ndctl/SOURCES/0117-cxl-list-Extend-decoder-objects-with-target-informat.patch

From 1279d1989ef77085d214a193c1458b624039c612 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams@intel.com>
Date: Sun, 23 Jan 2022 16:54:34 -0800
Subject: [PATCH 117/217] cxl/list: Extend decoder objects with target
 information

A target combines information about a dport along with its position in the
intereleave order. With targets enumerated decoders can also be filtered be
memory devices by seeing which decoders have a dport in the memory-device's
ancestry.

$ cxl list -D -d 3.1 -T -u
{
  "decoder":"decoder3.1",
  "resource":"0x8030000000",
  "size":"512.00 MiB (536.87 MB)",
  "volatile_capable":true,
  "nr_targets":2,
  "targets":[
    {
      "target":"cxl_host_bridge.1",
      "position":1,
      "id":"0x1"
    },
    {
      "target":"cxl_host_bridge.0",
      "position":0,
      "id":"0"
    }
  ]
}

Link: https://lore.kernel.org/r/164298567435.3021641.3771899644901785666.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 .clang-format                    |   1 +
 Documentation/cxl/cxl-list.txt   |   8 ++-
 Documentation/cxl/lib/libcxl.txt |  58 ++++++++++++++++
 cxl/filter.c                     |  25 +++++++
 cxl/filter.h                     |   1 +
 cxl/json.c                       |  46 +++++++++++++
 cxl/lib/libcxl.c                 | 115 +++++++++++++++++++++++++++++++
 cxl/lib/libcxl.sym               |  10 +++
 cxl/libcxl.h                     |  19 +++++
 cxl/list.c                       |   2 +
 10 files changed, 283 insertions(+), 2 deletions(-)

diff --git a/.clang-format b/.clang-format
index 16e28ac..47fb657 100644
--- a/.clang-format
+++ b/.clang-format
@@ -81,6 +81,7 @@ ForEachMacros:
   - 'cxl_bus_foreach'
   - 'cxl_port_foreach'
   - 'cxl_decoder_foreach'
+  - 'cxl_target_foreach'
   - 'cxl_endpoint_foreach'
   - 'daxctl_dev_foreach'
   - 'daxctl_mapping_foreach'
diff --git a/Documentation/cxl/cxl-list.txt b/Documentation/cxl/cxl-list.txt
index 84872b9..20ff2cb 100644
--- a/Documentation/cxl/cxl-list.txt
+++ b/Documentation/cxl/cxl-list.txt
@@ -44,8 +44,8 @@ would only list objects that are beneath port10 AND map mem0, mem1, OR
 mem2.
 
 Given that many topology queries seek to answer questions relative to a
-given memdev, buses, ports, and endpoints can be filtered by one or more
-memdevs. For example:
+given memdev, buses, ports, endpoints, and decoders can be filtered by
+one or more memdevs. For example:
 ----
 # cxl list -P -p switch,endpoint -m mem0
 [
@@ -270,6 +270,10 @@ OPTIONS
 	"decoder<port_id>.<instance_id>". The possible decoder type names are
 	"root", "switch", or "endpoint", similar to the port filter syntax.
 
+-T::
+--targets::
+	Extend decoder listings with downstream port target information.
+
 --debug::
 	If the cxl tool was built with debug enabled, turn on debug
 	messages.
diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
index 73af3d0..bd92fef 100644
--- a/Documentation/cxl/lib/libcxl.txt
+++ b/Documentation/cxl/lib/libcxl.txt
@@ -300,6 +300,7 @@ device-local-physical-address).
 struct cxl_decoder *cxl_decoder_get_first(struct cxl_port *port);
 struct cxl_decoder *cxl_decoder_get_next(struct cxl_decoder *decoder);
 struct cxl_ctx *cxl_decoder_get_ctx(struct cxl_decoder *decoder);
+struct cxl_decoder *cxl_target_get_decoder(struct cxl_target *target);
 
 #define cxl_decoder_foreach(port, decoder)                                  \
        for (decoder = cxl_decoder_get_first(port); decoder != NULL;         \
@@ -314,6 +315,7 @@ unsigned long long cxl_decoder_get_resource(struct cxl_decoder *decoder);
 unsigned long long cxl_decoder_get_size(struct cxl_decoder *decoder);
 const char *cxl_decoder_get_devname(struct cxl_decoder *decoder);
 int cxl_decoder_get_id(struct cxl_decoder *decoder);
+int cxl_decoder_get_nr_targets(struct cxl_decoder *decoder);
 
 enum cxl_decoder_target_type {
        CXL_DECODER_TTYPE_UNKNOWN,
@@ -352,6 +354,62 @@ Platform firmware may setup the CXL decode hierarchy before the OS
 boots, and may additionally require that the OS not change the decode
 settings. This property is indicated by the cxl_decoder_is_locked() API.
 
