attributes
needed for all decoder types. Before more type-specific attributes are
added to the common definition, reorganize 'struct cxl_decoder' into type
specific objects.
This patch, the first of three, factors out a cxl_switch_decoder type.
See the new kdoc for what a 'struct cxl_switch_decoder' represents in a
CXL topology.
Co-developed-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
Signed-off-by: Ben Widawsky <bwidawsk@xxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/cxl/acpi.c | 4 +
drivers/cxl/core/hdm.c | 33 +++++--
drivers/cxl/core/port.c | 188 ++++++++++++++++++++++++++++--------------
drivers/cxl/cxl.h | 30 +++++--
tools/testing/cxl/test/cxl.c | 23 ++++-
5 files changed, 189 insertions(+), 89 deletions(-)
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 541fc0b28b8f..62bf22ffb7aa 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -81,6 +81,7 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
int target_map[CXL_DECODER_MAX_INTERLEAVE];
struct cxl_cfmws_context *ctx = arg;
struct cxl_port *root_port = ctx->root_port;
+ struct cxl_switch_decoder *cxlsd;
struct device *dev = ctx->dev;
struct acpi_cedt_cfmws *cfmws;
struct cxl_decoder *cxld;
@@ -106,10 +107,11 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
for (i = 0; i < ways; i++)
target_map[i] = cfmws->interleave_targets[i];
- cxld = cxl_root_decoder_alloc(root_port, ways);
+ cxlsd = cxl_root_decoder_alloc(root_port, ways);
if (IS_ERR(cxld))
return 0;
+ cxld = &cxlsd->cxld;
cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
cxld->target_type = CXL_DECODER_EXPANDER;
cxld->hpa_range = (struct range) {
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index c524e772fdae..2f10d42798de 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -49,20 +49,20 @@ static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
*/
int devm_cxl_add_passthrough_decoder(struct cxl_port *port)
{
- struct cxl_decoder *cxld;
+ struct cxl_switch_decoder *cxlsd;
struct cxl_dport *dport;
int single_port_map[1];
- cxld = cxl_switch_decoder_alloc(port, 1);
- if (IS_ERR(cxld))
- return PTR_ERR(cxld);
+ cxlsd = cxl_switch_decoder_alloc(port, 1);
+ if (IS_ERR(cxlsd))
+ return PTR_ERR(cxlsd);
device_lock_assert(&port->dev);
dport = list_first_entry(&port->dports, typeof(*dport), list);
single_port_map[0] = dport->port_id;
- return add_hdm_decoder(port, cxld, single_port_map);
+ return add_hdm_decoder(port, &cxlsd->cxld, single_port_map);
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_add_passthrough_decoder, CXL);
@@ -255,14 +255,23 @@ int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
int rc, target_count = cxlhdm->target_count;
struct cxl_decoder *cxld;
- if (is_cxl_endpoint(port))
+ if (is_cxl_endpoint(port)) {
cxld = cxl_endpoint_decoder_alloc(port);
- else
- cxld = cxl_switch_decoder_alloc(port, target_count);
- if (IS_ERR(cxld)) {
- dev_warn(&port->dev,
- "Failed to allocate the decoder\n");
- return PTR_ERR(cxld);
+ if (IS_ERR(cxld)) {
+ dev_warn(&port->dev,
+ "Failed to allocate the decoder\n");
+ return PTR_ERR(cxld);
+ }
+ } else {
+ struct cxl_switch_decoder *cxlsd;
+
+ cxlsd = cxl_switch_decoder_alloc(port, target_count);
+ if (IS_ERR(cxlsd)) {
+ dev_warn(&port->dev,
+ "Failed to allocate the decoder\n");
+ return PTR_ERR(cxlsd);
+ }
+ cxld = &cxlsd->cxld;
}
rc = init_hdm_decoder(port, cxld, target_map, hdm, i);
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index f62c0a6e17ea..27a2a6b839aa 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -120,20 +120,21 @@ static ssize_t target_type_show(struct device *dev,
}
static DEVICE_ATTR_RO(target_type);
-static ssize_t emit_target_list(struct cxl_decoder *cxld, char *buf)
