From 5fb1b8a1630115f3aa3cd6bb7bc9ba5122867f66 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 23 Jan 2022 16:54:39 -0800 Subject: [PATCH 118/217] cxl/list: Use 'physical_node' for root port attachment detection Platform firmware objects like ACPI0016 link from /sys/bus/acpi to /sys/bus/pci via a 'physical_node' attribute. Consider that link when attempting to link memdevs to root ports. Emit it in the the target listing as the 'alias' for the listed target device. Link: https://lore.kernel.org/r/164298567943.3021641.12696733268157328279.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Vishal Verma --- Documentation/cxl/lib/libcxl.txt | 6 ++++++ cxl/json.c | 8 ++++++++ cxl/lib/libcxl.c | 16 +++++++++++++++- cxl/lib/libcxl.sym | 1 + cxl/lib/private.h | 1 + cxl/libcxl.h | 1 + 6 files changed, 32 insertions(+), 1 deletion(-) diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt index bd92fef..a68a58b 100644 --- a/Documentation/cxl/lib/libcxl.txt +++ b/Documentation/cxl/lib/libcxl.txt @@ -389,6 +389,7 @@ 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); +const char *cxl_target_get_physical_node(struct cxl_target *target); ---- The position of a decoder along with the interleave granularity dictate which address in the decoder's resource range map to which port. @@ -410,6 +411,11 @@ 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. +Some platform firmware implementations define an alias / companion +device to represent the root of a PCI device hierarchy. The +cxl_target_get_physical_node() helper returns the device name of that +companion object in the PCI hierarchy. + include::../../copyright.txt[] SEE ALSO diff --git a/cxl/json.c b/cxl/json.c index 3a37909..d81aed8 100644 --- a/cxl/json.c +++ b/cxl/json.c @@ -342,6 +342,7 @@ struct json_object *util_cxl_decoder_to_json(struct cxl_decoder *decoder, cxl_target_foreach(decoder, target) { struct json_object *jtarget = json_object_new_object(); + const char *phys_node; if (!jtarget) continue; @@ -351,6 +352,13 @@ struct json_object *util_cxl_decoder_to_json(struct cxl_decoder *decoder, if (jobj) json_object_object_add(jtarget, "target", jobj); + phys_node = cxl_target_get_physical_node(target); + if (phys_node) { + jobj = json_object_new_string(phys_node); + if (jobj) + json_object_object_add(jtarget, "alias", jobj); + } + val = cxl_target_get_position(target); jobj = json_object_new_int(val); if (jobj) diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c index 877f42c..7bf7949 100644 --- a/cxl/lib/libcxl.c +++ b/cxl/lib/libcxl.c @@ -72,6 +72,7 @@ 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->phys_path); free(target); } @@ -970,7 +971,11 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base) free(target); break; } - dbg(ctx, "%s: target%ld %s\n", devname, i, target->dev_path); + sprintf(port->dev_buf, "%s/dport%d/physical_node", port->dev_path, did); + target->phys_path = realpath(port->dev_buf, NULL); + dbg(ctx, "%s: target%ld %s phys_path: %s\n", devname, i, + target->dev_path, + target->phys_path ? target->phys_path : "none"); list_add(&decoder->targets, &target->list); } @@ -1138,9 +1143,18 @@ CXL_EXPORT bool cxl_target_maps_memdev(struct cxl_target *target, dbg(ctx, "memdev: %s target: %s\n", memdev->host_path, target->dev_path); + if (target->phys_path) + return !!strstr(memdev->host_path, target->phys_path); return !!strstr(memdev->host_path, target->dev_path); } +CXL_EXPORT const char *cxl_target_get_physical_node(struct cxl_target *target) +{ + if (!target->phys_path) + return NULL; + return devpath_to_devname(target->phys_path); +} + CXL_EXPORT struct cxl_target * cxl_decoder_get_target_by_memdev(struct cxl_decoder *decoder, struct cxl_memdev *memdev) diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym index cb33180..ce01298 100644 --- a/cxl/lib/libcxl.sym +++ b/cxl/lib/libcxl.sym @@ -141,4 +141,5 @@ global: cxl_target_get_id; cxl_target_get_devname; cxl_target_maps_memdev; + cxl_target_get_physical_node; } LIBCXL_1; diff --git a/cxl/lib/private.h b/cxl/lib/private.h index 1743a24..7e7742d 100644 --- a/cxl/lib/private.h +++ b/cxl/lib/private.h @@ -77,6 +77,7 @@ struct cxl_target { struct list_node list; struct cxl_decoder *decoder; char *dev_path; + char *phys_path; int id, position; }; diff --git a/cxl/libcxl.h b/cxl/libcxl.h index abda0e5..0e484cc 100644 --- a/cxl/libcxl.h +++ b/cxl/libcxl.h @@ -140,6 +140,7 @@ 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); +const char *cxl_target_get_physical_node(struct cxl_target *target); #define cxl_target_foreach(decoder, target) \ for (target = cxl_target_get_first(decoder); target != NULL; \ -- 2.27.0