+==== TARGETS
+A root or switch level decoder takes an SPA (system-physical-address) as
+input and routes it to a downstream port. Which downstream port depends
+on the downstream port's position in the interleave. A 'struct
+cxl_target' object represents the properties of a given downstream port
+relative to its interleave configuration.
+
+===== TARGET: Enumeration
+----
+struct cxl_target *cxl_decoder_get_target_by_memdev(struct cxl_decoder *decoder,
+                                                   struct cxl_memdev *memdev);
+struct cxl_target *
+cxl_decoder_get_target_by_position(struct cxl_decoder *decoder, int position);
+struct cxl_target *cxl_target_get_first(struct cxl_decoder *decoder);
+struct cxl_target *cxl_target_get_next(struct cxl_target *target);
+
+#define cxl_target_foreach(decoder, target)                                   \
+       for (target = cxl_target_get_first(decoder); target != NULL;           \
+            target = cxl_target_get_next(target))
+----
+Target objects can only be enumerated if the decoder has been
+configured, for switch decoders. For root decoders they are always
+available since the root decoder target mapping is static. The
+cxl_decoder_get_target_by_memdev() helper walks the topology to validate
+if the given memory device is capable of receiving cycles from this
+upstream decoder. It does not validate if the memory device is currently
+configured to participate in that decode.
+
+===== TARGET: Attributes
+----
+int cxl_target_get_position(struct cxl_target *target);
+unsigned long cxl_target_get_id(struct cxl_target *target);
+const char *cxl_target_get_devname(struct cxl_target *target);
+bool cxl_target_maps_memdev(struct cxl_target *target,
+                           struct cxl_memdev *memdev);
+----
+The position of a decoder along with the interleave granularity dictate
+which address in the decoder's resource range map to which port.
+
+The target id is an identifier that the CXL port uses to reference this
+downstream port. For CXL / PCIe downstream switch ports the id is
+defined by the PCIe Link Capability Port Number field. For root decoders
+the id is specified by platform firmware specific mechanism. For
+ACPI.CXL defined root ports the id comes from the CEDT.CHBS / ACPI0016
+_UID.
+
+The device name of a target is the name of the host device for the
+downstream port. For CXL / PCIe downstream ports the devname is
+downstream switch port PCI device. For CXL root ports the devname is a
+platform firmware object for the host bridge like a ACPI0016 device
+instance.
+
+The cxl_target_maps_memdev() helper is the companion of
+cxl_decoder_get_target_by_memdev() to determine which downstream ports /
+targets are capable of mapping which memdevs.
+
 include::../../copyright.txt[]
 
 SEE ALSO
diff --git a/cxl/filter.c b/cxl/filter.c
index dc052f6..05ede91 100644
--- a/cxl/filter.c
+++ b/cxl/filter.c
@@ -421,6 +421,26 @@ static struct cxl_decoder *util_cxl_decoder_filter(struct cxl_decoder *decoder,
 	return NULL;
 }
 
+static struct cxl_decoder *
+util_cxl_decoder_filter_by_memdev(struct cxl_decoder *decoder,
+				  const char *ident, const char *serial)
+{
+	struct cxl_ctx *ctx = cxl_decoder_get_ctx(decoder);
+	struct cxl_memdev *memdev;
+
+	if (!ident && !serial)
+		return decoder;
+
+	cxl_memdev_foreach(ctx, memdev) {
+		if (!util_cxl_memdev_filter(memdev, ident, serial))
+			continue;
+		if (cxl_decoder_get_target_by_memdev(decoder, memdev))
+			return decoder;
+	}
+
+	return NULL;
+}
+
 static unsigned long params_to_flags(struct cxl_filter_params *param)
 {
 	unsigned long flags = 0;
@@ -431,6 +451,8 @@ static unsigned long params_to_flags(struct cxl_filter_params *param)
 		flags |= UTIL_JSON_HUMAN;
 	if (param->health)
 		flags |= UTIL_JSON_HEALTH;
+	if (param->targets)
+		flags |= UTIL_JSON_TARGETS;
 	return flags;
 }
 