+static ssize_t emit_target_list(struct cxl_switch_decoder *cxlsd, char *buf)
{
+ struct cxl_decoder *cxld = &cxlsd->cxld;
ssize_t offset = 0;
int i, rc = 0;
for (i = 0; i < cxld->interleave_ways; i++) {
- struct cxl_dport *dport = cxld->target[i];
+ struct cxl_dport *dport = cxlsd->target[i];
struct cxl_dport *next = NULL;
if (!dport)
break;
if (i + 1 < cxld->interleave_ways)
- next = cxld->target[i + 1];
+ next = cxlsd->target[i + 1];
rc = sysfs_emit_at(buf, offset, "%d%s", dport->port_id,
next ? "," : "");
if (rc < 0)
@@ -144,18 +145,20 @@ static ssize_t emit_target_list(struct cxl_decoder *cxld, char *buf)
return offset;
}
+static struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev);
+
static ssize_t target_list_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- struct cxl_decoder *cxld = to_cxl_decoder(dev);
+ struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);
ssize_t offset;
unsigned int seq;
int rc;
do {
- seq = read_seqbegin(&cxld->target_lock);
- rc = emit_target_list(cxld, buf);
- } while (read_seqretry(&cxld->target_lock, seq));
+ seq = read_seqbegin(&cxlsd->target_lock);
+ rc = emit_target_list(cxlsd, buf);
+ } while (read_seqretry(&cxlsd->target_lock, seq));
if (rc < 0)
return rc;
@@ -233,14 +236,28 @@ static const struct attribute_group *cxl_decoder_endpoint_attribute_groups[] = {
NULL,
};
+static void __cxl_decoder_release(struct cxl_decoder *cxld)
+{
+ struct cxl_port *port = to_cxl_port(cxld->dev.parent);
+
+ ida_free(&port->decoder_ida, cxld->id);
+ put_device(&port->dev);
+}
+
static void cxl_decoder_release(struct device *dev)
{
struct cxl_decoder *cxld = to_cxl_decoder(dev);
- struct cxl_port *port = to_cxl_port(dev->parent);
- ida_free(&port->decoder_ida, cxld->id);
+ __cxl_decoder_release(cxld);
kfree(cxld);
- put_device(&port->dev);
+}
+
+static void cxl_switch_decoder_release(struct device *dev)
+{
+ struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);
+
+ __cxl_decoder_release(&cxlsd->cxld);
+ kfree(cxlsd);
}
static const struct device_type cxl_decoder_endpoint_type = {
@@ -251,13 +268,13 @@ static const struct device_type cxl_decoder_endpoint_type = {
static const struct device_type cxl_decoder_switch_type = {
.name = "cxl_decoder_switch",
- .release = cxl_decoder_release,
+ .release = cxl_switch_decoder_release,
.groups = cxl_decoder_switch_attribute_groups,
};
static const struct device_type cxl_decoder_root_type = {
.name = "cxl_decoder_root",
- .release = cxl_decoder_release,
+ .release = cxl_switch_decoder_release,
.groups = cxl_decoder_root_attribute_groups,
};
@@ -272,15 +289,29 @@ bool is_root_decoder(struct device *dev)
}
EXPORT_SYMBOL_NS_GPL(is_root_decoder, CXL);
+static bool is_switch_decoder(struct device *dev)
+{
+ return is_root_decoder(dev) || dev->type == &cxl_decoder_switch_type;
+}
+
struct cxl_decoder *to_cxl_decoder(struct device *dev)
{
- if (dev_WARN_ONCE(dev, dev->type->release != cxl_decoder_release,
+ if (dev_WARN_ONCE(dev,
+ !is_switch_decoder(dev) && !is_endpoint_decoder(dev),
"not a cxl_decoder device\n"))
return NULL;
return container_of(dev, struct cxl_decoder, dev);
}
EXPORT_SYMBOL_NS_GPL(to_cxl_decoder, CXL);
+static struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev)
+{
+ if (dev_WARN_ONCE(dev, !is_switch_decoder(dev),
+ "not a cxl_switch_decoder device\n"))
+ return NULL;
+ return container_of(dev, struct cxl_switch_decoder, cxld.dev);
+}
+
static void cxl_ep_release(struct cxl_ep *ep)
{
if (!ep)
@@ -1146,7 +1177,7 @@ struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port,
}
EXPORT_SYMBOL_NS_GPL(cxl_find_dport_by_dev, CXL);
