Patch "cxl: Add cxl_decoders_committed() helper" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    cxl: Add cxl_decoders_committed() helper

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cxl-add-cxl_decoders_committed-helper.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 0e03ff05833f6d325430ef301e358f12de327a74
Author: Dave Jiang <dave.jiang@xxxxxxxxx>
Date:   Mon Oct 16 10:57:48 2023 -0700

    cxl: Add cxl_decoders_committed() helper
    
    [ Upstream commit 458ba8189cb4380aa6a6cc4d52ab067f80a64829 ]
    
    Add a helper to retrieve the number of decoders committed for the port.
    Replace all the open coding of the calculation with the helper.
    
    Link: https://lore.kernel.org/linux-cxl/651c98472dfed_ae7e729495@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch/
    Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
    Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
    Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
    Reviewed-by: Jim Harris <jim.harris@xxxxxxxxxxx>
    Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
    Link: https://lore.kernel.org/r/169747906849.272156.1729290904857372335.stgit@djiang5-mobl3
    Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
    Stable-dep-of: 5558b92e8d39 ("cxl/core: Always hold region_rwsem while reading poison lists")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 22829267ccd86..54a535f6736bd 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -634,10 +634,11 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
 	if (cxld->flags & CXL_DECODER_F_ENABLE)
 		return 0;
 
-	if (port->commit_end + 1 != id) {
+	if (cxl_num_decoders_committed(port) != id) {
 		dev_dbg(&port->dev,
 			"%s: out of order commit, expected decoder%d.%d\n",
-			dev_name(&cxld->dev), port->id, port->commit_end + 1);
+			dev_name(&cxld->dev), port->id,
+			cxl_num_decoders_committed(port));
 		return -EBUSY;
 	}
 
@@ -847,7 +848,7 @@ static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
 			cxld->target_type = CXL_DECODER_HOSTONLYMEM;
 		else
 			cxld->target_type = CXL_DECODER_DEVMEM;
-		if (cxld->id != port->commit_end + 1) {
+		if (cxld->id != cxl_num_decoders_committed(port)) {
 			dev_warn(&port->dev,
 				 "decoder%d.%d: Committed out of order\n",
 				 port->id, cxld->id);
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index b91bb98869917..b12986b968da4 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1200,7 +1200,7 @@ int cxl_mem_sanitize(struct cxl_memdev *cxlmd, u16 cmd)
 	 * Require an endpoint to be safe otherwise the driver can not
 	 * be sure that the device is unmapped.
 	 */
-	if (endpoint && endpoint->commit_end == -1)
+	if (endpoint && cxl_num_decoders_committed(endpoint) == 0)
 		rc = __cxl_mem_sanitize(mds, cmd);
 	else
 		rc = -EBUSY;
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index fed9573cf355e..fc5c2b414793b 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -231,7 +231,7 @@ int cxl_trigger_poison_list(struct cxl_memdev *cxlmd)
 	if (rc)
 		return rc;
 
-	if (port->commit_end == -1) {
+	if (cxl_num_decoders_committed(port) == 0) {
 		/* No regions mapped to this memdev */
 		rc = cxl_get_poison_by_memdev(cxlmd);
 	} else {
@@ -282,7 +282,7 @@ static struct cxl_region *cxl_dpa_to_region(struct cxl_memdev *cxlmd, u64 dpa)
 		.dpa = dpa,
 	};
 	port = cxlmd->endpoint;
-	if (port && is_cxl_endpoint(port) && port->commit_end != -1)
+	if (port && is_cxl_endpoint(port) && cxl_num_decoders_committed(port))
 		device_for_each_child(&port->dev, &ctx, __cxl_dpa_to_region);
 
 	return ctx.cxlr;
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 1e0558d18b965..f430280fa6bd0 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -37,6 +37,13 @@ DECLARE_RWSEM(cxl_region_rwsem);
 static DEFINE_IDA(cxl_port_ida);
 static DEFINE_XARRAY(cxl_root_buses);
 
+int cxl_num_decoders_committed(struct cxl_port *port)
+{
+	lockdep_assert_held(&cxl_region_rwsem);
+
+	return port->commit_end + 1;
+}
+
 static ssize_t devtype_show(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index b5b015b661eae..6c6afda0e4c61 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -679,6 +679,7 @@ static inline bool is_cxl_root(struct cxl_port *port)
 	return port->uport_dev == port->dev.parent;
 }
 
+int cxl_num_decoders_committed(struct cxl_port *port);
 bool is_cxl_port(const struct device *dev);
 struct cxl_port *to_cxl_port(const struct device *dev);
 struct pci_bus;