@@ -521,6 +543,9 @@ static void walk_decoders(struct cxl_port *port, struct cxl_filter_params *p,
 		if (!util_cxl_decoder_filter_by_port(decoder, p->port_filter,
 						     pf_mode(p)))
 			continue;
+		if (!util_cxl_decoder_filter_by_memdev(
+			    decoder, p->memdev_filter, p->serial_filter))
+			continue;
 		if (!p->idle && cxl_decoder_get_size(decoder) == 0)
 			continue;
 		jdecoder = util_cxl_decoder_to_json(decoder, flags);
diff --git a/cxl/filter.h b/cxl/filter.h
index 5d7bf45..6fd469f 100644
--- a/cxl/filter.h
+++ b/cxl/filter.h
@@ -16,6 +16,7 @@ struct cxl_filter_params {
 	bool single;
 	bool endpoints;
 	bool decoders;
+	bool targets;
 	bool memdevs;
 	bool ports;
 	bool buses;
diff --git a/cxl/json.c b/cxl/json.c
index 548bc52..3a37909 100644
--- a/cxl/json.c
+++ b/cxl/json.c
@@ -268,6 +268,8 @@ struct json_object *util_cxl_decoder_to_json(struct cxl_decoder *decoder,
 	const char *devname = cxl_decoder_get_devname(decoder);
 	struct cxl_port *port = cxl_decoder_get_port(decoder);
 	struct json_object *jdecoder, *jobj;
+	struct json_object *jtargets;
+	struct cxl_target *target;
 	u64 val;
 
 	jdecoder = json_object_new_object();
@@ -321,7 +323,51 @@ struct json_object *util_cxl_decoder_to_json(struct cxl_decoder *decoder,
 					       jobj);
 	}
 
+	/* Endpoints don't have targets, they *are* targets */
+	if (cxl_port_is_endpoint(port))
+		return jdecoder;
+
+	val = cxl_decoder_get_nr_targets(decoder);
+	jobj = json_object_new_int(val);
+	if (jobj)
+		json_object_object_add(jdecoder, "nr_targets", jobj);
+
+	if (!(flags & UTIL_JSON_TARGETS) ||
+	    !cxl_decoder_get_nr_targets(decoder))
+		return jdecoder;
+
+	jtargets = json_object_new_array();
+	if (!jtargets)
+		return jdecoder;
+
+	cxl_target_foreach(decoder, target) {
+		struct json_object *jtarget = json_object_new_object();
+
+		if (!jtarget)
+			continue;
+
+		devname = cxl_target_get_devname(target);
+		jobj = json_object_new_string(devname);
+		if (jobj)
+			json_object_object_add(jtarget, "target", jobj);
+
+		val = cxl_target_get_position(target);
+		jobj = json_object_new_int(val);
+		if (jobj)
+			json_object_object_add(jtarget, "position", jobj);
+
+		val = cxl_target_get_id(target);
+		jobj = util_json_object_hex(val, flags);
+		if (jobj)
+			json_object_object_add(jtarget, "id", jobj);
+
+		json_object_array_add(jtargets, jtarget);
+	}
+
+	json_object_object_add(jdecoder, "targets", jtargets);
+
 	return jdecoder;
+
 }
 
 static struct json_object *__util_cxl_port_to_json(struct cxl_port *port,
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index 5e30923..877f42c 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -67,10 +67,22 @@ static void free_memdev(struct cxl_memdev *memdev, struct list_head *head)
 	free(memdev);
 }
 