-static int decoder_populate_targets(struct cxl_decoder *cxld,
+static int decoder_populate_targets(struct cxl_switch_decoder *cxlsd,
struct cxl_port *port, int *target_map)
{
int i, rc = 0;
@@ -1159,17 +1190,17 @@ static int decoder_populate_targets(struct cxl_decoder *cxld,
if (list_empty(&port->dports))
return -EINVAL;
- write_seqlock(&cxld->target_lock);
- for (i = 0; i < cxld->nr_targets; i++) {
+ write_seqlock(&cxlsd->target_lock);
+ for (i = 0; i < cxlsd->nr_targets; i++) {
struct cxl_dport *dport = find_dport(port, target_map[i]);
if (!dport) {
rc = -ENXIO;
break;
}
- cxld->target[i] = dport;
+ cxlsd->target[i] = dport;
}
- write_sequnlock(&cxld->target_lock);
+ write_sequnlock(&cxlsd->target_lock);
return rc;
}
@@ -1177,56 +1208,34 @@ static int decoder_populate_targets(struct cxl_decoder *cxld,
static struct lock_class_key cxl_decoder_key;
/**
- * cxl_decoder_alloc - Allocate a new CXL decoder
+ * cxl_decoder_alloc - Common decoder setup / initialization
* @port: owning port of this decoder
- * @nr_targets: downstream targets accessible by this decoder. All upstream
- * ports and root ports must have at least 1 target. Endpoint
- * devices will have 0 targets. Callers wishing to register an
- * endpoint device should specify 0.
- *
- * A port should contain one or more decoders. Each of those decoders enable
- * some address space for CXL.mem utilization. A decoder is expected to be
- * configured by the caller before registering.
+ * @cxld: common decoder properties to initialize
*
- * Return: A new cxl decoder to be registered by cxl_decoder_add(). The decoder
- * is initialized to be a "passthrough" decoder.
+ * A port may contain one or more decoders. Each of those decoders
+ * enable some address space for CXL.mem utilization. A decoder is
+ * expected to be configured by the caller before registering via
+ * cxl_decoder_add()
*/
-static struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port,
- unsigned int nr_targets)
+static int cxl_decoder_init(struct cxl_port *port, struct cxl_decoder *cxld)
{
- struct cxl_decoder *cxld;
struct device *dev;
- int rc = 0;
-
- if (nr_targets > CXL_DECODER_MAX_INTERLEAVE)
- return ERR_PTR(-EINVAL);
-
- cxld = kzalloc(struct_size(cxld, target, nr_targets), GFP_KERNEL);
- if (!cxld)
- return ERR_PTR(-ENOMEM);
+ int rc;
rc = ida_alloc(&port->decoder_ida, GFP_KERNEL);
if (rc < 0)
- goto err;
+ return rc;
/* need parent to stick around to release the id */
get_device(&port->dev);
cxld->id = rc;
- cxld->nr_targets = nr_targets;
- seqlock_init(&cxld->target_lock);
dev = &cxld->dev;
device_initialize(dev);
lockdep_set_class(&dev->mutex, &cxl_decoder_key);
device_set_pm_not_required(dev);
dev->parent = &port->dev;
dev->bus = &cxl_bus_type;
- if (is_cxl_root(port))
- cxld->dev.type = &cxl_decoder_root_type;
- else if (is_cxl_endpoint(port))
- cxld->dev.type = &cxl_decoder_endpoint_type;
- else
- cxld->dev.type = &cxl_decoder_switch_type;
/* Pre initialize an "empty" decoder */
cxld->interleave_ways = 1;
@@ -1237,10 +1246,19 @@ static struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port,
.end = -1,
};
- return cxld;
-err:
- kfree(cxld);
- return ERR_PTR(rc);
+ return 0;
+}
+
+static int cxl_switch_decoder_init(struct cxl_port *port,
+ struct cxl_switch_decoder *cxlsd,
+ int nr_targets)
+{
+ if (nr_targets > CXL_DECODER_MAX_INTERLEAVE)
+ return -EINVAL;
+
+ cxlsd->nr_targets = nr_targets;
+ seqlock_init(&cxlsd->target_lock);
+ return cxl_decoder_init(port, &cxlsd->cxld);
}
/**
@@ -1253,13 +1271,29 @@ static struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port,
* firmware description of CXL resources into a CXL standard decode
* topology.
*/
-struct cxl_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
- unsigned int nr_targets)
+struct cxl_switch_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
+ unsigned int nr_targets)
{
+ struct cxl_switch_decoder *cxlsd;
+ struct cxl_decoder *cxld;
+ int rc;
+
if (!is_cxl_root(port))
return ERR_PTR(-EINVAL);
- return cxl_decoder_alloc(port, nr_targets);
+ cxlsd = kzalloc(struct_size(cxlsd, target, nr_targets), GFP_KERNEL);
+ if (!cxlsd)
+ return ERR_PTR(-ENOMEM);
+
+ rc = cxl_switch_decoder_init(port, cxlsd, nr_targets);
+ if (rc) {
+ kfree(cxlsd);
+ return ERR_PTR(rc);
+ }
+
+ cxld = &cxlsd->cxld;
+ cxld->dev.type = &cxl_decoder_root_type;
+ return cxlsd;
}
EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, CXL);
@@ -1274,13 +1308,29 @@ EXPORT_SYMBOL_NS_GPL(cxl_root_decoder_alloc, CXL);
* that sit between Switch Upstream Ports / Switch Downstream Ports and
* Host Bridges / Root Ports.
*/
-struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
- unsigned int nr_targets)
+struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
+ unsigned int nr_targets)
{
+ struct cxl_switch_decoder *cxlsd;
+ struct cxl_decoder *cxld;
+ int rc;
+
if (is_cxl_root(port) || is_cxl_endpoint(port))
return ERR_PTR(-EINVAL);
- return cxl_decoder_alloc(port, nr_targets);
+ cxlsd = kzalloc(struct_size(cxlsd, target, nr_targets), GFP_KERNEL);
+ if (!cxlsd)
+ return ERR_PTR(-ENOMEM);
+
+ rc = cxl_switch_decoder_init(port, cxlsd, nr_targets);
+ if (rc) {
+ kfree(cxlsd);
+ return ERR_PTR(rc);
+ }
+
+ cxld = &cxlsd->cxld;
+ cxld->dev.type = &cxl_decoder_switch_type;
+ return cxlsd;
}
EXPORT_SYMBOL_NS_GPL(cxl_switch_decoder_alloc, CXL);
@@ -1292,10 +1342,24 @@ EXPORT_SYMBOL_NS_GPL(cxl_switch_decoder_alloc, CXL);
*/
struct cxl_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port)
{
+ struct cxl_decoder *cxld;
+ int rc;
+
if (!is_cxl_endpoint(port))
return ERR_PTR(-EINVAL);
- return cxl_decoder_alloc(port, 0);
+ cxld = kzalloc(sizeof(*cxld), GFP_KERNEL);
+ if (!cxld)
+ return ERR_PTR(-ENOMEM);
+
+ rc = cxl_decoder_init(port, cxld);
+ if (rc) {
+ kfree(cxld);
+ return ERR_PTR(rc);
+ }
+
+ cxld->dev.type = &cxl_decoder_endpoint_type;
+ return cxld;
}
EXPORT_SYMBOL_NS_GPL(cxl_endpoint_decoder_alloc, CXL);
@@ -1337,7 +1401,9 @@ int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map)
port = to_cxl_port(cxld->dev.parent);
if (!is_endpoint_decoder(dev)) {
- rc = decoder_populate_targets(cxld, port, target_map);
+ struct cxl_switch_decoder *cxlsd = to_cxl_switch_decoder(dev);
+
+ rc = decoder_populate_targets(cxlsd, port, target_map);
if (rc && (cxld->flags & CXL_DECODER_F_ENABLE)) {
dev_err(&port->dev,
"Failed to populate active decoder targets\n");
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 570bd9f8141b..0289c06ec72c 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -220,7 +220,7 @@ enum cxl_decoder_type {
#define CXL_DECODER_MAX_INTERLEAVE 16
/**
- * struct cxl_decoder - CXL address range decode configuration
+ * struct cxl_decoder - Common CXL HDM Decoder Attributes