+static void free_target(struct cxl_target *target, struct list_head *head)
+{
+	if (head)
+		list_del_from(head, &target->list);
+	free(target->dev_path);
+	free(target);
+}
+
 static void free_decoder(struct cxl_decoder *decoder, struct list_head *head)
 {
+	struct cxl_target *target, *_t;
+
 	if (head)
 		list_del_from(head, &decoder->list);
+	list_for_each_safe(&decoder->targets, target, _t, list)
+		free_target(target, &decoder->targets);
 	free(decoder->dev_buf);
 	free(decoder->dev_path);
 	free(decoder);
@@ -856,6 +868,7 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
 	struct cxl_port *port = parent;
 	struct cxl_ctx *ctx = cxl_port_get_ctx(port);
 	char buf[SYSFS_ATTR_SIZE];
+	char *target_id, *save;
 	size_t i;
 
 	dbg(ctx, "%s: base: \'%s\'\n", devname, cxldecoder_base);
@@ -870,6 +883,7 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
 	decoder->id = id;
 	decoder->ctx = ctx;
 	decoder->port = port;
+	list_head_init(&decoder->targets);
 
 	decoder->dev_path = strdup(cxldecoder_base);
 	if (!decoder->dev_path)
@@ -935,6 +949,36 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
 	}
 	}
 
+	sprintf(path, "%s/target_list", cxldecoder_base);
+	if (sysfs_read_attr(ctx, path, buf) < 0)
+		buf[0] = '\0';
+
+	for (i = 0, target_id = strtok_r(buf, ",", &save); target_id;
+	     target_id = strtok_r(NULL, ",", &save), i++) {
+		int did = strtoul(target_id, NULL, 0);
+		struct cxl_target *target = calloc(1, sizeof(*target));
+
+		if (!target)
+			break;
+
+		target->id = did;
+		target->position = i;
+		target->decoder = decoder;
+		sprintf(port->dev_buf, "%s/dport%d", port->dev_path, did);
+		target->dev_path = realpath(port->dev_buf, NULL);
+		if (!target->dev_path) {
+			free(target);
+			break;
+		}
+		dbg(ctx, "%s: target%ld %s\n", devname, i, target->dev_path);
+		list_add(&decoder->targets, &target->list);
+	}
+
+	if (target_id)
+		err(ctx, "%s: failed to parse target%ld\n",
+		    devpath_to_devname(cxldecoder_base), i);
+	decoder->nr_targets = i;
+
 	cxl_decoder_foreach(port, decoder_dup)
 		if (decoder_dup->id == decoder->id) {
 			free_decoder(decoder, NULL);
@@ -1044,11 +1088,82 @@ CXL_EXPORT bool cxl_decoder_is_locked(struct cxl_decoder *decoder)
 	return decoder->locked;
 }
 
+CXL_EXPORT int cxl_decoder_get_nr_targets(struct cxl_decoder *decoder)
+{
+	return decoder->nr_targets;
+}
+
 CXL_EXPORT const char *cxl_decoder_get_devname(struct cxl_decoder *decoder)
 {
 	return devpath_to_devname(decoder->dev_path);
 }
 