* @dev: this decoder's device
* @id: kernel device name id
* @hpa_range: Host physical address range mapped by this decoder
@@ -228,9 +228,6 @@ enum cxl_decoder_type {
* @interleave_granularity: data stride per dport
* @target_type: accelerator vs expander (type2 vs type3) selector
* @flags: memory type capabilities and locking
- * @target_lock: coordinate coherent reads of the target list
- * @nr_targets: number of elements in @target
- * @target: active ordered target list in current decoder configuration
*/
struct cxl_decoder {
struct device dev;
@@ -240,6 +237,23 @@ struct cxl_decoder {
int interleave_granularity;
enum cxl_decoder_type target_type;
unsigned long flags;
+};
+
+/**
+ * struct cxl_switch_decoder - Switch specific CXL HDM Decoder
+ * @cxld: base cxl_decoder object
+ * @target_lock: coordinate coherent reads of the target list
+ * @nr_targets: number of elements in @target
+ * @target: active ordered target list in current decoder configuration
+ *
+ * The 'switch' decoder type represents the decoder instances of cxl_port's that
+ * route from the root of a CXL memory decode topology to the endpoints. They
+ * come in two flavors, root-level decoders, statically defined by platform
+ * firmware, and mid-level decoders, where interleave-granularity,
+ * interleave-width, and the target list are mutable.
+ */
+struct cxl_switch_decoder {
+ struct cxl_decoder cxld;
seqlock_t target_lock;
int nr_targets;
struct cxl_dport *target[];
@@ -364,10 +378,10 @@ struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port,
struct cxl_decoder *to_cxl_decoder(struct device *dev);
bool is_root_decoder(struct device *dev);
bool is_endpoint_decoder(struct device *dev);
-struct cxl_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
- unsigned int nr_targets);
-struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
- unsigned int nr_targets);
+struct cxl_switch_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
+ unsigned int nr_targets);
+struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
+ unsigned int nr_targets);
int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
struct cxl_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 6e086fbc5c5b..7991ddc6e562 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -451,14 +451,23 @@ static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm)
struct cxl_decoder *cxld;
int rc;
- if (target_count)
- cxld = cxl_switch_decoder_alloc(port, target_count);
- else
+ if (target_count) {
+ struct cxl_switch_decoder *cxlsd;
+
+ cxlsd = cxl_switch_decoder_alloc(port, target_count);
+ if (IS_ERR(cxlsd)) {
+ dev_warn(&port->dev,
+ "Failed to allocate the decoder\n");
+ return PTR_ERR(cxlsd);
+ }
+ cxld = &cxlsd->cxld;
+ } else {
cxld = cxl_endpoint_decoder_alloc(port);
- if (IS_ERR(cxld)) {
- dev_warn(&port->dev,
- "Failed to allocate the decoder\n");
- return PTR_ERR(cxld);
+ if (IS_ERR(cxld)) {
+ dev_warn(&port->dev,
+ "Failed to allocate the decoder\n");
+ return PTR_ERR(cxld);
+ }
}
cxld->hpa_range = (struct range) {