+CXL_EXPORT struct cxl_target *cxl_target_get_first(struct cxl_decoder *decoder)
+{
+	return list_top(&decoder->targets, struct cxl_target, list);
+}
+
+CXL_EXPORT struct cxl_decoder *cxl_target_get_decoder(struct cxl_target *target)
+{
+	return target->decoder;
+}
+
+CXL_EXPORT struct cxl_target *cxl_target_get_next(struct cxl_target *target)
+{
+	struct cxl_decoder *decoder = cxl_target_get_decoder(target);
+
+	return list_next(&decoder->targets, target, list);
+}
+
+CXL_EXPORT const char *cxl_target_get_devname(struct cxl_target *target)
+{
+	return devpath_to_devname(target->dev_path);
+}
+
+CXL_EXPORT unsigned long cxl_target_get_id(struct cxl_target *target)
+{
+	return target->id;
+}
+
+CXL_EXPORT int cxl_target_get_position(struct cxl_target *target)
+{
+	return target->position;
+}
+
+CXL_EXPORT bool cxl_target_maps_memdev(struct cxl_target *target,
+					struct cxl_memdev *memdev)
+{
+	struct cxl_ctx *ctx = cxl_memdev_get_ctx(memdev);
+
+	dbg(ctx, "memdev: %s target: %s\n", memdev->host_path,
+	    target->dev_path);
+
+	return !!strstr(memdev->host_path, target->dev_path);
+}
+
+CXL_EXPORT struct cxl_target *
+cxl_decoder_get_target_by_memdev(struct cxl_decoder *decoder,
+				 struct cxl_memdev *memdev)
+{
+	struct cxl_target *target;
+
+	cxl_target_foreach(decoder, target)
+		if (cxl_target_maps_memdev(target, memdev))
+			return target;
+	return NULL;
+}
+
+CXL_EXPORT struct cxl_target *
+cxl_decoder_get_target_by_position(struct cxl_decoder *decoder, int position)
+{
+	struct cxl_target *target;
+
+	cxl_target_foreach(decoder, target)
+		if (target->position == position)
+			return target;
+	return NULL;
+}
+
 static void *add_cxl_port(void *parent, int id, const char *cxlport_base)
 {
 	const char *devname = devpath_to_devname(cxlport_base);
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 22babb7..cb33180 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -125,10 +125,20 @@ global:
 	cxl_decoder_get_resource;
 	cxl_decoder_get_size;
 	cxl_decoder_get_devname;
+	cxl_decoder_get_target_by_memdev;
+	cxl_decoder_get_target_by_position;
+	cxl_decoder_get_nr_targets;
 	cxl_decoder_get_target_type;
 	cxl_decoder_is_pmem_capable;
 	cxl_decoder_is_volatile_capable;
 	cxl_decoder_is_mem_capable;
 	cxl_decoder_is_accelmem_capable;
 	cxl_decoder_is_locked;
+	cxl_target_get_first;
+	cxl_target_get_next;
+	cxl_target_get_decoder;
+	cxl_target_get_position;
+	cxl_target_get_id;
+	cxl_target_get_devname;
+	cxl_target_maps_memdev;
 } LIBCXL_1;
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index 439ed93..abda0e5 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -104,6 +104,11 @@ struct cxl_decoder *cxl_decoder_get_next(struct cxl_decoder *decoder);
 unsigned long long cxl_decoder_get_resource(struct cxl_decoder *decoder);
 unsigned long long cxl_decoder_get_size(struct cxl_decoder *decoder);
 const char *cxl_decoder_get_devname(struct cxl_decoder *decoder);
+struct cxl_target *cxl_decoder_get_target_by_memdev(struct cxl_decoder *decoder,
+						    struct cxl_memdev *memdev);
+struct cxl_target *
+cxl_decoder_get_target_by_position(struct cxl_decoder *decoder, int position);
+int cxl_decoder_get_nr_targets(struct cxl_decoder *decoder);
 struct cxl_ctx *cxl_decoder_get_ctx(struct cxl_decoder *decoder);
 int cxl_decoder_get_id(struct cxl_decoder *decoder);
 struct cxl_port *cxl_decoder_get_port(struct cxl_decoder *decoder);
@@ -126,6 +131,20 @@ bool cxl_decoder_is_locked(struct cxl_decoder *decoder);
 	for (decoder = cxl_decoder_get_first(port); decoder != NULL;           \
 	     decoder = cxl_decoder_get_next(decoder))
 
+struct cxl_target;
+struct cxl_target *cxl_target_get_first(struct cxl_decoder *decoder);
+struct cxl_target *cxl_target_get_next(struct cxl_target *target);
+struct cxl_decoder *cxl_target_get_decoder(struct cxl_target *target);
+int cxl_target_get_position(struct cxl_target *target);
+unsigned long cxl_target_get_id(struct cxl_target *target);
+const char *cxl_target_get_devname(struct cxl_target *target);
+bool cxl_target_maps_memdev(struct cxl_target *target,
+			    struct cxl_memdev *memdev);
+
+#define cxl_target_foreach(decoder, target)                                    \
+	for (target = cxl_target_get_first(decoder); target != NULL;           \
+	     target = cxl_target_get_next(target))
+
 struct cxl_endpoint;
 struct cxl_endpoint *cxl_endpoint_get_first(struct cxl_port *parent);
 struct cxl_endpoint *cxl_endpoint_get_next(struct cxl_endpoint *endpoint);
diff --git a/cxl/list.c b/cxl/list.c
index d70192a..27c963a 100644
--- a/cxl/list.c
+++ b/cxl/list.c
@@ -41,6 +41,8 @@ static const struct option options[] = {
 		   "filter by CXL decoder device name(s) / class"),
 	OPT_BOOLEAN('D', "decoders", &param.decoders,
 		    "include CXL decoder info"),
+	OPT_BOOLEAN('T', "targets", &param.targets,
+		    "include CXL target data with decoders"),
 	OPT_BOOLEAN('i', "idle", &param.idle, "include disabled devices"),
 	OPT_BOOLEAN('u', "human", &param.human,
 		    "use human friendly number formats "),
-- 
2.27.0